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86530b38 AT |
1 | #! /usr/bin/env python |
2 | ||
3 | """Simple test script for imgfile.c | |
4 | Roger E. Masse | |
5 | """ | |
6 | ||
7 | from test.test_support import verbose, unlink, findfile | |
8 | ||
9 | import imgfile, uu, os | |
10 | ||
11 | ||
12 | def main(): | |
13 | ||
14 | uu.decode(findfile('testrgb.uue'), 'test.rgb') | |
15 | uu.decode(findfile('greyrgb.uue'), 'greytest.rgb') | |
16 | ||
17 | # Test a 3 byte color image | |
18 | testimage('test.rgb') | |
19 | ||
20 | # Test a 1 byte greyscale image | |
21 | testimage('greytest.rgb') | |
22 | ||
23 | unlink('test.rgb') | |
24 | unlink('greytest.rgb') | |
25 | ||
26 | def testimage(name): | |
27 | """Run through the imgfile's battery of possible methods | |
28 | on the image passed in name. | |
29 | """ | |
30 | ||
31 | import sys | |
32 | import os | |
33 | ||
34 | outputfile = '/tmp/deleteme' | |
35 | ||
36 | # try opening the name directly | |
37 | try: | |
38 | # This function returns a tuple (x, y, z) where x and y are the size | |
39 | # of the image in pixels and z is the number of bytes per pixel. Only | |
40 | # 3 byte RGB pixels and 1 byte greyscale pixels are supported. | |
41 | sizes = imgfile.getsizes(name) | |
42 | except imgfile.error: | |
43 | # get a more qualified path component of the script... | |
44 | if __name__ == '__main__': | |
45 | ourname = sys.argv[0] | |
46 | else: # ...or the full path of the module | |
47 | ourname = sys.modules[__name__].__file__ | |
48 | ||
49 | parts = ourname.split(os.sep) | |
50 | parts[-1] = name | |
51 | name = os.sep.join(parts) | |
52 | sizes = imgfile.getsizes(name) | |
53 | if verbose: | |
54 | print 'Opening test image: %s, sizes: %s' % (name, str(sizes)) | |
55 | # This function reads and decodes the image on the specified file, | |
56 | # and returns it as a python string. The string has either 1 byte | |
57 | # greyscale pixels or 4 byte RGBA pixels. The bottom left pixel | |
58 | # is the first in the string. This format is suitable to pass | |
59 | # to gl.lrectwrite, for instance. | |
60 | image = imgfile.read(name) | |
61 | ||
62 | # This function writes the RGB or greyscale data in data to | |
63 | # image file file. x and y give the size of the image, z is | |
64 | # 1 for 1 byte greyscale images or 3 for RGB images (which | |
65 | # are stored as 4 byte values of which only the lower three | |
66 | # bytes are used). These are the formats returned by gl.lrectread. | |
67 | if verbose: | |
68 | print 'Writing output file' | |
69 | imgfile.write (outputfile, image, sizes[0], sizes[1], sizes[2]) | |
70 | ||
71 | ||
72 | if verbose: | |
73 | print 'Opening scaled test image: %s, sizes: %s' % (name, str(sizes)) | |
74 | # This function is identical to read but it returns an image that | |
75 | # is scaled to the given x and y sizes. If the filter and blur | |
76 | # parameters are omitted scaling is done by simply dropping | |
77 | # or duplicating pixels, so the result will be less than perfect, | |
78 | # especially for computer-generated images. Alternatively, | |
79 | # you can specify a filter to use to smoothen the image after | |
80 | # scaling. The filter forms supported are 'impulse', 'box', | |
81 | # 'triangle', 'quadratic' and 'gaussian'. If a filter is | |
82 | # specified blur is an optional parameter specifying the | |
83 | # blurriness of the filter. It defaults to 1.0. readscaled | |
84 | # makes no attempt to keep the aspect ratio correct, so that | |
85 | # is the users' responsibility. | |
86 | if verbose: | |
87 | print 'Filtering with "impulse"' | |
88 | simage = imgfile.readscaled (name, sizes[0]/2, sizes[1]/2, 'impulse', 2.0) | |
89 | ||
90 | # This function sets a global flag which defines whether the | |
91 | # scan lines of the image are read or written from bottom to | |
92 | # top (flag is zero, compatible with SGI GL) or from top to | |
93 | # bottom(flag is one, compatible with X). The default is zero. | |
94 | if verbose: | |
95 | print 'Switching to X compatibility' | |
96 | imgfile.ttob (1) | |
97 | ||
98 | if verbose: | |
99 | print 'Filtering with "triangle"' | |
100 | simage = imgfile.readscaled (name, sizes[0]/2, sizes[1]/2, 'triangle', 3.0) | |
101 | if verbose: | |
102 | print 'Switching back to SGI compatibility' | |
103 | imgfile.ttob (0) | |
104 | ||
105 | if verbose: print 'Filtering with "quadratic"' | |
106 | simage = imgfile.readscaled (name, sizes[0]/2, sizes[1]/2, 'quadratic') | |
107 | if verbose: print 'Filtering with "gaussian"' | |
108 | simage = imgfile.readscaled (name, sizes[0]/2, sizes[1]/2, 'gaussian', 1.0) | |
109 | ||
110 | if verbose: | |
111 | print 'Writing output file' | |
112 | imgfile.write (outputfile, simage, sizes[0]/2, sizes[1]/2, sizes[2]) | |
113 | ||
114 | os.unlink(outputfile) | |
115 | ||
116 | main() |