def _adjustHueTf(self, x_np, delta_h):
with self.test_session():
x = array_ops.placeholder(dtypes.float32)
with self.test_scope():
y = gen_image_ops.adjust_hue(x, delta_h)
y_tf = y.eval({x: x_np})
return y_tf
def adjust_hue(image, delta, name=None):
"""Adjust hue of an RGB image.
This is a convenience method that converts an RGB image to float
representation, converts it to HSV, add an offset to the hue channel, converts
back to RGB and then back to the original data type. If several adjustments
are chained it is advisable to minimize the number of redundant conversions.
`image` is an RGB image. The image hue is adjusted by converting the
image to HSV and rotating the hue channel (H) by
`delta`. The image is then converted back to RGB.
`delta` must be in the interval `[-1, 1]`.
Args:
image: RGB image or images. Size of the last dimension must be 3.
delta: float. How much to add to the hue channel.
name: A name for this operation (optional).
Returns:
Adjusted image(s), same shape and DType as `image`.
"""
with ops.name_scope(name, 'adjust_hue', [image]) as name:
image = ops.convert_to_tensor(image, name='image')
# Remember original dtype to so we can convert back if needed
orig_dtype = image.dtype
flt_image = convert_image_dtype(image, dtypes.float32)
# TODO(zhengxq): we will switch to the fused version after we add a GPU
# kernel for that.
fused = os.environ.get('TF_ADJUST_HUE_FUSED', '')
fused = fused.lower() in ('true', 't', '1')
if not fused:
hsv = gen_image_ops.rgb_to_hsv(flt_image)
hue = array_ops.slice(hsv, [0, 0, 0], [-1, -1, 1])
saturation = array_ops.slice(hsv, [0, 0, 1], [-1, -1, 1])
value = array_ops.slice(hsv, [0, 0, 2], [-1, -1, 1])
# Note that we add 2*pi to guarantee that the resulting hue is a positive
# floating point number since delta is [-0.5, 0.5].
hue = math_ops.mod(hue + (delta + 1.), 1.)
hsv_altered = array_ops.concat_v2([hue, saturation, value], 2)
rgb_altered = gen_image_ops.hsv_to_rgb(hsv_altered)
else:
rgb_altered = gen_image_ops.adjust_hue(flt_image, delta)
return convert_image_dtype(rgb_altered, orig_dtype)
def testBatchAdjustHue(self):
x_shape = [2, 1, 2, 3]
x_data = [0, 5, 13, 54, 135, 226, 37, 8, 234, 90, 255, 1]
x_np = np.array(x_data, dtype=np.uint8).reshape(x_shape)
delta = 0.25
y_data = [13, 0, 11, 226, 54, 221, 234, 8, 92, 1, 217, 255]
y_np = np.array(y_data, dtype=np.uint8).reshape(x_shape)
with self.test_session():
x = array_ops.placeholder(x_np.dtype, shape=x_shape)
flt_x = image_ops.convert_image_dtype(x, dtypes.float32)
with self.test_scope():
y = gen_image_ops.adjust_hue(flt_x, delta)
y = image_ops.convert_image_dtype(y, x.dtype, saturate=True)
y_tf = y.eval({x: x_np})
self.assertAllEqual(y_tf, y_np)
def testAdjustNegativeHue(self):
x_shape = [2, 2, 3]
x_data = [0, 5, 13, 54, 135, 226, 37, 8, 234, 90, 255, 1]
x_np = np.array(x_data, dtype=np.uint8).reshape(x_shape)
delta = -0.25
y_data = [0, 13, 1, 54, 226, 59, 8, 234, 150, 255, 39, 1]
y_np = np.array(y_data, dtype=np.uint8).reshape(x_shape)
with self.test_session():
x = array_ops.placeholder(x_np.dtype, shape=x_shape)
flt_x = image_ops.convert_image_dtype(x, dtypes.float32)
with self.test_scope():
y = gen_image_ops.adjust_hue(flt_x, delta)
y = image_ops.convert_image_dtype(y, x.dtype, saturate=True)
y_tf = y.eval({x: x_np})
self.assertAllEqual(y_tf, y_np)
