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Diffstat (limited to 'Lib/dos_8x3/test_ima.py')
| -rw-r--r-- | Lib/dos_8x3/test_ima.py | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/Lib/dos_8x3/test_ima.py b/Lib/dos_8x3/test_ima.py new file mode 100644 index 0000000..fc8dadf --- /dev/null +++ b/Lib/dos_8x3/test_ima.py @@ -0,0 +1,165 @@ +#! /usr/bin/env python +"""Test script for the imageop module. This has the side + effect of partially testing the imgfile module as well. + Roger E. Masse +""" +from test_support import verbose + +import imageop + +def main(use_rgbimg=1): + + if use_rgbimg: + image, width, height = getrgbimage('test.rgb') + else: + image, width, height = getimage('test.rgb') + + # Return the selected part of image, which should by width by height + # in size and consist of pixels of psize bytes. + if verbose: + print 'crop' + newimage = imageop.crop (image, 4, width, height, 0, 0, 1, 1) + + # Return image scaled to size newwidth by newheight. No interpolation + # is done, scaling is done by simple-minded pixel duplication or removal. + # Therefore, computer-generated images or dithered images will + # not look nice after scaling. + if verbose: + print 'scale' + scaleimage = imageop.scale(image, 4, width, height, 1, 1) + + # Run a vertical low-pass filter over an image. It does so by computing + # each destination pixel as the average of two vertically-aligned source + # pixels. The main use of this routine is to forestall excessive flicker + # if the image two vertically-aligned source pixels, hence the name. + if verbose: + print 'tovideo' + videoimage = imageop.tovideo (image, 4, width, height) + + # Convert an rgb image to an 8 bit rgb + if verbose: + print 'rgb2rgb8' + greyimage = imageop.rgb2rgb8(image, width, height) + + # Convert an 8 bit rgb image to a 24 bit rgb image + if verbose: + print 'rgb82rgb' + image = imageop.rgb82rgb(greyimage, width, height) + + # Convert an rgb image to an 8 bit greyscale image + if verbose: + print 'rgb2grey' + greyimage = imageop.rgb2grey(image, width, height) + + # Convert an 8 bit greyscale image to a 24 bit rgb image + if verbose: + print 'grey2rgb' + image = imageop.grey2rgb(greyimage, width, height) + + # Convert a 8-bit deep greyscale image to a 1-bit deep image by + # tresholding all the pixels. The resulting image is tightly packed + # and is probably only useful as an argument to mono2grey. + if verbose: + print 'grey2mono' + monoimage = imageop.grey2mono (greyimage, width, height, 0) + + # monoimage, width, height = getimage('monotest.rgb') + # Convert a 1-bit monochrome image to an 8 bit greyscale or color image. + # All pixels that are zero-valued on input get value p0 on output and + # all one-value input pixels get value p1 on output. To convert a + # monochrome black-and-white image to greyscale pass the values 0 and + # 255 respectively. + if verbose: + print 'mono2grey' + greyimage = imageop.mono2grey (monoimage, width, height, 0, 255) + + # Convert an 8-bit greyscale image to a 1-bit monochrome image using a + # (simple-minded) dithering algorithm. + if verbose: + print 'dither2mono' + monoimage = imageop.dither2mono (greyimage, width, height) + + # Convert an 8-bit greyscale image to a 4-bit greyscale image without + # dithering. + if verbose: + print 'grey2grey4' + grey4image = imageop.grey2grey4 (greyimage, width, height) + + # Convert an 8-bit greyscale image to a 2-bit greyscale image without + # dithering. + if verbose: + print 'grey2grey2' + grey2image = imageop.grey2grey2 (greyimage, width, height) + + # Convert an 8-bit greyscale image to a 2-bit greyscale image with + # dithering. As for dither2mono, the dithering algorithm is currently + # very simple. + if verbose: + print 'dither2grey2' + grey2image = imageop.dither2grey2 (greyimage, width, height) + + # Convert a 4-bit greyscale image to an 8-bit greyscale image. + if verbose: + print 'grey42grey' + greyimage = imageop.grey42grey (grey4image, width, height) + + # Convert a 2-bit greyscale image to an 8-bit greyscale image. + if verbose: + print 'grey22grey' + image = imageop.grey22grey (grey2image, width, height) + +def getrgbimage(name): + """return a tuple consisting of image (in 'imgfile' format but + using rgbimg instead) width and height""" + + import rgbimg + + try: + sizes = rgbimg.sizeofimage(name) + except rgbimg.error: + name = get_qualified_path(name) + sizes = rgbimg.sizeofimage(name) + if verbose: + print 'rgbimg opening test image: %s, sizes: %s' % (name, str(sizes)) + + image = rgbimg.longimagedata(name) + return (image, sizes[0], sizes[1]) + +def getimage(name): + """return a tuple consisting of + image (in 'imgfile' format) width and height + """ + + import imgfile + + try: + sizes = imgfile.getsizes(name) + except imgfile.error: + name = get_qualified_path(name) + sizes = imgfile.getsizes(name) + if verbose: + print 'imgfile opening test image: %s, sizes: %s' % (name, str(sizes)) + + image = imgfile.read(name) + return (image, sizes[0], sizes[1]) + +def get_qualified_path(name): + """ return a more qualified path to name contructed from argv[1]""" + import sys + import os + import string + + # 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) + return name + +# rgbimg (unlike imgfile) is portable to platforms other than SGI. So we prefer to use it. +main(use_rgbimg=1) + |