add stylegan2 and pSp predictor (#113)

* add stylegan2 and pixel2style2pixel models, predictors and documents

applications/tools/pixel2style2pixel.py

+import paddle
+import os
+import sys
+sys.path.insert(0, os.getcwd())
+from ppgan.apps import Pixel2Style2PixelPredictor
+import argparse
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--input_image", type=str, help="path to source image")
+
+    parser.add_argument("--output_path",
+                        type=str,
+                        default='output_dir',
+                        help="path to output image dir")
+
+    parser.add_argument("--weight_path",
+                        type=str,
+                        default=None,
+                        help="path to model checkpoint path")
+
+    parser.add_argument("--model_type",
+                        type=str,
+                        default=None,
+                        help="type of model for loading pretrained model")
+
+    parser.add_argument("--seed",
+                        type=int,
+                        default=None,
+                        help="sample random seed for model's image generation")
+
+    parser.add_argument("--size",
+                        type=int,
+                        default=1024,
+                        help="resolution of output image")
+                        
+    parser.add_argument("--style_dim",
+                        type=int,
+                        default=512,
+                        help="number of style dimension")
+                        
+    parser.add_argument("--n_mlp",
+                        type=int,
+                        default=8,
+                        help="number of mlp layer depth")
+                        
+    parser.add_argument("--channel_multiplier",
+                        type=int,
+                        default=2,
+                        help="number of channel multiplier")
+
+    parser.add_argument("--cpu",
+                        dest="cpu",
+                        action="store_true",
+                        help="cpu mode.")
+
+    args = parser.parse_args()
+
+    if args.cpu:
+        paddle.set_device('cpu')
+
+    predictor = Pixel2Style2PixelPredictor(
+        output_path=args.output_path,
+        weight_path=args.weight_path,
+        model_type=args.model_type,
+        seed=args.seed,
+        size=args.size,
+        style_dim=args.style_dim,
+        n_mlp=args.n_mlp,
+        channel_multiplier=args.channel_multiplier
+    )
+    predictor.run(args.input_image)

applications/tools/styleganv2.py

+import paddle
+import os
+import sys
+sys.path.insert(0, os.getcwd())
+from ppgan.apps import StyleGANv2Predictor
+import argparse
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--output_path",
+                        type=str,
+                        default='output_dir',
+                        help="path to output image dir")
+
+    parser.add_argument("--weight_path",
+                        type=str,
+                        default=None,
+                        help="path to model checkpoint path")
+
+    parser.add_argument("--model_type",
+                        type=str,
+                        default=None,
+                        help="type of model for loading pretrained model")
+
+    parser.add_argument("--seed",
+                        type=int,
+                        default=None,
+                        help="sample random seed for model's image generation")
+                        
+    parser.add_argument("--size",
+                        type=int,
+                        default=1024,
+                        help="resolution of output image")
+                        
+    parser.add_argument("--style_dim",
+                        type=int,
+                        default=512,
+                        help="number of style dimension")
+                        
+    parser.add_argument("--n_mlp",
+                        type=int,
+                        default=8,
+                        help="number of mlp layer depth")
+                        
+    parser.add_argument("--channel_multiplier",
+                        type=int,
+                        default=2,
+                        help="number of channel multiplier")
+
+    parser.add_argument("--n_row",
+                        type=int,
+                        default=3,
+                        help="row number of output image grid")
+
+    parser.add_argument("--n_col",
+                        type=int,
+                        default=5,
+                        help="column number of output image grid")
+
+    parser.add_argument("--cpu",
+                        dest="cpu",
+                        action="store_true",
+                        help="cpu mode.")
+
+    args = parser.parse_args()
+
+    if args.cpu:
+        paddle.set_device('cpu')
+
+    predictor = StyleGANv2Predictor(
+        output_path=args.output_path,
+        weight_path=args.weight_path,
+        model_type=args.model_type,
+        seed=args.seed,
+        size=args.size,
+        style_dim=args.style_dim,
+        n_mlp=args.n_mlp,
+        channel_multiplier=args.channel_multiplier
+    )
+    predictor.run(args.n_row, args.n_col)

docs/en_US/tutorials/pixel2style2pixel.md

+# Pixel2Style2Pixel
+
+## Pixel2Style2Pixel introduction
+
+The task of Pixel2Style2Pixel is image encoding. It mainly encodes an input image as the style vector of StyleGAN V2 and uses StyleGAN V2 as the decoder.
+
+<div align="center">
+  <img src="../../imgs/pSp-teaser.jpg" width="500"/>
+</div>
+
+Pixel2Style2Pixel uses a fairly large model to encode images, and encodes the image into the style vector space of StyleGAN V2, so that the image before encoding and the image after decoding have a strong correlation.
+
+Its main functions are:
+
+- Convert image to hidden codes
+- Turn face to face
+- Generate images based on sketches or segmentation results
+- Convert low-resolution images to high-definition images
+
+At present, only the models of portrait reconstruction and portrait cartoonization are realized in PaddleGAN.
+
+## How to use
+
+### Generate
+
+The user could use the following command to generate and select the local image as input：
+
+```
+cd applications/
+python -u tools/styleganv2.py \
+       --input_image <YOUR INPUT IMAGE> \
+       --output_path <DIRECTORY TO STORE OUTPUT IMAGE> \
+       --weight_path <YOUR PRETRAINED MODEL PATH> \
+       --model_type ffhq-inversion \
+       --seed 233 \
+       --size 1024 \
+       --style_dim 512 \
+       --n_mlp 8 \
+       --channel_multiplier 2 \
+       --cpu
+```
+
+**params:**
+- input_image: the input image file path
+- output_path: the directory where the generated images are stored
+- weight_path: pretrained model path
+- model_type: inner model type in PaddleGAN. If you use an existing model type, `weight_path` will have no effect.
+  Currently available: `ffhq-inversion`， `ffhq-toonify`
+- seed: random number seed
+- size: model parameters, output image resolution
+- style_dim: model parameters, dimensions of style z
+- n_mlp: model parameters, the number of multi-layer perception layers for style z
+- channel_multiplier: model parameters, channel product, affect model size and the quality of generated pictures
+- cpu: whether to use cpu inference, if not, please remove it from the command
+
+### Train (TODO)
+
+In the future, training scripts will be added to facilitate users to train more types of Pixel2Style2Pixel image encoders.
+
+
+## Results
+
+Input portrait:
+
+<div align="center">
+    <img src="../../imgs/pSp-input.jpg" width="300"/> 
+</div>
+
+Cropped portrait-Reconstructed portrait-Cartoonized portrait:
+
+<div align="center">
+    <img src="../../imgs/pSp-input-crop.png" width="100"/>
+    <img src="../../imgs/pSp-inversion.png" width="100"/>
+    <img src="../../imgs/pSp-toonify.png" width="100"/> 
+</div>
+
+## Reference
+
+```
+@article{richardson2020encoding,
+  title={Encoding in Style: a StyleGAN Encoder for Image-to-Image Translation},
+  author={Richardson, Elad and Alaluf, Yuval and Patashnik, Or and Nitzan, Yotam and Azar, Yaniv and Shapiro, Stav and Cohen-Or, Daniel},
+  journal={arXiv preprint arXiv:2008.00951},
+  year={2020}
+}
+
+```

docs/en_US/tutorials/styleganv2.md

+# StyleGAN V2
+
+## StyleGAN V2 introduction
+
+The task of StyleGAN V2 is image generation. Given a vector of a specific length, generate the image corresponding to the vector. It is an upgraded version of StyleGAN, which solves the problem of artifacts generated by StyleGAN.
+
+<div align="center">
+  <img src="../../imgs/stylegan2-teaser-1024x256.png" width="500"/>
+</div>
+
+StyleGAN V2 can mix multi-level style vectors. Its core is adaptive style decoupling.
+
+Compared with StyleGAN, its main improvement is:
+
+- The quality of the generated image is significantly better (higher FID score, fewer artifacts)
+- Propose a new method to replace progressive training, with more perfect details such as teeth and eyes
+- Style mixing improved
+- Smoother interpolation
+- Train faster
+
+## How to use
+
+### Generate
+
+The user can generate different results by replacing the value of the seed or removing the seed. Use the following command to generate images：
+
+```
+cd applications/
+python -u tools/styleganv2.py \
+       --output_path <DIRECTORY TO STORE OUTPUT IMAGE> \
+       --weight_path <YOUR PRETRAINED MODEL PATH> \
+       --model_type ffhq-config-f \
+       --seed 233 \
+       --size 1024 \
+       --style_dim 512 \
+       --n_mlp 8 \
+       --channel_multiplier 2 \
+       --n_row 3 \
+       --n_col 5 \
+       --cpu
+```
+
+**params:**
+- output_path: the directory where the generated images are stored
+- weight_path: pretrained model path
+- model_type: inner model type in PaddleGAN. If you use an existing model type, `weight_path` will have no effect.
+  Currently available: `ffhq-config-f`, `animeface-512`
+- seed: random number seed
+- size: model parameters, output image resolution
+- style_dim: model parameters, dimensions of style z
+- n_mlp: model parameters, the number of multi-layer perception layers for style z
+- channel_multiplier: model parameters, channel product, affect model size and the quality of generated pictures
+- n_row: the number of rows of the sampled image
+- n_col: the number of columns of the sampled picture
+- cpu: whether to use cpu inference, if not, please remove it from the command
+
+### Train (TODO)
+
+In the future, training scripts will be added to facilitate users to train more types of StyleGAN V2 image generators.
+
+
+## Results
+
+Random Samples:
+
+![Samples](../../imgs/stylegan2-sample.png)
+
+Random Style Mixing:
+
+![Random Style Mixing](../../imgs/stylegan2-sample-mixing-0.png)
+
+
+## Reference
+
+```
+@inproceedings{Karras2019stylegan2,
+  title     = {Analyzing and Improving the Image Quality of {StyleGAN}},
+  author    = {Tero Karras and Samuli Laine and Miika Aittala and Janne Hellsten and Jaakko Lehtinen and Timo Aila},
+  booktitle = {Proc. CVPR},
+  year      = {2020}
+}
+
+```

