[WIP] Add vitdet (#6397)

* add cascade vitdet

* cascade vit

* fix for model export

* add vit cascade cfgs

configs/vitdet/README.md

+# Vision transformer Detection
+
+## Introduction
+
+- [Context Autoencoder for Self-Supervised Representation Learning](https://arxiv.org/abs/2202.03026)  
+- [Benchmarking Detection Transfer Learning with Vision Transformers](https://arxiv.org/pdf/2111.11429.pdf)  
+
+Object detection is a central downstream task used to
+test if pre-trained network parameters confer benefits, such
+as improved accuracy or training speed. The complexity
+of object detection methods can make this benchmarking
+non-trivial when new architectures, such as Vision Transformer (ViT) models, arrive.
+
+## Model Zoo
+
+| Backbone | Pretrained | Model | Scheduler | Images/GPU  | Box AP | Config | Download |
+|:------:|:--------:|:--------------:|:--------------:|:--------------:|:------:|:------:|:--------:|
+| ViT-base | CAE | Cascade RCNN  | 1x | 1 | -- | [config](./cascade_rcnn_vit_base_hrfpn_cae_1x_coco.yml) | [coming soon]() |
+| ViT-large | CAE | Cascade RCNN  | 1x | 1 | -- | [config](./cascade_rcnn_vit_large_hrfpn_cae_1x_coco.yml) | [coming soon]() |
+
+**Notes:**
+- Model is trained on COCO train2017 dataset and evaluated on val2017 results of `mAP(IoU=0.5:0.95)`.
+- Base model is trained on 8x32G V100 GPU, large model on 8x80G A100.
+
+
+## Citations
+```
+@article{chen2022context,
+  title={Context autoencoder for self-supervised representation learning},
+  author={Chen, Xiaokang and Ding, Mingyu and Wang, Xiaodi and Xin, Ying and Mo, Shentong and Wang, Yunhao and Han, Shumin and Luo, Ping and Zeng, Gang and Wang, Jingdong},
+  journal={arXiv preprint arXiv:2202.03026},
+  year={2022}
+}
+
+@article{DBLP:journals/corr/abs-2111-11429,
+  author    = {Yanghao Li and
+               Saining Xie and
+               Xinlei Chen and
+               Piotr Doll{\'{a}}r and
+               Kaiming He and
+               Ross B. Girshick},
+  title     = {Benchmarking Detection Transfer Learning with Vision Transformers},
+  journal   = {CoRR},
+  volume    = {abs/2111.11429},
+  year      = {2021},
+  url       = {https://arxiv.org/abs/2111.11429},
+  eprinttype = {arXiv},
+  eprint    = {2111.11429},
+  timestamp = {Fri, 26 Nov 2021 13:48:43 +0100},
+  biburl    = {https://dblp.org/rec/journals/corr/abs-2111-11429.bib},
+  bibsource = {dblp computer science bibliography, https://dblp.org}
+}
+
+@article{Cai_2019,
+   title={Cascade R-CNN: High Quality Object Detection and Instance Segmentation},
+   ISSN={1939-3539},
+   url={http://dx.doi.org/10.1109/tpami.2019.2956516},
+   DOI={10.1109/tpami.2019.2956516},
+   journal={IEEE Transactions on Pattern Analysis and Machine Intelligence},
+   publisher={Institute of Electrical and Electronics Engineers (IEEE)},
+   author={Cai, Zhaowei and Vasconcelos, Nuno},
+   year={2019},
+   pages={1–1}
+}
+```

configs/vitdet/_base_/optimizer_base_1x.yml

+epoch: 12
+
+LearningRate:
+  base_lr: 0.0001
+  schedulers:
+  - !PiecewiseDecay
+    gamma: 0.1
+    milestones: [9, 11]
+  - !LinearWarmup
+    start_factor: 0.001
+    steps: 1000
+
+OptimizerBuilder:
+  optimizer:
+    type: AdamWDL
+    betas: [0.9, 0.999]
+    layer_decay: 0.75
+    weight_decay: 0.02
+    num_layers: 12
+    filter_bias_and_bn: True
+    skip_decay_names: ['pos_embed', 'cls_token']
+    set_param_lr_func: 'layerwise_lr_decay'

