1"""Simple test script for imgfile.c
2   Roger E. Masse
3"""
4
5from test.test_support import verbose, unlink, findfile, import_module
6
7imgfile = import_module('imgfile', deprecated=True)
8import uu
9
10
11def testimage(name):
12    """Run through the imgfile's battery of possible methods
13       on the image passed in name.
14    """
15
16    import sys
17    import os
18
19    outputfile = '/tmp/deleteme'
20
21    # try opening the name directly
22    try:
23        # This function returns a tuple (x, y, z) where x and y are the size
24        # of the image in pixels and z is the number of bytes per pixel. Only
25        # 3 byte RGB pixels and 1 byte greyscale pixels are supported.
26        sizes = imgfile.getsizes(name)
27    except imgfile.error:
28        # get a more qualified path component of the script...
29        if __name__ == '__main__':
30            ourname = sys.argv[0]
31        else: # ...or the full path of the module
32            ourname = sys.modules[__name__].__file__
33
34        parts = ourname.split(os.sep)
35        parts[-1] = name
36        name = os.sep.join(parts)
37        sizes = imgfile.getsizes(name)
38    if verbose:
39        print 'Opening test image: %s, sizes: %s' % (name, str(sizes))
40    # This function reads and decodes the image on the specified file,
41    # and returns it as a python string. The string has either 1 byte
42    # greyscale pixels or 4 byte RGBA pixels. The bottom left pixel
43    # is the first in the string. This format is suitable to pass
44    # to gl.lrectwrite, for instance.
45    image = imgfile.read(name)
46
47    # This function writes the RGB or greyscale data in data to
48    # image file file. x and y give the size of the image, z is
49    # 1 for 1 byte greyscale images or 3 for RGB images (which
50    # are stored as 4 byte values of which only the lower three
51    # bytes are used). These are the formats returned by gl.lrectread.
52    if verbose:
53        print 'Writing output file'
54    imgfile.write (outputfile, image, sizes[0], sizes[1], sizes[2])
55
56
57    if verbose:
58        print 'Opening scaled test image: %s, sizes: %s' % (name, str(sizes))
59    # This function is identical to read but it returns an image that
60    # is scaled to the given x and y sizes. If the filter and blur
61    # parameters are omitted scaling is done by simply dropping
62    # or duplicating pixels, so the result will be less than perfect,
63    # especially for computer-generated images.  Alternatively,
64    # you can specify a filter to use to smoothen the image after
65    # scaling. The filter forms supported are 'impulse', 'box',
66    # 'triangle', 'quadratic' and 'gaussian'. If a filter is
67    # specified blur is an optional parameter specifying the
68    # blurriness of the filter. It defaults to 1.0.  readscaled
69    # makes no attempt to keep the aspect ratio correct, so that
70    # is the users' responsibility.
71    if verbose:
72        print 'Filtering with "impulse"'
73    simage = imgfile.readscaled (name, sizes[0]/2, sizes[1]/2, 'impulse', 2.0)
74
75    # This function sets a global flag which defines whether the
76    # scan lines of the image are read or written from bottom to
77    # top (flag is zero, compatible with SGI GL) or from top to
78    # bottom(flag is one, compatible with X). The default is zero.
79    if verbose:
80        print 'Switching to X compatibility'
81    imgfile.ttob (1)
82
83    if verbose:
84        print 'Filtering with "triangle"'
85    simage = imgfile.readscaled (name, sizes[0]/2, sizes[1]/2, 'triangle', 3.0)
86    if verbose:
87        print 'Switching back to SGI compatibility'
88    imgfile.ttob (0)
89
90    if verbose: print 'Filtering with "quadratic"'
91    simage = imgfile.readscaled (name, sizes[0]/2, sizes[1]/2, 'quadratic')
92    if verbose: print 'Filtering with "gaussian"'
93    simage = imgfile.readscaled (name, sizes[0]/2, sizes[1]/2, 'gaussian', 1.0)
94
95    if verbose:
96        print 'Writing output file'
97    imgfile.write (outputfile, simage, sizes[0]/2, sizes[1]/2, sizes[2])
98
99    os.unlink(outputfile)
100
101
102def test_main():
103
104    uu.decode(findfile('testrgb.uue'), 'test.rgb')
105    uu.decode(findfile('greyrgb.uue'), 'greytest.rgb')
106
107    # Test a 3 byte color image
108    testimage('test.rgb')
109
110    # Test a 1 byte greyscale image
111    testimage('greytest.rgb')
112
113    unlink('test.rgb')
114    unlink('greytest.rgb')
115
116if __name__ == '__main__':
117    test_main()
118