#define __OPENCV_BACKGROUND_SEGM_HPP__
#include "opencv2/core/core.hpp"
-
+#include <list>
namespace cv
{
//Tau= 0.5 means that if pixel is more than 2 times darker then it is not shadow
//See: Prati,Mikic,Trivedi,Cucchiarra,"Detecting Moving Shadows...",IEEE PAMI,2003.
};
-
+
+/**
+ * Background Subtractor module. Takes a series of images and returns a sequence of mask (8UC1)
+ * images of the same size, where 255 indicates Foreground and 0 represents Background.
+ * This class implements an algorithm described in "Visual Tracking of Human Visitors under
+ * Variable-Lighting Conditions for a Responsive Audio Art Installation," A. Godbehere,
+ * A. Matsukawa, K. Goldberg, American Control Conference, Montreal, June 2012.
+ */
+class CV_EXPORTS BackgroundSubtractorGMG: public cv::BackgroundSubtractor
+{
+private:
+ /**
+ * A general flexible datatype.
+ *
+ * Used internally to enable background subtraction algorithm to be robust to any input Mat type.
+ * Datatype can be char, unsigned char, int, unsigned int, long int, float, or double.
+ */
+ union flexitype{
+ char c;
+ uchar uc;
+ int i;
+ unsigned int ui;
+ long int li;
+ float f;
+ double d;
+
+ flexitype(){d = 0.0;} //!< Default constructor, set all bits of the union to 0.
+ flexitype(char cval){c = cval;} //!< Char type constructor
+
+ bool operator ==(flexitype& rhs)
+ {
+ return d == rhs.d;
+ }
+
+ //! Char type assignment operator
+ flexitype& operator =(char cval){
+ if (this->c == cval){return *this;}
+ c = cval; return *this;
+ }
+ flexitype(unsigned char ucval){uc = ucval;} //!< unsigned char type constructor
+
+ //! unsigned char type assignment operator
+ flexitype& operator =(unsigned char ucval){
+ if (this->uc == ucval){return *this;}
+ uc = ucval; return *this;
+ }
+ flexitype(int ival){i = ival;} //!< int type constructor
+ //! int type assignment operator
+ flexitype& operator =(int ival){
+ if (this->i == ival){return *this;}
+ i = ival; return *this;
+ }
+ flexitype(unsigned int uival){ui = uival;} //!< unsigned int type constructor
+
+ //! unsigned int type assignment operator
+ flexitype& operator =(unsigned int uival){
+ if (this->ui == uival){return *this;}
+ ui = uival; return *this;
+ }
+ flexitype(float fval){f = fval;} //!< float type constructor
+ //! float type assignment operator
+ flexitype& operator =(float fval){
+ if (this->f == fval){return *this;}
+ f = fval; return *this;
+ }
+ flexitype(long int lival){li = lival;} //!< long int type constructor
+ //! long int type assignment operator
+ flexitype& operator =(long int lival){
+ if (this->li == lival){return *this;}
+ li = lival; return *this;
+ }
+
+ flexitype(double dval){d=dval;} //!< double type constructor
+ //! double type assignment operator
+ flexitype& operator =(double dval){
+ if (this->d == dval){return *this;}
+ d = dval; return *this;
+ }
+ };
+ /**
+ * Used internally to represent a single feature in a histogram.
+ * Feature is a color and an associated likelihood (weight in the histogram).
+ */
+ struct HistogramFeatureGMG
+ {
+ /**
+ * Default constructor.
+ * Initializes likelihood of feature to 0, color remains uninitialized.
+ */
+ HistogramFeatureGMG(){likelihood = 0.0;}
+
+ /**
+ * Copy constructor.
+ * Required to use HistogramFeatureGMG in a std::vector
+ * @see operator =()
+ */
+ HistogramFeatureGMG(const HistogramFeatureGMG& orig){
+ color = orig.color; likelihood = orig.likelihood;
+ }
+
+ /**
+ * Assignment operator.
+ * Required to use HistogramFeatureGMG in a std::vector
+ */
+ HistogramFeatureGMG& operator =(const HistogramFeatureGMG& orig){
+ color = orig.color; likelihood = orig.likelihood; return *this;
+ }
+
+ /**
+ * Tests equality of histogram features.
+ * Equality is tested only by matching the color (feature), not the likelihood.
+ * This operator is used to look up an observed feature in a histogram.
+ */
+ bool operator ==(HistogramFeatureGMG &rhs);
+
+ //! Regardless of the image datatype, it is quantized and mapped to an integer and represented as a vector.
+ vector<size_t> color;
+
+ //! Represents the weight of feature in the histogram.
+ float likelihood;
+ friend class PixelModelGMG;
+ };
+
+ /**
+ * Representation of the statistical model of a single pixel for use in the background subtraction
+ * algorithm.
+ */
+ class PixelModelGMG
+ {
+ public:
+ PixelModelGMG();
+ virtual ~PixelModelGMG();
+
+ /**
+ * Incorporate the last observed feature into the statistical model.
+ *
+ * @param learningRate The adaptation parameter for the histogram. -1.0 to use default. Value
+ * should be between 0.0 and 1.0, the higher the value, the faster the
+ * adaptation. 1.0 is limiting case where fast adaptation means no memory.