configs/vitdet/_base_/reader.yml

+worker_num: 2
+TrainReader:
+  sample_transforms:
+  - Decode: {}
+  - RandomResizeCrop: {resizes: [400, 500, 600], cropsizes: [[384, 600], ], prob: 0.5}
+  - RandomResize: {target_size: [[480, 1333], [512, 1333], [544, 1333], [576, 1333], [608, 1333], [640, 1333], [672, 1333], [704, 1333], [736, 1333], [768, 1333], [800, 1333]], keep_ratio: True, interp: 2}
+  - RandomFlip: {prob: 0.5}
+  - NormalizeImage: {is_scale: true, mean: [0.485,0.456,0.406], std: [0.229, 0.224,0.225]}
+  - Permute: {}
+  batch_transforms:
+  - PadBatch: {pad_to_stride: 32}
+  batch_size: 2
+  shuffle: true
+  drop_last: true
+  collate_batch: false
+
+EvalReader:
+  sample_transforms:
+  - Decode: {}
+  - Resize: {interp: 2, target_size: [800, 1333], keep_ratio: True}
+  - NormalizeImage: {is_scale: true, mean: [0.485,0.456,0.406], std: [0.229, 0.224,0.225]}
+  - Permute: {}
+  batch_transforms:
+  - PadBatch: {pad_to_stride: 32}
+  batch_size: 1
+  shuffle: false
+  drop_last: false
+  drop_empty: false
+
+
+TestReader:
+  inputs_def:
+    image_shape: [-1, 3, 640, 640]
+  sample_transforms:
+  - Decode: {}
+  - LetterBoxResize: {target_size: 640}
+  - NormalizeImage: {is_scale: true, mean: [0.485,0.456,0.406], std: [0.229, 0.224,0.225]}
+  - Permute: {}
+  batch_size: 1
+  shuffle: false
+  drop_last: false

configs/vitdet/cascade_rcnn_vit_base_hrfpn_cae_1x_coco.yml

+
+_BASE_: [
+  '../datasets/coco_detection.yml',
+  '../runtime.yml',
+  './_base_/reader.yml',
+  './_base_/optimizer_base_1x.yml'
+]
+
+weights: output/cascade_rcnn_vit_base_hrfpn_cae_1x_coco/model_final
+
+
+# runtime
+log_iter: 100
+snapshot_epoch: 1
+find_unused_parameters: True
+
+use_gpu: true
+norm_type: sync_bn
+
+
+# reader
+worker_num: 2
+TrainReader:
+  batch_size: 1
+
+
+# model
+architecture: CascadeRCNN
+
+CascadeRCNN:
+  backbone: VisionTransformer
+  neck: HRFPN
+  rpn_head: RPNHead
+  bbox_head: CascadeHead
+  # post process
+  bbox_post_process: BBoxPostProcess
+
+
+VisionTransformer:
+  patch_size: 16
+  embed_dim: 768
+  depth: 12
+  num_heads: 12
+  mlp_ratio: 4
+  qkv_bias: True
+  drop_rate: 0.0
+  drop_path_rate: 0.2
+  init_values: 0.1
+  final_norm: False
+  use_rel_pos_bias: False
+  use_sincos_pos_emb: True
+  epsilon: 0.000001 # 1e-6
+  out_indices: [3, 5, 7, 11]
+  with_fpn: True
+  pretrained: ~
+
+HRFPN:
+  out_channel: 256
+  use_bias: True
+
+RPNHead:
+  anchor_generator:
+    aspect_ratios: [0.5, 1.0, 2.0]
+    anchor_sizes: [[32], [64], [128], [256], [512]]
+    strides: [4, 8, 16, 32, 64]
+  rpn_target_assign:
+    batch_size_per_im: 256
+    fg_fraction: 0.5
+    negative_overlap: 0.3
+    positive_overlap: 0.7
+    use_random: True
+  train_proposal:
+    min_size: 0.0
+    nms_thresh: 0.7
+    pre_nms_top_n: 2000
+    post_nms_top_n: 2000
+    topk_after_collect: True
+  test_proposal:
+    min_size: 0.0
+    nms_thresh: 0.7
+    pre_nms_top_n: 1000
+    post_nms_top_n: 1000
+  loss_rpn_bbox: SmoothL1Loss
+
+SmoothL1Loss:
+  beta: 0.1111111111111111
+
+
+CascadeHead:
+  head: CascadeXConvNormHead
+  roi_extractor:
+    resolution: 7
+    sampling_ratio: 0
+    aligned: True
+  bbox_assigner: BBoxAssigner
+  bbox_loss: GIoULoss
+  num_cascade_stages: 3
+  reg_class_agnostic: False
+  stage_loss_weights: [1, 0.5, 0.25]
+  loss_normalize_pos: True
+
+BBoxAssigner:
+  batch_size_per_im: 512
+  bg_thresh: 0.5
+  fg_thresh: 0.5
+  fg_fraction: 0.25
+  cascade_iou: [0.5, 0.6, 0.7]
+  use_random: True
+
+
+CascadeXConvNormHead:
+    norm_type: bn
+
+
+GIoULoss:
+  loss_weight: 10.
+  reduction: 'none'
+  eps: 0.000001
+
+
+BBoxPostProcess:
+  decode:
+    name: RCNNBox
+    prior_box_var: [30.0, 30.0, 15.0, 15.0]
+  nms:
+    name: MultiClassNMS
+    keep_top_k: 100
+    score_threshold: 0.05
+    nms_threshold: 0.5