docs/zh_CN/tutorials/pixel2style2pixel.md

+# Pixel2Style2Pixel
+
+## Pixel2Style2Pixel 原理
+
+Pixel2Style2Pixel 的任务是image encoding。它主要是将图像编码为StyleGAN V2的风格向量，将StyleGAN V2当作解码器。
+
+<div align="center">
+  <img src="../../imgs/pSp-teaser.jpg" width="500"/>
+</div>
+
+Pixel2Style2Pixel使用相当大的模型对图像进行编码，将图像编码到StyleGAN V2的风格向量空间中，使编码前的图像和解码后的图像具有强关联性。
+
+它的主要功能有:
+
+- 将图像转成隐藏编码
+- 将人脸转正
+- 根据草图或者分割结果生成图像
+- 将低分辨率图像转成高清图像
+
+目前在PaddleGAN中实现了人像重建和人像卡通化的模型。
+
+## 使用方法
+
+### 生成
+
+用户使用如下命令中进行生成，选择本地图像作为输入：
+
+```
+cd applications/
+python -u tools/styleganv2.py \
+       --input_image <替换为输入的图像路径> \
+       --output_path <替换为生成图片存放的文件夹> \
+       --weight_path <替换为你的预训练模型路径> \
+       --model_type ffhq-inversion \
+       --seed 233 \
+       --size 1024 \
+       --style_dim 512 \
+       --n_mlp 8 \
+       --channel_multiplier 2 \
+       --cpu
+```
+
+**参数说明:**
+- input_image: 输入的图像路径
+- output_path: 生成图片存放的文件夹
+- weight_path: 预训练模型路径
+- model_type: PaddleGAN内置模型类型，若输入PaddleGAN已存在的模型类型，`weight_path`将失效。
+  当前可用: `ffhq-inversion`， `ffhq-toonify`
+- seed: 随机数种子
+- size: 模型参数，输出图片的分辨率
+- style_dim: 模型参数，风格z的维度
+- n_mlp: 模型参数，风格z所输入的多层感知层的层数
+- channel_multiplier: 模型参数，通道乘积，影响模型大小和生成图片质量
+- cpu: 是否使用cpu推理，若不使用，请在命令中去除
+
+### 训练(TODO)
+
+未来还将添加训练脚本方便用户训练出更多类型的 Pixel2Style2Pixel 图像编码器。
+
+
+## 生成结果展示
+
+输入人像:
+
+<div align="center">
+    <img src="../../imgs/pSp-input.jpg" width="300"/> 
+</div>
+
+裁剪人像-重建人像-卡通化人像:
+
+<div align="center">
+    <img src="../../imgs/pSp-input-crop.png" width="100"/>
+    <img src="../../imgs/pSp-inversion.png" width="100"/>
+    <img src="../../imgs/pSp-toonify.png" width="100"/> 
+</div>
+
+## 参考文献
+
+```
+@article{richardson2020encoding,
+  title={Encoding in Style: a StyleGAN Encoder for Image-to-Image Translation},
+  author={Richardson, Elad and Alaluf, Yuval and Patashnik, Or and Nitzan, Yotam and Azar, Yaniv and Shapiro, Stav and Cohen-Or, Daniel},
+  journal={arXiv preprint arXiv:2008.00951},
+  year={2020}
+}
+
+```

docs/zh_CN/tutorials/styleganv2.md

+# StyleGAN V2
+
+## StyleGAN V2 原理
+
+StyleGAN V2 的任务是image generation，给定特定长度的向量，生成该向量对应的图像，是StyleGAN的升级版，解决了StyleGAN生成的伪像等问题。
+
+<div align="center">
+  <img src="../../imgs/stylegan2-teaser-1024x256.png" width="500"/>
+</div>
+
+StyleGAN V2 可对多级风格向量进行混合。其内核是自适应的风格解耦。
+
+相对于StyleGAN，其主要改进为:
+
+- 生成的图像质量明显更好(FID分数更高、artifacts减少)
+- 提出替代渐进式训练的新方法，牙齿、眼睛等细节更完美
+- 改善了风格混合
+- 更平滑的插值
+- 训练速度更快
+
+## 使用方法
+
+### 生成
+
+用户使用如下命令中进行生成，可通过替换seed的值或去掉seed生成不同的结果：
+
+```
+cd applications/
+python -u tools/styleganv2.py \
+       --output_path <替换为生成图片存放的文件夹> \
+       --weight_path <替换为你的预训练模型路径> \
+       --model_type ffhq-config-f \
+       --seed 233 \
+       --size 1024 \
+       --style_dim 512 \
+       --n_mlp 8 \
+       --channel_multiplier 2 \
+       --n_row 3 \
+       --n_col 5 \
+       --cpu
+```
+
+**参数说明:**
+- output_path: 生成图片存放的文件夹
+- weight_path: 预训练模型路径
+- model_type: PaddleGAN内置模型类型，若输入PaddleGAN已存在的模型类型，`weight_path`将失效。
+  当前可用: `ffhq-config-f`， `animeface-512`
+- seed: 随机数种子
+- size: 模型参数，输出图片的分辨率
+- style_dim: 模型参数，风格z的维度
+- n_mlp: 模型参数，风格z所输入的多层感知层的层数
+- channel_multiplier: 模型参数，通道乘积，影响模型大小和生成图片质量
+- n_row: 采样的图片的行数
+- n_col: 采样的图片的列数
+- cpu: 是否使用cpu推理，若不使用，请在命令中去除
+
+### 训练(TODO)
+
+未来还将添加训练脚本方便用户训练出更多类型的 StyleGAN V2 图像生成器。
+
+
+## 生成结果展示
+
+随机采样结果:
+
+![随机采样结果](../../imgs/stylegan2-sample.png)
+
+随机风格插值结果:
+
+![随机风格插值结果](../../imgs/stylegan2-sample-mixing-0.png)
+
+
+## 参考文献
+
+```
+@inproceedings{Karras2019stylegan2,
+  title     = {Analyzing and Improving the Image Quality of {StyleGAN}},
+  author    = {Tero Karras and Samuli Laine and Miika Aittala and Janne Hellsten and Jaakko Lehtinen and Timo Aila},
+  booktitle = {Proc. CVPR},
+  year      = {2020}
+}
+
+```

ppgan/apps/__init__.py

@@ -21,3 +21,5 @@ from .first_order_predictor import FirstOrderPredictor
 from .face_parse_predictor import FaceParsePredictor
 from .animegan_predictor import AnimeGANPredictor
 from .midas_predictor import MiDaSPredictor
+from .styleganv2_predictor import StyleGANv2Predictor
+from .pixel2style2pixel_predictor import Pixel2Style2PixelPredictor

