static double test_left, test_right;
// Canny Edge algorithm variables
-int edgeThresh = 1;
-int lowThreshold;
-int const max_lowThreshold = 100;
+int blur = 5;
+int lowThreshold = 30;
int ratio = 3;
int kernel_size = 3;
-/** Buffer for storing image data. Stored as a **/
-static CvMat * g_srcRGB = NULL; // Source Image
-static CvMat * g_srcGray = NULL; // Gray scale of source image
-static CvMat * g_edges = NULL; // Detected Edges
-static CvMat * g_data = NULL; // Image to mask edges onto
+/** 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
-
-/** Camera capture pointer **/
+/** 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 using left as left edge and right as right edge positions
s.val[i] *= exp( (test_right - x) / 25);
}
cvSet2D(g_srcRGB,y,x,s);
- // if( s.val[0] > 200)
- // printf("row: %d, col: %d, %f\n", y, x, s.val[0]);
}
}
- if (g_data == NULL)
+ if (g_srcGray == NULL)
{
- g_data = cvCreateMat(g_srcRGB->rows,g_srcRGB->cols,CV_8UC1); //IPL_DEPTH_8U?
+ g_srcGray = cvCreateMat(g_srcRGB->rows,g_srcRGB->cols,CV_8UC1);
}
- cvCvtColor(g_srcRGB,g_data,CV_RGB2GRAY);
+ 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()
{
- //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);
-void CannyThreshold()
-{
+ if( g_srcRGB == NULL)
+ result = false;
- if (g_data == NULL)
+ // Convert the image to grayscale
+ if (g_srcGray == NULL)
{
- g_data = cvCreateMat(g_srcGray->rows,g_srcGray->cols,CV_8UC1);
+ g_srcGray = cvCreateMat(g_srcRGB->rows,g_srcRGB->cols,CV_8UC1);
}
+ cvCvtColor(g_srcRGB,g_srcGray,CV_RGB2GRAY);
+
+ return result;
+}
+
+void CannyThreshold()
+{
if ( g_edges == NULL)
{
g_edges = cvCreateMat(g_srcGray->rows,g_srcGray->cols,CV_8UC1);
}
- //g_data = 0;
- cvShowImage("display", g_srcGray);
- cvWaitKey(0);
- // Reduce noise with a kernel 3x3. Input the grayscale source image, output to edges. (0's mean it's determined from kernel sizes)
- cvSmooth( g_srcGray, g_edges, CV_GAUSSIAN, 9, 9 ,0 ,0 );
+ // 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);
-
- // Mask the edges over G_data
- //.copyTo( g_data, g_edges);
-}
+ printf("hopeful\n");
-// Test algorithm
-static void Dilatometer_GetImageTest( )
-{
- //Generates Test image
- //Dilatometer_TestImage();
-
- //Load Test image
- g_srcGray = cvLoadImageM ("testimage.jpg",CV_LOAD_IMAGE_GRAYSCALE );
- CannyThreshold();
}
-
-/**
- * Read the dilatometer; gets the latest image, processes it, THEN DOES WHAT
+ /**
+ * 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)
-{
- //Get the latest image
- //Dilatometer_GetImage();
+bool Dilatometer_GetEdge( double * value, int samples)
+{
+ 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();
- Dilatometer_GetImageTest();
+ int width = g_edges->cols;
+ int height = g_edges->rows;
- int width = g_srcGray->cols;
- int height = g_srcGray->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;
+ 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};
- 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_srcGray, 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++)
{
- CvScalar value = cvGet2D(g_srcGray, sample_height, col);
+ // 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++;
}
- // 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;
}
- average_width /= (double) samples;
- return average_width;
+ 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);
+ }
+ 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
*/
test_left = 100;
test_right = 500;
Dilatometer_Init();
+
+ cvNamedWindow( "display", CV_WINDOW_AUTOSIZE);
+ //double width;
+
+ double edge;
+ Dilatometer_GetEdge(&edge,20000);
+ //For testing purposes, overlay the given average line over the image
+ Draw_Edge(edge);
+
+ cvDestroyWindow("display");
-// cvNamedWindow( "display", CV_WINDOW_AUTOSIZE);
-// cvShowImage("display", g_data);
-// cvWaitKey(0);
- double width;
- /*for( int i = 0; i < 20; ++i)
- {
- test_left -= i * (rand() % 1000) * 1e-3;
- test_right += i * (rand() % 1000) * 1e-3;
-
- //Make sure left and right positions are sane
- if( test_left < 0)
- test_left = 0;
- if( test_right > 639)
- test_right = 639;
- if( test_left > test_right)
- {
- int tmp = test_right;
- test_right = test_left;
- test_left = tmp;
- }
+ Dilatometer_Cleanup();
- width = Dilatometer_Read(5);
- cvNamedWindow( "display", CV_WINDOW_AUTOSIZE);
- cvShowImage("display", g_srcGray);
- cvWaitKey(0);
- double expected = test_right - test_left;
- double perc = 100 * (expected - width) / expected;
- printf("%d: Left: %.4f. Width: %.4f.\n Right: %.4f. Expected: %.4f. Percentage: %.4f\n", i, test_left, width, test_right, expected, perc);
- }*/
}