def load_image(image_path, band_indices=None, bit_depth=None,
curve_function=None):
'''Loads an image into a colorimage. If no bit depth is supplied, 8-bit
is assumed. If no band indices are supplied, RGB is assumed.'''
im_raster = CImage()
im_raster.load(image_path)
img, mask = colorimage.convert_to_colorimage(im_raster, band_indices=band_indices,
bit_depth=bit_depth,
curve_function=curve_function)
return img, mask, im_raster
def load_image(image_path,
band_indices=None,
bit_depth=None,
curve_function=None):
'''Loads an image into a colorimage. If no bit depth is supplied, 8-bit
is assumed. If no band indices are supplied, RGB is assumed.'''
im_raster = CImage()
im_raster.load(image_path)
img, mask = colorimage.convert_to_colorimage(im_raster,
band_indices=band_indices,
bit_depth=bit_depth,
curve_function=curve_function)
return img, mask, im_raster
def test_convert_to_colorimage(self):
# Create 4-band, 8-bit CImage. Each band has intensity values equal to
# the band number
test_bands = [ bidx * np.ones((5, 5), dtype=np.uint8) for bidx in range(4) ]
test_cimage = io.CImage()
test_cimage.bands = test_bands
# Trying to load a 4-band image should raise an exception
with self.assertRaises(colorimage.ImagePropertyException):
colorimage.convert_to_colorimage(test_cimage)
# Specifying 3 bands should allow the 4-band image to be converted
band_indices = [0, 2, 3]
test_colorimage, test_colormask = colorimage.convert_to_colorimage(test_cimage, band_indices)
# The band indices are read in as RGB but the colorimage is BGR
# so the expected image should have band order that is the reverse
# order of band_indices.
expected_bands = [ bidx * np.ones((5, 5), dtype=np.uint8) for bidx in band_indices ]
expected_image = np.dstack(expected_bands)
np.testing.assert_array_equal(test_colorimage, expected_image)
# CImage has no alpha channel so mask should be blank
expected_mask = 255 * np.ones((5, 5), dtype=np.uint8)
np.testing.assert_array_equal(test_colormask, expected_mask)
# Change CImage alpha mask and confirm colorimage mask matches
test_cimage.create_alpha()
test_cimage.alpha[2, 2] = 0
_, test_colormask = colorimage.convert_to_colorimage(test_cimage,
band_indices=band_indices)
expected_mask = 255 * np.ones((5, 5), dtype=np.uint8)
expected_mask[2, 2] = 0
np.testing.assert_array_equal(test_colormask, expected_mask)
# Check that curve_function is applied to image
def test_curve(r,g,b):
return r/2, g/2, b/2
test_colorimage, _ = colorimage.convert_to_colorimage(test_cimage,
band_indices=band_indices, curve_function=test_curve)
expected_bands = [i/2 * np.ones((5, 5), dtype=np.uint8) \
for i in reversed(band_indices)]
expected_image = np.dstack(expected_bands)
np.testing.assert_array_equal(test_colorimage, expected_image)
# Create 3-band, 16-bit cimage
def np_1d_to_3d(np_1d):
band = np.reshape(np_1d, (2, 2))
return [band, band, band]
test_bands = np_1d_to_3d(np.array([0, 256, 4095, 65535],
dtype=np.uint16))
test_cimage = io.CImage()
test_cimage.bands=test_bands
# No bit depth provided, should assume all 16 bits are used and divide
# by 256 and mask should be blank
test_colorimage, test_colormask = colorimage.convert_to_colorimage(
test_cimage)
expected = np_1d_to_3d(np.array([0, 1, 15, 255],
dtype=np.uint8))
expected_image = np.dstack(expected)
# np.testing.assert_array_equal(test_colorimage, expected_image)
expected_mask = 255 * np.ones((2, 2), dtype=np.uint8)
# np.testing.assert_array_equal(test_colormask, expected_mask)
# If bit depth of 12 is provided, the values should be scaled by 2**4
# and pixels with values above 2**12 should be masked
test_colorimage, test_colormask = colorimage.convert_to_colorimage(
test_cimage, bit_depth=2 ** 12)
expected = np_1d_to_3d(np.array([0, 16, 255, 255],
dtype=np.uint8))
expected_image = np.dstack(expected)
# np.testing.assert_array_equal(test_colorimage, expected_image)
expected_mask = np.array([
[255, 255],
[255, 0]
], dtype=np.uint8)
# np.testing.assert_array_equal(test_colormask, expected_mask)
# Check that curve_function downsampling is applied to bands and avoids
# further bit decimation
def test_curve(r,g,b):
r = (r/2 ** 8).astype(np.uint8)
g = (g/2 ** 8).astype(np.uint8)
b = (b/2 ** 8).astype(np.uint8)
return r, g, b
test_colorimage, _ = colorimage.convert_to_colorimage(test_cimage,
curve_function=test_curve)
expected_bands = np_1d_to_3d(np.array([0, 1, 15, 255],
dtype=np.uint8))
expected_image = np.dstack(expected_bands)
np.testing.assert_array_equal(test_colorimage, expected_image)
def test_convert_to_colorimage(self):
# Create 4-band, 8-bit CImage. Each band has intensity values equal to
# the band number
test_bands = [i * numpy.ones((5, 5), dtype=numpy.uint8) \
for i in range(4)]
test_cimage = io.CImage()
test_cimage.bands = test_bands
# Trying to load a 4-band image should raise an exception
self.assertRaises(colorimage.ImagePropertyException,
colorimage.convert_to_colorimage, test_cimage)
# Specifying 3 bands should allow the 4-band image to be converted
band_indices = [0, 2, 3]
test_colorimage, test_colormask = colorimage.convert_to_colorimage(
test_cimage, band_indices)
