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