git.maemo.org Git - opencv/blob - apps/Hawk/demos/DemHist.c

   1 /************************************************************************************\r
   2 *\r
   3 *\r
   4 *  This program is demonstration for histogram and functions: cvCreateHist(), \r
   5 *  cvSetHistThresh(), cvCalcHist(), cvNormalizeHist(), cvQueryHistValue_1D(),\r
   6 *  cvReleaseHist() and cvCopyHist().\r
   7 *\r
   8 *\r
   9 *  Trackbar specify normalize factor for histogram value.\r
  10 *\r
  11 *\r
  12 *\r
  13 *  Autor:  Denis Burenkov\r
  14 *\r
  15 *\r
  16 ************************************************************************************/\r
  17 \r
  18 #define DIMENSION_SIZE   50\r
  19 \r
  20 char file_name[] = "EXPO0002.bmp";\r
  21 \r
  22 char wndname01[] = "Source image";\r
  23 char wndname02[] = "Histogram";\r
  24 char barname01[] = "Normalize factor";\r
  25 int dims[1] = {DIMENSION_SIZE};\r
  26 float thresh[1][2] = { {0, 255} };\r
  27 float* pthresh[1] = { thresh[0] };\r
  28 int slider_pos[1] = {2000};\r
  29 \r
  30 // Load the source image. HighGUI use.\r
  31 IPLIMAGE image01 = load_iplimage( file_name );\r
  32 \r
  33 if(image01==NULL)\r
  34 {\r
  35     printf("File '%s' not found.\n", file_name);\r
  36     \r
  37 }\r
  38 \r
  39 // Create the destination images. HighGUI use.\r
  40 IplImage * image02 = cvCreateImage( cvSize(image01->width,image01->height),\r
  41                                     IPL_DEPTH_8U,\r
  42                                     1);\r
  43 IplImage * image03 = cvCreateImage( cvSize(image01->width,image01->height),\r
  44                                     IPL_DEPTH_8U,\r
  45                                     3);\r
  46                                     \r
  47 // Make onechannel image.\r
  48 cvCvtColor(image01,image02, CV_BGR2GRAY);\r
  49 \r
  50 \r
  51 // Created histogram headers. OpenCV use.\r
  52 CvHistogram* hist01 = cvCreateHist(1,               // Histogram dimension number.\r
  53                                    dims,            // Dimension size array.\r
  54                                    CV_HIST_ARRAY,   // Histogram type.\r
  55                                    0, 1);  \r
  56                                    \r
  57 CvHistogram* hist02 = cvCreateHist(1, dims, CV_HIST_ARRAY, 0, 1);\r
  58 \r
  59 \r
  60 // Set bounds of histogram bins. The histogram or back project are calculated \r
  61 // if within the specified boundaries. \r
  62 // OpenCV use.\r
  63 cvSetHistBinRanges( hist01,  // Destination histogram.\r
  64                  pthresh, 1); // Pointer to the array of threshold values.\r
  65 \r
  66 \r
  67 \r
  68 // Create windows. HighGUI use.\r
  69 named_window( wndname01, 0 );\r
  70 named_window( wndname02, 0 );\r
  71 \r
  72 // Show the image. HighGUI use.\r
  73 show_iplimage( wndname01, image02 );\r
  74 \r
  75 \r
  76 // Calculated the histogram. OpenCV use. \r
  77 cvCalcHist( &image02,  // Source images.\r
  78             hist01,    // Pointer to the histogram.\r
  79             0, 0 );       // Clear flag.\r
  80 \r
  81 \r
  82 // Define trackbar callback functon. This function normalize and draw histogram.\r
  83 void ShowHist(int h)\r
  84 {\r
  85     int i;\r
  86     CvPoint pt1, pt2;\r
  87     pt2.x=0;\r
  88     pt2.y=image01->height;\r
  89     \r
  90     // Clear image. OpenCV use.\r
  91     //cvFillImage(image03,0); //old code\r
  92     cvSetZero(image03);\r
  93     \r
  94     \r
  95     // Copy histogram to save data. OpenCV use.\r
  96     cvCopyHist(hist01,    // Source histogram.\r
  97                &hist02);  // Pointer to destination histogram.\r
  98     \r
  99     // Normalize histogram.\r
 100     // The sum of histogram bins becomes equal to factor.\r
 101     // OpenCV use.\r
 102     cvNormalizeHist( hist02,           //Pointer to the histogram.\r
 103                      slider_pos[0] );  //Normalize factor.\r
 104     \r
 105     // Draw histogram.\r
 106     for(i=0; i<DIMENSION_SIZE; i++)\r
 107     {\r
 108         pt1.x=pt1.x+5;\r
 109         pt1.y=image01->height -\r
 110          cvQueryHistValue_1D(hist02, // Pointer to the source histogram.\r
 111                              i);     // Address of a required element.\r
 112          // The function cvQueryHistValue_1D() returns the\r
 113          // value of the specified histogram bin.\r
 114          \r
 115         pt2.x=pt2.x+5;\r
 116         \r
 117         cvLine(image03, pt1, pt2, CV_RGB(200,0,0), 2, 8);\r
 118     }\r
 119     \r
 120     // Show the image. HighGUI use.\r
 121     show_iplimage( wndname02, image03 );\r
 122 }\r
 123 \r
 124 \r
 125 \r
 126 ShowHist(0);\r
 127 \r
 128 // Create toolbars. HighGUI use.\r
 129 create_trackbar(barname01, \r
 130                 wndname02,\r
 131                 &slider_pos[0],\r
 132                 4000,\r
 133                 ShowHist);\r
 134 \r
 135 // Wait for a key stroke; the same function arranges events processing                \r
 136 wait_key(0);\r
 137 cvReleaseImage(&image01);\r
 138 cvReleaseImage(&image02);\r
 139 cvReleaseImage(&image03);\r
 140 \r
 141 destroy_window(wndname01);\r
 142 destroy_window(wndname02);\r
 143 \r
 144 cvReleaseHist( &hist01 );\r
 145 cvReleaseHist( &hist02 );\r
 146 \r
 147 //                                    END