+ */
+ void insertFeature(double learningRate = -1.0);
+
+ /**
+ * Set the feature last observed, to save before incorporating it into the statistical
+ * model with insertFeature().
+ *
+ * @param feature The feature (color) just observed.
+ */
+ void setLastObservedFeature(BackgroundSubtractorGMG::HistogramFeatureGMG feature);
+ /**
+ * Set the upper limit for the number of features to store in the histogram. Use to adjust
+ * memory requirements.
+ *
+ * @param max size_t representing the max number of features.
+ */
+ void setMaxFeatures(size_t max) {
+ maxFeatures = max; histogram.resize(max); histogram.clear();
+ }
+ /**
+ * Normalize the histogram, so sum of weights of all features = 1.0
+ */
+ void normalizeHistogram();
+ /**
+ * Return the weight of a feature in the histogram. If the feature is not represented in the
+ * histogram, the weight returned is 0.0.
+ */
+ double getLikelihood(HistogramFeatureGMG f);
+ PixelModelGMG& operator *=(const float &rhs);
+ //friend class BackgroundSubtractorGMG;
+ //friend class HistogramFeatureGMG;
+ protected:
+ size_t numFeatures; //!< number of features in histogram
+ size_t maxFeatures; //!< max allowable features in histogram
+ std::list<HistogramFeatureGMG> histogram; //!< represents the histogram as a list of features
+ HistogramFeatureGMG lastObservedFeature;
+ //!< store last observed feature in case we need to add it to histogram
+ };
+
+public:
+ BackgroundSubtractorGMG();
+ virtual ~BackgroundSubtractorGMG();
+ virtual AlgorithmInfo* info() const;
+
+ /**
+ * Performs single-frame background subtraction and builds up a statistical background image
+ * model.
+ * @param image Input image
+ * @param fgmask Output mask image representing foreground and background pixels
+ */
+ virtual void operator()(InputArray image, OutputArray fgmask, double learningRate=-1.0);
+
+ /**
+ * Validate parameters and set up data structures for appropriate image type. Must call before
+ * running on data.
+ * @param image One sample image from dataset
+ * @param min minimum value taken on by pixels in image sequence. Usually 0
+ * @param max maximum value taken on by pixels in image sequence. e.g. 1.0 or 255
+ */
+ void initializeType(InputArray image, flexitype min, flexitype max);
+ /**
+ * Selectively update the background model. Only update background model for pixels identified
+ * as background.
+ * @param mask Mask image same size as images in sequence. Must be 8UC1 matrix, 255 for foreground
+ * and 0 for background.
+ */
+ void updateBackgroundModel(InputArray mask);
+ /**
+ * Retrieve the greyscale image representing the probability that each pixel is foreground given
+ * the current estimated background model. Values are 0.0 (black) to 1.0 (white).
+ * @param img The 32FC1 image representing per-pixel probabilities that the pixel is foreground.
+ */
+ void getPosteriorImage(OutputArray img);
+
+protected:
+ //! Total number of distinct colors to maintain in histogram.
+ int maxFeatures;
+ //! Set between 0.0 and 1.0, determines how quickly features are "forgotten" from histograms.
+ double learningRate;
+ //! Number of frames of video to use to initialize histograms.
+ int numInitializationFrames;
+ //! Number of discrete levels in each channel to be used in histograms.
+ int quantizationLevels;
+ //! Prior probability that any given pixel is a background pixel. A sensitivity parameter.
+ double backgroundPrior;
+
+ double decisionThreshold; //!< value above which pixel is determined to be FG.
+ int smoothingRadius; //!< smoothing radius, in pixels, for cleaning up FG image.
+
+ flexitype maxVal, minVal;
+
+ /*
+ * General Parameters
+ */
+ size_t imWidth; //!< width of image.
+ size_t imHeight; //!< height of image.
+ size_t numPixels;
+
+ int imageDepth; //!< Depth of image, e.g. CV_8U
+ unsigned int numChannels; //!< Number of channels in image.
+
+ bool isDataInitialized;
+ //!< After general parameters are set, data structures must be initialized.
+
+ size_t elemSize; //!< store image mat element sizes
+ size_t elemSize1;
+
+ /*
+ * Data Structures
+ */
+ vector<PixelModelGMG> pixels; //!< Probabilistic background models for each pixel in image.
+ int frameNum; //!< Frame number counter, used to count frames in training mode.
+ Mat posteriorImage; //!< Posterior probability image.
+ Mat fgMaskImage; //!< Foreground mask image.
+};
+
+bool initModule_BackgroundSubtractorGMG(void);
+
}
#endif
--- /dev/null
+/*M///////////////////////////////////////////////////////////////////////////////////////
+//
+// IMPORTANT: READ BEFORE DOWNLOADING, COPYING, INSTALLING OR USING.
+//
+// By downloading, copying, installing or using the software you agree to this license.
+// If you do not agree to this license, do not download, install,
+// copy or use the software.
+//
+//
+// License Agreement
+//
+// Copyright (C) 2000, Intel Corporation, all rights reserved.
+// Third party copyrights are property of their respective owners.
+//
+// Redistribution and use in source and binary forms, with or without modification,
+// are permitted provided that the following conditions are met:
+//
+// * Redistribution's of source code must retain the above copyright notice,
+// this list of conditions and the following disclaimer.
