libvips/test/test_colour.py

260 lines
9.8 KiB
Python
Executable File

#!/usr/bin/python
import unittest
import math
#import logging
#logging.basicConfig(level = logging.DEBUG)
import gi
gi.require_version('Vips', '8.0')
from gi.repository import Vips
Vips.leak_set(True)
unsigned_formats = [Vips.BandFormat.UCHAR,
Vips.BandFormat.USHORT,
Vips.BandFormat.UINT]
signed_formats = [Vips.BandFormat.CHAR,
Vips.BandFormat.SHORT,
Vips.BandFormat.INT]
float_formats = [Vips.BandFormat.FLOAT,
Vips.BandFormat.DOUBLE]
complex_formats = [Vips.BandFormat.COMPLEX,
Vips.BandFormat.DPCOMPLEX]
int_formats = unsigned_formats + signed_formats
noncomplex_formats = int_formats + float_formats
all_formats = int_formats + float_formats + complex_formats
colour_colourspaces = [Vips.Interpretation.XYZ,
Vips.Interpretation.LAB,
Vips.Interpretation.LCH,
Vips.Interpretation.CMC,
Vips.Interpretation.LABS,
Vips.Interpretation.SCRGB,
Vips.Interpretation.HSV,
Vips.Interpretation.SRGB,
Vips.Interpretation.YXY]
coded_colourspaces = [Vips.Interpretation.LABQ]
mono_colourspaces = [Vips.Interpretation.B_W]
sixteenbit_colourspaces = [Vips.Interpretation.GREY16,
Vips.Interpretation.RGB16]
all_colourspaces = colour_colourspaces + mono_colourspaces + \
coded_colourspaces + sixteenbit_colourspaces
# an expanding zip ... if either of the args is not a list, duplicate it down
# the other
def zip_expand(x, y):
if isinstance(x, list) and isinstance(y, list):
return list(zip(x, y))
elif isinstance(x, list):
return [[i, y] for i in x]
elif isinstance(y, list):
return [[x, j] for j in y]
else:
return [[x, y]]
# run a 1-ary function on a thing -- loop over elements if the
# thing is a list
def run_fn(fn, x):
if isinstance(x, list):
return [fn(i) for i in x]
else:
return fn(x)
# run a 2-ary function on two things -- loop over elements pairwise if the
# things are lists
def run_fn2(fn, x, y):
if isinstance(x, Vips.Image) or isinstance(y, Vips.Image):
return fn(x, y)
elif isinstance(x, list) or isinstance(y, list):
return [fn(i, j) for i, j in zip_expand(x, y)]
else:
return fn(x, y)
class TestColour(unittest.TestCase):
# test a pair of things which can be lists for approx. equality
def assertAlmostEqualObjects(self, a, b, places = 4, msg = ''):
#print 'assertAlmostEqualObjects %s = %s' % (a, b)
for x, y in zip_expand(a, b):
self.assertAlmostEqual(x, y, places = places, msg = msg)
# run a function on an image and on a single pixel, the results
# should match
def run_cmp(self, message, im, x, y, fn):
a = im(x, y)
v1 = fn(a)
im2 = fn(im)
v2 = im2(x, y)
self.assertAlmostEqualObjects(v1, v2, msg = message)
# run a function on a pair of images and on a pair of pixels, the results
# should match
def run_cmp2(self, message, left, right, x, y, fn):
a = left(x, y)
b = right(x, y)
v1 = fn(a, b)
after = fn(left, right)
v2 = after(x, y)
self.assertAlmostEqualObjects(v1, v2, msg = message)
# run a function on a pair of images
# 50,50 and 10,10 should have different values on the test image
def run_test2(self, message, left, right, fn):
self.run_cmp2(message, left, right, 50, 50,
lambda x, y: run_fn2(fn, x, y))
self.run_cmp2(message, left, right, 10, 10,
lambda x, y: run_fn2(fn, x, y))
def setUp(self):
im = Vips.Image.mask_ideal(100, 100, 0.5, reject = True, optical = True)
self.colour = im * [1, 2, 3] + [2, 3, 4]
self.mono = self.colour.extract_band(1)
self.all_images = [self.mono, self.colour]
def test_colourspace(self):
# mid-grey in Lab ... put 42 in the extra band, it should be copied
# unmodified
test = Vips.Image.black(100, 100) + [50, 0, 0, 42]
test = test.copy(interpretation = Vips.Interpretation.LAB)
# a long series should come in a circle
im = test
for col in colour_colourspaces + [Vips.Interpretation.LAB]:
im = im.colourspace(col)
self.assertEqual(im.interpretation, col)
for i in range(0, 4):
l = im.extract_band(i).min()
h = im.extract_band(i).max()
self.assertAlmostEqual(l, h)
pixel = im(10, 10)
self.assertAlmostEqual(pixel[3], 42, places = 2)
# alpha won't be equal for RGB16, but it should be preserved if we go
# there and back
im = im.colourspace(Vips.Interpretation.RGB16)
im = im.colourspace(Vips.Interpretation.LAB)
