CODEWITHSUNDEEP
delphifiremonkeydelphi-10.2-tokyo
Diego Bittencourt
Diego Bittencourt

Reputation: 605

How crop bitmap in selected area using firemonkey?

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:

enter image description here

Upvotes: 2

Views: 3633

Answers (2)

Joao Ishiwatari
Joao Ishiwatari

Reputation: 85

Another way to do:

var
  Tmp: TBitmap;
  Bmp: TBitmap;
  iRect: TRect;
begin
  Tmp := TBitmap.Create;
  Tmp := Image1.MakeScreenshot; //ignore the scale, so will F*ck the resolution, but resolve the scale issues
  Bmp := TBitmap.Create;
  try
    Bmp.Width := round(Rectangle1.Width);
    Bmp.Height := round(Rectangle1.Height);
    iRect.Left := round(Rectangle1.Position.X);
    iRect.Top := round(Rectangle1.Position.Y);
    iRect.Width := round(Rectangle1.Width);
    iRect.Height := round(Rectangle1.Height);
    Bmp.CopyFromBitmap(tmp, iRect, 0, 0);
    Image2.Bitmap := Bmp
  finally
    Tmp.Free;
    Bmp.Free;
  end;

Upvotes: 0

asd-tm
asd-tm

Reputation: 5263

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:

enter image description here

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

Here is a result of procedure functioning: enter image description here

Upvotes: 5

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