TIEVisionBackgroundSubtractor.selectMethodGMG

Declaration

procedure selectMethodGMG(initializationFrames: int32_t = 120; decisionThreshold: double = 0.8); safecall;

Description

Select the GMG Background Subtractor algorithm.

Parameter	Description
initializationFrames	Number of frames used to initialize the background models
decisionThreshold	Threshold value, above which it is marked foreground, else background

Demo

Demos\IEVision\BackgroundSubtract\BackgroundSubtract.dpr

// Demo TImageEnViews:
// ImageEnView1: Captured video
// ImageEnView4: Image to use as background
// ImageEnView2: Foreground Mask
// ImageEnView3: Output with replaced background

// Capture button
procedure TMainForm.CaptureButtonClick(Sender: TObject);
var
  w, h: integer;
  f: AnsiString;
begin
  VideoInputForm.Connect;

  // start capture
  ImageEnView1.IO.DShowParams.Run;

  // set up background subtractor
  m_backgroundSubtractor.selectMethodGMG();
end;

// We have a new frame
procedure TMainForm.ImageEnView1DShowNewFrame(Sender: TObject);
var
  fgmask: TIEVisionImage;
  learningRate: double;
begin
  // copy current sample to ImageEnView bitmap
  ImageEnView1.IO.DShowParams.GetSample(ImageEnView1.IEBitmap);

  // get foreground mask
  if CheckBoxLearning.Checked then
    learningRate := -1
  else
    learningRate := 0;
  fgmask := m_backgroundSubtractor.apply(ImageEnView1.IEBitmap.GetIEVisionImage(), learningRate);
  ImageEnView2.IEBitmap.AssignIEVisionImage(fgmask);

  // replace background using foreground mask
  ImageEnView4.Proc.ResampleTo(ImageEnView3.IEBitmap, ImageEnView1.IEBitmap.Width, ImageEnView1.IEBitmap.Height, rfNone);
  ImageEnView3.Proc.Merge(ImageEnView1.IEBitmap, ImageEnView2.IEBitmap);

  // refresh viewers
  ImageEnView1.Update();
  ImageEnView2.Update();
  ImageEnView3.Update();
end;

TIEVisionBackgroundSubtractor.selectMethodGMG