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copy-paste in jonas' code for srgb -> hsv

This commit is contained in:
John Cupitt 2015-06-10 09:16:06 +01:00
parent be2537938e
commit cda594d645
2 changed files with 58 additions and 4 deletions
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2
libvips/colour/HSV2sRGB.c
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@ -1,7 +1,7 @@
/* to sRGB from HSV
*
* 9/6/15
* - from HSV2sRGB.c
* - from sRGB2HSV.c
*/
/*

60
libvips/colour/sRGB2HSV.c
View File

@ -55,9 +55,63 @@ vips_sRGB2HSV_line( VipsColour *colour, VipsPel *out, VipsPel **in, int width )
int i;
for( i = 0; i < width; i++ ) {
q[0] = p[0];
q[1] = p[1];
q[2] = p[2];
unsigned char c_max;
unsigned char c_min;
unsigned char delta;
float wrap_around_hue;
float secondary_diff;
wrap_around_hue = 0;
secondary_diff = 0;
if( p[1] < p[2] ) {
if( p[2] < p[0] ) {
c_max = p[0];
c_min = p[1];
secondary_diff = p[1] - p[2];
wrap_around_hue = 255.0f;
}
else {
c_max = p[2];
c_min = VIPS_MIN( p[1], p[0] );
secondary_diff = p[0] - p[1];
wrap_around_hue = 170.0f;
}
}
else {
if( p[1] < p[0] ) {
c_max = p[0];
c_min = p[2];
secondary_diff = p[1] - p[2];
wrap_around_hue = 0.0f;
}
else {
c_max = p[1];
c_min = VIPS_MIN( p[2], p[0] );
secondary_diff = p[2] - p[0];
wrap_around_hue = 85.0f;
}
}
if( c_max == 0 ) {
q[0] = 0;
q[1] = 0;
q[2] = 0;
}
else {
q[2] = c_max;
delta = c_max - c_min;
if( delta == 0 )
q[0] = 0;
else {
q[0] = (unsigned char)
(42.5f * (secondary_diff / delta) +
wrap_around_hue);
}
q[1] = delta * 255.0f / c_max;
}
p += 3;
q += 3;