server/dilatometer.c

   1 /**
   2  * @file dilatometer.c
   3  * @purpose Implementation of dilatometer related functions
   4  */
   5
   6 #include "cv.h"
   7 #include "highgui_c.h"
   8 #include "dilatometer.h"
   9 #include <math.h>
  10
  11 /*-------------------------------------------------------------------
  12
  13 compile with:
  14 -I/usr/include/opencv -I/usr/include/opencv2/highgui -L/usr/lib -lopencv_highgui -lopencv_core -lopencv_ml -lopencv_imgproc -std=c99 -Wall -pedantic
  15
  16 --------------------------------------------------------------------*/
  17
  18 /** Buffer for storing image data. Stored as a  **/
  19 static CvMat * g_data = NULL;
  20
  21
  22 /** Camera capture pointer **/
  23 static CvCapture * g_capture = NULL;
  24
  25
  26 /**
  27  * Initialise the dilatometer
  28  */
  29 void Dilatometer_Init()
  30 {
  31
  32         // Make an initial reading (will allocate memory the first time only).
  33         Dilatometer_Read(1);
  34 }
  35
  36 /**
  37  * Cleanup Interferometer stuff
  38  */
  39 void Dilatometer_Cleanup()
  40 {
  41         if (g_data != NULL)
  42                 cvReleaseMat(&g_data);
  43
  44         if (g_capture != NULL)
  45                 cvReleaseCapture(&g_capture);
  46
  47 }
  48
  49 /**
  50  * Get an image from the Dilatometer
  51  */
  52 static void Dilatometer_GetImage()
  53 {
  54         //Need to supply test image
  55
  56         //Need to implement camera
  57 }
  58 /**
  59  * Read the dilatometer; gets the latest image, processes it, THEN DOES WHAT
  60  * @param samples - Number of rows to scan (increasing will slow down performance!)
  61  * @returns the average width of the can
  62  */
  63 double Dilatometer_Read(int samples)
  64 {
  65         //Get the latest image
  66         Dilatometer_GetImage();
  67
  68         int width = g_data->cols;
  69         int height = g_data->rows;
  70         // If the number of samples is greater than the image height, sample every row
  71         if( samples > height)
  72         {
  73                 Log(LOGNOTE, "Number of samples is greater than the dilatometer image height, sampling every row instead.\n");
  74                 samples = height;
  75         }
  76
  77         // Stores the width of the can at different sample locations. Not necessary unless we want to store this information
  78         //double widths[samples];
  79         // The average width of the can
  80         double average_width;
  81         int sample_height;
  82         for (int i=0; i<samples; i++)
  83         {
  84                 // Contains the locations of the 2 edges
  85                 double edges[2] = {0};
  86                 int pos = 0;    // Position in the edges array (start at left edge)
  87                 int num = 0;    // Keep track of the number of columns above threshold
  88
  89                 // Determine the position in the rows to find the edges.
  90                 sample_height = ceil(height * (i + 1) / samples) -1;
  91
  92                 for ( int col = 0; col < width; col++)
  93                 {
  94                         if ( CV_MAT_ELEM( *g_data, double, col, sample_height) > THRES)
  95                         {
  96                                 edges[pos] += col;
  97                                 num++;
  98                         }
  99                         // If num > 0 and we're not above threshold, we have left the threshold of the edge
 100                         else if( num > 0);
 101                         {
 102                                 // Find the mid point of the edge
 103                                 edges[pos] /= num;
 104                                 if( edges[1] == 0)
 105                                 {
 106                                         pos = 1;        // Move to the right edge
 107                                         num = 0;
 108                                 }
 109                                 else
 110                                         break;          // Exit the for loop
 111                         }
 112                 }
 113                 // Determine the width of the can at this row
 114                 //widths[i] = edges[1] - edges[0];
 115                 average_width += (edges[1] - edges[0]);
 116         }
 117                 average_width /= samples;
 118                 return average_width;
 119 }
 120