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 // test positions
  12 static double test_left, test_right;
  13
  14 /** Buffer for storing image data. Stored as a  **/
  15 static CvMat * g_data = NULL;
  16
  17
  18 /** Camera capture pointer **/
  19 static CvCapture * g_capture = NULL;
  20
  21 /**
  22  * Create a test image using left as left edge and right as right edge positions
  23  */
  24 void Dilatometer_TestImage()
  25 {
  26
  27         CvMat *g_dataRGB;
  28         g_dataRGB = cvCreateMat(480, 640, CV_8UC3);
  29         //Make sure left and right positions are sane
  30         if( test_left < 0)
  31                 test_left = 0;
  32         if( test_right > 639)
  33                 test_right = 639;
  34         if( test_left > test_right)
  35         {
  36                 int tmp = test_right;
  37                 test_right = test_left;
  38                 test_left = tmp;
  39         }
  40
  41         for( int x = 0; x < 640; ++x)
  42         {
  43                 for (int y = 0; y < 480; ++y)
  44                 {
  45                         CvScalar s;
  46                         for( int i = 0; i < 3; ++i)
  47                         {
  48                                 s.val[i]  =  220 + (rand() % 1000) * 1e-2 - (rand() % 1000) * 1e-2;
  49                                 // Produce an exponential decay around left edge
  50                                 if( x < test_left)
  51                                         s.val[i] *= exp( (x - test_left) / 25);
  52                                 else if( x < 320)
  53                                         s.val[i] *= exp( (test_left - x) / 25);
  54                                 // Produce an exponential decay around right edge
  55                                 else if( x < test_right)
  56                                         s.val[i] *= exp( (x - test_right) / 25);
  57                                 else
  58                                         s.val[i] *= exp( (test_right - x) / 25);
  59                         }
  60                         cvSet2D(g_dataRGB,y,x,s);
  61                 //      if( s.val[0] > 200)
  62                 //              printf("row: %d, col: %d, %f\n", y, x, s.val[0]);
  63                 }
  64
  65         }
  66         if (g_data == NULL)
  67         {
  68                 g_data = cvCreateMat(g_dataRGB->rows,g_dataRGB->cols,CV_8UC1); //IPL_DEPTH_8U?
  69         }
  70         cvCvtColor(g_dataRGB,g_data,CV_RGB2GRAY);
  71 }
  72
  73 /**
  74  * Initialise the dilatometer
  75  */
  76 void Dilatometer_Init()
  77 {
  78
  79         // Make an initial reading (will allocate memory the first time only).
  80         Dilatometer_Read(1);
  81 }
  82
  83 /**
  84  * Cleanup Interferometer stuff
  85  */
  86 void Dilatometer_Cleanup()
  87 {
  88         if (g_data != NULL)
  89                 cvReleaseMat(&g_data);
  90
  91         if (g_capture != NULL)
  92                 cvReleaseCapture(&g_capture);
  93
  94 }
  95
  96 /**
  97  * Get an image from the Dilatometer
  98  */
  99 static void Dilatometer_GetImage()
 100 {
 101         //Need to implement camera
 102 }
 103
 104 // Test algorithm
 105 static void Dilatometer_GetImageTest( )
 106 {
 107         //Test image
 108         Dilatometer_TestImage();
 109 }
 110
 111
 112 /**
 113  * Read the dilatometer; gets the latest image, processes it, THEN DOES WHAT
 114  * @param samples - Number of rows to scan (increasing will slow down performance!)
 115  * @returns the average width of the can
 116  */
 117 double Dilatometer_Read(int samples)
 118 {
 119         //Get the latest image
 120         //Dilatometer_GetImage();
 121
 122         Dilatometer_GetImageTest();
 123
 124         int width = g_data->cols;
 125         int height = g_data->rows;
 126         // If the number of samples is greater than the image height, sample every row
 127         if( samples > height)
 128         {
 129                 //Log(LOGNOTE, "Number of samples is greater than the dilatometer image height, sampling every row instead.\n");
 130                 samples = height;
 131         }
 132
 133         // Stores the width of the can at different sample locations. Not necessary unless we want to store this information
 134         //double widths[samples];
 135         // The average width of the can
 136         double average_width;
 137         int sample_height;
 138         for (int i=0; i<samples; i++)
 139         {
 140                 // Contains the locations of the 2 edges
 141                 double edges[2] = {0.0,0.0};
 142                 int pos = 0;    // Position in the edges array (start at left edge)
 143                 int num = 0;    // Keep track of the number of columns above threshold
 144
 145                 // Determine the position in the rows to find the edges.
 146                 sample_height = ceil(height * (i + 1) / samples) -1;
 147                 //printf("sample height is %d\n", sample_height);
 148
 149                 //CvScalar test = cvGet2D(g_data, 150,300);
 150                 //printf("test is %f,%f,%f,%f\n", test.val[0], test.val[1], test.val[2], test.val[3]);
 151
 152
 153                 for ( int col = 0; col < width; col++)
 154                 {
 155                         CvScalar value = cvGet2D(g_data, sample_height, col);
 156                         if( value.val[0]> THRES)
 157                         {
 158                                 edges[pos] += (double) col;
 159                                 num++;
 160                         }
 161                         // If num > 0 and we're not above threshold, we have left the threshold of the edge
 162                         else if( num > 0)
 163                         {
 164                                 // Find the mid point of the edge
 165                                 edges[pos] /= num;
 166                                 if( edges[1] == 0)
 167                                 {
 168                                         pos = 1;        // Move to the right edge
 169                                         num = 0;
 170                                 }
 171                                 else
 172                                         break;          // Exit the for loop
 173                         }
 174                 }
 175                 // Determine the width of the can at this row
 176                 //widths[i] = edges[1] - edges[0];
 177                 average_width += (edges[1] - edges[0]);
 178         }
 179         average_width /= (double) samples;
 180         return average_width;
 181 }
 182
 183 /**
 184  * For testing purposes
 185  */
 186 int main(int argc, char ** argv)
 187 {
 188         //cvNamedWindow( "display", CV_WINDOW_AUTOSIZE );// Create a window for display.
 189         //gettimeofday(&start, NULL);
 190         test_left = 100;
 191         test_right = 500;
 192         Dilatometer_Init();
 193
 194         cvNamedWindow( "display", CV_WINDOW_AUTOSIZE);
 195         cvShowImage("display", g_data);
 196         cvWaitKey(0);
 197         double width;
 198         for( int i = 0; i < 20; ++i)
 199         {
 200                 test_left  -= i * (rand() % 1000) * 1e-3;
 201                 test_right += i * (rand() % 1000) * 1e-3;
 202                 width = Dilatometer_Read(5);
 203                 cvNamedWindow( "display", CV_WINDOW_AUTOSIZE);
 204                 cvShowImage("display", g_data);
 205                 cvWaitKey(0);
 206                 double expected = test_right - test_left;
 207                 double perc = 100 * (expected - width) / expected;
 208                 printf("%d: Left: %.4f.    Width: %.4f.\n  Right: %.4f. Expected: %.4f. Percentage: %.4f\n", i, test_left, width, test_right, expected, perc);
 209         }
 210 }
 211