And no effect - image not changed. Why?
You must
multiply with the brightness factor.
And you have to care about arithmetic overflow.
Delphi-Quellcode:
function ClampByte(value:Integer):Byte;
begin
if value > 255 then
result := 255
(* not neccesary when a pixel is multiplied with a positive value
else if value < 0
result := 0
*)
else
result := Byte(value);
end;
...
Bits.R := ClampByte(Round(Bits.R * Brightness));