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Diffstat (limited to 'Lib/dos_8x3/test_img.py')
-rw-r--r-- | Lib/dos_8x3/test_img.py | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/Lib/dos_8x3/test_img.py b/Lib/dos_8x3/test_img.py new file mode 100644 index 0000000..8a3b91e --- /dev/null +++ b/Lib/dos_8x3/test_img.py @@ -0,0 +1,110 @@ +#! /usr/bin/env python +"""Simple test script for imgfile.c + Roger E. Masse +""" +from test_support import verbose + +import imgfile + + +def main(): + + # Test a 3 byte color image + testimage('test.rgb') + + # Test a 1 byte greyscale image + testimage('greytest.rgb') + + +def testimage(name): + """Run through the imgfile's battery of possible methods + on the image passed in name. + """ + + import sys + import os + import string + + 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 = string.splitfields(ourname, os.sep) + parts[-1] = name + name = string.joinfields(parts, os.sep) + 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() |