Pillow/selftest.py
Alexander Böhn 7b815a5f1d Added an image.entropy() method
This calculates the entropy for the image, based on the histogram.

Because this uses image histogram data directly, the existing C
function underpinning the `image.histogram()` method was abstracted
into a static function to parse extrema tuple arguments, and a new
C function was added to calculate image entropy, making use of the
new static extrema function.

The extrema-parsing function was written by @homm, based on the
macro abstraction I wrote, during the discussion of my first
entropy-method pull request: https://git.io/fhodS

The new `image.entropy()` method is based on `image.histogram()`,
and will accept the same arguments to calculate the histogram data
it will use to assess the entropy of the image.

The algorithm and methodology is based on existing Python code:

* https://git.io/fhmIU

... A test case in the `Tests/` directory, and doctest lines in
`selftest.py`, have both been added and checked.

Changes proposed in this pull request:

* Added “math.h” include to _imaging.c
* The addition of an `image.entropy()` method to the `Image`
  Python class,
* The abstraction of the extrema-parsing logic of of the C
  function `_histogram` into a static function, and
* The use of that static function in both the `_histogram` and
  `_entropy` C functions.
* Minor documentation addenda in the docstrings for both the
  `image.entropy()` and `image.histogram()` methods were also
  added.
* Removed outdated boilerplate from testing code
* Removed unused “unittest” import
2019-06-26 19:15:47 +10:00

205 lines
5.6 KiB
Python
Executable File

#!/usr/bin/env python
# minimal sanity check
from __future__ import print_function
import sys
import os
from PIL import Image
from PIL import features
try:
Image.core.ping
except ImportError as v:
print("***", v)
sys.exit()
except AttributeError:
pass
def _info(im):
im.load()
return im.format, im.mode, im.size
def testimage():
"""
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
>>> _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:
>>> im = Image.open("Tests/images/hopper.gif")
>>> _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 IOError 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.AFFINE, (1,0,0,0,1,0)))
(None, 'RGB', (512, 512))
>>> _info(im.transform((512, 512), Image.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.eval("float(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. If you're curious, check the handbook, available from:
http://www.pythonware.com
Cheers /F
"""
if __name__ == "__main__":
# check build sanity
exit_status = 0
print("-" * 68)
print("Pillow", Image.__version__, "TEST SUMMARY ")
print("-" * 68)
print("Python modules loaded from", os.path.dirname(Image.__file__))
print("Binary modules loaded from", os.path.dirname(Image.core.__file__))
print("-" * 68)
for name, feature in [
("pil", "PIL CORE"),
("tkinter", "TKINTER"),
("freetype2", "FREETYPE2"),
("littlecms2", "LITTLECMS2"),
("webp", "WEBP"),
("transp_webp", "WEBP Transparency"),
("webp_mux", "WEBPMUX"),
("webp_anim", "WEBP Animation"),
("jpg", "JPEG"),
("jpg_2000", "OPENJPEG (JPEG2000)"),
("zlib", "ZLIB (PNG/ZIP)"),
("libtiff", "LIBTIFF"),
("raqm", "RAQM (Bidirectional Text)"),
]:
if features.check(name):
print("---", feature, "support ok")
else:
print("***", feature, "support not installed")
print("-" * 68)
# 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("*** %s tests of %d failed." % status)
exit_status = 1
else:
print("--- %s tests passed." % status[1])
sys.exit(exit_status)