wip test

tests/utils_tests/image_tests/test_read_image.py

@@ -2,6 +2,8 @@
 import tempfile
 import unittest
 
+from PIL import Image
+
 import chainer
 from chainer import testing
 
@@ -15,13 +17,40 @@
     _cv2_available = False
 
 
-@testing.parameterize(*testing.product({
-    'size': [(48, 32)],
-    'color': [True, False],
-    'suffix': ['bmp', 'jpg', 'png'],
-    'dtype': [np.float32, np.uint8, bool],
-    'backend': ['cv2', 'PIL'],
-}))
+def _write_rgba_image(rgba, path):
+    rgba = rgba.transpose((1, 2, 0))
+    rgba = Image.fromarray(rgba, 'RGBA')
+    canvas = Image.new('RGBA', rgba.size, (255,255,255,255))
+    # Paste the image onto the canvas, using it's alpha channel as mask
+    canvas.paste(rgba, mask=rgba)
+    canvas.save(path)
+
+
+def _create_parameters():
+    params = testing.product({
+        'size': [(48, 32)],
+        'dtype': [np.float32, np.uint8, bool],
+        'backend': ['cv2', 'PIL']})
+    no_color_params = testing.product({
+        'color': [False],
+        'alpha': [None],
+        'suffix': ['bmp', 'jpg', 'png']})
+    no_alpha_params = testing.product({
+        'color': [True],
+        'alpha': [None],
+        'suffix': ['bmp', 'jpg', 'png']})
+    alpha_params = testing.product({
+        'color': [True],
+        'alpha': ['ignore', 'blend_with_white', 'blend_with_black'],
+        'suffix': ['png']  # writing alpha image with jpg encoding didn't work
+    })
+    params = testing.product_dict(
+        params,
+        no_color_params + no_alpha_params + alpha_params)
+    return params
+
+
+@testing.parameterize(*_create_parameters())
 class TestReadImage(unittest.TestCase):
 
     def setUp(self):
@@ -31,36 +60,42 @@ def setUp(self):
             suffix='.' + self.suffix, delete=False)
         self.path = self.file.name
 
-        if self.color:
-            self.img = np.random.randint(
-                0, 255, size=(3,) + self.size, dtype=np.uint8)
+        if self.alpha is None:
+            if self.color:
+                self.img = np.random.randint(
+                    0, 255, size=(3,) + self.size, dtype=np.uint8)
+            else:
+                self.img = np.random.randint(
+                    0, 255, size=(1,) + self.size, dtype=np.uint8)
+            write_image(self.img, self.path)
         else:
             self.img = np.random.randint(
-                0, 255, size=(1,) + self.size, dtype=np.uint8)
-        write_image(self.img, self.path)
+                0, 255, size=(4,) + self.size, dtype=np.uint8)
+            _write_rgba_image(self.img, self.path)
+
 
     def test_read_image_as_color(self):
-        img = read_image(self.path, dtype=self.dtype)
+        img = read_image(self.path, dtype=self.dtype, alpha=self.alpha)
 
         self.assertEqual(img.shape, (3,) + self.size)
         self.assertEqual(img.dtype, self.dtype)
 
-        if self.suffix in {'bmp', 'png'}:
+        if self.suffix in {'bmp', 'png'} and self.alpha is None:
             np.testing.assert_equal(
                 img,
                 np.broadcast_to(self.img, (3,) + self.size).astype(self.dtype))
 
     def test_read_image_as_grayscale(self):
-        img = read_image(self.path, dtype=self.dtype, color=False)
+        img = read_image(self.path, dtype=self.dtype, color=False, alpha=self.alpha)
 
         self.assertEqual(img.shape, (1,) + self.size)
         self.assertEqual(img.dtype, self.dtype)
 
-        if self.suffix in {'bmp', 'png'} and not self.color:
+        if self.suffix in {'bmp', 'png'} and not self.color and self.alpha is None:
             np.testing.assert_equal(img, self.img.astype(self.dtype))
 
     def test_read_image_mutable(self):
-        img = read_image(self.path)
+        img = read_image(self.path, alpha=self.alpha)
         img[:] = 0
         np.testing.assert_equal(img, 0)