Add ocl retina sample.

samples/ocl/CMakeLists.txt

 SET(OPENCV_OCL_SAMPLES_REQUIRED_DEPS opencv_core opencv_flann opencv_imgproc opencv_highgui
                                      opencv_ml opencv_video opencv_objdetect opencv_features2d
                                      opencv_calib3d opencv_legacy opencv_contrib opencv_ocl
-                                     opencv_nonfree)
+                                     opencv_nonfree opencv_bioinspired)
 
 ocv_check_dependencies(${OPENCV_OCL_SAMPLES_REQUIRED_DEPS})
 

samples/ocl/retina_ocl.cpp

+#include <iostream>
+#include <cstring>
+
+#include "opencv2/core.hpp"
+#include "opencv2/imgproc.hpp"
+#include "opencv2/highgui.hpp"
+#include "opencv2/ocl.hpp"
+#include "opencv2/bioinspired.hpp"
+
+using namespace cv;
+using namespace cv::ocl;
+using namespace std;
+
+const int total_loop_count = 50;
+
+static void help(CommandLineParser cmd, const String& errorMessage)
+{
+    cout << errorMessage << endl;
+    cout << "Avaible options:" << endl;
+    cmd.printMessage();
+}
+
+int main(int argc, char* argv[])
+{
+    //set this to save kernel compile time from second time you run
+    ocl::setBinaryDiskCache();
+    const char* keys =
+        "{ h   | help     | false           | print help message }"
+        "{ c   | use_cpp  | false           | use cpp (original version) or gpu(OpenCL) to process the image }"
+        "{ i   | image    | cat.jpg         | specify the input image }";
+
+    CommandLineParser cmd(argc, argv, keys);
+
+    if(cmd.get<bool>("help"))
+    {
+        help(cmd, "Usage: ./retina_ocl [options]");
+        return EXIT_FAILURE;
+    }
+
+    String fname = cmd.get<String>("i");
+    bool useCPP = cmd.get<bool>("c");
+
+    cv::Mat input = imread(fname);
+    if(input.empty())
+    {
+        help(cmd, fname + " not found!");
+        return EXIT_FAILURE;
+    }
+    //////////////////////////////////////////////////////////////////////////////
+    // 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::bioinspired::Retina> oclRetina;
+        cv::Ptr<cv::bioinspired::Retina> retina;
+        // declare retina output buffers
+        cv::ocl::oclMat retina_parvo_ocl;
+        cv::ocl::oclMat retina_magno_ocl;
+        cv::Mat retina_parvo;
+        cv::Mat retina_magno;
+
+        if(useCPP)
+        {
+            retina = cv::bioinspired::createRetina(input.size());
+            retina->clearBuffers();
+        }
+        else
+        {
+            oclRetina = cv::bioinspired::createRetina_OCL(input.size());
+            oclRetina->clearBuffers();
+        }
+
+        int64 temp_time = 0, total_time = 0;
+
+        int loop_counter = 0;
+        static bool initialized = false;
+        for(; loop_counter <= total_loop_count; ++loop_counter)
+        {
+            if(useCPP)
+            {
+                temp_time = cv::getTickCount();
+                retina->run(input);
+                retina->getParvo(retina_parvo);
+                retina->getMagno(retina_magno);
+            }
+            else
+            {
+                cv::ocl::oclMat input_ocl(input);
+                temp_time = cv::getTickCount();
+                oclRetina->run(input_ocl);
+                oclRetina->getParvo(retina_parvo_ocl);
+                oclRetina->getMagno(retina_magno_ocl);
+            }
+            // will not count the first loop, which is considered as warm-up period
+            if(initialized)
+            {
+                temp_time = (cv::getTickCount() - temp_time);
+                total_time += temp_time;
+                printf("Frame id %2d: %3.4fms\n", loop_counter, (double)temp_time / cv::getTickFrequency() * 1000.0);
+            }
+            else
+            {
+                initialized = true;
+            }
+            if(!useCPP)
+            {
+                retina_parvo = retina_parvo_ocl;
+                retina_magno = retina_magno_ocl;
+            }
+            cv::imshow("retina input", input);
+            cv::imshow("Retina Parvo", retina_parvo);
+            cv::imshow("Retina Magno", retina_magno);
+            cv::waitKey(10);
+        }
+        printf("Average: %.4fms\n", (double)total_time / total_loop_count / cv::getTickFrequency() * 1000.0);
+    }
+    catch(cv::Exception e)
+    {
+        std::cerr << "Error using Retina : " << e.what() << std::endl;
+    }
+    // Program end message
+    std::cout << "Retina demo end" << std::endl;
+    return EXIT_SUCCESS;
+}