Pillow/Tests/test_numpy.py
Matthew Brett 824a0c232c BF: fix conversion of bit images to numpy arrays
Numpy cannot form arrays from bits.  To convert bit images to numpy,
convert bits to bytes.

From suggestion by Alexander Karpinsky, with thanks.

Fixes gh-350.
2016-08-17 18:47:14 -07:00

198 lines
7.2 KiB
Python

from __future__ import print_function
from helper import unittest, PillowTestCase, hopper
from PIL import Image
try:
import site
import numpy
assert site # silence warning
assert numpy # silence warning
except ImportError:
# Skip via setUp()
pass
TEST_IMAGE_SIZE = (10, 10)
class TestNumpy(PillowTestCase):
def setUp(self):
try:
import site
import numpy
assert site # silence warning
assert numpy # silence warning
except ImportError:
self.skipTest("ImportError")
def test_numpy_to_image(self):
def to_image(dtype, bands=1, boolean=0):
if bands == 1:
if boolean:
data = [0, 1] * 50
else:
data = list(range(100))
a = numpy.array(data, dtype=dtype)
a.shape = TEST_IMAGE_SIZE
i = Image.fromarray(a)
if list(i.getdata()) != data:
print("data mismatch for", dtype)
else:
data = list(range(100))
a = numpy.array([[x]*bands for x in data], dtype=dtype)
a.shape = TEST_IMAGE_SIZE[0], TEST_IMAGE_SIZE[1], bands
i = Image.fromarray(a)
if list(i.split()[0].getdata()) != list(range(100)):
print("data mismatch for", dtype)
# print dtype, list(i.getdata())
return i
# Check supported 1-bit integer formats
self.assertRaises(TypeError, lambda: to_image(numpy.bool))
self.assertRaises(TypeError, lambda: to_image(numpy.bool8))
# Check supported 8-bit integer formats
self.assert_image(to_image(numpy.uint8), "L", TEST_IMAGE_SIZE)
self.assert_image(to_image(numpy.uint8, 3), "RGB", TEST_IMAGE_SIZE)
self.assert_image(to_image(numpy.uint8, 4), "RGBA", TEST_IMAGE_SIZE)
self.assert_image(to_image(numpy.int8), "I", TEST_IMAGE_SIZE)
# Check non-fixed-size integer types
# These may fail, depending on the platform, since we have no native
# 64 bit int image types.
# self.assert_image(to_image(numpy.uint), "I", TEST_IMAGE_SIZE)
# self.assert_image(to_image(numpy.int), "I", TEST_IMAGE_SIZE)
# Check 16-bit integer formats
if Image._ENDIAN == '<':
self.assert_image(to_image(numpy.uint16), "I;16", TEST_IMAGE_SIZE)
else:
self.assert_image(to_image(numpy.uint16), "I;16B", TEST_IMAGE_SIZE)
self.assert_image(to_image(numpy.int16), "I", TEST_IMAGE_SIZE)
# Check 32-bit integer formats
self.assert_image(to_image(numpy.uint32), "I", TEST_IMAGE_SIZE)
self.assert_image(to_image(numpy.int32), "I", TEST_IMAGE_SIZE)
# Check 64-bit integer formats
self.assertRaises(TypeError, lambda: to_image(numpy.uint64))
self.assertRaises(TypeError, lambda: to_image(numpy.int64))
# Check floating-point formats
self.assert_image(to_image(numpy.float), "F", TEST_IMAGE_SIZE)
self.assertRaises(TypeError, lambda: to_image(numpy.float16))
self.assert_image(to_image(numpy.float32), "F", TEST_IMAGE_SIZE)
self.assert_image(to_image(numpy.float64), "F", TEST_IMAGE_SIZE)
self.assert_image(to_image(numpy.uint8, 2), "LA", (10, 10))
self.assert_image(to_image(numpy.uint8, 3), "RGB", (10, 10))
