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