In doing this, I decided to exclude anything below
index[16],(215,211,231)
and above
index[239],(123,0,0)
which gives me two error colors to notify that I've exceeded bounds.
Samples, [dark] [normal] [light]
Two pixels in the "dark" image is errored.
Entire grout is errored, in which case I correct by finding appropriate match,
Or simply restoring old ground color.
In this case, I restored.
int shiftcolor(int pixel, int direction)
{
int check, limit, bump;
check = pixel & 0xF0;
if ((check > 143) && (check < 224))
limit = check + 15;
else
limit = pixel & 0xF8 + 7;
bump = pixel;
if ((pixel > 15) && (pixel < 240))
{ bump = bump + direction;
if (bump < check) bump = 10;
if (bump > limit) bump = 240;
}
return bump;
}