#include "dilatometer.h"
#include <math.h>
-/** Buffer for storing image data. Stored as a **/
-static CvMat * g_data = NULL;
+// test positions
+static double test_left, test_right;
+// Canny Edge algorithm variables
+int blur = 5;
+int lowThreshold = 30;
+int ratio = 3;
+int kernel_size = 3;
-/** Camera capture pointer **/
+/** Buffers for storing image data. **/
+static CvMat * g_srcRGB = NULL; // Source Image
+static CvMat * g_srcGray = NULL; // Gray scale of source image
+static CvMat * g_edges = NULL; // Detected Edges
+
+/** Pointers for capturing image **/
static CvCapture * g_capture = NULL;
+static IplImage * frame = NULL; // This is required as you can not use capture with CvMat in C
+
/**
- * Create a test image
+ * Create a test image using left as left edge and right as right edge positions
*/
void Dilatometer_TestImage()
{
- CvMat *g_dataRGB;
- g_dataRGB = cvCreateMat(480, 640, CV_8UC3); //32
+ g_srcRGB = cvCreateMat(480, 640, CV_8UC3);
- //Make a rectangle from col=300 to 500, row=150 to 350
- /*for (int x = 100; x < 500; ++x)
- {
- CvScalar s;
- s.val[0] = 150; s.val[1] = 233; s.val[2] = 244;
- cvSet2D(g_dataRGB,150,x,s);
- cvSet2D(g_dataRGB,350,x,s);
- }*/
- for (int y = 0; y < 480; ++y)
+ for( int x = 0; x < 640; ++x)
{
- CvScalar s;
- s.val[0] = 200; s.val[1] = 233; s.val[2] = 244;
- cvSet2D(g_dataRGB,y,100,s);
- cvSet2D(g_dataRGB,y,500,s);
+ for (int y = 0; y < 480; ++y)
+ {
+ CvScalar s;
+ for( int i = 0; i < 3; ++i)
+ {
+ s.val[i] = 210 + (rand() % 1000) * 1e-0 - (rand() % 1000) * 1e-0;
+ // Produce an exponential decay around left edge
+ if( x < test_left)
+ s.val[i] *= exp( (x - test_left) / 25);
+ else if( x < 320)
+ s.val[i] *= exp( (test_left - x) / 25);
+ // Produce an exponential decay around right edge
+ else if( x < test_right)
+ s.val[i] *= exp( (x - test_right) / 25);
+ else
+ s.val[i] *= exp( (test_right - x) / 25);
+ }
+ cvSet2D(g_srcRGB,y,x,s);
+ }
+
}
- if (g_data == NULL)
+ if (g_srcGray == NULL)
{
- g_data = cvCreateMat(g_dataRGB->rows,g_dataRGB->cols,CV_8UC1); //IPL_DEPTH_8U?
- cvCvtColor(g_dataRGB,g_data,CV_RGB2GRAY);
+ g_srcGray = cvCreateMat(g_srcRGB->rows,g_srcRGB->cols,CV_8UC1);
}
+ cvCvtColor(g_srcRGB,g_srcGray,CV_RGB2GRAY);
}
/**
- * Initialise the dilatometer
- */
-void Dilatometer_Init()
-{
-
- // Make an initial reading (will allocate memory the first time only).