ppgan/apps/pixel2style2pixel_predictor.py

+#   Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserve.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import os
+import cv2
+import scipy
+import random
+import numpy as np
+import paddle
+import paddle.vision.transforms as T
+import ppgan.faceutils as futils
+from .base_predictor import BasePredictor
+from ppgan.models.generators import Pixel2Style2Pixel
+from ppgan.utils.download import get_path_from_url
+from PIL import Image
+
+
+model_cfgs = {
+    'ffhq-inversion': {
+        'model_urls': 'https://paddlegan.bj.bcebos.com/models/pSp-ffhq-inversion.pdparams',
+        'transform': T.Compose([
+            T.Resize((256, 256)),
+            T.Transpose(),
+            T.Normalize([127.5, 127.5, 127.5], [127.5, 127.5, 127.5])
+        ]),
+        'size': 1024,
+        'style_dim': 512,
+        'n_mlp': 8,
+        'channel_multiplier': 2
+    },
+    'ffhq-toonify': {
+        'model_urls': 'https://paddlegan.bj.bcebos.com/models/pSp-ffhq-toonify.pdparams',
+        'transform': T.Compose([
+            T.Resize((256, 256)),
+            T.Transpose(),
+            T.Normalize([127.5, 127.5, 127.5], [127.5, 127.5, 127.5])
+        ]),
+        'size': 1024,
+        'style_dim': 512,
+        'n_mlp': 8,
+        'channel_multiplier': 2
+    },
+    'default': {
+        'transform': T.Compose([
+            T.Resize((256, 256)),
+            T.Transpose(),
+            T.Normalize([127.5, 127.5, 127.5], [127.5, 127.5, 127.5])
+        ])
+    }
+}
+
+
+def run_alignment(image_path):
+    img = Image.open(image_path).convert("RGB")
+    face = futils.dlib.detect(img)
+    if not face:
+        raise Exception('Could not find a face in the given image.')
+    face_on_image = face[0]
+    lm = futils.dlib.landmarks(img, face_on_image)
+    lm = np.array(lm)[:,::-1]
+    lm_eye_left      = lm[36 : 42]
+    lm_eye_right     = lm[42 : 48]
+    lm_mouth_outer   = lm[48 : 60]
+
+    output_size = 1024
+    transform_size = 4096
+    enable_padding = True
+
+    # Calculate auxiliary vectors.
+    eye_left     = np.mean(lm_eye_left, axis=0)
+    eye_right    = np.mean(lm_eye_right, axis=0)
+    eye_avg      = (eye_left + eye_right) * 0.5
+    eye_to_eye   = eye_right - eye_left
+    mouth_left   = lm_mouth_outer[0]
+    mouth_right  = lm_mouth_outer[6]
+    mouth_avg    = (mouth_left + mouth_right) * 0.5
+    eye_to_mouth = mouth_avg - eye_avg
+
+    # Choose oriented crop rectangle.
+    x = eye_to_eye - np.flipud(eye_to_mouth) * [-1, 1]
+    x /= np.hypot(*x)
+    x *= max(np.hypot(*eye_to_eye) * 2.0, np.hypot(*eye_to_mouth) * 1.8)
+    y = np.flipud(x) * [-1, 1]
+    c = eye_avg + eye_to_mouth * 0.1
+    quad = np.stack([c - x - y, c - x + y, c + x + y, c + x - y])
+    qsize = np.hypot(*x) * 2
+
+    # Shrink.
+    shrink = int(np.floor(qsize / output_size * 0.5))
+    if shrink > 1:
+        rsize = (int(np.rint(float(img.size[0]) / shrink)), int(np.rint(float(img.size[1]) / shrink)))
+        img = img.resize(rsize, Image.ANTIALIAS)
+        quad /= shrink
+        qsize /= shrink
+
+    # Crop.
+    border = max(int(np.rint(qsize * 0.1)), 3)
+    crop = (int(np.floor(min(quad[:,0]))), int(np.floor(min(quad[:,1]))), int(np.ceil(max(quad[:,0]))), int(np.ceil(max(quad[:,1]))))
+    crop = (max(crop[0] - border, 0), max(crop[1] - border, 0), min(crop[2] + border, img.size[0]), min(crop[3] + border, img.size[1]))
+    if crop[2] - crop[0] < img.size[0] or crop[3] - crop[1] < img.size[1]:
+        img = img.crop(crop)
+        quad -= crop[0:2]
+
+    # Pad.
+    pad = (int(np.floor(min(quad[:,0]))), int(np.floor(min(quad[:,1]))), int(np.ceil(max(quad[:,0]))), int(np.ceil(max(quad[:,1]))))
+    pad = (max(-pad[0] + border, 0), max(-pad[1] + border, 0), max(pad[2] - img.size[0] + border, 0), max(pad[3] - img.size[1] + border, 0))
+    if enable_padding and max(pad) > border - 4:
+        pad = np.maximum(pad, int(np.rint(qsize * 0.3)))
+        img = np.pad(np.float32(img), ((pad[1], pad[3]), (pad[0], pad[2]), (0, 0)), 'reflect')
+        h, w, _ = img.shape
+        y, x, _ = np.ogrid[:h, :w, :1]
+        mask = np.maximum(1.0 - np.minimum(np.float32(x) / pad[0], np.float32(w-1-x) / pad[2]), 1.0 - np.minimum(np.float32(y) / pad[1], np.float32(h-1-y) / pad[3]))
+        blur = qsize * 0.02
+        img += (scipy.ndimage.gaussian_filter(img, [blur, blur, 0]) - img) * np.clip(mask * 3.0 + 1.0, 0.0, 1.0)
+        img += (np.median(img, axis=(0,1)) - img) * np.clip(mask, 0.0, 1.0)
+        img = Image.fromarray(np.uint8(np.clip(np.rint(img), 0, 255)), 'RGB')
+        quad += pad[:2]
+
+    # Transform.
+    img = img.transform((transform_size, transform_size), Image.QUAD, (quad + 0.5).flatten(), Image.BILINEAR)
+
+    return img
+
+
+class AttrDict(dict):
+    def __init__(self, *args, **kwargs):
+        super(AttrDict, self).__init__(*args, **kwargs)
+        self.__dict__ = self
+
+
+class Pixel2Style2PixelPredictor(BasePredictor):
+    def __init__(self,
+                 output_path='output_dir',
+                 weight_path=None,
+                 model_type=None,
+                 seed=None,
+                 size=1024,
+                 style_dim=512,
+                 n_mlp=8,
+                 channel_multiplier=2):
+        self.output_path = output_path
+
+        if weight_path is None and model_type != 'default':
+            if model_type in model_cfgs.keys():
+                weight_path = get_path_from_url(model_cfgs[model_type]['model_urls'])
+                size = model_cfgs[model_type].get('size', size)
+                style_dim = model_cfgs[model_type].get('style_dim', style_dim)
+                n_mlp = model_cfgs[model_type].get('n_mlp', n_mlp)
+                channel_multiplier = model_cfgs[model_type].get('channel_multiplier', channel_multiplier)
+                checkpoint = paddle.load(weight_path)
+            else:
+                raise ValueError('Predictor need a weight path or a pretrained model type')
+        else:
+            checkpoint = paddle.load(weight_path)
+
+        opts = checkpoint.pop('opts')
+        opts = AttrDict(opts)
+        opts['size'] = size
+        opts['style_dim'] = style_dim
+        opts['n_mlp'] = n_mlp
+        opts['channel_multiplier'] = channel_multiplier
+
+        self.generator = Pixel2Style2Pixel(opts)
+        self.generator.set_state_dict(checkpoint)
+        self.generator.eval()
+        
+        if seed is not None:
+            paddle.seed(seed)
+            random.seed(seed)
+            np.random.seed(seed)
+
+        self.model_type = 'default' if model_type is None else model_type
+
+    def run(self, image):
+        src_img = run_alignment(image)
+        src_img = np.asarray(src_img)
+        transformed_image = model_cfgs[self.model_type]['transform'](src_img)
+        dst_img = (self.generator(paddle.to_tensor(transformed_image[None, ...]))
+                  * 0.5 + 0.5)[0].numpy() * 255
+        dst_img = dst_img.transpose((1, 2, 0))
+
+        os.makedirs(self.output_path, exist_ok=True)
+        save_src_path = os.path.join(self.output_path, 'src.png')
+        cv2.imwrite(save_src_path, cv2.cvtColor(src_img, cv2.COLOR_RGB2BGR))
+        save_dst_path = os.path.join(self.output_path, 'dst.png')
+        cv2.imwrite(save_dst_path, cv2.cvtColor(dst_img, cv2.COLOR_RGB2BGR))
+
+        return src_img

