TImageEnProc.BeginImageProcessing

Declaration

function BeginImageProcessing(AllowedFormats: TIEPixelFormats; var X1, Y1, X2, Y2: Integer; const OpName: string; var ProcBitmap: TIEBitmap; var Mask: TIEMask; OpID: Integer = 0; ExtractROI: Boolean = True): Boolean;

Description

BeginImageProcessing and EndImageProcessing allow you to create custom image processing functions that automatically handle selection area, pixel format consistency and undo.

Parameter	Description
AllowedFormats	The permitted pixel formats
X1, Y1, X2, Y2	The destination rectangle coordinates to apply the function
OpName	A string describing the function (for the undo caption)
ProcBitmap	The bitmap to process
Mask	The selection mask
OpID	An optional ID for the task which is saved with the undo (and available via GetUndoInfo). Any value can be specified or a Undo Constant. Use -1 to skip saving of the undo
ExtractROI	If True (default) ProcBitmap contains only the Region Of Interest, otherwise it contains the full original bitmap

By using BeginImageProcessing/EndImageProcessing, you can avoid considering if the selection is rectangle, elliptical, irregular or magic wand, just process the bitmap as a rectangle.

Example

procedure CustomNegative( proc: TImageEnProc );
var
  procBmp: TIEBitmap;
  mask: TIEMask;
  X1, Y1, X2, Y2: Integer;
  x, y: Integer;
  px: PRGB;
begin
  if not proc.BeginImageProcessing([ie24RGB], X1, Y1, X2, Y2, 'CustomNegative', procBmp, mask) then
    exit;

  for y := Y1 to Y2 - 1 do
  begin
    px := ProcBitmap.Scanline[y];
    for x := X1 to X2 - 1 do
    begin
      with px^ do
      begin
        r := 255-r;
        g := 255-g;
        b := 255-b;
      end;
      Inc( px );
    end;
  end;
  // finalize
  proc.EndImageProcessing( procBmp, mask );
end;

..
ImageEnView1.SelectEllipse( 100, 100, 100, 100 );
CustomNegative( ImageEnView1.Proc );

TImageEnProc.BeginImageProcessing