- Dilatometer_Read(1);
-}
-
-/**
- * Cleanup Interferometer stuff
+ * Cleanup Dilatometer pointers
*/
void Dilatometer_Cleanup()
{
- if (g_data != NULL)
- cvReleaseMat(&g_data);
-
if (g_capture != NULL)
cvReleaseCapture(&g_capture);
-
+ if (g_srcRGB != NULL)
+ cvReleaseMat(&g_srcRGB);
+ if (g_srcGray != NULL)
+ cvReleaseMat(&g_srcGray);
+ if (g_edges != NULL)
+ cvReleaseMat(&g_edges);
+ if (frame != NULL)
+ cvReleaseImageHeader(&frame);
}
/**
* Get an image from the Dilatometer
*/
-static void Dilatometer_GetImage()
+static bool Dilatometer_GetImage()
{
- //Test image
- Dilatometer_TestImage();
- //Need to implement camera
+ bool result = true;
+ // If more than one camera is connected, then input needs to be determined, however the camera ID may change after being unplugged
+ g_capture = cvCreateCameraCapture(0);
+ //If cvCreateCameraCapture returns NULL there is an error with the camera
+ if( g_capture == NULL)
+ result = false;
+
+ // Get the frame and convert it to CvMat
+ frame = cvQueryFrame(g_capture);
+ CvMat stub;
+ g_srcRGB = cvGetMat(frame,&stub,0,0);
+
+ if( g_srcRGB == NULL)
+ result = false;
+
+ // Convert the image to grayscale
+ if (g_srcGray == NULL)
+ {
+ g_srcGray = cvCreateMat(g_srcRGB->rows,g_srcRGB->cols,CV_8UC1);
+ }
+
+ cvCvtColor(g_srcRGB,g_srcGray,CV_RGB2GRAY);
+
+ return result;
}
-/**
- * Read the dilatometer; gets the latest image, processes it, THEN DOES WHAT
+
+void CannyThreshold()
+{
+ if ( g_edges == NULL)
+ {
+ g_edges = cvCreateMat(g_srcGray->rows,g_srcGray->cols,CV_8UC1);
+ }
+
+ // Commented out lines are used during testing to show the image to screen, can also save the test images
+ //cvShowImage("display", g_srcGray);
+ //cvWaitKey(0);
+
+ // Reduce noise with a kernel blurxblur. Input the grayscale source image, output to edges. (0's mean it's determined from kernel sizes)
+ cvSmooth( g_srcGray, g_edges, CV_GAUSSIAN, blur, blur ,0 ,0 );
+
+ //Save the image
+ //cvSaveImage("test_blurred.jpg",g_edges,0);
+ printf("what about here?\n");
+
+ cvShowImage("display", g_edges);
+ cvWaitKey(0);
+ // Find the edges in the image
+ cvCanny( g_edges, g_edges, lowThreshold, lowThreshold*ratio, kernel_size );
+
+ //Save the image
+ //cvSaveImage("test_edge.jpg",g_edges,0);
+
+ cvShowImage("display", g_edges);
+ cvWaitKey(0);
+ printf("hopeful\n");
+
+}
+
+ /**
+ * Read the dilatometer image. The value changed will correspond to the new location of the edge.
+ * @param val - Will store the read value if successful
* @param samples - Number of rows to scan (increasing will slow down performance!)
- * @returns the average width of the can
+ * @returns true on successful read
*/
-double Dilatometer_Read(int samples)
+bool Dilatometer_GetEdge( double * value, int samples)
{
- //Get the latest image
- Dilatometer_GetImage();
+ bool result = false;
+ double average = 0;
+ // Get the image from the camera
+ result = Dilatometer_GetImage();
+ // If an error occured when capturing image then return
+ if (!result)
+ return result;
+
+ // Apply the Canny Edge theorem to the image
+ CannyThreshold();
- int width = g_data->cols;
- int height = g_data->rows;
+ int width = g_edges->cols;
+ int height = g_edges->rows;
+
// If the number of samples is greater than the image height, sample every row
if( samples > height)
{
- //Log(LOGNOTE, "Number of samples is greater than the dilatometer image height, sampling every row instead.\n");
samples = height;
}
-
- // Stores the width of the can at different sample locations. Not necessary unless we want to store this information
- //double widths[samples];
- // The average width of the can
- double average_width;
+
int sample_height;
- printf("here2; %d\n", width);
+ int num_edges = 0; // Number of edges. if each sample location has an edge, then num_edges = samples
+
for (int i=0; i<samples; i++)
{
- // Contains the locations of the 2 edges
- double edges[2] = {0.0,0.0};
- printf("edges init %f; %f\n", edges[0], edges[1]);
- int pos = 0; // Position in the edges array (start at left edge)
- int num = 0; // Keep track of the number of columns above threshold
-
// Determine the position in the rows to find the edges.