ppgan/apps/styleganv2_predictor.py

+#   Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserve.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import os
+import random
+import numpy as np
+import paddle
+from .base_predictor import BasePredictor
+from ppgan.models.generators import StyleGANv2Generator
+from ppgan.utils.download import get_path_from_url
+from ppgan.utils.visual import make_grid, tensor2img, save_image
+
+
+model_cfgs = {
+    'ffhq-config-f': {
+        'model_urls': 'https://paddlegan.bj.bcebos.com/models/stylegan2-ffhq-config-f.pdparams',
+        'size': 1024,
+        'style_dim': 512,
+        'n_mlp': 8,
+        'channel_multiplier': 2
+    },
+    'animeface-512': {
+        'model_urls': 'https://paddlegan.bj.bcebos.com/models/stylegan2-animeface-512.pdparams',
+        'size': 512,
+        'style_dim': 512,
+        'n_mlp': 8,
+        'channel_multiplier': 2
+    }
+}
+
+
+@paddle.no_grad()
+def get_mean_style(generator):
+    mean_style = None
+
+    for i in range(10):
+        style = generator.mean_latent(1024)
+
+        if mean_style is None:
+            mean_style = style
+
+        else:
+            mean_style += style
+
+    mean_style /= 10
+    return mean_style
+
+
+@paddle.no_grad()
+def sample(generator, mean_style, n_sample):
+    image = generator(
+        [paddle.randn([n_sample, generator.style_dim])],
+        truncation=0.7,
+        truncation_latent=mean_style,
+    )[0]
+    
+    return image
+
+
+@paddle.no_grad()
+def style_mixing(generator, mean_style, n_source, n_target):
+    source_code = paddle.randn([n_source, generator.style_dim])
+    target_code = paddle.randn([n_target, generator.style_dim])
+
+    resolution = 2 ** ((generator.n_latent + 2) // 2)
+
+    images = [paddle.ones([1, 3, resolution, resolution]) * -1]
+
+    source_image = generator(
+        [source_code], truncation_latent=mean_style, truncation=0.7
+    )[0]
+    target_image = generator(
+        [target_code], truncation_latent=mean_style, truncation=0.7
+    )[0]
+
+    images.append(source_image)
+
+    for i in range(n_target):
+        image = generator(
+            [target_code[i].unsqueeze(0).tile([n_source, 1]), source_code],
+            truncation_latent=mean_style,
+            truncation=0.7,
+        )[0]
+        images.append(target_image[i].unsqueeze(0))
+        images.append(image)
+
+    images = paddle.concat(images, 0)
+    
+    return images
+
+
+class StyleGANv2Predictor(BasePredictor):
+    def __init__(self,
+                 output_path='output_dir',
+                 weight_path=None,
+                 model_type=None,
+                 seed=None,
+                 size=1024,
+                 style_dim=512,
+                 n_mlp=8,
+                 channel_multiplier=2):
+        self.output_path = output_path
+
+        if weight_path is None:
+            if model_type in model_cfgs.keys():
+                weight_path = get_path_from_url(model_cfgs[model_type]['model_urls'])
+                size = model_cfgs[model_type].get('size', size)
+                style_dim = model_cfgs[model_type].get('style_dim', style_dim)
+                n_mlp = model_cfgs[model_type].get('n_mlp', n_mlp)
+                channel_multiplier = model_cfgs[model_type].get('channel_multiplier', channel_multiplier)
+                checkpoint = paddle.load(weight_path)
+            else:
+                raise ValueError('Predictor need a weight path or a pretrained model type')
+        else:
+            checkpoint = paddle.load(weight_path)
+
+        self.generator = StyleGANv2Generator(size, style_dim, n_mlp, channel_multiplier)
+        self.generator.set_state_dict(checkpoint)
+        self.generator.eval()
+        
+        if seed is not None:
+            paddle.seed(seed)
+            random.seed(seed)
+            np.random.seed(seed)
+
+    def run(self, n_row=3, n_col=5):
+        os.makedirs(self.output_path, exist_ok=True)
+        mean_style = get_mean_style(self.generator)
+
+        img = sample(self.generator, mean_style, n_row * n_col)
+        save_image(tensor2img(make_grid(img, nrow=n_col)), f'{self.output_path}/sample.png')
+
+        for j in range(2):
+            img = style_mixing(self.generator, mean_style, n_col, n_row)
+            save_image(tensor2img(make_grid(
+                img, nrow=n_col + 1
+            )), f'{self.output_path}/sample_mixing_{j}.png')

ppgan/models/discriminators/__init__.py

@@ -17,3 +17,4 @@ from .nlayers import NLayerDiscriminator, NLayerDiscriminatorWithClassification
 from .discriminator_ugatit import UGATITDiscriminator
 from .dcdiscriminator import DCDiscriminator
 from .discriminator_animegan import AnimeDiscriminator
+from .discriminator_styleganv2 import StyleGANv2Discriminator

ppgan/models/discriminators/discriminator_styleganv2.py

+#   Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserve.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import math
+import paddle
+import paddle.nn as nn
+import paddle.nn.functional as F
+
+from .builder import DISCRIMINATORS
+from ...modules.equalized import EqualLinear, EqualConv2D
+from ...modules.fused_act import FusedLeakyReLU
+from ...modules.upfirdn2d import Upfirdn2dBlur
+
+
+class ConvLayer(nn.Sequential):
+    def __init__(
+        self,
+        in_channel,
+        out_channel,
+        kernel_size,
+        downsample=False,
+        blur_kernel=[1, 3, 3, 1],
+        bias=True,
+        activate=True,
+    ):
+        layers = []
+ 
+        if downsample:
+            factor = 2
+            p = (len(blur_kernel) - factor) + (kernel_size - 1)
+            pad0 = (p + 1) // 2
+            pad1 = p // 2
+ 
+            layers.append(Upfirdn2dBlur(blur_kernel, pad=(pad0, pad1)))
+ 
+            stride = 2
+            self.padding = 0
+ 
+        else:
+            stride = 1
+            self.padding = kernel_size // 2
+ 
+        layers.append(
+            EqualConv2D(
+                in_channel,
+                out_channel,
+                kernel_size,
+                padding=self.padding,
+                stride=stride,
+                bias=bias and not activate,
+            )
+        )
+ 
+        if activate:
+            layers.append(FusedLeakyReLU(out_channel, bias=bias))
+ 
+        super().__init__(*layers)
+ 
+ 
+class ResBlock(nn.Layer):
+    def __init__(self, in_channel, out_channel, blur_kernel=[1, 3, 3, 1]):
+        super().__init__()
+ 
+        self.conv1 = ConvLayer(in_channel, in_channel, 3)
+        self.conv2 = ConvLayer(in_channel, out_channel, 3, downsample=True)
+ 
+        self.skip = ConvLayer(
+            in_channel, out_channel, 1, downsample=True, activate=False, bias=False
+        )
+ 
+    def forward(self, input):
+        out = self.conv1(input)
+        out = self.conv2(out)
+ 
+        skip = self.skip(input)
+        out = (out + skip) / math.sqrt(2)
+ 
+        return out
+ 
+ 
+@DISCRIMINATORS.register()
+class StyleGANv2Discriminator(nn.Layer):
+    def __init__(self, size, channel_multiplier=2, blur_kernel=[1, 3, 3, 1]):
+        super().__init__()
+ 
+        channels = {
+            4: 512,
+            8: 512,
+            16: 512,
+            32: 512,
+            64: 256 * channel_multiplier,
+            128: 128 * channel_multiplier,
+            256: 64 * channel_multiplier,
+            512: 32 * channel_multiplier,
+            1024: 16 * channel_multiplier,
+        }
+ 
+        convs = [ConvLayer(3, channels[size], 1)]
+ 
+        log_size = int(math.log(size, 2))
+ 
+        in_channel = channels[size]
+ 
+        for i in range(log_size, 2, -1):
+            out_channel = channels[2 ** (i - 1)]
+ 
+            convs.append(ResBlock(in_channel, out_channel, blur_kernel))
+ 
+            in_channel = out_channel
+ 
+        self.convs = nn.Sequential(*convs)
+ 
+        self.stddev_group = 4
+        self.stddev_feat = 1
+ 
+        self.final_conv = ConvLayer(in_channel + 1, channels[4], 3)
+        self.final_linear = nn.Sequential(
+            EqualLinear(channels[4] * 4 * 4, channels[4], activation="fused_lrelu"),
+            EqualLinear(channels[4], 1),
+        )
+ 
+    def forward(self, input):
+        out = self.convs(input)
+ 
+        batch, channel, height, width = out.shape
+        group = min(batch, self.stddev_group)
+        stddev = out.reshape((
+            group, -1, self.stddev_feat, channel // self.stddev_feat, height, width
+        ))
+        stddev = paddle.sqrt(stddev.var(0, unbiased=False) + 1e-8)
+        stddev = stddev.mean([2, 3, 4], keepdim=True).squeeze(2)
+        stddev = stddev.tile((group, 1, height, width))
+        out = paddle.concat([out, stddev], 1)
+ 
+        out = self.final_conv(out)
+ 
+        out = out.reshape((batch, -1))
+        out = self.final_linear(out)
+ 
+        return out

ppgan/models/generators/__init__.py

@@ -20,4 +20,6 @@ from .deep_conv import DeepConvGenerator, ConditionalDeepConvGenerator
 from .resnet_ugatit import ResnetUGATITGenerator
 from .dcgenerator import DCGenerator
 from .generater_animegan import AnimeGenerator, AnimeGeneratorLite
-from .wav2lip import Wav2Lip
\ No newline at end of file
+from .wav2lip import Wav2Lip
+from .generator_styleganv2 import StyleGANv2Generator
+from .generator_pixel2style2pixel import Pixel2Style2Pixel