+//
+// * Redistribution's in binary form must reproduce the above copyright notice,
+// this list of conditions and the following disclaimer in the documentation
+// and/or other materials provided with the distribution.
+//
+// * The name of Intel Corporation may not be used to endorse or promote products
+// derived from this software without specific prior written permission.
+//
+// This software is provided by the copyright holders and contributors "as is" and
+// any express or implied warranties, including, but not limited to, the implied
+// warranties of merchantability and fitness for a particular purpose are disclaimed.
+// In no event shall the Intel Corporation or contributors be liable for any direct,
+// indirect, incidental, special, exemplary, or consequential damages
+// (including, but not limited to, procurement of substitute goods or services;
+// loss of use, data, or profits; or business interruption) however caused
+// and on any theory of liability, whether in contract, strict liability,
+// or tort (including negligence or otherwise) arising in any way out of
+// the use of this software, even if advised of the possibility of such damage.
+//
+//M*/
+
+/*
+ * This class implements an algorithm described in "Visual Tracking of Human Visitors under
+ * Variable-Lighting Conditions for a Responsive Audio Art Installation," A. Godbehere,
+ * A. Matsukawa, K. Goldberg, American Control Conference, Montreal, June 2012.
+ *
+ * Prepared and integrated by Andrew B. Godbehere.
+ */
+
+#include "precomp.hpp"
+
+using namespace std;
+
+namespace cv
+{
+
+BackgroundSubtractorGMG::BackgroundSubtractorGMG()
+{
+ /*
+ * Default Parameter Values. Override with algorithm "set" method.
+ */
+ maxFeatures = 64;
+ learningRate = 0.025;
+ numInitializationFrames = 120;
+ quantizationLevels = 16;
+ backgroundPrior = 0.8;
+ decisionThreshold = 0.8;
+ smoothingRadius = 7;
+}
+
+void BackgroundSubtractorGMG::initializeType(InputArray _image,flexitype min, flexitype max)
+{
+ minVal = min;
+ maxVal = max;
+
+ if (minVal == maxVal)
+ {
+ CV_Error_(CV_StsBadArg,("minVal and maxVal cannot be the same."));
+ }
+
+ /*
+ * Parameter validation
+ */
+ if (maxFeatures <= 0)
+ {
+ CV_Error_(CV_StsBadArg,
+ ("maxFeatures parameter must be 1 or greater. Instead, it is %d.",maxFeatures));
+ }
+ if (learningRate < 0.0 || learningRate > 1.0)
+ {
+ CV_Error_(CV_StsBadArg,
+ ("learningRate parameter must be in the range [0.0,1.0]. Instead, it is %f.",
+ learningRate));
+ }
+ if (numInitializationFrames < 1)
+ {
+ CV_Error_(CV_StsBadArg,
+ ("numInitializationFrames must be at least 1. Instead, it is %d.",
+ numInitializationFrames));
+ }
+ if (quantizationLevels < 1)
+ {
+ CV_Error_(CV_StsBadArg,
+ ("quantizationLevels must be at least 1 (preferably more). Instead it is %d.",
+ quantizationLevels));
+ }
+ if (backgroundPrior < 0.0 || backgroundPrior > 1.0)
+ {
+ CV_Error_(CV_StsBadArg,
+ ("backgroundPrior must be a probability, between 0.0 and 1.0. Instead it is %f.",
+ backgroundPrior));
+ }
+
+ /*
+ * Detect and accommodate the image depth
+ */
+ Mat image = _image.getMat();
+ imageDepth = image.depth(); // 32f, 8u, etc.
+ numChannels = image.channels();
+
+ /*
+ * Color quantization [0 | | | | max] --> [0 | | max]
+ * (0) Use double as intermediary to convert all types to int.
+ * (i) Shift min to 0,
+ * (ii) max/(num intervals) = factor. x/factor * factor = quantized result, after integer operation.
+ */
+
+ /*
+ * Data Structure Initialization
+ */
+ Size imsize = image.size();
+ imWidth = imsize.width;
+ imHeight = imsize.height;
+ numPixels = imWidth*imHeight;
+ pixels.resize(numPixels);
+ frameNum = 0;
+
+ // used to iterate through matrix of type unknown at compile time
+ elemSize = image.elemSize();
+ elemSize1 = image.elemSize1();
+
+ vector<PixelModelGMG>::iterator pixel;
+ vector<PixelModelGMG>::iterator pixel_end = pixels.end();
+ for (pixel = pixels.begin(); pixel != pixel_end; ++pixel)
+ {
+ pixel->setMaxFeatures(maxFeatures);
+ }
+
+ fgMaskImage = Mat::zeros(imHeight,imWidth,CV_8UC1); // 8-bit unsigned mask. 255 for FG, 0 for BG
+ posteriorImage = Mat::zeros(imHeight,imWidth,CV_32FC1); // float for storing probabilities. Can be viewed directly with imshow.
