lib-python.2.5.test.test_imgfile.py Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of jython Show documentation
Show all versions of jython Show documentation
Jython is an implementation of the high-level, dynamic, object-oriented
language Python written in 100% Pure Java, and seamlessly integrated with
the Java platform. It thus allows you to run Python on any Java platform.
#! /usr/bin/env python
"""Simple test script for imgfile.c
Roger E. Masse
"""
from test.test_support import verbose, unlink, findfile
import imgfile, uu, os
def main():
uu.decode(findfile('testrgb.uue'), 'test.rgb')
uu.decode(findfile('greyrgb.uue'), 'greytest.rgb')
# Test a 3 byte color image
testimage('test.rgb')
# Test a 1 byte greyscale image
testimage('greytest.rgb')
unlink('test.rgb')
unlink('greytest.rgb')
def testimage(name):
"""Run through the imgfile's battery of possible methods
on the image passed in name.
"""
import sys
import os
outputfile = '/tmp/deleteme'
# try opening the name directly
try:
# This function returns a tuple (x, y, z) where x and y are the size
# of the image in pixels and z is the number of bytes per pixel. Only
# 3 byte RGB pixels and 1 byte greyscale pixels are supported.
sizes = imgfile.getsizes(name)
except imgfile.error:
# get a more qualified path component of the script...
if __name__ == '__main__':
ourname = sys.argv[0]
else: # ...or the full path of the module
ourname = sys.modules[__name__].__file__
parts = ourname.split(os.sep)
parts[-1] = name
name = os.sep.join(parts)
sizes = imgfile.getsizes(name)
if verbose:
print 'Opening test image: %s, sizes: %s' % (name, str(sizes))
# This function reads and decodes the image on the specified file,
# and returns it as a python string. The string has either 1 byte
# greyscale pixels or 4 byte RGBA pixels. The bottom left pixel
# is the first in the string. This format is suitable to pass
# to gl.lrectwrite, for instance.
image = imgfile.read(name)
# This function writes the RGB or greyscale data in data to
# image file file. x and y give the size of the image, z is
# 1 for 1 byte greyscale images or 3 for RGB images (which
# are stored as 4 byte values of which only the lower three
# bytes are used). These are the formats returned by gl.lrectread.
if verbose:
print 'Writing output file'
imgfile.write (outputfile, image, sizes[0], sizes[1], sizes[2])
if verbose:
print 'Opening scaled test image: %s, sizes: %s' % (name, str(sizes))
# This function is identical to read but it returns an image that
# is scaled to the given x and y sizes. If the filter and blur
# parameters are omitted scaling is done by simply dropping
# or duplicating pixels, so the result will be less than perfect,
# especially for computer-generated images. Alternatively,
# you can specify a filter to use to smoothen the image after
# scaling. The filter forms supported are 'impulse', 'box',
# 'triangle', 'quadratic' and 'gaussian'. If a filter is
# specified blur is an optional parameter specifying the
# blurriness of the filter. It defaults to 1.0. readscaled
# makes no attempt to keep the aspect ratio correct, so that
# is the users' responsibility.
if verbose:
print 'Filtering with "impulse"'
simage = imgfile.readscaled (name, sizes[0]/2, sizes[1]/2, 'impulse', 2.0)
# This function sets a global flag which defines whether the
# scan lines of the image are read or written from bottom to
# top (flag is zero, compatible with SGI GL) or from top to
# bottom(flag is one, compatible with X). The default is zero.
if verbose:
print 'Switching to X compatibility'
imgfile.ttob (1)
if verbose:
print 'Filtering with "triangle"'
simage = imgfile.readscaled (name, sizes[0]/2, sizes[1]/2, 'triangle', 3.0)
if verbose:
print 'Switching back to SGI compatibility'
imgfile.ttob (0)
if verbose: print 'Filtering with "quadratic"'
simage = imgfile.readscaled (name, sizes[0]/2, sizes[1]/2, 'quadratic')
if verbose: print 'Filtering with "gaussian"'
simage = imgfile.readscaled (name, sizes[0]/2, sizes[1]/2, 'gaussian', 1.0)
if verbose:
print 'Writing output file'
imgfile.write (outputfile, simage, sizes[0]/2, sizes[1]/2, sizes[2])
os.unlink(outputfile)
main()