How to use Wand - 10 common examples

def error_image(msg, width=420, height=600):
    """Creates an error frontpage"""
    width, height = int(width), int(height)
    img = WandImage(width=width, height=height)
    with Drawing() as draw:
        draw.text_alignment = 'center'
        draw.text(img.width // 2, img.height // 3, msg)
        draw(img)
    background = WandImage(
        width=img.width,
        height=img.height,
        background=Color('white'),
    )
    background.format = 'jpeg'
    background.composite(img, 0, 0)
    return background

def rotate():
    """Rotates an image."""
    with Image(filename=asset('rotatetest.gif')) as img:
        assert 150 == img.width
        assert 100 == img.height
        with img.clone() as cloned:
            cloned.rotate(360)
            assert img.size == cloned.size
            with Color('black') as black:
                assert black == cloned[0, 50] == cloned[74, 50]
                assert black == cloned[0, 99] == cloned[74, 99]
            with Color('white') as white:
                assert white == cloned[75, 50] == cloned[75, 99]
        with img.clone() as cloned:
            cloned.rotate(90)
            assert 100 == cloned.width
            assert 150 == cloned.height
            with Color('black') as black:
                with Color('white') as white:

@tests.test
def setitem():
    with Image(filename=asset('apple.ico')) as imga:
        with Image(filename=asset('google.ico')) as imgg:
            imga.sequence[2] = imgg
        assert len(imga.sequence) == 4
        assert imga.sequence[2].size == (16, 16)
        expire(imga)
        assert imga.sequence[2].size == (16, 16)

@tests.test
def extend_offset():
    with Image(filename=asset('apple.ico')) as a:
        instances = list(a.sequence)
        with Image(filename=asset('github.ico')) as b:
            a.sequence.extend(list(b.sequence)[::-1], 2)
            instances[2:2] = list(b.sequence)[::-1]
            assert list(a.sequence) == instances
            expire(a)
            assert list(a.sequence) == instances
        assert len(a.sequence) == 6

def equals():
    """Equality test."""
    assert Color('#fff') == Color('#ffffff') == Color('white')
    assert Color('#000') == Color('#000000') == Color('black')
    assert Color('rgba(0, 0, 0, 0)') == Color('rgba(0, 0, 0, 0)')
    assert Color('rgba(0, 0, 0, 0)') == Color('rgba(1, 1, 1, 0)')

def set_get_text_under_color(wand):
    with Color('#333333') as black:
        wand.text_under_color = black
    assert wand.text_under_color == Color('#333333')

def not_equals():
    """Equality test."""
    assert Color('#000') != Color('#fff')
    assert Color('rgba(0, 0, 0, 0)') != Color('rgba(0, 0, 0, 1)')
    assert Color('rgba(0, 0, 0, 1)') != Color('rgba(1, 1, 1, 1)')

def equals():
    """Equality test."""
    assert Color('#fff') == Color('#ffffff') == Color('white')
    assert Color('#000') == Color('#000000') == Color('black')
    assert Color('rgba(0, 0, 0, 0)') == Color('rgba(0, 0, 0, 0)')
    assert Color('rgba(0, 0, 0, 0)') == Color('rgba(1, 1, 1, 0)')

def test_fit_liquid(self):
        pipeline = [giraffe.ImageOp('liquid', {'width': 100, 'height': 100})]
        try:
            img = giraffe.process_image(self.image, pipeline)
        except MissingDelegateError:
            pytest.skip("ImageMagick doesn't have Liquid Rescale support compiled in")
        self.assertEqual(img.size, (100, 100))

def liquid_rescale():
    def assert_equal_except_alpha(a, b):
        with a:
            with b:
                assert (a.red == b.red and
                        a.green == b.green and
                        a.blue == b.blue)
    with Image(filename=asset('beach.jpg')) as orig:
        with orig.clone() as img:
            try:
                img.liquid_rescale(600, 600)
            except MissingDelegateError:
                warnings.warn('skip liquid_rescale test; has no LQR delegate')
            else:
                assert img.size == (600, 600)
                for x in 0, -1:
                    for y in 0, -1:
                        assert_equal_except_alpha(img[x, y], img[x, y])