+ isDataInitialized = true;
+}
+
+void BackgroundSubtractorGMG::operator()(InputArray _image, OutputArray _fgmask, double newLearningRate)
+{
+ if (!isDataInitialized)
+ {
+ CV_Error(CV_StsError,"BackgroundSubstractorGMG has not been initialized. Call initialize() first.\n");
+ }
+
+ /*
+ * Update learning rate parameter, if desired
+ */
+ if (newLearningRate != -1.0)
+ {
+ if (newLearningRate < 0.0 || newLearningRate > 1.0)
+ {
+ CV_Error(CV_StsOutOfRange,"Learning rate for Operator () must be between 0.0 and 1.0.\n");
+ }
+ this->learningRate = newLearningRate;
+ }
+
+ Mat image = _image.getMat();
+
+ _fgmask.create(Size(imHeight,imWidth),CV_8U);
+ fgMaskImage = _fgmask.getMat(); // 8-bit unsigned mask. 255 for FG, 0 for BG
+
+ /*
+ * Iterate over pixels in image
+ */
+ // grab data at each pixel (1,2,3 channels, int, float, etc.)
+ // grab data as an array of bytes. Then, send that array to a function that reads data into vector of appropriate types... and quantizing... before saving as a feature, which is a vector of flexitypes, so code can be portable.
+ // multiple channels do have sequential storage, use mat::elemSize() and mat::elemSize1()
+ vector<PixelModelGMG>::iterator pixel;
+ vector<PixelModelGMG>::iterator pixel_end = pixels.end();
+ size_t i;
+//#pragma omp parallel
+ for (i = 0, pixel=pixels.begin(); pixel != pixel_end; ++i,++pixel)
+ {
+ HistogramFeatureGMG newFeature;
+ newFeature.color.clear();
+ for (size_t c = 0; c < numChannels; ++c)
+ {
+ /*
+ * Perform quantization. in each channel. (color-min)*(levels)/(max-min).
+ * Shifts min to 0 and scales, finally casting to an int.
+ */
+ size_t quantizedColor;
+ // pixel at data+elemSize*i. Individual channel c at data+elemSize*i+elemSize1*c
+ if (imageDepth == CV_8U)
+ {
+ uchar *color = (uchar*)(image.data+elemSize*i+elemSize1*c);
+ quantizedColor = (size_t)((double)(*color-minVal.uc)*quantizationLevels/(maxVal.uc-minVal.uc));
+ }
+ else if (imageDepth == CV_8S)
+ {
+ char *color = (char*)(image.data+elemSize*i+elemSize1*c);
+ quantizedColor = (size_t)((double)(*color-minVal.c)*quantizationLevels/(maxVal.c-minVal.c));
+ }
+ else if (imageDepth == CV_16U)
+ {
+ unsigned int *color = (unsigned int*)(image.data+elemSize*i+elemSize1*c);
+ quantizedColor = (size_t)((double)(*color-minVal.ui)*quantizationLevels/(maxVal.ui-minVal.ui));
+ }
+ else if (imageDepth == CV_16S)
+ {
+ int *color = (int*)(image.data+elemSize*i+elemSize1*c);
+ quantizedColor = (size_t)((double)(*color-minVal.i)*quantizationLevels/(maxVal.i-minVal.i));
+ }
+ else if (imageDepth == CV_32F)
+ {
+ float *color = (float*)image.data+elemSize*i+elemSize1*c;
+ quantizedColor = (size_t)((double)(*color-minVal.ui)*quantizationLevels/(maxVal.ui-minVal.ui));
+ }
+ else if (imageDepth == CV_32S)
+ {
+ long int *color = (long int*)(image.data+elemSize*i+elemSize1*c);
+ quantizedColor = (size_t)((double)(*color-minVal.li)*quantizationLevels/(maxVal.li-minVal.li));
+ }
+ else if (imageDepth == CV_64F)
+ {
+ double *color = (double*)image.data+elemSize*i+elemSize1*c;
+ quantizedColor = (size_t)((double)(*color-minVal.d)*quantizationLevels/(maxVal.d-minVal.d));
+ }
+ newFeature.color.push_back(quantizedColor);
+ }
+ // now that the feature is ready for use, put it in the histogram
+
+ if (frameNum > numInitializationFrames) // typical operation
+ {
+ newFeature.likelihood = learningRate;
+ /*
+ * (1) Query histogram to find posterior probability of feature under model.
+ */
+ float likelihood = (float)pixel->getLikelihood(newFeature);
+
+ // see Godbehere, Matsukawa, Goldberg (2012) for reasoning behind this implementation of Bayes rule
+ float posterior = (likelihood*backgroundPrior)/(likelihood*backgroundPrior+(1-likelihood)*(1-backgroundPrior));
+
+ /*
+ * (2) feed posterior probability into the posterior image
+ */
+ int row,col;
+ col = i%imWidth;
+ row = (i-col)/imWidth;
+ posteriorImage.at<float>(row,col) = (1.0-posterior);
+ }
+ pixel->setLastObservedFeature(newFeature);
+ }
+ /*
+ * (3) Perform filtering and threshold operations to yield final mask image.
