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验证码识别之中值滤波
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, ExtCtrls, StdCtrls;
type
TForm1 = class(TForm)
Button1: TButton;
Image1: TImage;
Image2: TImage;
procedure Button1Click(Sender: TObject);
procedure SelectionSort(var a: array of integer);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
RvalueArray, GvalueArray, BvalueArray: array[0..8] of integer;
implementation
{$R *.dfm}
procedure TForm1.Button1Click(Sender: TObject);
var
bmp1, bmp2: Tbitmap;
p1, p2, p3, p4: pbytearray;
i, j: integer;
begin
//设置双缓冲
self.DoubleBuffered := true;
//创建两个位图实例
bmp1 := Tbitmap.Create;
bmp2 := Tbitmap.Create;
//加在位图
bmp1.Assign(image1.Picture.Bitmap);
//设置位图的象素格式
bmp1.PixelFormat := pf24bit;
//位图的大小
bmp1.Width := image1.Picture.Graphic.Width;
bmp1.Height := image1.Picture.Graphic.Height;
//加载备份的位图
bmp2.Assign(image1.Picture.Bitmap);
bmp2.PixelFormat := pf24bit;
for j := 1 to bmp1.Height - 2 do
begin
//三条扫描线
p1 := bmp1.ScanLine[j];
p2 := bmp2.ScanLine[j - 1];
p3 := bmp2.ScanLine[j];
p4 := bmp2.ScanLine[j + 1];
for i := 1 to bmp1.Width - 2 do
begin
//对存储9个R分量的数组进行赋值
RvalueArray[0] := p2[3 * (i - 1) + 2];
RvalueArray[1] := p2[3 * i + 2];
RvalueArray[2] := p2[3 * (i + 1) + 2];
RvalueArray[3] := p3[3 * (i - 1) + 2];
RvalueArray[4] := p3[3 * i + 2];
RvalueArray[5] := p3[3 * (i + 1) + 2];
RvalueArray[6] := p4[3 * (i - 1) + 2];
RvalueArray[7] := p4[3 * i + 2];
RvalueArray[8] := p4[3 * (i + 1) + 2];
//调用排序过程
SelectionSort(RvalueArray);
//获取R分量的中间值
p1[3 * i + 2] := RvalueArray[4];
//对存储9个G分量的数组进行赋值
GvalueArray[0] := p2[3 * (i - 1) + 1];
GvalueArray[1] := p2[3 * i + 1];
GvalueArray[2] := p2[3 * (i + 1) + 1];
GvalueArray[3] := p3[3 * (i - 1) + 1];
GvalueArray[4] := p3[3 * i + 1];
GvalueArray[5] := p3[3 * (i + 1) + 1];
GvalueArray[6] := p4[3 * (i - 1) + 1];
GvalueArray[7] := p4[3 * i + 1];
GvalueArray[8] := p4[3 * (i + 1) + 1];
//调用选择排序
SelectionSort(RvalueArray);
//获取G分量的中间值
p1[3 * i + 1] := RvalueArray[4];
//对存储9个B分量的数组进行赋值
BvalueArray[0] := p2[3 * (i - 1)];
BvalueArray[1] := p2[3 * i];
BvalueArray[2] := p2[3 * (i + 1)];
BvalueArray[3] := p3[3 * (i - 1)];
BvalueArray[4] := p3[3 * i];
BvalueArray[5] := p3[3 * (i + 1)];
BvalueArray[6] := p4[3 * (i - 1)];
BvalueArray[7] := p4[3 * i];
BvalueArray[8] := p4[3 * (i + 1)];
//调用选择排序过程
SelectionSort(RvalueArray);
//获取G分量的中间值
p1[3 * i] := RvalueArray[4];
end;
end;
Image2.Picture.Bitmap.Assign(Bmp1);
Bmp1.Free;
bmp2.Free;
end;
//选择排序过程
procedure TForm1.SelectionSort(var a: array of integer);
var
i, j, t: integer;
begin
for i := low(a) to high(a) - 1 do
for j := high(a) downto i + 1 do
if a[i] > a[j] then
begin
//交换值(a[i], a[j], i, j);
t := a[i];
a[i] := a[j];
a[j] := t;
end;
end;
end.
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