Hi, I am working on Segmentation task in Cityscapes. To do that I downloaded the dataset and when I visualise trainset and valset I can see the images and masks correctly. But for images in test set it returns only a black mask. For masks I use _leftImg8bit.png' in dataset. I mean I am using 3-channel masks.
Here is a short script of how I visualise masks:

img_root = os.path.join(root_path,'test')

mask_root = os.path.join(root_path,'test_labels')

img_city_list = os.listdir(img_root)

mask_city_list = os.listdir(mask_root)

assert img_city_list==mask_city_list

cities = img_city_list

cities

berlin_img_list= sorted(os.listdir(os.path.join(img_root,'berlin'))) 

berlin_mask_list= sorted(os.listdir(os.path.join(mask_root,'berlin')))

img_sample = berlin_img_list[10]

img_sample:```



```berlin_000010_000019_leftImg8bit.png```

Here I visualise images:

```image = Image.open(os.path.join(img_root,'berlin',img_sample))
plt.imshow(image)```

now we have the following files in label folder:

```mask_lists = ['berlin_000010_000019_gtFine_color.png',
 'berlin_000010_000019_gtFine_instanceIds.png',
 'berlin_000010_000019_gtFine_labelIds.png',
 'berlin_000010_000019_gtFine_polygons.json']```

And when I visualise it using the following code:

```mask1 = Image.open(os.path.join(mask_root,'berlin',mask_lists[0])).convert('RGB')

mask2 = Image.open(os.path.join(mask_root,'berlin',mask_lists[2])).convert('L')```

```plt.imshow(mask1)```

```plt.imshow(mask2)```

I would just get a black mask. I would appreciate any help.