ppgan/models/generators/generator_pixel2style2pixel.py

+#   Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserve.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import math
+import numpy as np
+import paddle
+import paddle.nn as nn
+import paddle.nn.functional as F
+
+from collections import namedtuple
+
+from .builder import GENERATORS
+from .generator_styleganv2 import StyleGANv2Generator
+from ...modules.equalized import EqualLinear
+
+
+class Flatten(nn.Layer):
+    def forward(self, input):
+        return input.reshape((input.shape[0], -1))
+
+
+def l2_norm(input, axis=1):
+    norm = paddle.norm(input, 2, axis, True)
+    output = paddle.div(input, norm)
+    return output
+
+
+class Bottleneck(namedtuple('Block', ['in_channel', 'depth', 'stride'])):
+    """ A named tuple describing a ResNet block. """
+
+
+def get_block(in_channel, depth, num_units, stride=2):
+    return [Bottleneck(in_channel, depth, stride)] + [Bottleneck(depth, depth, 1) for i in range(num_units - 1)]
+
+
+def get_blocks(num_layers):
+    if num_layers == 50:
+        blocks = [
+            get_block(in_channel=64, depth=64, num_units=3),
+            get_block(in_channel=64, depth=128, num_units=4),
+            get_block(in_channel=128, depth=256, num_units=14),
+            get_block(in_channel=256, depth=512, num_units=3)
+        ]
+    elif num_layers == 100:
+        blocks = [
+            get_block(in_channel=64, depth=64, num_units=3),
+            get_block(in_channel=64, depth=128, num_units=13),
+            get_block(in_channel=128, depth=256, num_units=30),
+            get_block(in_channel=256, depth=512, num_units=3)
+        ]
+    elif num_layers == 152:
+        blocks = [
+            get_block(in_channel=64, depth=64, num_units=3),
+            get_block(in_channel=64, depth=128, num_units=8),
+            get_block(in_channel=128, depth=256, num_units=36),
+            get_block(in_channel=256, depth=512, num_units=3)
+        ]
+    else:
+        raise ValueError("Invalid number of layers: {}. Must be one of [50, 100, 152]".format(num_layers))
+    return blocks
+
+
+class SEModule(nn.Layer):
+    def __init__(self, channels, reduction):
+        super(SEModule, self).__init__()
+        self.avg_pool = nn.AdaptiveAvgPool2D(1)
+        self.fc1 = nn.Conv2D(channels, channels // reduction, kernel_size=1, padding=0, bias_attr=False)
+        self.relu = nn.ReLU()
+        self.fc2 = nn.Conv2D(channels // reduction, channels, kernel_size=1, padding=0, bias_attr=False)
+        self.sigmoid = nn.Sigmoid()
+
+    def forward(self, x):
+        module_input = x
+        x = self.avg_pool(x)
+        x = self.fc1(x)
+        x = self.relu(x)
+        x = self.fc2(x)
+        x = self.sigmoid(x)
+        return module_input * x
+
+
+class BottleneckIR(nn.Layer):
+    def __init__(self, in_channel, depth, stride):
+        super(BottleneckIR, self).__init__()
+        if in_channel == depth:
+            self.shortcut_layer = nn.MaxPool2D(1, stride)
+        else:
+            self.shortcut_layer = nn.Sequential(
+                nn.Conv2D(in_channel, depth, (1, 1), stride, bias_attr=False),
+                nn.BatchNorm2D(depth)
+            )
+        self.res_layer = nn.Sequential(
+            nn.BatchNorm2D(in_channel),
+            nn.Conv2D(in_channel, depth, (3, 3), (1, 1), 1, bias_attr=False), nn.PReLU(depth),
+            nn.Conv2D(depth, depth, (3, 3), stride, 1, bias_attr=False), nn.BatchNorm2D(depth)
+        )
+
+    def forward(self, x):
+        shortcut = self.shortcut_layer(x)
+        res = self.res_layer(x)
+        return res + shortcut
+
+
+class BottleneckIRSE(nn.Layer):
+    def __init__(self, in_channel, depth, stride):
+        super(BottleneckIRSE, self).__init__()
+        if in_channel == depth:
+            self.shortcut_layer = nn.MaxPool2D(1, stride)
+        else:
+            self.shortcut_layer = nn.Sequential(
+                nn.Conv2D(in_channel, depth, (1, 1), stride, bias_attr=False),
+                nn.BatchNorm2D(depth)
+            )
+        self.res_layer = nn.Sequential(
+            nn.BatchNorm2D(in_channel),
+            nn.Conv2D(in_channel, depth, (3, 3), (1, 1), 1, bias_attr=False),
+            nn.PReLU(depth),
+            nn.Conv2D(depth, depth, (3, 3), stride, 1, bias_attr=False),
+            nn.BatchNorm2D(depth),
+            SEModule(depth, 16)
+        )
+
+    def forward(self, x):
+        shortcut = self.shortcut_layer(x)
+        res = self.res_layer(x)
+        return res + shortcut
+
+
+class GradualStyleBlock(nn.Layer):
+    def __init__(self, in_c, out_c, spatial):
+        super(GradualStyleBlock, self).__init__()
+        self.out_c = out_c
+        self.spatial = spatial
+        num_pools = int(np.log2(spatial))
+        modules = []
+        modules += [nn.Conv2D(in_c, out_c, kernel_size=3, stride=2, padding=1),
+                    nn.LeakyReLU()]
+        for i in range(num_pools - 1):
+            modules += [
+                nn.Conv2D(out_c, out_c, kernel_size=3, stride=2, padding=1),
+                nn.LeakyReLU()
+            ]
+        self.convs = nn.Sequential(*modules)
+        self.linear = EqualLinear(out_c, out_c, lr_mul=1)
+
+    def forward(self, x):
+        x = self.convs(x)
+        x = x.reshape((-1, self.out_c))
+        x = self.linear(x)
+        return x
+
+
+class GradualStyleEncoder(nn.Layer):
+    def __init__(self, num_layers, mode='ir', opts=None):
+        super(GradualStyleEncoder, self).__init__()
+        assert num_layers in [50, 100, 152], 'num_layers should be 50,100, or 152'
+        assert mode in ['ir', 'ir_se'], 'mode should be ir or ir_se'
+        blocks = get_blocks(num_layers)
+        if mode == 'ir':
+            unit_module = BottleneckIR
+        elif mode == 'ir_se':
+            unit_module = BottleneckIRSE
+        self.input_layer = nn.Sequential(nn.Conv2D(opts.input_nc, 64, (3, 3), 1, 1, bias_attr=False),
+                                         nn.BatchNorm2D(64),
+                                         nn.PReLU(64))
+        modules = []
+        for block in blocks:
+            for bottleneck in block:
+                modules.append(unit_module(bottleneck.in_channel,
+                                           bottleneck.depth,
+                                           bottleneck.stride))
+        self.body = nn.Sequential(*modules)
+
+        self.styles = nn.LayerList()
+        self.style_count = 18
+        self.coarse_ind = 3
+        self.middle_ind = 7
+        for i in range(self.style_count):
+            if i < self.coarse_ind:
+                style = GradualStyleBlock(512, 512, 16)
+            elif i < self.middle_ind:
+                style = GradualStyleBlock(512, 512, 32)
+            else:
+                style = GradualStyleBlock(512, 512, 64)
+            self.styles.append(style)
+        self.latlayer1 = nn.Conv2D(256, 512, kernel_size=1, stride=1, padding=0)
+        self.latlayer2 = nn.Conv2D(128, 512, kernel_size=1, stride=1, padding=0)
+
+    def _upsample_add(self, x, y):
+        '''Upsample and add two feature maps.
+        Args:
+          x: (Tensor) top feature map to be upsampled.
+          y: (Tensor) lateral feature map.
+        Returns:
+          (Tensor) added feature map.
+        Note in Pypaddle, when input size is odd, the upsampled feature map
+        with `F.upsample(..., scale_factor=2, mode='nearest')`
