Vignette effect

[sx2008]

Zitat von WojTec:

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));