How to resize PNG file in Delphi ?

In case that you need to change PNG file size (width, height), you can use below function.

procedure copy_to_resized_png( tar, src:string; w, h: Integer);
var
	bmp: TBitmap;
	png, output: TPngImage;
begin
	png := TPngImage.Create;
	png.LoadFromFile( src);

	bmp := TBitmap.Create;
	bmp.Width := w;
	bmp.Height := h;

	bmp.Canvas.StretchDraw( RECT( 0, 0, w, h), png);

	output := TPngImage.Create;
	output.Assign( bmp);
	output.SaveToFile( tar);

	output.Free;
	bmp.Free;
	png.Free;
end;

In order to implement above function, I used TPngImage.