#! /usr/bin/env python | |
"""Simple test script for imgfile.c | |
Roger E. Masse | |
""" | |
from test.test_support import verbose, unlink, findfile, import_module | |
imgfile = import_module('imgfile', deprecated=True) | |
import uu | |
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) | |
def test_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') | |
if __name__ == '__main__': | |
test_main() |