added retina code tutorial

samples/cpp/tutorial_code/contrib/retina_tutorial.cpp

+//============================================================================
+// Name        : retina_tutorial.cpp
+// Author      : Alexandre Benoit, benoit.alexandre.vision@gmail.com
+// Version     : 0.1
+// Copyright   : LISTIC/GIPSA French Labs, july 2012
+// Description : Gipsa/LISTIC Labs retina demo in C++, Ansi-style
+//============================================================================
+
+#include <iostream>
+#include <cstring>
+
+#include "opencv2/opencv.hpp"
+
+static void help(std::string errorMessage)
+{
+    std::cout<<"Program init error : "<<errorMessage<<std::endl;
+    std::cout<<"\nProgram call procedure : retinaDemo [processing mode] [Optional : media target] [Optional LAST parameter: \"log\" to activate retina log sampling]"<<std::endl;
+    std::cout<<"\t[processing mode] :"<<std::endl;
+    std::cout<<"\t -image : for still image processing"<<std::endl;
+    std::cout<<"\t -video : for video stream processing"<<std::endl;
+    std::cout<<"\t[Optional : media target] :"<<std::endl;
+    std::cout<<"\t if processing an image or video file, then, specify the path and filename of the target to process"<<std::endl;
+    std::cout<<"\t leave empty if processing video stream coming from a connected video device"<<std::endl;
+    std::cout<<"\t[Optional : activate retina log sampling] : an optional last parameter can be specified for retina spatial log sampling"<<std::endl;
+    std::cout<<"\t set \"log\" without quotes to activate this sampling, output frame size will be divided by 4"<<std::endl;
+    std::cout<<"\nExamples:"<<std::endl;
+    std::cout<<"\t-Image processing : ./retinaDemo -image lena.jpg"<<std::endl;
+    std::cout<<"\t-Image processing with log sampling : ./retinaDemo -image lena.jpg log"<<std::endl;
+    std::cout<<"\t-Video processing : ./retinaDemo -video myMovie.mp4"<<std::endl;
+    std::cout<<"\t-Live video processing : ./retinaDemo -video"<<std::endl;
+    std::cout<<"\nPlease start again with new parameters"<<std::endl;
+    std::cout<<"****************************************************"<<std::endl;
+    std::cout<<" NOTE : this program generates the default retina parameters file 'RetinaDefaultParameters.xml'"<<std::endl;
+    std::cout<<" => you can use this to fine tune parameters and load them if you save to file 'RetinaSpecificParameters.xml'"<<std::endl;
+}
+
+int main(int argc, char* argv[]) {
+    // welcome message
+    std::cout<<"****************************************************"<<std::endl;
+    std::cout<<"* Retina demonstration : demonstrates the use of is a wrapper class of the Gipsa/Listic Labs retina model."<<std::endl;
+    std::cout<<"* This demo will try to load the file 'RetinaSpecificParameters.xml' (if exists).\nTo create it, copy the autogenerated template 'RetinaDefaultParameters.xml'.\nThen twaek it with your own retina parameters."<<std::endl;
+    // basic input arguments checking
+    if (argc<2)
+    {
+        help("bad number of parameter");
+        return -1;
+    }
+
+    bool useLogSampling = !strcmp(argv[argc-1], "log"); // check if user wants retina log sampling processing
+
+    std::string inputMediaType=argv[1];
+
+    // declare the retina input buffer... that will be fed differently in regard of the input media
+    cv::Mat inputFrame;
+    cv::VideoCapture videoCapture; // in case a video media is used, its manager is declared here
+
+    //////////////////////////////////////////////////////////////////////////////
+    // checking input media type (still image, video file, live video acquisition)
+    if (!strcmp(inputMediaType.c_str(), "-image") && argc >= 3)
+    {
+        std::cout<<"RetinaDemo: processing image "<<argv[2]<<std::endl;
+        // image processing case
+        inputFrame = cv::imread(std::string(argv[2]), 1); // load image in RGB mode
+    }else
+        if (!strcmp(inputMediaType.c_str(), "-video"))
+        {
+            if (argc == 2 || (argc == 3 && useLogSampling)) // attempt to grab images from a video capture device
+            {
+                videoCapture.open(0);
+            }else// attempt to grab images from a video filestream
+            {
+                std::cout<<"RetinaDemo: processing video stream "<<argv[2]<<std::endl;
+                videoCapture.open(argv[2]);
+            }
+
+            // grab a first frame to check if everything is ok
+            videoCapture>>inputFrame;
+        }else
+        {
+            // bad command parameter
+            help("bad command parameter");
+            return -1;
+        }
+
+    if (inputFrame.empty())
+    {
+        help("Input media could not be loaded, aborting");
+        return -1;
+    }
+
+
+    //////////////////////////////////////////////////////////////////////////////
+    // Program start in a try/catch safety context (Retina may throw errors)
+    try
+    {
+        // create a retina instance with default parameters setup, uncomment the initialisation you wanna test
+        cv::Ptr<cv::Retina> myRetina;
+
+        // if the last parameter is 'log', then activate log sampling (favour foveal vision and subsamples peripheral vision)
+        if (useLogSampling)
+        {
+                        myRetina = new cv::Retina(inputFrame.size(), true, cv::RETINA_COLOR_BAYER, true, 2.0, 10.0);
+        }
+        else// -> else allocate "classical" retina :
+            myRetina = new cv::Retina(inputFrame.size());
+
+        // save default retina parameters file in order to let you see this and maybe modify it and reload using method "setup"
+        myRetina->write("RetinaDefaultParameters.xml");
+
+        // load parameters if file exists
+        myRetina->setup("RetinaSpecificParameters.xml");
+
+	// reset all retina buffers (imagine you close your eyes for a long time)
+        myRetina->clearBuffers();
+
+        // declare retina output buffers
+        cv::Mat retinaOutput_parvo;
+        cv::Mat retinaOutput_magno;
+
+        // processing loop with no stop condition
+        while(true)
+        {
+            // if using video stream, then, grabbing a new frame, else, input remains the same
+            if (videoCapture.isOpened())
+                videoCapture>>inputFrame;
+
+            // run retina filter on the loaded input frame
+            myRetina->run(inputFrame);
+            // Retrieve and display retina output
+            myRetina->getParvo(retinaOutput_parvo);
+            myRetina->getMagno(retinaOutput_magno);
+            cv::imshow("retina input", inputFrame);
+            cv::imshow("Retina Parvo", retinaOutput_parvo);
+            cv::imshow("Retina Magno", retinaOutput_magno);
+            cv::waitKey(10);
+        }
+    }catch(cv::Exception e)
+    {
+        std::cerr<<"Error using Retina : "<<e.what()<<std::endl;
+    }
+
+    // Program end message
+    std::cout<<"Retina demo end"<<std::endl;
+
+    return 0;
+}
+