bool Color::isDark() const
{
float r, g, b, a, h, s, v;
getRGBA(r, g, b, a);
convertRGBToHSV(r, g, b, h, s, v);
return a > 0.5 && v < 0.5;
}
Color Color::dark() const
{
float r, g, b, a, h, s, v;
getRGBA(r, g, b, a);
convertRGBToHSV(r, g, b, h, s, v);
v = max(0.0f, min(v - 0.33f, 1.0f));
convertHSVToRGB(h, s, v, r, g, b);
return Color((int)(r * 255), (int)(g * 255), (int)(b * 255), (int)(a * 255));
}
/*!
* pixcmapConvertRGBToHSV()
*
* Input: colormap
* Return: 0 if OK; 1 on error
*
* Notes:
* - in-place transform
* - See convertRGBToHSV() for def'n of HSV space.
* - replaces: r --> h, g --> s, b --> v
*/
l_int32
pixcmapConvertRGBToHSV(PIXCMAP *cmap)
{
l_int32 i, ncolors, rval, gval, bval, hval, sval, vval;
PROCNAME("pixcmapConvertRGBToHSV");
if (!cmap)
return ERROR_INT("cmap not defined", procName, 1);
ncolors = pixcmapGetCount(cmap);
for (i = 0; i < ncolors; i++) {
pixcmapGetColor(cmap, i, &rval, &gval, &bval);
convertRGBToHSV(rval, gval, bval, &hval, &sval, &vval);
pixcmapResetColor(cmap, i, hval, sval, vval);
}
return 0;
}