before = test(10, 10)
after = im(10, 10)
self.assertAlmostEqualObjects(before, after, places = 1)
# go between every pair of colour spaces
for start in colour_colourspaces:
for end in colour_colourspaces:
im = test.colourspace(start)
im2 = im.colourspace(end)
im3 = im2.colourspace(Vips.Interpretation.LAB)
before = test(10, 10)
after = im3(10, 10)
self.assertAlmostEqualObjects(before, after, places = 1)
# test Lab->XYZ on mid-grey
# checked against http://www.brucelindbloom.com
im = test.colourspace(Vips.Interpretation.XYZ)
after = im(10, 10)
self.assertAlmostEqualObjects(after, [17.5064, 18.4187, 20.0547, 42])
# grey->colour->grey should be equal
for mono_fmt in mono_colourspaces:
test_grey = test.colourspace(mono_fmt)
im = test_grey
for col in colour_colourspaces + [mono_fmt]:
im = im.colourspace(col)
self.assertEqual(im.interpretation, col)
[before, alpha_before] = test_grey(10, 10)
[after, alpha_after] = im(10, 10)
self.assertLess(abs(alpha_after - alpha_before), 1)
if mono_fmt == Vips.Interpretation.GREY16:
# GREY16 can wind up rather different due to rounding
self.assertLess(abs(after - before), 30)
else:
# but 8-bit we should hit exactly
self.assertLess(abs(after - before), 1)
# test results from Bruce Lindbloom's calculator:
# http://www.brucelindbloom.com
def test_dE00(self):
# put 42 in the extra band, it should be copied unmodified
reference = Vips.Image.black(100, 100) + [50, 10, 20, 42]
reference = reference.copy(interpretation = Vips.Interpretation.LAB)
sample = Vips.Image.black(100, 100) + [40, -20, 10]
sample = sample.copy(interpretation = Vips.Interpretation.LAB)
difference = reference.dE00(sample)
result, alpha = difference(10, 10)
self.assertAlmostEqual(result, 30.238, places = 3)
self.assertAlmostEqual(alpha, 42.0, places = 3)
def test_dE76(self):
# put 42 in the extra band, it should be copied unmodified
reference = Vips.Image.black(100, 100) + [50, 10, 20, 42]
reference = reference.copy(interpretation = Vips.Interpretation.LAB)
sample = Vips.Image.black(100, 100) + [40, -20, 10]
sample = sample.copy(interpretation = Vips.Interpretation.LAB)
difference = reference.dE76(sample)
result, alpha = difference(10, 10)
self.assertAlmostEqual(result, 33.166, places = 3)
self.assertAlmostEqual(alpha, 42.0, places = 3)
# the vips CMC calculation is based on distance in a colorspace derived from
# the CMC formula, so it won't match exactly ... see vips_LCh2CMC() for
# details
def test_dECMC(self):
reference = Vips.Image.black(100, 100) + [50, 10, 20, 42]
reference = reference.copy(interpretation = Vips.Interpretation.LAB)
sample = Vips.Image.black(100, 100) + [55, 11, 23]
sample = sample.copy(interpretation = Vips.Interpretation.LAB)
difference = reference.dECMC(sample)
result, alpha = difference(10, 10)
self.assertLess(abs(result - 4.97), 0.5)
self.assertAlmostEqual(alpha, 42.0, places = 3)
def test_icc(self):
test = Vips.Image.new_from_file("images/IMG_4618.jpg")
im = test.icc_import().icc_export()
self.assertLess(im.dE76(test).max(), 6)
im = test.icc_import()
im2 = im.icc_export(depth = 16)
self.assertEqual(im2.format, Vips.BandFormat.USHORT)
im3 = im2.icc_import()
self.assertLess((im - im3).abs().max(), 3)
im = test.icc_import(intent = Vips.Intent.ABSOLUTE)
im2 = im.icc_export(intent = Vips.Intent.ABSOLUTE)
self.assertLess(im2.dE76(test).max(), 6)
im = test.icc_import()
im2 = im.icc_export(output_profile = "images/sRGB.icm")
im3 = im.colourspace(Vips.Interpretation.SRGB)
self.assertLess(im2.dE76(im3).max(), 6)
before_profile = test.get_value("icc-profile-data")
im = test.icc_transform("images/sRGB.icm")
after_profile = im.get_value("icc-profile-data")
im2 = test.icc_import()
im3 = im2.colourspace(Vips.Interpretation.SRGB)
self.assertLess(im.dE76(im3).max(), 6)
self.assertNotEqual(len(before_profile), len(after_profile))
im = test.icc_import(input_profile = "images/sRGB.icm")
im2 = test.icc_import()
self.assertLess(6, im.dE76(im2).max())
im = test.icc_import(pcs = Vips.PCS.XYZ)
self.assertEqual(im.interpretation, Vips.Interpretation.XYZ)
im = test.icc_import()
self.assertEqual(im.interpretation, Vips.Interpretation.LAB)
if __name__ == '__main__':
unittest.main()