cpython/Lib/test/test_imageop.py

210 lines
6.7 KiB
Python

"""Test script for the imageop module. This has the side
effect of partially testing the imgfile module as well.
Roger E. Masse
"""
from test.test_support import verbose, unlink, import_module, run_unittest
imageop = import_module('imageop', deprecated=True)
import uu, os, unittest
SIZES = (1, 2, 3, 4)
_VALUES = (1, 2, 2**10, 2**15-1, 2**15, 2**15+1, 2**31-2, 2**31-1)
VALUES = tuple( -x for x in reversed(_VALUES) ) + (0,) + _VALUES
AAAAA = "A" * 1024
MAX_LEN = 2**20
class InputValidationTests(unittest.TestCase):
def _check(self, name, size=None, *extra):
func = getattr(imageop, name)
for height in VALUES:
for width in VALUES:
strlen = abs(width * height)
if size:
strlen *= size
if strlen < MAX_LEN:
data = "A" * strlen
else:
data = AAAAA
if size:
arguments = (data, size, width, height) + extra
else:
arguments = (data, width, height) + extra
try:
func(*arguments)
except (ValueError, imageop.error):
pass
def check_size(self, name, *extra):
for size in SIZES:
self._check(name, size, *extra)
def check(self, name, *extra):
self._check(name, None, *extra)
def test_input_validation(self):
self.check_size("crop", 0, 0, 0, 0)
self.check_size("scale", 1, 0)
self.check_size("scale", -1, -1)
self.check_size("tovideo")
self.check("grey2mono", 128)
self.check("grey2grey4")
self.check("grey2grey2")
self.check("dither2mono")
self.check("dither2grey2")
self.check("mono2grey", 0, 0)
self.check("grey22grey")
self.check("rgb2rgb8") # nlen*4 == len
self.check("rgb82rgb")
self.check("rgb2grey")
self.check("grey2rgb")
def test_main():
run_unittest(InputValidationTests)
try:
import imgfile
except ImportError:
return
# Create binary test files
uu.decode(get_qualified_path('testrgb'+os.extsep+'uue'), 'test'+os.extsep+'rgb')
image, width, height = getimage('test'+os.extsep+'rgb')
# Return the selected part of image, which should by width by height
# in size and consist of pixels of psize bytes.
if verbose:
print 'crop'
newimage = imageop.crop (image, 4, width, height, 0, 0, 1, 1)
# Return image scaled to size newwidth by newheight. No interpolation
# is done, scaling is done by simple-minded pixel duplication or removal.
# Therefore, computer-generated images or dithered images will
# not look nice after scaling.
if verbose:
print 'scale'
scaleimage = imageop.scale(image, 4, width, height, 1, 1)
# Run a vertical low-pass filter over an image. It does so by computing
# each destination pixel as the average of two vertically-aligned source
# pixels. The main use of this routine is to forestall excessive flicker
# if the image two vertically-aligned source pixels, hence the name.
if verbose:
print 'tovideo'
videoimage = imageop.tovideo (image, 4, width, height)
# Convert an rgb image to an 8 bit rgb
if verbose:
print 'rgb2rgb8'
greyimage = imageop.rgb2rgb8(image, width, height)
# Convert an 8 bit rgb image to a 24 bit rgb image
if verbose:
print 'rgb82rgb'
image = imageop.rgb82rgb(greyimage, width, height)
# Convert an rgb image to an 8 bit greyscale image
if verbose:
print 'rgb2grey'
greyimage = imageop.rgb2grey(image, width, height)
# Convert an 8 bit greyscale image to a 24 bit rgb image
if verbose:
print 'grey2rgb'
image = imageop.grey2rgb(greyimage, width, height)
# Convert a 8-bit deep greyscale image to a 1-bit deep image by
# thresholding all the pixels. The resulting image is tightly packed
# and is probably only useful as an argument to mono2grey.
if verbose:
print 'grey2mono'
monoimage = imageop.grey2mono (greyimage, width, height, 0)
# monoimage, width, height = getimage('monotest.rgb')
# Convert a 1-bit monochrome image to an 8 bit greyscale or color image.
# All pixels that are zero-valued on input get value p0 on output and
# all one-value input pixels get value p1 on output. To convert a
# monochrome black-and-white image to greyscale pass the values 0 and
# 255 respectively.
if verbose:
print 'mono2grey'
greyimage = imageop.mono2grey (monoimage, width, height, 0, 255)
# Convert an 8-bit greyscale image to a 1-bit monochrome image using a
# (simple-minded) dithering algorithm.
if verbose:
print 'dither2mono'
monoimage = imageop.dither2mono (greyimage, width, height)
# Convert an 8-bit greyscale image to a 4-bit greyscale image without
# dithering.
if verbose:
print 'grey2grey4'
grey4image = imageop.grey2grey4 (greyimage, width, height)
# Convert an 8-bit greyscale image to a 2-bit greyscale image without
# dithering.
if verbose:
print 'grey2grey2'
grey2image = imageop.grey2grey2 (greyimage, width, height)
# Convert an 8-bit greyscale image to a 2-bit greyscale image with
# dithering. As for dither2mono, the dithering algorithm is currently
# very simple.
if verbose:
print 'dither2grey2'
grey2image = imageop.dither2grey2 (greyimage, width, height)
# Convert a 4-bit greyscale image to an 8-bit greyscale image.
if verbose:
print 'grey42grey'
greyimage = imageop.grey42grey (grey4image, width, height)
# Convert a 2-bit greyscale image to an 8-bit greyscale image.
if verbose:
print 'grey22grey'
image = imageop.grey22grey (grey2image, width, height)
# Cleanup
unlink('test'+os.extsep+'rgb')
def getimage(name):
"""return a tuple consisting of
image (in 'imgfile' format) width and height
"""
import imgfile
try:
sizes = imgfile.getsizes(name)
except imgfile.error:
name = get_qualified_path(name)
sizes = imgfile.getsizes(name)
if verbose:
print 'imgfile opening test image: %s, sizes: %s' % (name, str(sizes))
image = imgfile.read(name)
return (image, sizes[0], sizes[1])
def get_qualified_path(name):
""" return a more qualified path to name"""
import sys
import os
path = sys.path
try:
path = [os.path.dirname(__file__)] + path
except NameError:
pass
for dir in path:
fullname = os.path.join(dir, name)
if os.path.exists(fullname):
return fullname
return name
if __name__ == '__main__':
test_main()