+ *
+ * 2 options. First is morphological open/close as before. Second is "median filtering" which Jon Barron says is good to remove noise
+ */
+ Mat thresholdedPosterior;
+ threshold(posteriorImage,thresholdedPosterior,decisionThreshold,1.0,THRESH_BINARY);
+ thresholdedPosterior.convertTo(fgMaskImage,CV_8U,255); // convert image to integer space for further filtering and mask creation
+ medianBlur(fgMaskImage,fgMaskImage,smoothingRadius);
+
+ fgMaskImage.copyTo(_fgmask);
+
+ ++frameNum; // keep track of how many frames we have processed
+}
+
+void BackgroundSubtractorGMG::getPosteriorImage(OutputArray _img)
+{
+ _img.create(Size(imWidth,imHeight),CV_32F);
+ Mat img = _img.getMat();
+ posteriorImage.copyTo(img);
+}
+
+void BackgroundSubtractorGMG::updateBackgroundModel(InputArray _mask)
+{
+ CV_Assert(_mask.size() == Size(imWidth,imHeight)); // mask should be same size as image
+
+ Mat maskImg = _mask.getMat();
+//#pragma omp parallel
+ for (size_t i = 0; i < imHeight; ++i)
+ {
+//#pragma omp parallel
+ for (size_t j = 0; j < imWidth; ++j)
+ {
+ if (frameNum <= numInitializationFrames + 1)
+ {
+ // insert previously observed feature into the histogram. -1.0 parameter indicates training.
+ pixels[i*imWidth+j].insertFeature(-1.0);
+ if (frameNum >= numInitializationFrames+1) // training is done, normalize
+ {
+ pixels[i*imWidth+j].normalizeHistogram();
+ }
+ }
+ // if mask is 0, pixel is identified as a background pixel, so update histogram.
+ else if (maskImg.at<uchar>(i,j) == 0)
+ {
+ pixels[i*imWidth+j].insertFeature(learningRate); // updates the histogram for the next iteration.
+ }
+ }
+ }
+}
+
+BackgroundSubtractorGMG::~BackgroundSubtractorGMG()
+{
+
+}
+
+BackgroundSubtractorGMG::PixelModelGMG::PixelModelGMG()
+{
+ numFeatures = 0;
+ maxFeatures = 0;
+}
+
+BackgroundSubtractorGMG::PixelModelGMG::~PixelModelGMG()
+{
+
+}
+
+void BackgroundSubtractorGMG::PixelModelGMG::setLastObservedFeature(HistogramFeatureGMG f)
+{
+ this->lastObservedFeature = f;
+}
+
+double BackgroundSubtractorGMG::PixelModelGMG::getLikelihood(BackgroundSubtractorGMG::HistogramFeatureGMG f)
+{
+ std::list<HistogramFeatureGMG>::iterator feature = histogram.begin();
+ std::list<HistogramFeatureGMG>::iterator feature_end = histogram.end();
+
+ for (feature = histogram.begin(); feature != feature_end; ++feature)
+ {
+ // comparing only feature color, not likelihood. See equality operator for HistogramFeatureGMG
+ if (f == *feature)
+ {
+ return feature->likelihood;
+ }
+ }
+
+ return 0.0; // not in histogram, so return 0.
+}
+
+void BackgroundSubtractorGMG::PixelModelGMG::insertFeature(double learningRate)
+{
+
+ std::list<HistogramFeatureGMG>::iterator feature;
+ std::list<HistogramFeatureGMG>::iterator swap_end;
+ std::list<HistogramFeatureGMG>::iterator last_feature = histogram.end();
+ /*
+ * If feature is in histogram already, add the weights, and move feature to front.
+ * If there are too many features, remove the end feature and push new feature to beginning
+ */
+ if (learningRate == -1.0) // then, this is a training-mode update.
+ {
+ /*
+ * (1) Check if feature already represented in histogram
+ */
+ lastObservedFeature.likelihood = 1.0;
+
+ for (feature = histogram.begin(); feature != last_feature; ++feature)
+ {
+ if (lastObservedFeature == *feature) // feature in histogram
+ {
+ feature->likelihood += lastObservedFeature.likelihood;
+ // now, move feature to beginning of list and break the loop
+ HistogramFeatureGMG tomove = *feature;
+ histogram.erase(feature);
+ histogram.push_front(tomove);
+ return;
+ }
+ }
+ if (numFeatures == maxFeatures)
+ {
+ histogram.pop_back(); // discard oldest feature
+ histogram.push_front(lastObservedFeature);
+ }
+ else
+ {
+ histogram.push_front(lastObservedFeature);
+ ++numFeatures;
+ }
+ }
+ else
+ {
+ /*
+ * (1) Scale entire histogram by scaling factor
+ * (2) Scale input feature.
+ * (3) Check if feature already represented. If so, simply add.
+ * (4) If feature is not represented, remove old feature, distribute weight evenly among existing features, add in new feature.
+ */
+ *this *= (1.0-learningRate);
+ lastObservedFeature.likelihood = learningRate;
+
+ for (feature = histogram.begin(); feature != last_feature; ++feature)
+ {
+ if (lastObservedFeature == *feature) // feature in histogram
+ {
+ lastObservedFeature.likelihood += feature->likelihood;
+ histogram.erase(feature);
+ histogram.push_front(lastObservedFeature);
+ return; // done with the update.
