Pillow

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#!/usr/bin/env python3
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# minimal sanity check
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from __future__ import annotations
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import sys
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from PIL import Image, features
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try:
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    Image.core.ping
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except ImportError as v:
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    print("***", v)
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    sys.exit()
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except AttributeError:
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    pass
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def testimage() -> None:
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    """
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    PIL lets you create in-memory images with various pixel types:
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    >>> from PIL import Image, ImageDraw, ImageFilter, ImageMath
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    >>> im = Image.new("1", (128, 128)) # monochrome
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    >>> def _info(im): return im.format, im.mode, im.size
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    >>> _info(im)
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    (None, '1', (128, 128))
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    >>> _info(Image.new("L", (128, 128))) # grayscale (luminance)
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    (None, 'L', (128, 128))
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    >>> _info(Image.new("P", (128, 128))) # palette
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    (None, 'P', (128, 128))
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    >>> _info(Image.new("RGB", (128, 128))) # truecolor
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    (None, 'RGB', (128, 128))
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    >>> _info(Image.new("I", (128, 128))) # 32-bit integer
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    (None, 'I', (128, 128))
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    >>> _info(Image.new("F", (128, 128))) # 32-bit floating point
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    (None, 'F', (128, 128))
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    Or open existing files:
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    >>> with Image.open("Tests/images/hopper.gif") as im:
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    ...     _info(im)
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    ('GIF', 'P', (128, 128))
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    >>> _info(Image.open("Tests/images/hopper.ppm"))
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    ('PPM', 'RGB', (128, 128))
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    >>> try:
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    ...  _info(Image.open("Tests/images/hopper.jpg"))
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    ... except OSError as v:
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    ...  print(v)
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    ('JPEG', 'RGB', (128, 128))
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    PIL doesn't actually load the image data until it's needed,
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    or you call the "load" method:
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    >>> im = Image.open("Tests/images/hopper.ppm")
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    >>> print(im._im) # internal image attribute
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    None
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    >>> a = im.load()
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    >>> type(im.im) # doctest: +ELLIPSIS
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    <... '...ImagingCore'>
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    You can apply many different operations on images.  Most
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    operations return a new image:
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    >>> im = Image.open("Tests/images/hopper.ppm")
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    >>> _info(im.convert("L"))
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    (None, 'L', (128, 128))
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    >>> _info(im.copy())
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    (None, 'RGB', (128, 128))
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    >>> _info(im.crop((32, 32, 96, 96)))
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    (None, 'RGB', (64, 64))
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    >>> _info(im.filter(ImageFilter.BLUR))
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    (None, 'RGB', (128, 128))
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    >>> im.getbands()
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    ('R', 'G', 'B')
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    >>> im.getbbox()
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    (0, 0, 128, 128)
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    >>> len(im.getdata())
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    16384
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    >>> im.getextrema()
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    ((0, 255), (0, 255), (0, 255))
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    >>> im.getpixel((0, 0))
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    (20, 20, 70)
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    >>> len(im.getprojection())
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    2
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    >>> len(im.histogram())
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    768
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    >>> '%.7f' % im.entropy()
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    '8.8212866'
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    >>> _info(im.point(list(range(256))*3))
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    (None, 'RGB', (128, 128))
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    >>> _info(im.resize((64, 64)))
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    (None, 'RGB', (64, 64))
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    >>> _info(im.rotate(45))
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    (None, 'RGB', (128, 128))
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    >>> [_info(ch) for ch in im.split()]
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    [(None, 'L', (128, 128)), (None, 'L', (128, 128)), (None, 'L', (128, 128))]
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    >>> len(im.convert("1").tobitmap())
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    10456
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    >>> len(im.tobytes())
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    49152
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    >>> _info(im.transform((512, 512), Image.Transform.AFFINE, (1,0,0,0,1,0)))
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    (None, 'RGB', (512, 512))
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    >>> _info(im.transform((512, 512), Image.Transform.EXTENT, (32,32,96,96)))
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    (None, 'RGB', (512, 512))
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    The ImageDraw module lets you draw stuff in raster images:
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    >>> im = Image.new("L", (128, 128), 64)
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    >>> d = ImageDraw.ImageDraw(im)
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    >>> d.line((0, 0, 128, 128), fill=128)
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    >>> d.line((0, 128, 128, 0), fill=128)
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    >>> im.getextrema()
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    (64, 128)
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    In 1.1.4, you can specify colors in a number of ways:
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    >>> xy = 0, 0, 128, 128
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    >>> im = Image.new("RGB", (128, 128), 0)
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    >>> d = ImageDraw.ImageDraw(im)
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    >>> d.rectangle(xy, "#f00")
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    >>> im.getpixel((0, 0))
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    (255, 0, 0)
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    >>> d.rectangle(xy, "#ff0000")
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    >>> im.getpixel((0, 0))
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    (255, 0, 0)
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    >>> d.rectangle(xy, "rgb(255,0,0)")
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    >>> im.getpixel((0, 0))
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    (255, 0, 0)
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    >>> d.rectangle(xy, "rgb(100%,0%,0%)")
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    >>> im.getpixel((0, 0))
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    (255, 0, 0)
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    >>> d.rectangle(xy, "hsl(0, 100%, 50%)")
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    >>> im.getpixel((0, 0))
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    (255, 0, 0)
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    >>> d.rectangle(xy, "red")
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    >>> im.getpixel((0, 0))
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    (255, 0, 0)
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    In 1.1.6, you can use the ImageMath module to do image
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    calculations.
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    >>> im = ImageMath.lambda_eval( \
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      lambda args: args["float"](args["im"] + 20), im=im.convert("L") \
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    )
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    >>> im.mode, im.size
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    ('F', (128, 128))
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    PIL can do many other things, but I'll leave that for another
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    day.
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    Cheers /F
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    """
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if __name__ == "__main__":
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    # check build sanity
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    exit_status = 0
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    features.pilinfo(sys.stdout, False)
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    # use doctest to make sure the test program behaves as documented!
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    import doctest
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    print("Running selftest:")
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    status = doctest.testmod(sys.modules[__name__])
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    if status[0]:
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        print(f"*** {status[0]} tests of {status[1]} failed.")
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        exit_status = 1
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    else:
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        print(f"--- {status[1]} tests passed.")
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    sys.exit(exit_status)
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