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apply patch from lightmare fixing rgb->hsv conversion - refs #1493

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This commit is contained in:
Dane Springmeyer 2012-10-01 18:54:47 -07:00
parent d35b4eb6d4
commit f10939fac6
1 changed files with 22 additions and 10 deletions
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32
boost/gil/extension/toolbox/hsv.hpp
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@ -60,9 +60,16 @@ struct default_color_converter_impl< rgb_t, hsv_t >
bits32f temp_blue = channel_convert<bits32f>( get_color( src, blue_t() ));
bits32f hue, saturation, value;
bits32f min_color, max_color;
bits32f min_color = std::min(temp_red,std::min(temp_green, temp_blue));
bits32f max_color = std::max(temp_red,std::max(temp_green, temp_blue));
if( temp_red < temp_green ) {
min_color = std::min( temp_blue, temp_red );
max_color = std::max( temp_blue, temp_green );
}
else {
min_color = std::min( temp_blue, temp_green );
max_color = std::max( temp_blue, temp_red );
}
value = max_color;
@ -85,7 +92,7 @@ struct default_color_converter_impl< rgb_t, hsv_t >
}
else
{
if( std::abs( boost::numeric_cast<int>(temp_red - max_color) ) < 0.0001f )
if( temp_red == max_color )
{
hue = ( temp_green - temp_blue )
/ diff;
@ -149,18 +156,23 @@ struct default_color_converter_impl<hsv_t,rgb_t>
frac = h - i;
// p = value * (1 - saturation)
p = get_color( src, value_t() )
* ( 1.f - get_color( src, saturation_t() ));
// q = value * (1 - saturation * hue_frac)
// it drops with increasing distance from floor(hue)
q = get_color( src, value_t() )
* ( 1.f - ( get_color( src, saturation_t() ) * frac ));
// t = value * (1 - (saturation * (1 - hue_frac))
// it grows with increasing distance from floor(hue)
t = get_color( src, value_t() )
* ( 1.f - ( get_color( src, saturation_t() ) * ( 1.f - frac )));
switch( i )
switch( i % 6 )
{
case 0:
case 0: // red to yellow
{
red = get_color( src, value_t() );
green = t;
@ -169,7 +181,7 @@ struct default_color_converter_impl<hsv_t,rgb_t>
break;
}
case 1:
case 1: // yellow to green
{
red = q;
green = get_color( src, value_t() );
@ -178,7 +190,7 @@ struct default_color_converter_impl<hsv_t,rgb_t>
break;
}
case 2:
case 2: // green to cyan
{
red = p;
green = get_color( src, value_t() );
@ -187,7 +199,7 @@ struct default_color_converter_impl<hsv_t,rgb_t>
break;
}
case 3:
case 3: // cyan to blue
{
red = p;
green = q;
@ -196,7 +208,7 @@ struct default_color_converter_impl<hsv_t,rgb_t>
break;
}
case 4:
case 4: // blue to magenta
{
red = t;
green = p;
@ -205,7 +217,7 @@ struct default_color_converter_impl<hsv_t,rgb_t>
break;
}
case 5:
case 5: // magenta to red
{
red = get_color( src, value_t() );
green = p;