Pillow/Tests/test_numpy.py

from tester import *

from PIL import Image
import struct

try:
    import site
    import numpy
except ImportError:
    skip()

def test_numpy_to_image():

    def to_image(dtype, bands=1, bool=0):
        if bands == 1:
            if bool:
                data = [0, 1] * 50
            else:
                data = list(range(100))
            a = numpy.array(data, dtype=dtype)
            a.shape = 10, 10
            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 = 10, 10, 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

    # assert_image(to_image(numpy.bool, bool=1), "1", (10, 10))
    # assert_image(to_image(numpy.bool8, bool=1), "1", (10, 10))

    assert_exception(TypeError, lambda: to_image(numpy.uint))
    assert_image(to_image(numpy.uint8), "L", (10, 10))
    assert_exception(TypeError, lambda: to_image(numpy.uint16))
    assert_exception(TypeError, lambda: to_image(numpy.uint32))
    assert_exception(TypeError, lambda: to_image(numpy.uint64))

    assert_image(to_image(numpy.int8), "I", (10, 10))
    if Image._ENDIAN == '<': # Little endian
        assert_image(to_image(numpy.int16), "I;16", (10, 10))
    else:
        assert_image(to_image(numpy.int16), "I;16B", (10, 10))
    assert_image(to_image(numpy.int32), "I", (10, 10))
    assert_exception(TypeError, lambda: to_image(numpy.int64))

    assert_image(to_image(numpy.float), "F", (10, 10))
    assert_image(to_image(numpy.float32), "F", (10, 10))
    assert_image(to_image(numpy.float64), "F", (10, 10))

    assert_image(to_image(numpy.uint8, 3), "RGB", (10, 10))
    assert_image(to_image(numpy.uint8, 4), "RGBA", (10, 10))


# based on an erring example at http://is.gd/6F0esS  (which resolves to)
# http://stackoverflow.com/questions/10854903/what-is-causing-dimension-dependent-attributeerror-in-pil-fromarray-function
def test_3d_array():
    a = numpy.ones((10, 10, 10), dtype=numpy.uint8)
    assert_image(Image.fromarray(a[1, :, :]), "L", (10, 10))
    assert_image(Image.fromarray(a[:, 1, :]), "L", (10, 10))
    assert_image(Image.fromarray(a[:, :, 1]), "L", (10, 10))


def _test_img_equals_nparray(img, np):
    assert_equal(img.size, np.shape[0:2])
    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)):
            assert_deep_equal(px[x,y], np[y,x])


def test_16bit():
    img = Image.open('Tests/images/16bit.cropped.tif')
    np_img = numpy.array(img)
    _test_img_equals_nparray(img, np_img)
    assert_equal(np_img.dtype, numpy.dtype('<u2'))

def test_to_array():

    def _to_array(mode, dtype):
        img = lena(mode)            
        np_img = numpy.array(img)
        _test_img_equals_nparray(img, np_img)
        assert_equal(np_img.dtype, numpy.dtype(dtype))
    
     
    modes = [("L", 'uint8'),
             ("I", 'int32'),
             ("F", 'float32'),
             ("RGB", 'uint8'),
             ("RGBA", 'uint8'),
             ("RGBX", 'uint8'),
             ("CMYK", 'uint8'),
             ("YCbCr", 'uint8'),
             ("I;16", '<u2'),
             ("I;16B", '>u2'),
             ("I;16L", '<u2'),
             ]
    

    for mode in modes:
        assert_no_exception(lambda: _to_array(*mode))