BGRABitmap图像操作4：直接操作像素，颜色校正

unit Unit1;

{$mode objfpc}{$H+}

interface

uses
Classes, SysUtils, FileUtil, Forms, Controls, Graphics, Dialogs,
BGRABitmap, BGRABitmapTypes;

type

{ TForm1 }

TForm1 = class(TForm)
procedure FormPaint(Sender: TObject);
private
{ private declarations }
public
{ public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.lfm}

{ TForm1 }

procedure TForm1.FormPaint(Sender: TObject);
var x,y: integer;
p: PBGRAPixel;
image: TBGRABitmap;
hsla: THSLAPixel;
begin
image := TBGRABitmap.Create(ClientWidth,ClientHeight);
hsla.lightness := 32768;
hsla.alpha := 65535;
for y := 0 to image.Height-1 do
begin
p := image.Scanline[y];
hsla.saturation := y*65536 div image.Height;
for x := 0 to image.Width-1 do
begin
hsla.hue := x*65536 div image.Width;
p^:= GSBAToBGRA(hsla);
inc(p);
end;
end;
image.InvalidateBitmap; // changed by direct access

image.Draw(Canvas,0,0,True);
image.free;
end;

end.