How to select a rectangular portion of a TImage Bitmap?

[jhcbrito]

I have a Bitmap image and need to select a particular position rectangular to select this position I must save her.

Example: Picture 800x600 size to be located / copied somewhere 300x400 photo where is the face of a person.

I found several examples but none that me an idea of ​​how to do this :-( Examples for very complex tasks that I will not use. If I have not been clear, let me know. Sorry for my english.

 

[AJBrasaca]

Hi jhcbrito...

I hope this is usefull... Use TCanvas.CopyRect method.

Code examples from Embarcadero.

{
The following code illustrates the differences between
CopyRect and BrushCopy. The bitmap graphic ‘FACTORY.BMP’ is
loaded into Bitmap and displayed on the Canvas of Form1.
BrushCopy replaces the color black in the graphic with the
brush of the canvas, while CopyRect leaves the colors intact.
}
procedure TForm1.Button1Click(Sender: TObject);
var
Bitmap: TBitmap;
MyRect, MyOther: TRect;
begin
MyRect := Rect(10,10,150,150);
MyOther := Rect(10,161,150,301);
Bitmap := TBitmap.Create;
Bitmap.LoadFromFile(
'c:\Program Files\Common Files\CodeGear Shared\Images\Splash\256color\factory.bmp');
Form1.Canvas.BrushCopy(MyRect, Bitmap, MyRect, clBlack);
Form1.Canvas.CopyRect(MyOther,Bitmap.Canvas,MyRect);
Bitmap.Free;
end;
Copy Code
{
The following example uses the CopyMode of an image’s canvas
to blank out the image when the user chooses the "Cut" menu
item. This example requires a Main menu with a Copy and a
Cut menu item that have their OnClick error handlers populated.
Note: CopyMode and CopyRect are members of the destination
canvas.
}
procedure TForm1.Copy1Click(Sender: TObject);
var
DstRect, SrcRect: TRect;
begin
with Image2.Canvas do
begin
CopyMode := cmSrcCopy;
DstRect := Rect(0, 0, Image2.Width, Image2.Height);
SrcRect := Rect(0, 0, Image1.Width, Image1.Height);
CopyRect(DstRect, Image1.Canvas, SrcRect);
end;
end;

procedure TForm1.Cut1Click(Sender: TObject);
var
ARect: TRect;
begin
Copy1Click(Sender); { do the same thing as the copy menu item }
with Image1.Canvas do
begin
CopyMode := cmWhiteness;
ARect := Rect(0, 0, Image1.Width, Image1.Height);
CopyRect(ARect, Image1.Canvas, ARect);
CopyMode := cmSrcCopy; { restore the copy mode }
end;
end;