def _get_elephant(target_size):
# For models that don't include a Flatten step,
# the default is to accept variable-size inputs
# even when loading ImageNet weights (since it is possible).
# In this case, default to 299x299.
if target_size[0] is None:
target_size = (299, 299)
test_image = data_utils.get_file('elephant.jpg', TEST_IMAGE_PATH)
img = image_utils.load_img(test_image, target_size=tuple(target_size))
x = image_utils.img_to_array(img)
return np.expand_dims(x, axis=0)
def test_load_img(self):
tmpdir = self.create_tempdir()
filename_rgb = os.path.join(tmpdir.full_path, "rgb_utils.png")
filename_rgba = os.path.join(tmpdir.full_path, "rgba_utils.png")
filename_grayscale_8bit = os.path.join(tmpdir.full_path,
"grayscale_8bit_utils.png")
filename_grayscale_16bit = os.path.join(tmpdir.full_path,
"grayscale_16bit_utils.tiff")
filename_grayscale_32bit = os.path.join(tmpdir.full_path,
"grayscale_32bit_utils.tiff")
original_rgb_array = np.array(255 * np.random.rand(100, 100, 3),
dtype=np.uint8)
original_rgb = image_utils.array_to_img(original_rgb_array,
scale=False)
original_rgb.save(filename_rgb)
original_rgba_array = np.array(255 * np.random.rand(100, 100, 4),
dtype=np.uint8)
original_rgba = image_utils.array_to_img(original_rgba_array,
scale=False)
original_rgba.save(filename_rgba)
original_grayscale_8bit_array = np.array(255 *
np.random.rand(100, 100, 1),
dtype=np.uint8)
original_grayscale_8bit = image_utils.array_to_img(
original_grayscale_8bit_array, scale=False)
original_grayscale_8bit.save(filename_grayscale_8bit)
original_grayscale_16bit_array = np.array(
np.random.randint(-2147483648, 2147483647, (100, 100, 1)),
dtype=np.int16,
)
original_grayscale_16bit = image_utils.array_to_img(
original_grayscale_16bit_array, scale=False, dtype="int16")
original_grayscale_16bit.save(filename_grayscale_16bit)
original_grayscale_32bit_array = np.array(
np.random.randint(-2147483648, 2147483647, (100, 100, 1)),
dtype=np.int32,
)
original_grayscale_32bit = image_utils.array_to_img(
original_grayscale_32bit_array, scale=False, dtype="int32")
original_grayscale_32bit.save(filename_grayscale_32bit)
# Test that loaded image is exactly equal to original.
loaded_im = image_utils.load_img(filename_rgb)
loaded_im_array = image_utils.img_to_array(loaded_im)
self.assertEqual(loaded_im_array.shape, original_rgb_array.shape)
self.assertAllClose(loaded_im_array, original_rgb_array)
loaded_im = image_utils.load_img(filename_rgba, color_mode="rgba")
loaded_im_array = image_utils.img_to_array(loaded_im)
self.assertEqual(loaded_im_array.shape, original_rgba_array.shape)
self.assertAllClose(loaded_im_array, original_rgba_array)
loaded_im = image_utils.load_img(filename_rgb, color_mode="grayscale")
loaded_im_array = image_utils.img_to_array(loaded_im)
self.assertEqual(
loaded_im_array.shape,
(original_rgb_array.shape[0], original_rgb_array.shape[1], 1),
)
loaded_im = image_utils.load_img(filename_grayscale_8bit,
color_mode="grayscale")
loaded_im_array = image_utils.img_to_array(loaded_im)
self.assertEqual(loaded_im_array.shape,
original_grayscale_8bit_array.shape)
self.assertAllClose(loaded_im_array, original_grayscale_8bit_array)
loaded_im = image_utils.load_img(filename_grayscale_16bit,
color_mode="grayscale")
loaded_im_array = image_utils.img_to_array(loaded_im, dtype="int16")
self.assertEqual(loaded_im_array.shape,
original_grayscale_16bit_array.shape)
self.assertAllClose(loaded_im_array, original_grayscale_16bit_array)
# test casting int16 image to float32
loaded_im_array = image_utils.img_to_array(loaded_im)
self.assertAllClose(loaded_im_array, original_grayscale_16bit_array)
loaded_im = image_utils.load_img(filename_grayscale_32bit,
color_mode="grayscale")
loaded_im_array = image_utils.img_to_array(loaded_im, dtype="int32")
self.assertEqual(loaded_im_array.shape,
original_grayscale_32bit_array.shape)
self.assertAllClose(loaded_im_array, original_grayscale_32bit_array)
# test casting int32 image to float32
loaded_im_array = image_utils.img_to_array(loaded_im)
self.assertAllClose(loaded_im_array, original_grayscale_32bit_array)
