Fix monodepth2, add demoDepth:

- Fix monodepth2 network, now works with both cuDNN and tensorRT
- Substitute cuDNN ELU with tkDNN one
- add DepthNN class
- add demoDepth demo, now only works with monodepth2 net

Signed-off-by: Micaela Verucchi <micaelaverucchi@gmail.com>
               Francesco Gatti <gattifrancesco@hotmail.it>

demo/demo/demoDepth.cpp

@@ -0,0 +1,103 @@
+#include <iostream>
+#include <signal.h>
+#include <stdlib.h>     /* srand, rand */
+//#include <unistd.h>
+#include <mutex>
+
+#include "tkDNN/DepthNN.h"
+
+bool gRun;
+
+void sig_handler(int signo) {
+    std::cout<<"request gateway stop\n";
+    gRun = false;
+}
+
+int main(int argc, char *argv[]) {
+
+    signal(SIGINT, sig_handler);
+
+    std::string net = "monodepth2_fp32.rt";
+    if(argc > 1)
+        net = argv[1]; 
+    #ifdef __linux__ 
+        std::string input = "../demo/yolo_test.mp4";
+    #elif _WIN32
+        std::string input = "..\\..\\..\\demo\\yolo_test.mp4";
+    #endif
+    if(argc > 2)
+        input = argv[2]; 
+    bool show = true;
+    if(argc > 3)
+        show = atoi(argv[3]); 
+    bool save = true;
+    if(argc > 4)
+        save = atoi(argv[4]); 
+
+    std::cout   <<"Net settings - net: "<< net
+                <<"\n"; 
+    std::cout   <<"Demo settings - input: "<< input
+                <<", show: "<< show
+                <<", save: "<< save<<"\n\n"; 
+    
+    tk::dnn::DepthNN depthNN;  
+
+    // create depth network 
+    int n_batch = 1;
+    depthNN.init(net, n_batch);
+
+    // open video stream
+    cv::VideoCapture cap(input);
+    if(!cap.isOpened())
+        gRun = false; 
+    else
+        std::cout<<"camera started\n";
+
+    cv::VideoWriter resultVideo;
+    if(save) {
+        int w = cap.get(cv::CAP_PROP_FRAME_WIDTH);
+        int h = cap.get(cv::CAP_PROP_FRAME_HEIGHT);
+        resultVideo.open("result.mp4", cv::VideoWriter::fourcc('M','P','4','V'), 30, cv::Size(w, h));
+    }
+
+    if(show)
+        cv::namedWindow("depth", cv::WINDOW_NORMAL);
+
+    cv::Mat frame;
+    std::vector<cv::Mat> batch_frame;
+    std::vector<cv::Mat> batch_dnn_input;
+
+    // start detection loop
+    gRun = true;
+    while(gRun) {
+        batch_dnn_input.clear();
+        batch_frame.clear();
+
+        //read frame
+        cap >> frame; 
+        if(!frame.data) 
+            break;
+        batch_frame.push_back(frame);
+        batch_dnn_input.push_back(frame.clone());
+    
+        //inference
+        depthNN.update(batch_dnn_input, 1);
+        if(show){
+            cv::imshow("depth", depthNN.depthMats[0]);
+            cv::waitKey(1);
+
+        }
+    }
+
+    std::cout<<"detection end\n";   
+    
+    double mean = 0; 
+    std::cout<<COL_GREENB<<"\n\nTime stats depth:\n";
+    std::cout<<"Min: "<<*std::min_element(depthNN.stats.begin(), depthNN.stats.end())<<" ms\n";    
+    std::cout<<"Max: "<<*std::max_element(depthNN.stats.begin(), depthNN.stats.end())<<" ms\n";    
+    for(int i=0; i<depthNN.stats.size(); i++) mean += depthNN.stats[i]; mean /= depthNN.stats.size();
+    std::cout<<"Avg: "<<mean<<" ms\t"<<1000/(mean)<<" FPS\n";   
+
+    return 0;
+}
+