configs/vitdet/cascade_rcnn_vit_large_hrfpn_cae_1x_coco.yml

+_BASE_: [
+  './cascade_rcnn_vit_base_hrfpn_cae_1x_coco.yml'
+]
+
+weights: output/cascade_rcnn_vit_large_hrfpn_cae_1x_coco/model_final
+
+
+depth: &depth 24
+dim: &dim 1024
+
+VisionTransformer:
+  img_size: [800, 1344]
+  embed_dim: *dim
+  depth: *depth
+  num_heads: 16
+  drop_path_rate: 0.25
+  out_indices: [7, 11, 15, 23]
+  pretrained: ~
+
+HRFPN:
+  in_channels: [*dim, *dim, *dim, *dim]
+
+OptimizerBuilder:
+  optimizer:
+    layer_decay: 0.9
+    weight_decay: 0.02
+    num_layers: *depth

ppdet/modeling/backbones/vision_transformer.py

@@ -578,9 +578,10 @@ class VisionTransformer(nn.Layer):
 
         x = self.patch_embed(x)
 
-        x_shape = paddle.shape(x)  # b * c * h * w
+        B, D, Hp, Wp = x.shape  # b * c * h * w
 
-        cls_tokens = self.cls_token.expand((x_shape[0], -1, -1))
+        cls_tokens = self.cls_token.expand(
+            (B, self.cls_token.shape[-2], self.cls_token.shape[-1]))
         x = x.flatten(2).transpose([0, 2, 1])  # b * hw * c
         x = paddle.concat([cls_tokens, x], axis=1)
 
@@ -593,8 +594,6 @@ class VisionTransformer(nn.Layer):
         rel_pos_bias = self.rel_pos_bias(
         ) if self.rel_pos_bias is not None else None
 
-        B, _, Hp, Wp = x_shape
-
         feats = []
         for idx, blk in enumerate(self.blocks):
             if self.use_checkpoint:
@@ -607,7 +606,7 @@ class VisionTransformer(nn.Layer):
                 xp = paddle.reshape(
                     paddle.transpose(
                         self.norm(x[:, 1:, :]), perm=[0, 2, 1]),
-                    shape=[B, -1, Hp, Wp])
+                    shape=[B, D, Hp, Wp])
                 feats.append(xp)
 
         if self.with_fpn:

ppdet/modeling/heads/bbox_head.py

@@ -257,7 +257,13 @@ class BBoxHead(nn.Layer):
             pred = self.get_prediction(scores, deltas)
             return pred, self.head
 
