如何制作照片底片效果的图像(即反色)

unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, shellapi,OleCtrls, SHDocVw, Menus, ExtCtrls, ComCtrls;

type
TForm1 = class(TForm)

Image1: TImage;

Button1: TButton;

P: TProgressBar;

procedure Button1Click(Sender: TObject);    

private
{ Private declarations }

public

{ Public declarations }

end;

var

Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);

var 

r,g,b,i,j:integer;

begin
  
  p.Max:=image1.Width;
  
  for i:=0 to image1.Width-1 do
  
  begin
    
    p.Position:=i;
    
    for j:=0 to image1.Height-1 do
    
    begin
      
    r:=255-getrvalue(image1.Canvas.Pixels[i,j]);//取得各点红色值
    g:=255-getgvalue(image1.Canvas.Pixels[i,j]);//取得各点绿色值
    b:=255-getbvalue(image1.Canvas.Pixels[i,j]);//取得各点蓝色值
    image1.Canvas.Pixels[i,j]:=rgb(r,g,b);//重新设置各点的rgb值

    end;
    
    image1.Refresh;
    
  end;
  
end;


end.