+        maybe not equal to the lateral feature map size.
+        e.g.
+        original input size: [N,_,15,15] ->
+        conv2d feature map size: [N,_,8,8] ->
+        upsampled feature map size: [N,_,16,16]
+        So we choose bilinear upsample which supports arbitrary output sizes.
+        '''
+        _, _, H, W = y.shape
+        return F.interpolate(x, size=(H, W), mode='bilinear', align_corners=True) + y
+
+    def forward(self, x):
+        x = self.input_layer(x)
+
+        latents = []
+        modulelist = list(self.body._sub_layers.values())
+        for i, l in enumerate(modulelist):
+            x = l(x)
+            if i == 6:
+                c1 = x
+            elif i == 20:
+                c2 = x
+            elif i == 23:
+                c3 = x
+
+        for j in range(self.coarse_ind):
+            latents.append(self.styles[j](c3))
+
+        p2 = self._upsample_add(c3, self.latlayer1(c2))
+        for j in range(self.coarse_ind, self.middle_ind):
+            latents.append(self.styles[j](p2))
+
+        p1 = self._upsample_add(p2, self.latlayer2(c1))
+        for j in range(self.middle_ind, self.style_count):
+            latents.append(self.styles[j](p1))
+
+        out = paddle.stack(latents, 1)
+        return out
+
+
+class BackboneEncoderUsingLastLayerIntoW(nn.Layer):
+    def __init__(self, num_layers, mode='ir', opts=None):
+        super(BackboneEncoderUsingLastLayerIntoW, self).__init__()
+        print('Using BackboneEncoderUsingLastLayerIntoW')
+        assert num_layers in [50, 100, 152], 'num_layers should be 50,100, or 152'
+        assert mode in ['ir', 'ir_se'], 'mode should be ir or ir_se'
+        blocks = get_blocks(num_layers)
+        if mode == 'ir':
+            unit_module = BottleneckIR
+        elif mode == 'ir_se':
+            unit_module = BottleneckIRSE
+        self.input_layer = nn.Sequential(nn.Conv2D(opts.input_nc, 64, (3, 3), 1, 1, bias_attr=False),
+                                         nn.BatchNorm2D(64),
+                                         nn.PReLU(64))
+        self.output_pool = nn.AdaptiveAvgPool2D((1, 1))
+        self.linear = EqualLinear(512, 512, lr_mul=1)
+        modules = []
+        for block in blocks:
+            for bottleneck in block:
+                modules.append(unit_module(bottleneck.in_channel,
+                                           bottleneck.depth,
+                                           bottleneck.stride))
+        self.body = nn.Sequential(*modules)
+
+    def forward(self, x):
+        x = self.input_layer(x)
+        x = self.body(x)
+        x = self.output_pool(x)
+        x = x.reshape((-1, 512))
+        x = self.linear(x)
+        return x
+
+
+class BackboneEncoderUsingLastLayerIntoWPlus(nn.Layer):
+    def __init__(self, num_layers, mode='ir', opts=None):
+        super(BackboneEncoderUsingLastLayerIntoWPlus, self).__init__()
+        print('Using BackboneEncoderUsingLastLayerIntoWPlus')
+        assert num_layers in [50, 100, 152], 'num_layers should be 50,100, or 152'
+        assert mode in ['ir', 'ir_se'], 'mode should be ir or ir_se'
+        blocks = get_blocks(num_layers)
+        if mode == 'ir':
+            unit_module = BottleneckIR
+        elif mode == 'ir_se':
+            unit_module = BottleneckIRSE
+        self.input_layer = nn.Sequential(nn.Conv2D(opts.input_nc, 64, (3, 3), 1, 1, bias_attr=False),
+                                         nn.BatchNorm2D(64),
+                                         nn.PReLU(64))
+        self.output_layer_2 = nn.Sequential(nn.BatchNorm2D(512),
+                                            nn.AdaptiveAvgPool2D((7, 7)),
+                                            Flatten(),
+                                            nn.Linear(512 * 7 * 7, 512))
+        self.linear = EqualLinear(512, 512 * 18, lr_mul=1)
+        modules = []
+        for block in blocks:
+            for bottleneck in block:
+                modules.append(unit_module(bottleneck.in_channel,
+                                           bottleneck.depth,
+                                           bottleneck.stride))
+        self.body = nn.Sequential(*modules)
+
+    def forward(self, x):
+        x = self.input_layer(x)
+        x = self.body(x)
+        x = self.output_layer_2(x)
+        x = self.linear(x)
+        x = x.reshape((-1, 18, 512))
+        return x
+
+
+@GENERATORS.register()
+class Pixel2Style2Pixel(nn.Layer):
+    def __init__(self, opts):
+        super(Pixel2Style2Pixel, self).__init__()
+        self.set_opts(opts)
+        # Define architecture
+        self.encoder = self.set_encoder()
+        self.decoder = StyleGANv2Generator(opts.size, opts.style_dim, opts.n_mlp, opts.channel_multiplier)
+        self.face_pool = nn.AdaptiveAvgPool2D((256, 256))
+        self.style_dim = self.decoder.style_dim
+        self.n_latent = self.decoder.n_latent
+        if self.opts.start_from_latent_avg:
+            if self.opts.learn_in_w:
+                self.register_buffer('latent_avg', paddle.zeros([1, self.style_dim]))
+            else:
+                self.register_buffer('latent_avg', paddle.zeros([1, self.n_latent, self.style_dim]))
+
+    def set_encoder(self):
+        if self.opts.encoder_type == 'GradualStyleEncoder':
+            encoder = GradualStyleEncoder(50, 'ir_se', self.opts)
+        elif self.opts.encoder_type == 'BackboneEncoderUsingLastLayerIntoW':
+            encoder = BackboneEncoderUsingLastLayerIntoW(50, 'ir_se', self.opts)
+        elif self.opts.encoder_type == 'BackboneEncoderUsingLastLayerIntoWPlus':
+            encoder = BackboneEncoderUsingLastLayerIntoWPlus(50, 'ir_se', self.opts)
+        else:
+            raise Exception('{} is not a valid encoders'.format(self.opts.encoder_type))
+        return encoder
+
+    def forward(self, x, resize=True, latent_mask=None, input_code=False, randomize_noise=True,
+                inject_latent=None, return_latents=False, alpha=None):
+        if input_code:
+            codes = x
+        else:
+            codes = self.encoder(x)
+            # normalize with respect to the center of an average face
+            if self.opts.start_from_latent_avg:
+                if self.opts.learn_in_w:
+                    codes = codes + self.latent_avg.tile([codes.shape[0], 1])
+                else:
+                    codes = codes + self.latent_avg.tile([codes.shape[0], 1, 1])
+
+
+        if latent_mask is not None:
+            for i in latent_mask:
+                if inject_latent is not None:
+                    if alpha is not None:
+                        codes[:, i] = alpha * inject_latent[:, i] + (1 - alpha) * codes[:, i]
+                    else:
+                        codes[:, i] = inject_latent[:, i]
+                else:
+                    codes[:, i] = 0
+
+        input_is_latent = not input_code
+        images, result_latent = self.decoder([codes],
+                                             input_is_latent=input_is_latent,
+                                             randomize_noise=randomize_noise,
+                                             return_latents=return_latents)
+
+        if resize:
+            images = self.face_pool(images)
+
+        if return_latents:
+            return images, result_latent
+        else:
+            return images
+
+    def set_opts(self, opts):
+        self.opts = opts

