再学GDI+[91]: TGPImage（11） - 转灰度图像

再学GDI+[91]: TGPImage（11） - 转灰度图像2012-05-27 cnblogs 万一本例效果图:

代码文件:

unit Unit1;
interface
uses
 Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
 Dialogs, StdCtrls;
type
 TForm1 = class（TForm）
  CheckBox1: TCheckBox;
  procedure FormCreate（Sender: TObject）;
  procedure FormPaint（Sender: TObject）;
  procedure CheckBox1Click（Sender: TObject）;
 end;
var
 Form1: TForm1;
implementation
{$R *.dfm}
uses GDIPOBJ, GDIPAPI;
const
 {一般模式}
 ColorMatrix1: TColorMatrix = （
  （1.0, 0.0, 0.0, 0.0, 0.0）,
  （0.0, 1.0, 0.0, 0.0, 0.0）,
  （0.0, 0.0, 1.0, 0.0, 0.0）,
  （0.0, 0.0, 0.0, 1.0, 0.0）,
  （0.0, 0.0, 0.0, 0.0, 1.0））;
 {灰度模式}
 ColorMatrix2: TColorMatrix = （
  （0.3, 0.3, 0.3, 0.0, 0.0）,
  （0.59, 0.59, 0.59, 0.0, 0.0）,
  （0.11, 0.11, 0.11, 0.0, 0.0）,
  （0.0, 0.0, 0.0, 1.0, 0.0）,
  （0.0, 0.0, 0.0, 0.0, 1.0））;
procedure TForm1.FormCreate（Sender: TObject）;
begin
 CheckBox1.Caption := "转为灰度";
end;
procedure TForm1.FormPaint（Sender: TObject）;
var
 g: TGPGraphics;
 img: TGPImage;
 ImageAttributes: TGPImageAttributes;
begin
 g := TGPGraphics.Create（Canvas.Handle）;
 img := TGPImage.Create（"c:	emp	est.png"）;
 ImageAttributes := TGPImageAttributes.Create;
 if CheckBox1.Checked then
  ImageAttributes.SetColorMatrix（ColorMatrix2）
 else
  ImageAttributes.SetColorMatrix（ColorMatrix1）;
 g.DrawImage（img,
       MakeRect（4, 4, img.GetWidth, img.GetHeight）,
       0,
       0,
       img.GetWidth,
       img.GetHeight,
       UnitPixel,
       ImageAttributes
       ）;
 ImageAttributes.Free;
 img.Free;
 g.Free;
end;
procedure TForm1.CheckBox1Click（Sender: TObject）;
begin
 Repaint;
end;
end.

窗体文件:

object Form1: TForm1
 Left = 0
 Top = 0
 Caption = "Form1"
 ClientHeight = 216
 ClientWidth = 269
 Color = clBtnFace
 Font.Charset = DEFAULT_CHARSET
 Font.Color = clWindowText
 Font.Height = -11
 Font.Name = "Tahoma"
 Font.Style = []
 OldCreateOrder = False
 Position = poDesktopCenter
 OnCreate = FormCreate
 OnPaint = FormPaint
 PixelsPerInch = 96
 TextHeight = 13
 object CheckBox1: TCheckBox
  Left = 183
  Top = 191
  Width = 79
  Height = 17
  Caption = "CheckBox1"
  TabOrder = 0
  OnClick = CheckBox1Click
 end
end