# Test that nothing is changed when target size is equal to original.
loaded_im = image_utils.load_img(filename_rgb, target_size=(100, 100))
loaded_im_array = image_utils.img_to_array(loaded_im)
self.assertEqual(loaded_im_array.shape, original_rgb_array.shape)
self.assertAllClose(loaded_im_array, original_rgb_array)
loaded_im = image_utils.load_img(filename_rgba,
color_mode="rgba",
target_size=(100, 100))
loaded_im_array = image_utils.img_to_array(loaded_im)
self.assertEqual(loaded_im_array.shape, original_rgba_array.shape)
self.assertAllClose(loaded_im_array, original_rgba_array)
loaded_im = image_utils.load_img(filename_rgb,
color_mode="grayscale",
target_size=(100, 100))
loaded_im_array = image_utils.img_to_array(loaded_im)
self.assertEqual(
loaded_im_array.shape,
(original_rgba_array.shape[0], original_rgba_array.shape[1], 1),
)
loaded_im = image_utils.load_img(
filename_grayscale_8bit,
color_mode="grayscale",
target_size=(100, 100),
)
loaded_im_array = image_utils.img_to_array(loaded_im)
self.assertEqual(loaded_im_array.shape,
original_grayscale_8bit_array.shape)
self.assertAllClose(loaded_im_array, original_grayscale_8bit_array)
loaded_im = image_utils.load_img(
filename_grayscale_16bit,
color_mode="grayscale",
target_size=(100, 100),
)
loaded_im_array = image_utils.img_to_array(loaded_im, dtype="int16")
self.assertEqual(loaded_im_array.shape,
original_grayscale_16bit_array.shape)
self.assertAllClose(loaded_im_array, original_grayscale_16bit_array)
loaded_im = image_utils.load_img(
filename_grayscale_32bit,
color_mode="grayscale",
target_size=(100, 100),
)
loaded_im_array = image_utils.img_to_array(loaded_im, dtype="int32")
self.assertEqual(loaded_im_array.shape,
original_grayscale_32bit_array.shape)
self.assertAllClose(loaded_im_array, original_grayscale_32bit_array)
# Test down-sampling with bilinear interpolation.
loaded_im = image_utils.load_img(filename_rgb, target_size=(25, 25))
loaded_im_array = image_utils.img_to_array(loaded_im)
self.assertEqual(loaded_im_array.shape, (25, 25, 3))
loaded_im = image_utils.load_img(filename_rgba,
color_mode="rgba",
target_size=(25, 25))
loaded_im_array = image_utils.img_to_array(loaded_im)
self.assertEqual(loaded_im_array.shape, (25, 25, 4))
loaded_im = image_utils.load_img(filename_rgb,
color_mode="grayscale",
target_size=(25, 25))
loaded_im_array = image_utils.img_to_array(loaded_im)
self.assertEqual(loaded_im_array.shape, (25, 25, 1))
loaded_im = image_utils.load_img(
filename_grayscale_8bit,
color_mode="grayscale",
target_size=(25, 25),
)
loaded_im_array = image_utils.img_to_array(loaded_im)
self.assertEqual(loaded_im_array.shape, (25, 25, 1))
loaded_im = image_utils.load_img(
filename_grayscale_16bit,
color_mode="grayscale",
target_size=(25, 25),
)
loaded_im_array = image_utils.img_to_array(loaded_im, dtype="int16")
self.assertEqual(loaded_im_array.shape, (25, 25, 1))
loaded_im = image_utils.load_img(
filename_grayscale_32bit,
color_mode="grayscale",
target_size=(25, 25),
)
loaded_im_array = image_utils.img_to_array(loaded_im, dtype="int32")
self.assertEqual(loaded_im_array.shape, (25, 25, 1))
