32 lines
877 B
Text
32 lines
877 B
Text
-- demo\rosetta\Bitmap_read_ppm.exw (runnable version)
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function read_ppm(string filename)
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sequence image, line
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integer dimx, dimy, maxcolor
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atom fn = open(filename, "rb")
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if fn<0 then
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return -1 -- unable to open
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end if
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line = gets(fn)
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if line!="P6\n" then
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return -1 -- only ppm6 files are supported
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end if
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line = gets(fn)
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{{dimx,dimy}} = scanf(line,"%d %d%s")
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line = gets(fn)
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{{maxcolor}} = scanf(line,"%d%s")
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image = repeat(repeat(0,dimy),dimx)
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for y=1 to dimy do
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for x=1 to dimx do
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image[x][y] = getc(fn)*#10000 + getc(fn)*#100 + getc(fn)
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end for
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end for
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close(fn)
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return image
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end function
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--include ppm.e -- read_ppm(), write_ppm(), to_grey() (as distributed, instead of the above)
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sequence img = read_ppm("Lena.ppm")
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img = to_grey(img)
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write_ppm("LenaGray.ppm",img)
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