TIEVisionBackgroundSubtractor.selectMethodMOG

Declaration

procedure selectMethodMOG(history: int32_t = 200; nmixtures: int32_t = 5; backgroundRatio: double = 0.7; noiseSigma: double = 0); safecall;

Description

Select the mixture-of-gaussian background subtractor algorithm.

Parameter	Description
history	Length of the history
nmixtures	Number of Gaussian mixtures
backgroundRatio	Background ratio
noiseSigma	Noise strength (standard deviation of the brightness or each color channel)

Demo

Demos\IEVision\BackgroundSubtract\BackgroundSubtract.dpr

Example

// 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.selectMethodMOG();
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.selectMethodMOG