self.assert_image(to_image(numpy.uint8, 4), "RGBA", (10, 10))
# based on an erring example at
# http://stackoverflow.com/questions/10854903/what-is-causing-dimension-dependent-attributeerror-in-pil-fromarray-function
def test_3d_array(self):
size = (5, TEST_IMAGE_SIZE[0], TEST_IMAGE_SIZE[1])
a = numpy.ones(size, dtype=numpy.uint8)
self.assert_image(Image.fromarray(a[1, :, :]), "L", TEST_IMAGE_SIZE)
size = (TEST_IMAGE_SIZE[0], 5, TEST_IMAGE_SIZE[1])
a = numpy.ones(size, dtype=numpy.uint8)
self.assert_image(Image.fromarray(a[:, 1, :]), "L", TEST_IMAGE_SIZE)
size = (TEST_IMAGE_SIZE[0], TEST_IMAGE_SIZE[1], 5)
a = numpy.ones(size, dtype=numpy.uint8)
self.assert_image(Image.fromarray(a[:, :, 1]), "L", TEST_IMAGE_SIZE)
def _test_img_equals_nparray(self, img, np):
np_size = np.shape[1], np.shape[0]
self.assertEqual(img.size, np_size)
px = img.load()
for x in range(0, img.size[0], int(img.size[0]/10)):
for y in range(0, img.size[1], int(img.size[1]/10)):
self.assert_deep_equal(px[x, y], np[y, x])
def test_16bit(self):
img = Image.open('Tests/images/16bit.cropped.tif')
np_img = numpy.array(img)
self._test_img_equals_nparray(img, np_img)
self.assertEqual(np_img.dtype, numpy.dtype('<u2'))
def test_1bit(self):
# Test that 1-bit arrays convert to numpy and back
# See: https://github.com/python-pillow/Pillow/issues/350
arr = numpy.array([[1, 0, 0, 1, 0], [0, 1, 0, 0, 0]], 'u1')
img = Image.fromarray(arr * 255).convert('1')
self.assertEqual(img.mode, '1')
arr_back = numpy.array(img)
numpy.testing.assert_array_equal(arr, arr_back)
def test_save_tiff_uint16(self):
'''
Open a single-channel uint16 greyscale image and verify that it can be saved without
losing precision.
'''
tmpfile = self.tempfile("temp.tif")
pixel_value = 0x1234
filename = "Tests/images/uint16_1_4660.tif"
a = numpy.array([pixel_value] * TEST_IMAGE_SIZE[0] * TEST_IMAGE_SIZE[1], dtype=numpy.uint16)
a.shape = TEST_IMAGE_SIZE
Image.fromarray(a).save(tmpfile)
im_test = Image.open(tmpfile)
im_good = Image.open(filename)
self.assert_image_equal(im_good, im_test)
def test_to_array(self):
def _to_array(mode, dtype):
img = hopper(mode)
# Resize to non-square
img = img.crop((3, 0, 124, 127))
self.assertEqual(img.size, (121, 127))
np_img = numpy.array(img)
self._test_img_equals_nparray(img, np_img)
self.assertEqual(np_img.dtype, numpy.dtype(dtype))
modes = [("L", 'uint8'),
("I", 'int32'),
("F", 'float32'),
("LA", 'uint8'),
("RGB", 'uint8'),
("RGBA", 'uint8'),
("RGBX", 'uint8'),
("CMYK", 'uint8'),
("YCbCr", 'uint8'),
("I;16", '<u2'),
("I;16B", '>u2'),
("I;16L", '<u2'),
("HSV", 'uint8'),
]
for mode in modes:
_to_array(*mode)
def test_point_lut(self):
# see https://github.com/python-pillow/Pillow/issues/439
data = list(range(256))*3
lut = numpy.array(data, dtype='uint8')
im = hopper()
im.point(lut)
def test_putdata(self):
# shouldn't segfault
# see https://github.com/python-pillow/Pillow/issues/1008
im = Image.new('F', (150, 100))
arr = numpy.zeros((15000,), numpy.float32)
im.putdata(arr)
self.assertEqual(len(im.getdata()), len(arr))
if __name__ == '__main__':
unittest.main()