+ }
+ }
+ if (numFeatures == maxFeatures)
+ {
+ histogram.pop_back(); // discard oldest feature
+ histogram.push_front(lastObservedFeature);
+ normalizeHistogram();
+ }
+ else
+ {
+ histogram.push_front(lastObservedFeature);
+ ++numFeatures;
+ }
+ }
+}
+
+BackgroundSubtractorGMG::PixelModelGMG& BackgroundSubtractorGMG::PixelModelGMG::operator *=(const float &rhs)
+{
+ /*
+ * Used to scale histogram by a constant factor
+ */
+ list<HistogramFeatureGMG>::iterator feature;
+ list<HistogramFeatureGMG>::iterator last_feature = histogram.end();
+ for (feature = histogram.begin(); feature != last_feature; ++feature)
+ {
+ feature->likelihood *= rhs;
+ }
+ return *this;
+}
+
+void BackgroundSubtractorGMG::PixelModelGMG::normalizeHistogram()
+{
+ /*
+ * First, calculate the total weight in the histogram
+ */
+ list<HistogramFeatureGMG>::iterator feature;
+ list<HistogramFeatureGMG>::iterator last_feature = histogram.end();
+ double total = 0.0;
+ for (feature = histogram.begin(); feature != last_feature; ++feature)
+ {
+ total += feature->likelihood;
+ }
+
+ /*
+ * Then, if weight is not 0, divide every feature by the total likelihood to re-normalize.
+ */
+ for (feature = histogram.begin(); feature != last_feature; ++feature)
+ {
+ if (total != 0.0)
+ feature->likelihood /= total;
+ }
+}
+
+bool BackgroundSubtractorGMG::HistogramFeatureGMG::operator ==(HistogramFeatureGMG &rhs)
+{
+ CV_Assert(color.size() == rhs.color.size());
+
+ std::vector<size_t>::iterator color_a;
+ std::vector<size_t>::iterator color_b;
+ std::vector<size_t>::iterator color_a_end = this->color.end();
+ std::vector<size_t>::iterator color_b_end = rhs.color.end();
+ for (color_a = color.begin(),color_b =rhs.color.begin();color_a!=color_a_end;++color_a,++color_b)
+ {
+ if (*color_a != *color_b)
+ {
+ return false;
+ }
+ }
+ return true;
+}
+
+
+}
+
#include "opencv2/imgproc/imgproc_c.h"
#include "opencv2/core/internal.hpp"
+#include <list>
+#include <stdint.h>
+
#ifdef HAVE_TEGRA_OPTIMIZATION
#include "opencv2/video/video_tegra.hpp"
#endif
///////////////////////////////////////////////////////////////////////////////////////////////////////////
+CV_INIT_ALGORITHM(BackgroundSubtractorGMG, "BackgroundSubtractor.GMG",
+ obj.info()->addParam(obj, "maxFeatures", obj.maxFeatures,false,0,0,
+ "Maximum number of features to store in histogram. Harsh enforcement of sparsity constraint.");
+ obj.info()->addParam(obj, "learningRate", obj.learningRate,false,0,0,
+ "Adaptation rate of histogram. Close to 1, slow adaptation. Close to 0, fast adaptation, features forgotten quickly.");
+ obj.info()->addParam(obj, "initializationFrames", obj.numInitializationFrames,false,0,0,
+ "Number of frames to use to initialize histograms of pixels.");
+ obj.info()->addParam(obj, "quantizationLevels", obj.quantizationLevels,false,0,0,
+ "Number of discrete colors to be used in histograms. Up-front quantization.");
+ obj.info()->addParam(obj, "backgroundPrior", obj.backgroundPrior,false,0,0,
+ "Prior probability that each individual pixel is a background pixel.");
+ obj.info()->addParam(obj, "smoothingRadius", obj.smoothingRadius,false,0,0,
+ "Radius of smoothing kernel to filter noise from FG mask image.");
+ obj.info()->addParam(obj, "decisionThreshold", obj.decisionThreshold,false,0,0,
+ "Threshold for FG decision rule. Pixel is FG if posterior probability exceeds threshold."));
+
bool initModule_video(void)
{
bool all = true;
all &= !BackgroundSubtractorMOG_info_auto.name().empty();
all &= !BackgroundSubtractorMOG2_info_auto.name().empty();
+ all &= !BackgroundSubtractorGMG_info_auto.name().empty();
return all;
}
--- /dev/null
+/*
+ * BackgroundSubtractorGBH_test.cpp
+ *
+ * Created on: Jun 14, 2012
+ * Author: andrewgodbehere
+ */
+
+#include "test_precomp.hpp"
+
+using namespace cv;
+
+class CV_BackgroundSubtractorTest : public cvtest::BaseTest
+{
+public:
+ CV_BackgroundSubtractorTest();
+protected:
+ void run(int);
+};
+
+CV_BackgroundSubtractorTest::CV_BackgroundSubtractorTest()
+{
+}
+
+/**
+ * This test checks the following:
+ * (i) BackgroundSubtractorGMG can operate with matrices of various types and sizes
+ * (ii) Training mode returns empty fgmask
+ * (iii) End of training mode, and anomalous frame yields every pixel detected as FG
+ */
+void CV_BackgroundSubtractorTest::run(int)
+{
+ int code = cvtest::TS::OK;
+ RNG& rng = ts->get_rng();
+ int type = ((unsigned int)rng)%7; //!< pick a random type, 0 - 6, defined in types_c.h
+ int channels = 1 + ((unsigned int)rng)%4; //!< random number of channels from 1 to 4.
