Accept RGBA image as input (#2877)

internal_controlnet/args.py

@@ -16,6 +16,7 @@
     HiResFixOption,
     PuLIDMode,
 )
+from annotator.util import HWC3
 
 
 def _unimplemented_func(*args, **kwargs):
@@ -279,9 +280,11 @@ def parse_image(cls, image) -> np.ndarray:
         else:
             raise ValueError(f"Unrecognized image format {image}.")
 
-        # [H, W] => [H, W, 3]
-        if np_image.ndim == 2:
-            np_image = np.stack([np_image, np_image, np_image], axis=-1)
+        # Convert following image shapes to shape [H, W, C=3].
+        # - [H, W]
+        # - [H, W, 1]
+        # - [H, W, 4]
+        np_image = HWC3(np_image)
         assert np_image.ndim == 3
         assert np_image.shape[2] == 3
         return np_image

unit_tests/args_test.py

@@ -10,7 +10,7 @@
 img1 = np.ones(shape=[H, W, 3], dtype=np.uint8)
 img2 = np.ones(shape=[H, W, 3], dtype=np.uint8) * 2
 mask_diff = np.ones(shape=[H - 1, W - 1, 3], dtype=np.uint8) * 2
-mask_2d = np.ones(shape=[H, W])
+mask_2d = np.ones(shape=[H, W], dtype=np.uint8)
 img_bad_channel = np.ones(shape=[H, W, 2], dtype=np.uint8) * 2
 img_bad_dim = np.ones(shape=[1, H, W, 3], dtype=np.uint8) * 2
 ui_img_diff = np.ones(shape=[H - 1, W - 1, 4], dtype=np.uint8) * 2
@@ -104,9 +104,12 @@ def test_model_valid(set_cls_funcs):
         # UI
         dict(image=dict(image=img1)),
         dict(image=dict(image=img1, mask=img2)),
-        # 2D mask should be accepted.
+        # Grey-scale mask/image should be accepted.
         dict(image=dict(image=img1, mask=mask_2d)),
         dict(image=img1, mask=mask_2d),
+        dict(image=np.zeros(shape=[H, W, 1], dtype=np.uint8)),
+        # RGBA image input should be accepted.
+        dict(image=np.zeros(shape=[H, W, 4], dtype=np.uint8)),
     ],
 )
 def test_valid_image_formats(set_cls_funcs, d):