OpenCvBackgroundSubtraction.cpp

#include <poly/Log.h>
#include <OpenCvBackgroundSubtraction.h>

namespace poly {

  OpenCvBackgroundSubtraction::OpenCvBackgroundSubtraction()
    :subtractor(NULL)
    ,width(0)
    ,height(0)
  {
  }

  int OpenCvBackgroundSubtraction::init(int w, int h) {

    if (w <= 0) {
      SX_ERROR("w should be bigger then 0.");
      return -1;
    }

    if (h <= 0) {
      SX_ERROR("h should be bigger then 0.");
      return -2;
    }

    width = w;
    height = h;
    
    subtractor = cv::createBackgroundSubtractorMOG2(20, 16, true);
    if (NULL == subtractor) {
      SX_ERROR("Failed to create the background subtractor.");
      return -1;
    }
    
    return 0;
  }

  int OpenCvBackgroundSubtraction::update(uint8_t* pixels) {
    
    if (NULL == pixels) {
      SX_ERROR("Given pixels are NULL.");
      return -1;
    }

    if (0 == width) {
      SX_ERROR("width is 0. call init().");
      return -2;
    }

    if (0 == height) {
      SX_ERROR("height is 0. call init().");
      return -3;
    }

    if (NULL == subtractor) {
      SX_ERROR("subtractor is NULL. call init().");
      return -4;
    }

    cv::Mat frame(height, width, CV_8UC1, pixels, CV_AUTOSTEP);
    if (true == mask.empty()) {
      mask.create(frame.size(), frame.type());
    }

    subtractor->apply(frame, mask, -1);
    
    return 0;
  }
  
} /* namespace poly */

OpenCvBackgroundSubtraction.h

#ifndef POLY_OPENCV_BACKGROUND_SUBTRACTION_H
#define POLY_OPENCV_BACKGROUND_SUBTRACTION_H

#include <opencv2/imgproc.hpp>
#include <opencv2/video/background_segm.hpp>

namespace poly {

  class OpenCvBackgroundSubtraction {
  public:
    OpenCvBackgroundSubtraction();
    int init(int w, int h);
    int update(uint8_t* pixels);

  private:
    cv::BackgroundSubtractor* subtractor;
    cv::Mat mask;
    int width;
    int height;
  }; 
  
} /* namespace poly */

#endif