再学 GDI+[94]: TGPImage(14) - 增减图像的红、绿、蓝三色的成分

本例效果图:

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代码文件:

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unit Unit1;



interface



uses

  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

  Dialogs, StdCtrls, ComCtrls;



type

  TForm1 = class(TForm)

    TrackBar1: TTrackBar;

    TrackBar2: TTrackBar;

    TrackBar3: TTrackBar;

    Label1: TLabel;

    Label2: TLabel;

    Label3: TLabel;

    Button1: TButton;

    procedure FormPaint(Sender: TObject);

    procedure FormCreate(Sender: TObject);

    procedure FormDestroy(Sender: TObject);

    procedure TrackBar1Change(Sender: TObject);

    procedure TrackBar2Change(Sender: TObject);

    procedure TrackBar3Change(Sender: TObject);

    procedure Button1Click(Sender: TObject);

  end;



var

  Form1: TForm1;



implementation



{$R *.dfm}



uses GDIPOBJ, GDIPAPI;



var

  img: TGPImage;

  var

  ColorMatrix: 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));



procedure TForm1.FormCreate(Sender: TObject);

begin

  img := TGPImage.Create('c:\temp\test.png');



  TrackBar1.Height := 23;

  TrackBar1.ShowSelRange := False;

  TrackBar1.Min := -100;

  TrackBar1.Max := 100;

  TrackBar1.Position := 0;



  TrackBar2.Height := 23;

  TrackBar2.ShowSelRange := False;

  TrackBar2.Min := -100;

  TrackBar2.Max := 100;

  TrackBar2.Position := 0;



  TrackBar3.Height := 23;

  TrackBar3.ShowSelRange := False;

  TrackBar3.Min := -100;

  TrackBar3.Max := 100;

  TrackBar3.Position := 0;



  DoubleBuffered := True;

end;



procedure TForm1.FormDestroy(Sender: TObject);

begin

  img.Free;

end;



procedure TForm1.FormPaint(Sender: TObject);

var

  g: TGPGraphics;

  ImageAttributes: TGPImageAttributes;

begin

  g := TGPGraphics.Create(Canvas.Handle);



  ImageAttributes := TGPImageAttributes.Create;

  ColorMatrix[4,0] := TrackBar1.Position / 100; {增减红色}

  ColorMatrix[4,1] := TrackBar2.Position / 100; {增减绿色}

  ColorMatrix[4,2] := TrackBar3.Position / 100; {增减蓝色}



  ImageAttributes.SetColorMatrix(ColorMatrix);



  g.DrawImage(img,                                           {要绘制的图像}

              MakeRect(10, 10, img.GetWidth, img.GetHeight), {图像将放缩以适合此矩形}

              0, 0,                                          {绘图位置}

              img.GetWidth, img.GetHeight,                   {大小}

              UnitPixel,                                     {单位}

              ImageAttributes                                {图像属性}

              );



  ImageAttributes.Free;

  g.Free;

end;



procedure TForm1.TrackBar1Change(Sender: TObject);

begin

  Repaint;

end;



procedure TForm1.TrackBar2Change(Sender: TObject);

begin

  Repaint;

end;



procedure TForm1.TrackBar3Change(Sender: TObject);

begin

  Repaint;

end;



procedure TForm1.Button1Click(Sender: TObject);

begin

  TrackBar1.Position := 0;

  TrackBar2.Position := 0;

  TrackBar3.Position := 0;

  Repaint;

end;



end.


 
   

窗体文件:

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object Form1: TForm1

  Left = 0

  Top = 0

  Caption = 'Form1'

  ClientHeight = 291

  ClientWidth = 219

  Color = clBtnFace

  Font.Charset = DEFAULT_CHARSET

  Font.Color = clWindowText

  Font.Height = -11

  Font.Name = 'Tahoma'

  Font.Style = []

  OldCreateOrder = False

  Position = poDesktopCenter

  OnCreate = FormCreate

  OnDestroy = FormDestroy

  OnPaint = FormPaint

  PixelsPerInch = 96

  TextHeight = 13

  object Label1: TLabel

    Left = 12

    Top = 188

    Width = 24

    Height = 13

    Caption = #32418#33394

  end

  object Label2: TLabel

    Left = 12

    Top = 212

    Width = 24

    Height = 13

    Caption = #32511#33394

  end

  object Label3: TLabel

    Left = 12

    Top = 234

    Width = 24

    Height = 13

    Caption = #34013#33394

  end

  object TrackBar1: TTrackBar

    Left = 39

    Top = 185

    Width = 172

    Height = 45

    TabOrder = 0

    OnChange = TrackBar1Change

  end

  object TrackBar2: TTrackBar

    Left = 39

    Top = 207

    Width = 172

    Height = 45

    TabOrder = 1

    OnChange = TrackBar2Change

  end

  object TrackBar3: TTrackBar

    Left = 39

    Top = 229

    Width = 172

    Height = 45

    TabOrder = 2

    OnChange = TrackBar3Change

  end

  object Button1: TButton

    Left = 88

    Top = 258

    Width = 75

    Height = 25

    Caption = #24674#22797#40664#35748

    TabOrder = 3

    OnClick = Button1Click

  end

end