+ int channelsAndType = CV_MAKETYPE(type,channels);
+ int width = 2 + ((unsigned int)rng)%98; //!< Mat will be 2 to 100 in width and height
+ int height = 2 + ((unsigned int)rng)%98;
+
+ Ptr<BackgroundSubtractorGMG> fgbg =
+ Algorithm::create<BackgroundSubtractorGMG>("BackgroundSubtractor.GMG");
+ Mat fgmask;
+
+ if (fgbg == NULL)
+ CV_Error(CV_StsError,"Failed to create Algorithm\n");
+
+ /**
+ * Set a few parameters
+ */
+ fgbg->set("smoothingRadius",7);
+ fgbg->set("decisionThreshold",0.7);
+ fgbg->set("initializationFrames",120);
+
+ /**
+ * Generate bounds for the values in the matrix for each type
+ */
+ uchar maxuc,minuc = 0;
+ char maxc,minc = 0;
+ uint maxui,minui = 0;
+ int maxi,mini = 0;
+ long int maxli,minli = 0;
+ float maxf,minf = 0.0;
+ double maxd,mind = 0.0;
+
+ /**
+ * Max value for simulated images picked randomly in upper half of type range
+ * Min value for simulated images picked randomly in lower half of type range
+ */
+ if (type == CV_8U)
+ {
+ unsigned char half = UCHAR_MAX/2;
+ maxuc = (unsigned char)rng.uniform(half+32,UCHAR_MAX);
+ minuc = (unsigned char)rng.uniform(0,half-32);
+ }
+ else if (type == CV_8S)
+ {
+ char half = CHAR_MAX/2 + CHAR_MIN/2;
+ maxc = (char)rng.uniform(half+32,CHAR_MAX);
+ minc = (char)rng.uniform(CHAR_MIN,half-32);
+ }
+ else if (type == CV_16U)
+ {
+ uint half = UINT_MAX/2;
+ maxui = (unsigned int)rng.uniform((int)half+32,UINT_MAX);
+ minui = (unsigned int)rng.uniform(0,(int)half-32);
+ }
+ else if (type == CV_16S)
+ {
+ int half = INT_MAX/2 + INT_MIN/2;
+ maxi = rng.uniform(half+32,INT_MAX);
+ mini = rng.uniform(INT_MIN,half-32);
+ }
+ else if (type == CV_32S)
+ {
+ long int half = LONG_MAX/2 + LONG_MIN/2;
+ maxli = rng.uniform((int)half+32,(int)LONG_MAX);
+ minli = rng.uniform((int)LONG_MIN,(int)half-32);
+ }
+ else if (type == CV_32F)
+ {
+ float half = FLT_MAX/2.0 + FLT_MIN/2.0;
+ maxf = rng.uniform(half+(float)32.0*FLT_EPSILON,FLT_MAX);
+ minf = rng.uniform(FLT_MIN,half-(float)32.0*FLT_EPSILON);
+ }
+ else if (type == CV_64F)
+ {
+ double half = DBL_MAX/2.0 + DBL_MIN/2.0;
+ maxd = rng.uniform(half+(double)32.0*DBL_EPSILON,DBL_MAX);
+ mind = rng.uniform(DBL_MIN,half-(double)32.0*DBL_EPSILON);
+ }
+
+ Mat simImage = Mat::zeros(height,width,channelsAndType);
+ const uint numLearningFrames = 120;
+ for (uint i = 0; i < numLearningFrames; ++i)
+ {
+ /**
+ * Genrate simulated "image" for any type. Values always confined to upper half of range.
+ */
+ if (type == CV_8U)
+ {
+ rng.fill(simImage,RNG::UNIFORM,(unsigned char)(minuc/2+maxuc/2),maxuc);
+ if (i == 0)
+ fgbg->initializeType(simImage,minuc,maxuc);
+ }
+ else if (type == CV_8S)
+ {
+ rng.fill(simImage,RNG::UNIFORM,(char)(minc/2+maxc/2),maxc);
+ if (i==0)
+ fgbg->initializeType(simImage,minc,maxc);
+ }
+ else if (type == CV_16U)
+ {
+ rng.fill(simImage,RNG::UNIFORM,(unsigned int)(minui/2+maxui/2),maxui);
+ if (i==0)
+ fgbg->initializeType(simImage,minui,maxui);
+ }
+ else if (type == CV_16S)
+ {
+ rng.fill(simImage,RNG::UNIFORM,(int)(mini/2+maxi/2),maxi);
+ if (i==0)
+ fgbg->initializeType(simImage,mini,maxi);
+ }
+ else if (type == CV_32F)
+ {
+ rng.fill(simImage,RNG::UNIFORM,(float)(minf/2.0+maxf/2.0),maxf);
+ if (i==0)
+ fgbg->initializeType(simImage,minf,maxf);
+ }
+ else if (type == CV_32S)
+ {
+ rng.fill(simImage,RNG::UNIFORM,(long int)(minli/2+maxli/2),maxli);
+ if (i==0)
+ fgbg->initializeType(simImage,minli,maxli);
+ }
+ else if (type == CV_64F)
+ {
+ rng.fill(simImage,RNG::UNIFORM,(double)(mind/2.0+maxd/2.0),maxd);
+ if (i==0)
+ fgbg->initializeType(simImage,mind,maxd);
+ }
+
+ /**
+ * Feed simulated images into background subtractor
+ */
+ (*fgbg)(simImage,fgmask);
+ Mat fullbg = Mat::zeros(Size(simImage.cols,simImage.rows),CV_8U);
+ fgbg->updateBackgroundModel(fullbg);
+
+ //! fgmask should be entirely background during training