# Test down-sampling with nearest neighbor interpolation.
loaded_im_nearest = image_utils.load_img(filename_rgb,
target_size=(25, 25),
interpolation="nearest")
loaded_im_array_nearest = image_utils.img_to_array(loaded_im_nearest)
self.assertEqual(loaded_im_array_nearest.shape, (25, 25, 3))
self.assertTrue(np.any(loaded_im_array_nearest != loaded_im_array))
loaded_im_nearest = image_utils.load_img(
filename_rgba,
color_mode="rgba",
target_size=(25, 25),
interpolation="nearest",
)
loaded_im_array_nearest = image_utils.img_to_array(loaded_im_nearest)
self.assertEqual(loaded_im_array_nearest.shape, (25, 25, 4))
self.assertTrue(np.any(loaded_im_array_nearest != loaded_im_array))
loaded_im = image_utils.load_img(
filename_grayscale_8bit,
color_mode="grayscale",
target_size=(25, 25),
interpolation="nearest",
)
loaded_im_array = image_utils.img_to_array(loaded_im)
self.assertEqual(loaded_im_array.shape, (25, 25, 1))
loaded_im = image_utils.load_img(
filename_grayscale_16bit,
color_mode="grayscale",
target_size=(25, 25),
interpolation="nearest",
)
loaded_im_array = image_utils.img_to_array(loaded_im, dtype="int16")
self.assertEqual(loaded_im_array.shape, (25, 25, 1))
loaded_im = image_utils.load_img(
filename_grayscale_32bit,
color_mode="grayscale",
target_size=(25, 25),
interpolation="nearest",
)
loaded_im_array = image_utils.img_to_array(loaded_im, dtype="int32")
self.assertEqual(loaded_im_array.shape, (25, 25, 1))
# Test different path type
with open(filename_grayscale_32bit, "rb") as f:
path_ = io.BytesIO(f.read()) # io.Bytesio
loaded_im = image_utils.load_img(path_, color_mode="grayscale")
loaded_im_array = image_utils.img_to_array(loaded_im, dtype=np.int32)
self.assertAllClose(loaded_im_array, original_grayscale_32bit_array)
path_ = filename_grayscale_32bit # str
loaded_im = image_utils.load_img(path_, color_mode="grayscale")
loaded_im_array = image_utils.img_to_array(loaded_im, dtype=np.int32)
self.assertAllClose(loaded_im_array, original_grayscale_32bit_array)
path_ = filename_grayscale_32bit.encode() # bytes
loaded_im = image_utils.load_img(path_, color_mode="grayscale")
loaded_im_array = image_utils.img_to_array(loaded_im, dtype=np.int32)
self.assertAllClose(loaded_im_array, original_grayscale_32bit_array)
path_ = pathlib.Path(
os.path.join(tmpdir.full_path, "grayscale_32bit_utils.tiff"))
loaded_im = image_utils.load_img(path_, color_mode="grayscale")
loaded_im_array = image_utils.img_to_array(loaded_im, dtype=np.int32)
self.assertAllClose(loaded_im_array, original_grayscale_32bit_array)
