How crop bitmap in selected area using firemonkey?

Question

I need create a crop effect to my app. I have a TRectangle over a TImage, and I need when the user press the save button, copy just the area that the TRectangle uses. There is some way that I can cut just a specific area from the Image1.Bitmap? I printed a image to better ilustrate what I need:

Answer 1

Here is a sample that works for me:

procedure TForm1.Button1Click(Sender: TObject);
var
  Bmp: TBitmap;
  xScale, yScale: extended;
  iRect: TRect;
begin

  Bmp := TBitmap.Create;
  xScale := Image1.Bitmap.Width / Image1.Width;
  yScale := Image1.Bitmap.Height / Image1.Height;
  try
    Bmp.Width := round(Rectangle1.Width * xScale);
    Bmp.Height := round(Rectangle1.Height * yScale);
    iRect.Left := round(Rectangle1.Position.X * xScale);
    iRect.Top := round(Rectangle1.Position.Y * yScale);
    iRect.Width := round(Rectangle1.Width * xScale);
    iRect.Height := round(Rectangle1.Height * yScale);
    Bmp.CopyFromBitmap(Image1.Bitmap, iRect, 0, 0);
    Image2.Bitmap := Bmp
  finally
    Bmp.Free;
  end;
end;

I assume here that Rectangle1 has Image1 as its Parent:

Otherwise you will need to consider the offset of Position.X and Position.Y properties.

Here is a result of procedure functioning: