36 lines
960 B
C
36 lines
960 B
C
#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include "gd.h"
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#include "gd_color.h"
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/**
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* The threshold method works relatively well but it can be improved.
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* Maybe L*a*b* and Delta-E will give better results (and a better
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* granularity).
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*/
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int gdColorMatch(gdImagePtr im, int col1, int col2, float threshold)
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{
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const int dr = gdImageRed(im, col1) - gdImageRed(im, col2);
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const int dg = gdImageGreen(im, col1) - gdImageGreen(im, col2);
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const int db = gdImageBlue(im, col1) - gdImageBlue(im, col2);
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const int da = gdImageAlpha(im, col1) - gdImageAlpha(im, col2);
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const int dist = dr * dr + dg * dg + db * db + da * da;
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return (100.0 * dist / 195075) < threshold;
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}
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/*
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* To be implemented when we have more image formats.
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* Buffer like gray8 gray16 or rgb8 will require some tweak
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* and can be done in this function (called from the autocrop
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* function. (Pierre)
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*/
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#if 0
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static int colors_equal (const int col1, const in col2)
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{
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}
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#endif
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