# Check that exception is raised if interpolation not supported.
loaded_im = image_utils.load_img(filename_rgb,
interpolation="unsupported")
with self.assertRaises(ValueError):
loaded_im = image_utils.load_img(filename_rgb,
target_size=(25, 25),
interpolation="unsupported")
# Check that the aspect ratio of a square is the same
filename_red_square = os.path.join(tmpdir.full_path,
"red_square_utils.png")
arr = np.zeros((50, 100, 3), dtype=np.uint8) # rectangle image 100x50
arr[20:30, 45:55, 0] = 255 # red square 10x10
red_square_array = np.array(arr)
red_square = image_utils.array_to_img(red_square_array, scale=False)
red_square.save(filename_red_square)
loaded_im = image_utils.load_img(filename_red_square,
target_size=(25, 25),
keep_aspect_ratio=True)
loaded_im_array = image_utils.img_to_array(loaded_im)
self.assertEqual(loaded_im_array.shape, (25, 25, 3))
red_channel_arr = loaded_im_array[:, :, 0].astype(np.bool)
square_width = np.sum(np.sum(red_channel_arr, axis=0))
square_height = np.sum(np.sum(red_channel_arr, axis=1))
aspect_ratio_result = square_width / square_height
# original square had 1:1 ratio
self.assertNear(aspect_ratio_result, 1.0, 0.01)
def test_array_to_img_and_img_to_array(self):
height, width = 10, 8
# Test the data format
# Test RGB 3D
x = np.random.random((3, height, width))
img = image_utils.array_to_img(x, data_format="channels_first")
self.assertEqual(img.size, (width, height))
x = image_utils.img_to_array(img, data_format="channels_first")
self.assertEqual(x.shape, (3, height, width))
# Test RGBA 3D
x = np.random.random((4, height, width))
img = image_utils.array_to_img(x, data_format="channels_first")
self.assertEqual(img.size, (width, height))
x = image_utils.img_to_array(img, data_format="channels_first")
self.assertEqual(x.shape, (4, height, width))
# Test 2D
x = np.random.random((1, height, width))
img = image_utils.array_to_img(x, data_format="channels_first")
self.assertEqual(img.size, (width, height))
x = image_utils.img_to_array(img, data_format="channels_first")
self.assertEqual(x.shape, (1, height, width))
# grayscale 32-bit signed integer
x = np.array(
np.random.randint(-2147483648, 2147483647, (1, height, width)),
dtype=np.int32,
)
img = image_utils.array_to_img(x, data_format="channels_first")
self.assertEqual(img.size, (width, height))
x = image_utils.img_to_array(img, data_format="channels_first")
self.assertEqual(x.shape, (1, height, width))
# Test tf data format
# Test RGB 3D
x = np.random.random((height, width, 3))
img = image_utils.array_to_img(x, data_format="channels_last")
self.assertEqual(img.size, (width, height))
x = image_utils.img_to_array(img, data_format="channels_last")
self.assertEqual(x.shape, (height, width, 3))
# Test RGBA 3D
x = np.random.random((height, width, 4))
img = image_utils.array_to_img(x, data_format="channels_last")
self.assertEqual(img.size, (width, height))
x = image_utils.img_to_array(img, data_format="channels_last")
self.assertEqual(x.shape, (height, width, 4))
# Test 2D
x = np.random.random((height, width, 1))
img = image_utils.array_to_img(x, data_format="channels_last")
self.assertEqual(img.size, (width, height))
x = image_utils.img_to_array(img, data_format="channels_last")
self.assertEqual(x.shape, (height, width, 1))
# grayscale 16-bit signed integer
x = np.array(
np.random.randint(-2147483648, 2147483647, (height, width, 1)),
dtype=np.int16,
)
img = image_utils.array_to_img(x, data_format="channels_last")
self.assertEqual(img.size, (width, height))
x = image_utils.img_to_array(img, data_format="channels_last")
self.assertEqual(x.shape, (height, width, 1))
# grayscale 32-bit signed integer
x = np.array(
np.random.randint(-2147483648, 2147483647, (height, width, 1)),
dtype=np.int32,
)
img = image_utils.array_to_img(x, data_format="channels_last")
self.assertEqual(img.size, (width, height))
x = image_utils.img_to_array(img, data_format="channels_last")
self.assertEqual(x.shape, (height, width, 1))
# Test invalid use case
with self.assertRaises(ValueError):
x = np.random.random((height, width)) # not 3D
img = image_utils.array_to_img(x, data_format="channels_first")
with self.assertRaises(ValueError):
x = np.random.random((height, width, 3))
# unknown data_format
img = image_utils.array_to_img(x, data_format="channels")
with self.assertRaises(ValueError):
# neither RGB, RGBA, or gray-scale
x = np.random.random((height, width, 5))
img = image_utils.array_to_img(x, data_format="channels_last")
with self.assertRaises(ValueError):
x = np.random.random((height, width, 3))
# unknown data_format
img = image_utils.img_to_array(x, data_format="channels")
with self.assertRaises(ValueError):
# neither RGB, RGBA, or gray-scale
x = np.random.random((height, width, 5, 3))
img = image_utils.img_to_array(x, data_format="channels_last")