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# $Id: selftest.py 2813 2006-10-07 10:11:35Z fredrik $
# minimal sanity check
import sys
sys.path.insert(0, ".")
sys.path.insert(1, "PIL")
import Image
import ImageDraw
import ImageFilter
import ImageMath
try:
Image.core.ping
except ImportError, 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:
>>> 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("Images/lena.gif")
>>> _info(im)
('GIF', 'P', (128, 128))
>>> _info(Image.open("Images/lena.ppm"))
('PPM', 'RGB', (128, 128))
>>> _info(Image.open("Images/lena.jpg"))
('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("Images/lena.ppm")
>>> print im.im # internal image attribute
None
>>> a = im.load()
>>> type(im.im)
<type 'ImagingCore'>
You can apply many different operations on images. Most
operations return a new image:
>>> im = Image.open("Images/lena.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()
((61, 255), (26, 234), (44, 223))
>>> im.getpixel((0, 0))
(223, 162, 133)
>>> len(im.getprojection())
2
>>> len(im.histogram())
768
>>> _info(im.point(range(256)*3))
(None, 'RGB', (128, 128))
>>> _info(im.resize((64, 64)))
(None, 'RGB', (64, 64))
>>> _info(im.rotate(45))
(None, 'RGB', (128, 128))
>>> map(_info, im.split())
[(None, 'L', (128, 128)), (None, 'L', (128, 128)), (None, 'L', (128, 128))]
>>> len(im.convert("1").tobitmap())
10456
>>> len(im.tostring())
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__":
# use doctest to make sure the test program behaves as documented!
import doctest, selftest
status = doctest.testmod(selftest)
if status[0]:
print "*** %s tests of %d failed." % status
else:
print "%s tests passed." % status[1]
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