ppgan/models/generators/generator_styleganv2.py

+#   Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserve.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import math
+import random
+import paddle
+import paddle.nn as nn
+import paddle.nn.functional as F
+
+from .builder import GENERATORS
+from ...modules.equalized import EqualLinear
+from ...modules.fused_act import FusedLeakyReLU
+from ...modules.upfirdn2d import Upfirdn2dUpsample, Upfirdn2dBlur
+
+
+class PixelNorm(nn.Layer):
+    def __init__(self):
+        super().__init__()
+ 
+    def forward(self, input):
+        return input * paddle.rsqrt(paddle.mean(input ** 2, 1, keepdim=True) + 1e-8)
+ 
+ 
+class ModulatedConv2D(nn.Layer):
+    def __init__(
+        self,
+        in_channel,
+        out_channel,
+        kernel_size,
+        style_dim,
+        demodulate=True,
+        upsample=False,
+        downsample=False,
+        blur_kernel=[1, 3, 3, 1],
+    ):
+        super().__init__()
+ 
+        self.eps = 1e-8
+        self.kernel_size = kernel_size
+        self.in_channel = in_channel
+        self.out_channel = out_channel
+        self.upsample = upsample
+        self.downsample = downsample
+ 
+        if upsample:
+            factor = 2
+            p = (len(blur_kernel) - factor) - (kernel_size - 1)
+            pad0 = (p + 1) // 2 + factor - 1
+            pad1 = p // 2 + 1
+ 
+            self.blur = Upfirdn2dBlur(blur_kernel, pad=(pad0, pad1), upsample_factor=factor)
+ 
+        if downsample:
+            factor = 2
+            p = (len(blur_kernel) - factor) + (kernel_size - 1)
+            pad0 = (p + 1) // 2
+            pad1 = p // 2
+ 
+            self.blur = Upfirdn2dBlur(blur_kernel, pad=(pad0, pad1))
+ 
+        fan_in = in_channel * kernel_size ** 2
+        self.scale = 1 / math.sqrt(fan_in)
+        self.padding = kernel_size // 2
+ 
+        self.weight = self.create_parameter(
+            (1, out_channel, in_channel, kernel_size, kernel_size), default_initializer=nn.initializer.Normal()
+        )
+ 
+        self.modulation = EqualLinear(style_dim, in_channel, bias_init=1)
+ 
+        self.demodulate = demodulate
+ 
+    def __repr__(self):
+        return (
+            f"{self.__class__.__name__}({self.in_channel}, {self.out_channel}, {self.kernel_size}, "
+            f"upsample={self.upsample}, downsample={self.downsample})"
+        )
+ 
+    def forward(self, input, style):
+        batch, in_channel, height, width = input.shape
+ 
+        style = self.modulation(style).reshape((batch, 1, in_channel, 1, 1))
+        weight = self.scale * self.weight * style
+ 
+        if self.demodulate:
+            demod = paddle.rsqrt(weight.pow(2).sum([2, 3, 4]) + 1e-8)
+            weight = weight * demod.reshape((batch, self.out_channel, 1, 1, 1))
+ 
+        weight = weight.reshape((
+            batch * self.out_channel, in_channel, self.kernel_size, self.kernel_size
+        ))
+ 
+        if self.upsample:
+            input = input.reshape((1, batch * in_channel, height, width))
+            weight = weight.reshape((
+                batch, self.out_channel, in_channel, self.kernel_size, self.kernel_size
+            ))
+            weight = weight.transpose((0, 2, 1, 3, 4)).reshape((
+                batch * in_channel, self.out_channel, self.kernel_size, self.kernel_size
+            ))
+            out = F.conv2d_transpose(input, weight, padding=0, stride=2, groups=batch)
+            _, _, height, width = out.shape
+            out = out.reshape((batch, self.out_channel, height, width))
+            out = self.blur(out)
+ 
+        elif self.downsample:
+            input = self.blur(input)
+            _, _, height, width = input.shape
+            input = input.reshape((1, batch * in_channel, height, width))
+            out = F.conv2d(input, weight, padding=0, stride=2, groups=batch)
+            _, _, height, width = out.shape
+            out = out.reshape((batch, self.out_channel, height, width))
+ 
+        else:
+            input = input.reshape((1, batch * in_channel, height, width))
+            out = F.conv2d(input, weight, padding=self.padding, groups=batch)
+            _, _, height, width = out.shape
+            out = out.reshape((batch, self.out_channel, height, width))
+ 
+        return out
+ 
+ 
+class NoiseInjection(nn.Layer):
+    def __init__(self):
+        super().__init__()
+ 
+        self.weight = self.create_parameter((1,), default_initializer=nn.initializer.Constant(0.0))
+ 
+    def forward(self, image, noise=None):
+        if noise is None:
+            batch, _, height, width = image.shape
+            noise = paddle.randn((batch, 1, height, width))
+ 
+        return image + self.weight * noise
+ 
+ 
+class ConstantInput(nn.Layer):
+    def __init__(self, channel, size=4):
+        super().__init__()
+ 
+        self.input = self.create_parameter((1, channel, size, size), default_initializer=nn.initializer.Normal())
+ 
+    def forward(self, input):
+        batch = input.shape[0]
+        out = self.input.tile((batch, 1, 1, 1))
+ 
+        return out
+ 
+ 
+class StyledConv(nn.Layer):
+    def __init__(
+        self,
+        in_channel,
+        out_channel,
+        kernel_size,
+        style_dim,
+        upsample=False,
+        blur_kernel=[1, 3, 3, 1],
+        demodulate=True,
+    ):
+        super().__init__()
+ 
+        self.conv = ModulatedConv2D(
+            in_channel,
+            out_channel,
+            kernel_size,
+            style_dim,
+            upsample=upsample,
+            blur_kernel=blur_kernel,
+            demodulate=demodulate,
+        )
+ 
+        self.noise = NoiseInjection()
+        self.activate = FusedLeakyReLU(out_channel)
+ 
+    def forward(self, input, style, noise=None):
+        out = self.conv(input, style)
+        out = self.noise(out, noise=noise)
+        out = self.activate(out)
+ 
+        return out
+ 
+ 
+class ToRGB(nn.Layer):
+    def __init__(self, in_channel, style_dim, upsample=True, blur_kernel=[1, 3, 3, 1]):
+        super().__init__()
+ 
+        if upsample:
+            self.upsample = Upfirdn2dUpsample(blur_kernel)
+ 
+        self.conv = ModulatedConv2D(in_channel, 3, 1, style_dim, demodulate=False)
+        self.bias = self.create_parameter((1, 3, 1, 1), nn.initializer.Constant(0.0))
+ 
+    def forward(self, input, style, skip=None):
+        out = self.conv(input, style)
+        out = out + self.bias
+ 
+        if skip is not None:
+            skip = self.upsample(skip)
+ 
+            out = out + skip
+ 
+        return out
+ 
+ 
+@GENERATORS.register()
+class StyleGANv2Generator(nn.Layer):
+    def __init__(
+        self,
+        size,
+        style_dim,
+        n_mlp,
+        channel_multiplier=2,
+        blur_kernel=[1, 3, 3, 1],
+        lr_mlp=0.01,
+    ):
+        super().__init__()
+ 
+        self.size = size
+ 
+        self.style_dim = style_dim
+ 
+        layers = [PixelNorm()]
+ 
+        for i in range(n_mlp):
+            layers.append(
+                EqualLinear(
+                    style_dim, style_dim, lr_mul=lr_mlp, activation="fused_lrelu"
+                )
+            )
+ 
+        self.style = nn.Sequential(*layers)
+ 
+        self.channels = {
+            4: 512,
+            8: 512,
+            16: 512,
+            32: 512,
+            64: 256 * channel_multiplier,
+            128: 128 * channel_multiplier,
+            256: 64 * channel_multiplier,
+            512: 32 * channel_multiplier,
+            1024: 16 * channel_multiplier,
+        }
+ 
+        self.input = ConstantInput(self.channels[4])
+        self.conv1 = StyledConv(
+            self.channels[4], self.channels[4], 3, style_dim, blur_kernel=blur_kernel
+        )
+        self.to_rgb1 = ToRGB(self.channels[4], style_dim, upsample=False)
+ 
+        self.log_size = int(math.log(size, 2))
+        self.num_layers = (self.log_size - 2) * 2 + 1
+ 
+        self.convs = nn.LayerList()
+        self.upsamples = nn.LayerList()
+        self.to_rgbs = nn.LayerList()
+        self.noises = nn.Layer()
+ 
+        in_channel = self.channels[4]
+ 
+        for layer_idx in range(self.num_layers):
+            res = (layer_idx + 5) // 2
+            shape = [1, 1, 2 ** res, 2 ** res]
+            self.noises.register_buffer(f"noise_{layer_idx}", paddle.randn(shape))
+ 
+        for i in range(3, self.log_size + 1):
+            out_channel = self.channels[2 ** i]
+ 
+            self.convs.append(
+                StyledConv(
+                    in_channel,
+                    out_channel,
+                    3,
+                    style_dim,
+                    upsample=True,
+                    blur_kernel=blur_kernel,
+                )
+            )
+ 
+            self.convs.append(
+                StyledConv(
+                    out_channel, out_channel, 3, style_dim, blur_kernel=blur_kernel
+                )
+            )
+ 
+            self.to_rgbs.append(ToRGB(out_channel, style_dim))
+ 
+            in_channel = out_channel
+ 
+        self.n_latent = self.log_size * 2 - 2
+ 
+    def make_noise(self):
+        noises = [paddle.randn((1, 1, 2 ** 2, 2 ** 2))]
+ 
+        for i in range(3, self.log_size + 1):
+            for _ in range(2):
+                noises.append(paddle.randn((1, 1, 2 ** i, 2 ** i)))
+ 
+        return noises
+ 
+    def mean_latent(self, n_latent):
+        latent_in = paddle.randn((
+            n_latent, self.style_dim
+        ))
+        latent = self.style(latent_in).mean(0, keepdim=True)
+ 
+        return latent
+ 
+    def get_latent(self, input):
+        return self.style(input)
+ 
+    def forward(
+        self,
+        styles,
+        return_latents=False,
+        inject_index=None,
+        truncation=1,
+        truncation_latent=None,
+        input_is_latent=False,
+        noise=None,
+        randomize_noise=True,
+    ):
+        if not input_is_latent:
+            styles = [self.style(s) for s in styles]
+ 
+        if noise is None:
+            if randomize_noise:
+                noise = [None] * self.num_layers
+            else:
+                noise = [
+                    getattr(self.noises, f"noise_{i}") for i in range(self.num_layers)
+                ]
+ 
+        if truncation < 1:
+            style_t = []
+ 
+            for style in styles:
+                style_t.append(
+                    truncation_latent + truncation * (style - truncation_latent)
+                )
+ 
+            styles = style_t
+ 
+        if len(styles) < 2:
+            inject_index = self.n_latent
+ 
+            if styles[0].ndim < 3:
+                latent = styles[0].unsqueeze(1).tile((1, inject_index, 1))
+ 
+            else:
+                latent = styles[0]
+ 
+        else:
+            if inject_index is None:
+                inject_index = random.randint(1, self.n_latent - 1)
+ 
+            latent = styles[0].unsqueeze(1).tile((1, inject_index, 1))
+            latent2 = styles[1].unsqueeze(1).tile((1, self.n_latent - inject_index, 1))
+ 
+            latent = paddle.concat([latent, latent2], 1)
+ 
+        out = self.input(latent)
+        out = self.conv1(out, latent[:, 0], noise=noise[0])
+ 
+        skip = self.to_rgb1(out, latent[:, 1])
+ 
+        i = 1
+        for conv1, conv2, noise1, noise2, to_rgb in zip(
+            self.convs[::2], self.convs[1::2], noise[1::2], noise[2::2], self.to_rgbs
+        ):
+            out = conv1(out, latent[:, i], noise=noise1)
+            out = conv2(out, latent[:, i + 1], noise=noise2)
+            skip = to_rgb(out, latent[:, i + 2], skip)
+ 
+            i += 2
+ 
+        image = skip
+ 
+        if return_latents:
+            return image, latent
+ 
+        else:
+            return image, None

