URGENT:: opposite color

[qfang]

I try to find out how to calculate the opposite color. For example, if white is given, black should be the output color.

[Philip Nicoletti]

There are probably numerous ways to define opposite color, but
here is one way ...



COLORREF original_color = RGB(100,300,50); // whatever you want it

//
// determine the opposite color
//

int opp_red = 255 - GetRValue(original_color);
int opp_green = 255 - GetGValue(original_color);
int opp_blue = 255 - GetBValue(original_color);

COLORREF oposite_color = RGB(opp_red,opp_green,opp_blue);

[qfang]

In that way, RGB(128, 128, 128) will return RGB(127,127,127). That is almost same color instead of opposite color. Do you have another way?

[Philip Nicoletti]

Not off hand ... I am not sure what the opposite of medium gray would even be. The opposite of light gray is dark gray. What do you think the opposite of medium gray should be ? I'll let you know if I can think of anything else.

[mr. blonde]

The opposite of medium gray (128,128,128) is medium gray (127,127,127). Try it in MS Paint. It's analogous to finding the opposite of zero. Nothing is darker than black so it can't be the center point of inversion. The center point is medium grey (128,128,128).

mr. blonde