+ code = cvtest::cmpEps2( ts, fgmask, fullbg, 0, false, "The training foreground mask" );
+ if (code < 0)
+ ts->set_failed_test_info( code );
+ }
+ //! generate last image, distinct from training images
+ if (type == CV_8U)
+ rng.fill(simImage,RNG::UNIFORM,minuc,minuc);
+ else if (type == CV_8S)
+ rng.fill(simImage,RNG::UNIFORM,minc,minc);
+ else if (type == CV_16U)
+ rng.fill(simImage,RNG::UNIFORM,minui,minui);
+ else if (type == CV_16S)
+ rng.fill(simImage,RNG::UNIFORM,mini,mini);
+ else if (type == CV_32F)
+ rng.fill(simImage,RNG::UNIFORM,minf,minf);
+ else if (type == CV_32S)
+ rng.fill(simImage,RNG::UNIFORM,minli,minli);
+ else if (type == CV_64F)
+ rng.fill(simImage,RNG::UNIFORM,mind,mind);
+
+ (*fgbg)(simImage,fgmask);
+ //! now fgmask should be entirely foreground
+ Mat fullfg = 255*Mat::ones(Size(simImage.cols,simImage.rows),CV_8U);
+ code = cvtest::cmpEps2( ts, fgmask, fullfg, 255, false, "The final foreground mask" );
+ if (code < 0)
+ {
+ ts->set_failed_test_info( code );
+ }
+
+}
+
+TEST(VIDEO_BGSUBGMG, accuracy) { CV_BackgroundSubtractorTest test; test.safe_run(); }
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/imgproc/imgproc_c.h"
#include "opencv2/video/tracking.hpp"
+#include "opencv2/video/background_segm.hpp"
#include "opencv2/highgui/highgui.hpp"
#include <iostream>
--- /dev/null
+/*
+ * FGBGTest.cpp
+ *
+ * Created on: May 7, 2012
+ * Author: Andrew B. Godbehere
+ */
+
+#include <opencv2/opencv.hpp>
+#include <iostream>
+#include <sstream>
+
+using namespace cv;
+
+static void help()
+{
+ std::cout <<
+ "\nA program demonstrating the use and capabilities of a particular BackgroundSubtraction\n"
+ "algorithm described in A. Godbehere, A. Matsukawa, K. Goldberg, \n"
+ "\"Visual Tracking of Human Visitors under Variable-Lighting Conditions for a Responsive\n"
+ "Audio Art Installation\", American Control Conference, 2012, used in an interactive\n"
+ "installation at the Contemporary Jewish Museum in San Francisco, CA from March 31 through\n"
+ "July 31, 2011.\n"
+ "Call:\n"
+ "./BackgroundSubtractorGMG_sample\n"
+ "Using OpenCV version " << CV_VERSION << "\n"<<std::endl;
+}
+
+int main(int argc, char** argv)
+{
+ help();
+ setUseOptimized(true);
+ setNumThreads(8);
+
+ Ptr<BackgroundSubtractorGMG> fgbg = Algorithm::create<BackgroundSubtractorGMG>("BackgroundSubtractor.GMG");
+ if (fgbg == NULL)
+ {
+ CV_Error(CV_StsError,"Failed to create Algorithm\n");
+ }
+ fgbg->set("smoothingRadius",7);
+ fgbg->set("decisionThreshold",0.7);
+
+ VideoCapture cap;
+ if( argc > 1 )
+ cap.open(argv[1]);
+ else
+ cap.open(0);
+
+ if (!cap.isOpened())
+ {
+ std::cout << "error: cannot read video. Try moving video file to sample directory.\n";
+ return -1;
+ }
+
+ Mat img, downimg, downimg2, fgmask, upfgmask, posterior, upposterior;
+
+ bool first = true;
+ namedWindow("posterior");
+ namedWindow("fgmask");
+ namedWindow("FG Segmentation");
+ int i = 0;
+ for (;;)
+ {
+ std::stringstream txt;
+ txt << "frame: ";
+ txt << i++;
+
+ cap >> img;
+ putText(img,txt.str(),Point(20,40),FONT_HERSHEY_SIMPLEX,0.8,Scalar(1.0,0.0,0.0));
+
+ resize(img,downimg,Size(160,120),0,0,INTER_NEAREST); // Size(cols, rows) or Size(width,height)
+ if (first)
+ {
+ fgbg->initializeType(downimg,0,255);
+ first = false;
+ }
+ if (img.empty())
+ {
+ return 0;
+ }
+ (*fgbg)(downimg,fgmask);
+ fgbg->updateBackgroundModel(Mat::zeros(120,160,CV_8U));
+ fgbg->getPosteriorImage(posterior);
+ resize(fgmask,upfgmask,Size(640,480),0,0,INTER_NEAREST);
+ Mat coloredFG = Mat::zeros(480,640,CV_8UC3);
+ coloredFG.setTo(Scalar(100,100,0),upfgmask);
+
+ resize(posterior,upposterior,Size(640,480),0,0,INTER_NEAREST);
+ imshow("posterior",upposterior);
+ imshow("fgmask",upfgmask);
+ resize(img, downimg2, Size(640, 480),0,0,INTER_LINEAR);
+ imshow("FG Segmentation",downimg2 + coloredFG);
+ int c = waitKey(30);
+ if( c == 'q' || c == 'Q' || (c & 255) == 27 )
+ break;
+ }
+}
+