-    def get_loss(self, scores, deltas, targets, rois, bbox_weight):
+    def get_loss(self,
+                 scores,
+                 deltas,
+                 targets,
+                 rois,
+                 bbox_weight,
+                 loss_normalize_pos=False):
         """
         scores (Tensor): scores from bbox head outputs
         deltas (Tensor): deltas from bbox head outputs
@@ -280,8 +286,15 @@ class BBoxHead(nn.Layer):
         else:
             tgt_labels = tgt_labels.cast('int64')
             tgt_labels.stop_gradient = True
-            loss_bbox_cls = F.cross_entropy(
-                input=scores, label=tgt_labels, reduction='mean')
+
+            if not loss_normalize_pos:
+                loss_bbox_cls = F.cross_entropy(
+                    input=scores, label=tgt_labels, reduction='mean')
+            else:
+                loss_bbox_cls = F.cross_entropy(
+                    input=scores, label=tgt_labels,
+                    reduction='none').sum() / (tgt_labels.shape[0] + 1e-7)
+
             loss_bbox[cls_name] = loss_bbox_cls
 
         # bbox reg
@@ -322,9 +335,16 @@ class BBoxHead(nn.Layer):
         if self.bbox_loss is not None:
             reg_delta = self.bbox_transform(reg_delta)
             reg_target = self.bbox_transform(reg_target)
-            loss_bbox_reg = self.bbox_loss(
-                reg_delta, reg_target).sum() / tgt_labels.shape[0]
-            loss_bbox_reg *= self.num_classes
+
+            if not loss_normalize_pos:
+                loss_bbox_reg = self.bbox_loss(
+                    reg_delta, reg_target).sum() / tgt_labels.shape[0]
+                loss_bbox_reg *= self.num_classes
+
+            else:
+                loss_bbox_reg = self.bbox_loss(
+                    reg_delta, reg_target).sum() / (tgt_labels.shape[0] + 1e-7)
+
         else:
             loss_bbox_reg = paddle.abs(reg_delta - reg_target).sum(
             ) / tgt_labels.shape[0]

ppdet/modeling/heads/cascade_head.py

@@ -162,7 +162,8 @@ class CascadeHead(BBoxHead):
                  num_cascade_stages=3,
                  bbox_loss=None,
                  reg_class_agnostic=True,
-                 stage_loss_weights=None):
+                 stage_loss_weights=None,
+                 loss_normalize_pos=False):
 
         nn.Layer.__init__(self, )
         self.head = head
@@ -184,6 +185,7 @@ class CascadeHead(BBoxHead):
 
         self.reg_class_agnostic = reg_class_agnostic
         num_bbox_delta = 4 if reg_class_agnostic else 4 * num_classes
+        self.loss_normalize_pos = loss_normalize_pos
 
         self.bbox_score_list = []
         self.bbox_delta_list = []
@@ -242,9 +244,16 @@ class CascadeHead(BBoxHead):
 
             # TODO (lyuwenyu) Is it correct for only one class ?
             if not self.reg_class_agnostic and i < self.num_cascade_stages - 1:
-                deltas = deltas.reshape([-1, self.num_classes, 4])
+                deltas = deltas.reshape([deltas.shape[0], self.num_classes, 4])
                 labels = scores[:, :-1].argmax(axis=-1)
-                deltas = deltas[paddle.arange(deltas.shape[0]), labels]
+
+                if self.training:
+                    deltas = deltas[paddle.arange(deltas.shape[0]), labels]
+                else:
+                    deltas = deltas[(deltas * F.one_hot(
+                        labels, num_classes=self.num_classes).unsqueeze(-1) != 0
+                                     ).nonzero(as_tuple=True)].reshape(
+                                         [deltas.shape[0], 4])
 
             head_out_list.append([scores, deltas, rois])
             pred_bbox = self._get_pred_bbox(deltas, rois, self.bbox_weight[i])
@@ -253,8 +262,13 @@ class CascadeHead(BBoxHead):
             loss = {}
             for stage, value in enumerate(zip(head_out_list, targets_list)):
                 (scores, deltas, rois), targets = value
-                loss_stage = self.get_loss(scores, deltas, targets, rois,
-                                           self.bbox_weight[stage])
+                loss_stage = self.get_loss(
+                    scores,
+                    deltas,
+                    targets,
+                    rois,
+                    self.bbox_weight[stage],
+                    loss_normalize_pos=self.loss_normalize_pos)
                 for k, v in loss_stage.items():
                     loss[k + "_stage{}".format(
                         stage)] = v * self.stage_loss_weights[stage]