fix cyclegan download (#4198)

* fix cyclegan download

dygraph/cycle_gan/README.md

@@ -35,12 +35,24 @@ Cycle GAN 是一种image to image 的图像生成网络，实现了非对称图
 
 ## 数据准备
 
-本教程使用 cityscapes 数据集 来进行模型的训练测试工作，可以通过指定 `python download.py --dataset cityscapes` 下载得到。
+CycleGAN 支持的数据集可以参考download.py中的`cycle_pix_dataset`，可以通过指定`python download.py --dataset xxx` 下载得到。
 
-cityscapes 训练集包含2975张街景实拍图片，2975张对应真实街景的语义分割图片。测试集包含499张实拍图片和499张语义分割图片。
+由于版权问题，cityscapes 数据集无法通过脚本直接获得，需要从[官方](https://www.cityscapes-dataset.com/)下载数据，
+下载完之后执行`python prepare_cityscapes_dataset.py --gtFine_dir ./gtFine/ --leftImg8bit_dir ./leftImg8bit --output_dir ./data/cityscapes/`处理，
+将数据存放在`data/cityscapes`。
 
-数据下载处理完毕后，并组织为以下路径结构：
+数据下载处理完毕后，需要您将数据组织为以下路径结构：
+```
+data
+|-- cityscapes
+|   |-- testA
+|   |-- testB
+|   |-- trainA
+|   |-- trainB
+
+```
 
+然后运行txt生成脚本：`python generate_txt.py`，最终数据组织如下所示:
 ```
 data
 |-- cityscapes

dygraph/cycle_gan/download.py

@@ -153,7 +153,7 @@ if __name__ == '__main__':
     args = parser.parse_args()
     cycle_pix_dataset = [
         'apple2orange', 'summer2winter_yosemite', 'horse2zebra', 'monet2photo',
-        'cezanne2photo', 'ukiyoe2photo', 'vangogh2photo', 'maps', 'cityscapes',
+        'cezanne2photo', 'ukiyoe2photo', 'vangogh2photo', 'maps',
         'facades', 'iphone2dslr_flower', 'ae_photos', 'mini'
     ]
 

dygraph/cycle_gan/generate_txt.py

+import sys
+import os
+import argparse
+
+def gen_txt(dir_path):
+    dataname = "cityscapes"
+    ### generator .txt file according to dirs
+    dirs = os.listdir(os.path.join(dir_path, '{}'.format(dataname)))
+    for d in dirs:
+        txt_file = d + '.txt'
+        txt_dir = os.path.join(dir_path, dataname)
+        f = open(os.path.join(txt_dir, txt_file), 'w')
+        for fil in os.listdir(os.path.join(txt_dir, d)):
+            wl = d + '/' + fil + '\n'
+            f.write(wl)
+        f.close()
+    sys.stderr.write("\n")
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(description=__doc__)
+    # yapf: disable
+    parser.add_argument('--output_dir',       type=str,     default="datasets",       help='Path to output Cityscapes directory.')
+    # yapf: enable
+    args = parser.parse_args()
+    gen_txt(args.output_dir)
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dygraph/cycle_gan/prepare_cityscapes_dataset.py

+import os
+import argparse
+import functools
+import glob
+import sys
+from PIL import Image
+''' Based on https://github.com/junyanz/CycleGAN'''
+
+
+def load_image(path):
+    return Image.open(path).convert('RGB').resize((256, 256))
+
+
+def propress_cityscapes(gtFine_dir, leftImg8bit_dir, output_dir, phase):
+    save_dir = os.path.join(output_dir, phase)
+    try:
+        os.makedirs(save_dir)
+    except Exception as e:
+        print("{} makedirs".format(e))
+        pass
+    try:
+        os.makedirs(save_dir + 'A')
+    except Exception as e:
+        print("{} makedirs".format(e))
+    try:
+        os.makedirs(save_dir + 'B')
+    except Exception as e:
+        print("{} makedirs".format(e))
+
+    seg_expr = os.path.join(gtFine_dir, phase, "*", "*_color.png")
+    seg_paths = glob.glob(seg_expr)
+    seg_paths = sorted(seg_paths)
+
+    photo_expr = os.path.join(leftImg8bit_dir, phase, "*", '*_leftImg8bit.png')
+    photo_paths = glob.glob(photo_expr)
+    photo_paths = sorted(photo_paths)
+
+    assert len(seg_paths) == len(photo_paths), \
+          "[%d] gtFine images NOT match [%d] leftImg8bit images. Aborting." % (len(seg_paths), len(photo_paths))
+
+    for i, (seg_path, photo_path) in enumerate(zip(seg_paths, photo_paths)):
+        seg_image = load_image(seg_path)
+        photo_image = load_image(photo_path)
+        # save image
+        save_path = os.path.join(save_dir+'A', "%d_A.jpg" % i)
+        photo_image.save(save_path, format='JPEG', subsampling=0, quality=100)
+        save_path = os.path.join(save_dir+'B', "%d_B.jpg" % i)
+        seg_image.save(save_path, format='JPEG', subsampling=0, quality=100)
+
+        if i % 10 == 0:
+            print("proprecess %d ~ %d images." % (i, i + 10))
+
+
+if __name__ == '__main__':
+    parser = argparse.ArgumentParser(description=__doc__)
+    # yapf: disable
+    parser.add_argument('--gtFine_dir',       type=str,     default=None,       help='Path to Cityscapes gtFine directory.')
+    parser.add_argument('--leftImg8bit_dir',  type=str,     default=None,       help='Path to Cityscapes leftImg8bit_trainvaltest directory.')
+    parser.add_argument('--output_dir',       type=str,     default=None,       help='Path to output Cityscapes directory.')
+    # yapf: enable
+    args = parser.parse_args()
+
+    print('Preparing Cityscapes Dataset for test phase')
+    propress_cityscapes(args.gtFine_dir, args.leftImg8bit_dir, args.output_dir,
+                        'test')
+
+    print('Preparing Cityscapes Dataset for train phase')
+    propress_cityscapes(args.gtFine_dir, args.leftImg8bit_dir, args.output_dir,
+                        'train')
+
+    print("DONE!!!")
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