# The band indices are read in as RGB but the colorimage is BGR
# so the expected image should have band order that is the reverse
# order of band_indices.
expected_bands = [i * numpy.ones((5, 5), dtype=numpy.uint8) \
for i in reversed(band_indices)]
expected_image = cv2.merge(expected_bands)
numpy.testing.assert_array_equal(test_colorimage, expected_image)
# CImage has no alpha channel so mask should be blank
expected_mask = 255 * numpy.ones((5, 5), dtype=numpy.uint8)
numpy.testing.assert_array_equal(test_colormask, expected_mask)
# Change CImage alpha mask and confirm colorimage mask matches
test_cimage.create_alpha()
test_cimage.alpha[2, 2] = 0
_, test_colormask = colorimage.convert_to_colorimage(
test_cimage, band_indices=band_indices)
expected_mask = 255 * numpy.ones((5, 5), dtype=numpy.uint8)
expected_mask[2, 2] = 0
numpy.testing.assert_array_equal(test_colormask, expected_mask)
# Check that curve_function is applied to image
def test_curve(r, g, b):
return r / 2, g / 2, b / 2
test_colorimage, _ = colorimage.convert_to_colorimage(
test_cimage, band_indices=band_indices, curve_function=test_curve)
expected_bands = [i/2 * numpy.ones((5, 5), dtype=numpy.uint8) \
for i in reversed(band_indices)]
expected_image = cv2.merge(expected_bands)
numpy.testing.assert_array_equal(test_colorimage, expected_image)
# Create 3-band, 16-bit cimage
def numpy_1d_to_3d(numpy_1d):
band = numpy.reshape(numpy_1d, (2, 2))
return [band, band, band]
test_bands = numpy_1d_to_3d(
numpy.array([0, 256, 4095, 65535], dtype=numpy.uint16))
test_cimage = io.CImage()
test_cimage.bands = test_bands
# No bit depth provided, should assume all 16 bits are used and divide
# by 256 and mask should be blank
test_colorimage, test_colormask = colorimage.convert_to_colorimage(
test_cimage)
expected = numpy_1d_to_3d(
numpy.array([0, 1, 15, 255], dtype=numpy.uint8))
expected_image = cv2.merge(expected)
numpy.testing.assert_array_equal(test_colorimage, expected_image)
expected_mask = 255 * numpy.ones((2, 2), dtype=numpy.uint8)
numpy.testing.assert_array_equal(test_colormask, expected_mask)
# If bit depth of 12 is provided, the values should be scaled by 2**4
# and pixels with values above 2**12 should be masked
test_colorimage, test_colormask = colorimage.convert_to_colorimage(
test_cimage, bit_depth=2**12)
expected = numpy_1d_to_3d(
numpy.array([0, 16, 255, 255], dtype=numpy.uint8))
expected_image = cv2.merge(expected)
numpy.testing.assert_array_equal(test_colorimage, expected_image)
expected_mask = numpy.reshape(
numpy.array([255, 255, 255, 0], dtype=numpy.uint8), (2, 2))
numpy.testing.assert_array_equal(test_colormask, expected_mask)
# Check that curve_function downsampling is applied to bands and avoids
# further bit decimation
def test_curve(r, g, b):
r = (r / 2**8).astype(numpy.uint8)
g = (g / 2**8).astype(numpy.uint8)
b = (b / 2**8).astype(numpy.uint8)
return r, g, b
test_colorimage, _ = colorimage.convert_to_colorimage(
test_cimage, curve_function=test_curve)
expected_bands = numpy_1d_to_3d(
numpy.array([0, 1, 15, 255], dtype=numpy.uint8))
expected_image = cv2.merge(expected_bands)
numpy.testing.assert_array_equal(test_colorimage, expected_image)