+ // This will give you a number of evenly spaced samples
sample_height = ceil(height * (i + 1) / samples) -1;
- printf("sample height is %d\n", sample_height);
-
- //CvScalar test = cvGet2D(g_data, 150,300);
- //printf("test is %f,%f,%f,%f\n", test.val[0], test.val[1], test.val[2], test.val[3]);
-
-
+
+ // Need to go through each pixel of a row and find all the locations of a line. If there is more than one pixel, average it. note this only works if the canny edge algorithm returns lines about the actual line (no outliers).
+
+ int edge_location=0;
+ int num=0;
for ( int col = 0; col < width; col++)
{
- //if ( CV_MAT_ELEM( *g_data, double, col, sample_height) > THRES)
-
- //printf("val is %f\n", cvGet2D(g_data, col, sample_height));
- //printf("position is col: %d, row: %d\n",col, sample_height);
- CvScalar value = cvGet2D(g_data, sample_height, col);
- //printf("value is %f\n", value.val[0]);
+ // Count the number of points
+ // Get the threshold of the pixel at the current location
+ CvScalar value = cvGet2D(g_edges, sample_height, col);
if( value.val[0]> THRES)
{
- edges[pos] += (double) col;
+ edge_location += col;
num++;
- printf("here; %f\n", edges[pos]);
- }
- // If num > 0 and we're not above threshold, we have left the threshold of the edge
- else if( num > 0)
- {
- // Find the mid point of the edge
- edges[pos] /= num;
- if( edges[1] == 0)
- {
- pos = 1; // Move to the right edge
- num = 0;
- }
- else
- break; // Exit the for loop
}
}
- // Determine the width of the can at this row
- //widths[i] = edges[1] - edges[0];
- average_width += (edges[1] - edges[0]);
+ if( num > 0)
+ {
+ average += ( edge_location / num );
+ num_edges++;
+ }
+ }
+ if (num_edges > 0)
+ average /= num_edges;
+
+ if( average > 0)
+ {
+ result = true; //Successfully found an edge
+ *value = average;
+ }
+ return result;
+}
+
+ /**
+ * Read the dilatometer image. The value changed will correspond to the new location of the edge.
+ * @param val - Will store the read value if successful
+ * @returns true on successful read
+ */
+bool Dilatometer_Read( double * value)
+{
+ bool result = Dilatometer_GetEdge(value, SAMPLES);
+ return result;
+}
+
+/**
+ * Initialise the dilatometer
+ */
+void Dilatometer_Init()
+{
+ // Make an initial reading (will allocate memory the first time only).
+ double val;
+ Dilatometer_GetEdge(&val, 1);
+}
+
+// Overlays a line over the given edge position
+void Draw_Edge(double edge)
+{
+ CvScalar value;
+ value.val[0]=244;
+ for( int i = 0; i < g_srcGray->rows; i++)
+ {
+ cvSet2D(g_edges,i,edge,value);
}
- average_width /= samples;
- printf("the average width is %f\n", average_width);
- return average_width;
+ cvShowImage("display", g_edges);
+ cvWaitKey(0);
+ //cvSaveImage("test_edge_avg.jpg",g_edges,0);
}
+/* // Test algorithm
+static void Dilatometer_GetImageTest( )
+{
+ //Generates Test image
+ //Dilatometer_TestImage();
+
+ //Load Test image
+ g_srcGray = cvLoadImageM ("testimage4.jpg",CV_LOAD_IMAGE_GRAYSCALE );
+}*/
+
/**
* For testing purposes
*/
{
//cvNamedWindow( "display", CV_WINDOW_AUTOSIZE );// Create a window for display.
//gettimeofday(&start, NULL);
-
+ test_left = 100;
+ test_right = 500;
Dilatometer_Init();
-
+
cvNamedWindow( "display", CV_WINDOW_AUTOSIZE);
- cvShowImage("display", g_data);
- cvWaitKey(0);
- Dilatometer_Read(5);
+ //double width;
+
+ double edge;
+ Dilatometer_GetEdge(&edge,20000);
+ //For testing purposes, overlay the given average line over the image
+ Draw_Edge(edge);
+
+ cvDestroyWindow("display");
+
+ Dilatometer_Cleanup();
+
}