ppgan/modules/equalized.py

+#   Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserve.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import math
+import paddle
+import paddle.nn as nn
+import paddle.nn.functional as F
+
+from .fused_act import fused_leaky_relu
+
+
+class EqualConv2D(nn.Layer):
+    """This convolutional layer class stabilizes the learning rate changes of its parameters.
+    Equalizing learning rate keeps the weights in the network at a similar scale during training.
+    """
+    def __init__(
+        self, in_channel, out_channel, kernel_size, stride=1, padding=0, bias=True
+    ):
+        super().__init__()
+ 
+        self.weight = self.create_parameter(
+            (out_channel, in_channel, kernel_size, kernel_size), default_initializer=nn.initializer.Normal()
+        )
+        self.scale = 1 / math.sqrt(in_channel * kernel_size ** 2)
+ 
+        self.stride = stride
+        self.padding = padding
+ 
+        if bias:
+            self.bias = self.create_parameter((out_channel,), nn.initializer.Constant(0.0))
+ 
+        else:
+            self.bias = None
+ 
+    def forward(self, input):
+        out = F.conv2d(
+            input,
+            self.weight * self.scale,
+            bias=self.bias,
+            stride=self.stride,
+            padding=self.padding,
+        )
+ 
+        return out
+ 
+    def __repr__(self):
+        return (
+            f"{self.__class__.__name__}({self.weight.shape[1]}, {self.weight.shape[0]},"
+            f" {self.weight.shape[2]}, stride={self.stride}, padding={self.padding})"
+        )
+ 
+ 
+class EqualLinear(nn.Layer):
+    """This linear layer class stabilizes the learning rate changes of its parameters.
+    Equalizing learning rate keeps the weights in the network at a similar scale during training.
+    """
+    def __init__(
+        self, in_dim, out_dim, bias=True, bias_init=0, lr_mul=1, activation=None
+    ):
+        super().__init__()
+ 
+        self.weight = self.create_parameter((in_dim, out_dim), default_initializer=nn.initializer.Normal())
+        self.weight[:] = (self.weight / lr_mul).detach()
+ 
+        if bias:
+            self.bias = self.create_parameter((out_dim,), nn.initializer.Constant(bias_init))
+ 
+        else:
+            self.bias = None
+ 
+        self.activation = activation
+ 
+        self.scale = (1 / math.sqrt(in_dim)) * lr_mul
+        self.lr_mul = lr_mul
+ 
+    def forward(self, input):
+        if self.activation:
+            out = F.linear(input, self.weight * self.scale)
+            out = fused_leaky_relu(out, self.bias * self.lr_mul)
+ 
+        else:
+            out = F.linear(
+                input, self.weight * self.scale, bias=self.bias * self.lr_mul
+            )
+ 
+        return out
+ 
+    def __repr__(self):
+        return (
+            f"{self.__class__.__name__}({self.weight.shape[0]}, {self.weight.shape[1]})"
+        )

ppgan/modules/fused_act.py

+# Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserve.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import paddle
+import paddle.nn as nn
+import paddle.nn.functional as F
+ 
+ 
+class FusedLeakyReLU(nn.Layer):
+    def __init__(self, channel, bias=True, negative_slope=0.2, scale=2 ** 0.5):
+        super().__init__()
+ 
+        if bias:
+            self.bias = self.create_parameter((channel,), default_initializer=nn.initializer.Constant(0.0))
+ 
+        else:
+            self.bias = None
+ 
+        self.negative_slope = negative_slope
+        self.scale = scale
+ 
+    def forward(self, input):
+        return fused_leaky_relu(input, self.bias, self.negative_slope, self.scale)
+ 
+ 
+def fused_leaky_relu(input, bias=None, negative_slope=0.2, scale=2 ** 0.5):
+    if bias is not None:
+        rest_dim = [1] * (input.ndim - bias.ndim - 1)
+        return (
+            F.leaky_relu(
+                input + bias.reshape((1, bias.shape[0], *rest_dim)), negative_slope=0.2
+            )
+            * scale
+        )
+ 
+    else:
+        return F.leaky_relu(input, negative_slope=0.2) * scale

ppgan/modules/upfirdn2d.py

+#   Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserve.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import paddle
+import paddle.nn as nn
+import paddle.nn.functional as F
+ 
+ 
+def upfirdn2d_native(
+    input, kernel, up_x, up_y, down_x, down_y, pad_x0, pad_x1, pad_y0, pad_y1
+):
+    _, channel, in_h, in_w = input.shape
+    input = input.reshape((-1, in_h, in_w, 1))
+ 
+    _, in_h, in_w, minor = input.shape
+    kernel_h, kernel_w = kernel.shape
+ 
+    out = input.reshape((-1, in_h, 1, in_w, 1, minor))
+    out = out.transpose((0,1,3,5,2,4))
+    out = out.reshape((-1,1,1,1))
+    out = F.pad(out, [0, up_x - 1, 0, up_y - 1])
+    out = out.reshape((-1, in_h, in_w, minor, up_y, up_x))
+    out = out.transpose((0,3,1,4,2,5))
+    out = out.reshape((-1, minor, in_h * up_y, in_w * up_x))
+ 
+    out = F.pad(
+        out, [max(pad_x0, 0), max(pad_x1, 0), max(pad_y0, 0), max(pad_y1, 0)]
+    )
+    out = out[
+        :,:,
+        max(-pad_y0, 0) : out.shape[2] - max(-pad_y1, 0),
+        max(-pad_x0, 0) : out.shape[3] - max(-pad_x1, 0),
+    ]
+ 
+    out = out.reshape((
+        [-1, 1, in_h * up_y + pad_y0 + pad_y1, in_w * up_x + pad_x0 + pad_x1]
+    ))
+    w = paddle.flip(kernel, [0, 1]).reshape((1, 1, kernel_h, kernel_w))
+    out = F.conv2d(out, w)
+    out = out.reshape((
+        -1,
+        minor,
+        in_h * up_y + pad_y0 + pad_y1 - kernel_h + 1,
+        in_w * up_x + pad_x0 + pad_x1 - kernel_w + 1,
+    ))
+    out = out.transpose((0, 2, 3, 1))
+    out = out[:, ::down_y, ::down_x, :]
+ 
+    out_h = (in_h * up_y + pad_y0 + pad_y1 - kernel_h) // down_y + 1
+    out_w = (in_w * up_x + pad_x0 + pad_x1 - kernel_w) // down_x + 1
+ 
+    return out.reshape((-1, channel, out_h, out_w))
+
+ 
+def upfirdn2d(input, kernel, up=1, down=1, pad=(0, 0)):
+    out = upfirdn2d_native(
+        input, kernel, up, up, down, down, pad[0], pad[1], pad[0], pad[1]
+    )
+ 
+    return out
+
+
+def make_kernel(k):
+    k = paddle.to_tensor(k, dtype='float32')
+ 
+    if k.ndim == 1:
+        k = k.unsqueeze(0) * k.unsqueeze(1)
+ 
+    k /= k.sum()
+ 
+    return k
+ 
+ 
+class Upfirdn2dUpsample(nn.Layer):
+    def __init__(self, kernel, factor=2):
+        super().__init__()
+ 
+        self.factor = factor
+        kernel = make_kernel(kernel) * (factor ** 2)
+        self.register_buffer("kernel", kernel)
+ 
+        p = kernel.shape[0] - factor
+ 
+        pad0 = (p + 1) // 2 + factor - 1
+        pad1 = p // 2
+ 
+        self.pad = (pad0, pad1)
+ 
+    def forward(self, input):
+        out = upfirdn2d(input, self.kernel, up=self.factor, down=1, pad=self.pad)
+ 
+        return out
+ 
+ 
+class Upfirdn2dDownsample(nn.Layer):
+    def __init__(self, kernel, factor=2):
+        super().__init__()
+ 
+        self.factor = factor
+        kernel = make_kernel(kernel)
+        self.register_buffer("kernel", kernel)
+ 
+        p = kernel.shape[0] - factor
+ 
+        pad0 = (p + 1) // 2
+        pad1 = p // 2
+ 
+        self.pad = (pad0, pad1)
+ 
+    def forward(self, input):
+        out = upfirdn2d(input, self.kernel, up=1, down=self.factor, pad=self.pad)
+ 
+        return out
+ 
+ 
+class Upfirdn2dBlur(nn.Layer):
+    def __init__(self, kernel, pad, upsample_factor=1):
+        super().__init__()
+ 
+        kernel = make_kernel(kernel)
+ 
+        if upsample_factor > 1:
+            kernel = kernel * (upsample_factor ** 2)
+ 
+        self.register_buffer("kernel", kernel)
+ 
+        self.pad = pad
+ 
+    def forward(self, input):
+        out = upfirdn2d(input, self.kernel, pad=self.pad)
+ 
+        return out