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验证码识别之图像二值化
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, ExtDlgs, StdCtrls, ExtCtrls, Buttons;
type
TForm1 = class(TForm)
Image1: TImage;
Image2: TImage;
Button1: TButton;
Button2: TButton;
OpenPictureDialog1: TOpenPictureDialog;
BitBtn1: TBitBtn;
SavePictureDialog1: TSavePictureDialog;
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
procedure BitBtn1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
uses math;
{$R *.dfm}
procedure TForm1.Button1Click(Sender: TObject);
begin
Self.OpenPictureDialog1.Filter := '*.bmp|*.bmp';
if self.OpenPictureDialog1.Execute then
begin
Image1.Picture.Bitmap.LoadFromFile(OpenPictureDialog1.FileName);
end;
end;
procedure TForm1.Button2Click(Sender: TObject);
var
p: PByteArray;
Gray, x, y: Integer;
Bmp: TBitmap;
begin
Bmp := TBitmap.Create;
Bmp.Assign(Image1.Picture.Bitmap);
//设置为24位真彩色
Bmp.PixelFormat := pf24Bit;
randomize;
for y := 0 to Bmp.Height - 1 do
begin
p := Bmp.scanline[y];
for x := 0 to Bmp.Width - 1 do
begin
//一个象素点三个字节
Gray := Round(p[x * 3 + 2] * 0.3 + p[x * 3 + 1] * 0.59 + p[x
* 3] * 0.11);
if gray > 128 then //全局阀值128
begin
p[x * 3] := 255;
p[x * 3 + 1] := 255;
p[x * 3 + 2] := 255;
end
else
begin
p[x * 3] := 0;
p[x * 3 + 1] := 0;
p[x * 3 + 2] := 0;
end;
end;
end;
Image2.Picture.Bitmap.Assign(Bmp);
Bmp.Free;
end;
procedure TForm1.BitBtn1Click(Sender: TObject);
begin
Self.savepictureDialog1.Filter := '*.bmp|*.bmp';
if self.savePictureDialog1.Execute then
begin
Image2.Picture.Bitmap.savetoFile(savePictureDialog1.FileName);
end;
end;
end.
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