图像处理；关于bmp的缩放；（20分探路；300分放送）

Question

虽然我的方法有点笨，但是总算可以完成了。大家如果有其他方法，敬请赐教。procedure TForm1.Button1Click(Sender: TObject);
var
  Rect : TRect;
  Image1,Image2 : TImage;
begin
  Image1 := TImage.Create(Form1);
  Image2 := TImage.Create(Form1);
  if OpenDialog1.Execute then
    Image1.Picture.LoadFromFile(OpenDialog1.FileName);  Image1.Width := 864;
  Image1.Height := 600;
  Image1.Stretch := True;  Image2.Width := 864;
  Image2.Height := Image1.Height;
  Rect.Left := Image2.Left;
  Rect.Top := Image2.Top;
  Rect.Right := Image2.Left + Image2.Width;
  Rect.Bottom := Image2.Top + + Image2.Height;
  Image2.Canvas.StretchDraw(Rect,Image1.Picture.Graphic);
  if SaveDialog1.Execute then
    Image2.Picture.SaveToFile(SaveDialog1.FileName);
  Image1.Free;
  Image2.Free;
end;

Answer 1

楼上的回答有问题，图象有可能不能全切procedure TForm1.Button1Click(Sender: TObject);
var
  Image1,Image2: TImage;
begin
  Image1 := TImage.Create(self);  try
     Image2 := TImage.Create(self);
     try
        if OpenDialog1.Execute then
        begin
             Image1.Picture.LoadFromFile(OpenDialog1.FileName);
             Image2.width:=864;
             Image2.Height :=Trunc(864*Image1.Picture.Height/Image1.Picture.Width);
             Image2.Canvas.StretchDraw(Rect(0,0,864,Trunc(864*Image1.Picture.Height/Image1.Picture.Width)),Image1.Picture.Bitmap );//用Bitmap 而非Graphic
        end;
        if SaveDialog1.Execute then
             Image2.Picture.SaveToFile(SaveDialog1.FileName);
     finally
     Image2.Free;
     end;
  finally
  Image1.Free;
  end;
end;

Answer 2

procedure TForm1.Button1Click(Sender: TObject);
var
b1,b2:Tbitmap;
begin
b1:=tbitmap.Create;
b2:=tbitmap.Create;
b2.LoadFromFile('g:\111.bmp');b1.Width:=864;
b1.Height:=600;StretchBlt(b1.canvas.Handle,0,0,b1.Width,b1.Height,b2.Canvas.Handle,0,0,b2.Width,b2.Height,SRCCOPY );
b1.SaveToFile('g:\222.bmp');
b2.FreeImage;
b1.FreeImage;
b2.free;
b1.free;
end;

Answer 3

谢谢；楼上几位；更高要求；把非单色 的bmp 转为 单色的

Answer 4

delphi自带的一个demo中，imageview里有缩放的例子，看一下吧

Answer 5

此话怎讲?
单色是什么意思?
你是指灰度图象吗?
gray := (r + g + b) div 3;
或 gray := round(r*0.5 + g *0.3 + b * 0.2)(系数记得不太清,还请查查书);
r,g,b分别指三个分量上的灰度直.
还要注意越界!

Answer 6

var 
  bmp1,bmp2: TBitmap; 
begin 
  bmp1:=TBitmap.Create; 
  bmp2:=TBitmap.Create; 
  try 
    bmp1.loadfromfile('c:\1.bmp'); //  
    bmp2.width:=200;                  //   
    bmp2.height:=300;                 // 以上可以改为你需要的尺寸 
    bmp2.canvas.stretchdraw(rect(0,0,bmp2.width,bmp2.height),bmp1); 
    bmp2.savetofile('c:\2.bmp'); 
  finally 
    bmp1.Free; 
    bmp2.Free; 
  end;

Answer 7

Gray := 0.3*R + 0.59*G + 0.11*B

Answer 8

单色就是黑白的；没有灰度；比如 orc的图像