ViBe是一种像素级视频背景建模或前景检测的算法,效果优于所熟知的几种算法,对硬件内存占用也少,很简单。我之前根据stellar0的代码(在这里,非常感谢stellar0)改写成一个Mat格式的代码了,现在摆上来和大家交流,具体如下:(在VS2010+OpenCV2.4.2中测试通过)
ViBe.h
- #pragma once
- #include <iostream>
- #include "opencv2/opencv.hpp"
- using namespace cv;
- using namespace std;
- #define NUM_SAMPLES 20 //每个像素点的样本个数
- #define MIN_MATCHES 2 //#min指数
- #define RADIUS 20 //Sqthere半径
- #define SUBSAMPLE_FACTOR 16 //子采样概率
- class ViBe_BGS
- {
- public:
- ViBe_BGS(void);
- ~ViBe_BGS(void);
- void init(const Mat _image); //初始化
- void processFirstFrame(const Mat _image);
- void testAndUpdate(const Mat _image); //更新
- Mat getMask(void){return m_mask;};
- private:
- Mat m_samples[NUM_SAMPLES];
- Mat m_foregroundMatchCount;
- Mat m_mask;
- };
ViBe.cpp
- #include <opencv2/opencv.hpp>
- #include <iostream>
- #include "ViBe.h"
- using namespace std;
- using namespace cv;
- int c_xoff[9] = {-1, 0, 1, -1, 1, -1, 0, 1, 0}; //x的邻居点
- int c_yoff[9] = {-1, 0, 1, -1, 1, -1, 0, 1, 0}; //y的邻居点
- ViBe_BGS::ViBe_BGS(void)
- {
- }
- ViBe_BGS::~ViBe_BGS(void)
- {
- }
- /**************** Assign space and init ***************************/
- void ViBe_BGS::init(const Mat _image)
- {
- for(int i = 0; i < NUM_SAMPLES; i++)
- {
- m_samples[i] = Mat::zeros(_image.size(), CV_8UC1);
- }
- m_mask = Mat::zeros(_image.size(),CV_8UC1);
- m_foregroundMatchCount = Mat::zeros(_image.size(),CV_8UC1);
- }
- /**************** Init model from first frame ********************/
- void ViBe_BGS::processFirstFrame(const Mat _image)
- {
- RNG rng;
- int row, col;
- for(int i = 0; i < _image.rows; i++)
- {
- for(int j = 0; j < _image.cols; j++)
- {
- for(int k = 0 ; k < NUM_SAMPLES; k++)
- {
- // Random pick up NUM_SAMPLES pixel in neighbourhood to construct the model
- int random = rng.uniform(0, 9);
- row = i + c_yoff[random];
- if (row < 0)
- row = 0;
- if (row >= _image.rows)
- row = _image.rows - 1;
- col = j + c_xoff[random];
- if (col < 0)
- col = 0;
- if (col >= _image.cols)
- col = _image.cols - 1;
- m_samples[k].at<uchar>(i, j) = _image.at<uchar>(row, col);
- }
- }
- }
- }
- /**************** Test a new frame and update model ********************/
- void ViBe_BGS::testAndUpdate(const Mat _image)
- {
- RNG rng;
- for(int i = 0; i < _image.rows; i++)
- {
- for(int j = 0; j < _image.cols; j++)
- {
- int matches(0), count(0);
- float dist;
- while(matches < MIN_MATCHES && count < NUM_SAMPLES)
- {
- dist = abs(m_samples[count].at<uchar>(i, j) - _image.at<uchar>(i, j));
- if (dist < RADIUS)
- matches++;
- count++;
- }
- if (matches >= MIN_MATCHES)
- {
- // It is a background pixel
- m_foregroundMatchCount.at<uchar>(i, j) = 0;
- // Set background pixel to 0
- m_mask.at<uchar>(i, j) = 0;
- // 如果一个像素是背景点,那么它有 1 / defaultSubsamplingFactor 的概率去更新自己的模型样本值
- int random = rng.uniform(0, SUBSAMPLE_FACTOR);
- if (random == 0)
- {
- random = rng.uniform(0, NUM_SAMPLES);
- m_samples[random].at<uchar>(i, j) = _image.at<uchar>(i, j);
- }
- // 同时也有 1 / defaultSubsamplingFactor 的概率去更新它的邻居点的模型样本值
- random = rng.uniform(0, SUBSAMPLE_FACTOR);
- if (random == 0)
- {
- int row, col;
- random = rng.uniform(0, 9);
- row = i + c_yoff[random];
- if (row < 0)
- row = 0;
- if (row >= _image.rows)
- row = _image.rows - 1;
- random = rng.uniform(0, 9);
- col = j + c_xoff[random];
- if (col < 0)
- col = 0;
- if (col >= _image.cols)
- col = _image.cols - 1;
- random = rng.uniform(0, NUM_SAMPLES);
- m_samples[random].at<uchar>(row, col) = _image.at<uchar>(i, j);
- }
- }
- else
- {
- // It is a foreground pixel
- m_foregroundMatchCount.at<uchar>(i, j)++;
- // Set background pixel to 255
- m_mask.at<uchar>(i, j) = 255;
- //如果某个像素点连续N次被检测为前景,则认为一块静止区域被误判为运动,将其更新为背景点
- if (m_foregroundMatchCount.at<uchar>(i, j) > 50)
- {
- int random = rng.uniform(0, SUBSAMPLE_FACTOR);
- if (random == 0)
- {
- random = rng.uniform(0, NUM_SAMPLES);
- m_samples[random].at<uchar>(i, j) = _image.at<uchar>(i, j);
- }
- }
- }
- }
- }
- }
Main.cpp
- // This is based on
- // "VIBE: A POWERFUL RANDOM TECHNIQUE TO ESTIMATE THE BACKGROUND IN VIDEO SEQUENCES"
- // by Olivier Barnich and Marc Van Droogenbroeck
- // Author : zouxy
- // Date : 2013-4-13
- // HomePage : http://blog.youkuaiyun.com/zouxy09
- // Email : zouxy09@qq.com
- #include "opencv2/opencv.hpp"
- #include "ViBe.h"
- #include <iostream>
- #include <cstdio>
- using namespace cv;
- using namespace std;
- int main(int argc, char* argv[])
- {
- Mat frame, gray, mask;
- VideoCapture capture;
- capture.open("video.avi");
- if (!capture.isOpened())
- {
- cout<<"No camera or video input!\n"<<endl;
- return -1;
- }
- ViBe_BGS Vibe_Bgs;
- int count = 0;
- while (1)
- {
- count++;
- capture >> frame;
- if (frame.empty())
- break;
- cvtColor(frame, gray, CV_RGB2GRAY);
- if (count == 1)
- {
- Vibe_Bgs.init(gray);
- Vibe_Bgs.processFirstFrame(gray);
- cout<<" Training GMM complete!"<<endl;
- }
- else
- {
- Vibe_Bgs.testAndUpdate(gray);
- mask = Vibe_Bgs.getMask();
- morphologyEx(mask, mask, MORPH_OPEN, Mat());
- imshow("mask", mask);
- }
- imshow("input", frame);
- if ( cvWaitKey(10) == 'q' )
- break;
- }
- return 0;
- }