"SimpleFlow" optical flow estimation algorithm (GSoC project) declaration in includes, implementation, usage example, test

2012-08-19 15:56:19 +04:00
parent 2367a195c5
commit c77d099018
6 changed files with 1235 additions and 1 deletions
--- a/samples/cpp/simpleflow_demo.cpp
+++ b/samples/cpp/simpleflow_demo.cpp
@@ -0,0 +1,96 @@
+#include "opencv2/video/tracking.hpp"
+#include "opencv2/imgproc/imgproc.hpp"
+#include "opencv2/highgui/highgui.hpp"
+
+#include <cstdio>
+#include <iostream>
+
+using namespace cv;
+using namespace std;
+
+static void help()
+{
+    // print a welcome message, and the OpenCV version
+    printf("This is a demo of SimpleFlow optical flow algorithm,\n"
+           "Using OpenCV version %s\n\n", CV_VERSION);
+
+    printf("Usage: simpleflow_demo frame1 frame2 output_flow"
+           "\nApplication will write estimated flow "
+           "\nbetween 'frame1' and 'frame2' in binary format"
+           "\ninto file 'output_flow'"
+           "\nThen one can use code from http://vision.middlebury.edu/flow/data/"
+           "\nto convert flow in binary file to image\n");
+}
+
+// binary file format for flow data specified here:
+// http://vision.middlebury.edu/flow/data/
+static void writeOpticalFlowToFile(const Mat& u, const Mat& v, FILE* file) {
+  int cols = u.cols;
+  int rows = u.rows;
+  
+  fprintf(file, "PIEH");
+   
+  if (fwrite(&cols, sizeof(int), 1, file) != 1 ||
+      fwrite(&rows, sizeof(int), 1, file) != 1) {
+    fprintf(stderr, "writeOpticalFlowToFile : problem writing header\n");
+    exit(1);
+  }
+
+  for (int i= 0; i < u.rows; ++i) {
+    for (int j = 0; j < u.cols; ++j) {
+      float uPoint = u.at<double>(i, j);
+      float vPoint = v.at<double>(i, j);
+
+      if (fwrite(&uPoint, sizeof(float), 1, file) != 1 ||
+          fwrite(&vPoint, sizeof(float), 1, file) != 1) {
+        fprintf(stderr, "writeOpticalFlowToFile : problem writing data\n");
+        exit(1);
+      }
+    }
+  }
+}
+int main(int argc, char** argv) {
+    help();
+
+    if (argc < 4) {
+      fprintf(stderr, "Wrong number of command line arguments : %d (expected %d)\n", argc, 4);
+      exit(1);
+    }
+    
+    Mat frame1 = imread(argv[1]);
+    Mat frame2 = imread(argv[2]);
+
+    if (frame1.empty() || frame2.empty()) {
+      fprintf(stderr, "simpleflow_demo : Images cannot be read\n");
+      exit(1);
+    }
+
+    if (frame1.rows != frame2.rows && frame1.cols != frame2.cols) {
+      fprintf(stderr, "simpleflow_demo : Images should be of equal sizes\n");
+      exit(1);
+    }
+
+    if (frame1.type() != 16 || frame2.type() != 16) {
+      fprintf(stderr, "simpleflow_demo : Images should be of equal type CV_8UC3\n");
+      exit(1);
+    }
+
+    printf("simpleflow_demo : Read two images of size [rows = %d, cols = %d]\n", 
+           frame1.rows, frame1.cols);
+
+    Mat flowX, flowY;
+
+    calcOpticalFlowSF(frame1, frame2, 
+                      flowX, flowY,
+                      3, 2, 4, 4.1, 25.5, 18, 55.0, 25.5, 0.35, 18, 55.0, 25.5, 10);
+
+  FILE* file = fopen(argv[3], "wb");
+  if (file == NULL) {
+    fprintf(stderr, "simpleflow_demo : Unable to open file '%s' for writing\n", argv[3]); 
+    exit(1);
+  }
+  printf("simpleflow_demo : Writing to file\n");
+  writeOpticalFlowToFile(flowX, flowY, file);
+  fclose(file);
+  return 0;
+}