Delphi GDI+ 图形处理（3）
探究Delphi的图形处理 之七 -- 柔化和锐化处理
第三章 基本图像处理算法
3.1柔化和锐化处理
柔化处理的原理是将图片中每一个像素都由与其相邻的n*n个像素的平均值来代替。N的取值决定了其模糊程度。下面是柔化处理的程序。
程序3.1
unit Unit1;
{柔化处理}
Interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, GraphicProcess, StdCtrls, ExtCtrls;
type
TForm1 = class(TForm)
PaintBox1: TPaintBox;
btnExe: TButton;
txtN: TEdit;
Label1: TLabel;
procedure FormCreate(Sender: TObject);
procedure PaintBox1Paint(Sender: TObject);
procedure btnExeClick(Sender: TObject);
procedure FormDestroy(Sender: TObject);
private
Procedure SmoothPicture(const Bit : TBitmap;var n : Integer);
public
{ Public declarations }
end;
procedure WritePixel(Pic: TBitmap; tPix: TPixels);
procedure ReadPixel(Pic: Tbitmap; var tPix: TPixels);
var
Form1: TForm1;
Bits : TBitmap;
implementation
{$R *.dfm}
procedure TForm1.FormCreate(Sender: TObject);
begin
Bits:=TBitmap.Create;
Bits.LoadFromFile(‘Test.Bmp‘);
end;
procedure TForm1.PaintBox1Paint(Sender: TObject);
begin
PaintBox1.Canvas.StretchDraw(Rect(0,0,400,300),Bits);
end;
procedure TForm1.SmoothPicture(const Bit: TBitmap;var n: Integer);
var R,G,B:Integer;
i,j,k,l : Integer;
Pix : TPixels;
nDiv : Integer;
nDivRs : Integer;
jP,jM,ip,im:Integer;
OpCount : Integer;
begin
ReadPixel(Bit,Pix);
if n mod 2 = 0 then n := n +1;
nDiv := n * n;
nDivRs := n div 2;
For i := 0 to Bit.Width-1 do begin
ip:= i + nDivRs;
im := i ;
if im < 0 then im := 0;
if ip > Bit.Width -1 then ip := Bit.Width-1;
For j := 0 to Bit.Height -1 do
begin
R:=0;
G:=0;
B:=0;
jP := j + nDivRs;
jM := j - nDivRs;
if Jp > bit.Height-1 then
jp := Bit.Height-1;
if jm <0 then jm :=0;
OpCount := (ip - im+1) *(jp-jm+1);
For k := im to Ip do begin
For l := jm to jp do
begin
R := R + Pix[k,l].rgbtRed;
G := G + Pix[k,l].rgbtGreen;
B := B + Pix[k,l].rgbtBlue;
end;
end;
Pix[i,j].rgbtBlue := B div opCount;
Pix[i,j].rgbtGreen := G div opCount;
Pix[i,j].rgbtRed := R div opCount;
end;
end;
WritePixel(Bit,Pix);
end;
procedure ReadPixel(Pic: Tbitmap; var tPix: TPixels);
Var PixPtr:PbyteArray;i,j,m:Integer;
begin
SetLength(tPix,Pic.Width,Pic.Height);
Pic.PixelFormat := pf24bit;
Pic.HandleType:=bmDIB;
For i :=0 to pic.Height-1 do begin
PixPtr:=Pic.ScanLine[i];
for j:= 0 to pic.Width-1 do begin
m := j*3;
tPix[j,i].rgbtBlue:=PixPtr[m];
tPix[j,i].rgbtGreen := PixPtr[m+1];
tPix[j,i].rgbtRed := PixPtr[m+2];
end;
end;
end;
procedure WritePixel(Pic: TBitmap; tPix: TPixels);
var PixPtr:PByteArray;i,j,m:Integer;
begin
pic.PixelFormat := pf24bit;
pic.HandleType:=bmDIB;
Pic.Height := High(tPix[0])+1;
Pic.Width:= High(tPix)+1;
For i :=0 to pic.Height-1 do begin
PixPtr:=Pic.ScanLine[i];
for j:= 0 to pic.Width-1 do begin
m := j*3;
PixPtr[M] := tPix[j,i].rgbtBlue;
PixPtr[m+1] := tPix[j,i].rgbtGreen;
PixPtr[m+2] := tPix[j,i].rgbtRed;
end;
end;
end;
procedure TForm1.btnExeClick(Sender: TObject);
var n :Integer;
begin
n := StrToInt(txtN.Text);
Bits.LoadFromFile(‘Test.bmp‘);
SmoothPicture(Bits,n);
PaintBox1.Refresh;
end;
procedure TForm1.FormDestroy(Sender: TObject);
begin
Bits.Free;
end;
end.
程序的运行结果如下图所示。
原图
柔化系数=21
锐化处理的原理是把每一像素的值与该像素斜上方的像素值之差乘以一个系数再加上该像素原来的颜色值。
如果记图像中任意一个像素(x,y) (x∈[1,图像宽度-1],y∈[1,图像高度-1])修改前的RGB分值分别为OldRed, OldGreen, OldBlue, 修改后的RGB分值分别为NewR,NewG,NewB,有：
newR = (oldR - (x-1,y-1)的Red分值)×待定系数 + OldRed
newG = (oldG - (x-1,y-1)的Green分值)×待定系数 + OldGreen
newB = (oldB - (x-1,y-1)的Blue分值)×待定系数 + OldBlue
根据这个公式，我们的程序如下：
程序3.12
unit Sharp;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, ExtCtrls;
type
TPixels = Array of Array of TRGBTriple;
TfrmMain = class(TForm)
PaintBox1: TPaintBox;
btnExecute: TButton;
lblCap: TLabel;
txtS: TEdit;
procedure FormCreate(Sender: TObject);
procedure FormDestroy(Sender: TObject);
procedure btnExecuteClick(Sender: TObject);
procedure PaintBox1Paint(Sender: TObject);
private
Procedure SharpPic(Bit : TBitmap; n : Single);
public
{ Public declarations }
end;
procedure WritePixel(Pic: TBitmap; tPix: TPixels);
procedure ReadPixel(Pic: Tbitmap; var tPi
补充：软件开发 , Delphi ,
