Done a bunch of changes to image handling

diff --git a/server/image.c b/server/image.c
index 1d35264..3c30467 100644 (file)
--- a/server/image.c
+++ b/server/image.c
@@ -3,64 +3,73 @@
 #include "image.h"
 #include <string.h>
 #include <stdio.h>
+#include <pthread.h>
 
 CvCapture *capture;
 int captureID = -1;
 
 void Image_Handler(FCGIContext * context, char * params)
 {
-       int num = 0, width = 800, height = 600;
+       int num = 0, width = 1600, height = 1200;       // Set Default values
        FCGIValue val[] = {
                {"num", &num, FCGI_INT_T},
                {"width", &width, FCGI_INT_T},
                {"height", &height, FCGI_INT_T}
        };
-       if (!FCGI_ParseRequest(context, params, val, 3))
+       if (!FCGI_ParseRequest(context, params, val, 3))        // Populate val
                return;
-       else if (num < 0 || num > 1) {
+       // Ensure the camera id is 0 or 1. Even though we plan to only have 1 camera attached at a time, this will allow 2. increase
+       else if (num < 0 || num > 1) {                          
                FCGI_RejectJSON(context, "Invalid capture number");
                return;
+       // Ensure valid widths
        } else if (width <= 0 || height <= 0) {
                FCGI_RejectJSON(context, "Invalid width/height");
                return;
        }
+       
+       CvMat * g_src = NULL;   // Source Image
+       CvMat * g_encoded;      // Encoded Image
 
-       if (captureID != num) {
-               if (captureID >= 0) {
-                       cvReleaseCapture(&capture);
-               }
-               capture = cvCreateCameraCapture(num);
-               captureID = num;
-       }
+       Camera_GetImage( num, width, height ,g_src); 
+       g_encoded = cvEncodeImage("test_encode.jpg",g_src,0);
+
+       Log(LOGNOTE, "Sending image!");
+       FCGI_PrintRaw("Content-type: image/jpg\r\n");
+       FCGI_PrintRaw("Cache-Control: no-cache, no-store, must-revalidate\r\n\r\n");
+       //FCGI_PrintRaw("Content-Length: %d", g_encoded->rows*g_encoded->cols);
+       FCGI_WriteBinary(g_encoded->data.ptr,1,g_encoded->rows*g_encoded->cols);
+       
+       cvReleaseMat(&g_encoded);
+       cvReleaseMat(&g_src);
+}
+
+ bool Camera_GetImage(int num, int width, int height,  CvMat * image)
+ {
+       static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER; // Need to use a mutex to ensure 2 captures are not open at once
+       pthread_mutex_lock(&mutex);
+       bool result = false;
+
+       capture = cvCreateCameraCapture(num);
 
        cvSetCaptureProperty(capture, CV_CAP_PROP_FRAME_WIDTH, width);
        cvSetCaptureProperty(capture, CV_CAP_PROP_FRAME_HEIGHT, height);
 
-       static int p[] = {CV_IMWRITE_JPEG_QUALITY, 100, 0};
-
        IplImage * frame = cvQueryFrame(capture);
-       assert(frame != NULL);
-
-//        CvMat stub;
- //       CvMat * background = cvGetMat(frame, &stub, 0, 0);
+       if( frame == NULL)
+               return result;
 
-//     CvMat *cv8u = cvCreateMat(frame->width, frame->height, CV_8U);
-//     double min, max;
-//     CvPoint a,b;    
-//     cvMinMaxLoc(background, &min, &max, &a, &b, 0);
-       
-//     double ccscale = 255.0/(max-min);
-//     double ccshift = -min;
-       //cvCvtScale(frame, cv8u, ccscale, ccshift);
-       CvMat * jpg = cvEncodeImage(".jpg", frame, p);
+       // Convert the IplImage pointer to CvMat
+        CvMat stub;
+        image = cvGetMat(frame, &stub, 0, 0);
+       if( image == NULL)
+               return result;
 
-       // Will this work?
-       Log(LOGNOTE, "Sending image!");
-       FCGI_PrintRaw("Content-type: image/jpg\r\n");
-       FCGI_PrintRaw("Cache-Control: no-cache, no-store, must-revalidate\r\n\r\n");
-       //FCGI_PrintRaw("Content-Length: %d", jpg->rows*jpg->cols);
-       FCGI_WriteBinary(jpg->data.ptr,1,jpg->rows*jpg->cols);
-       
-       cvReleaseMat(&jpg);
+       // Release the capture and IplImage pointers
        cvReleaseImageHeader(&frame);
+       cvReleaseCapture(&capture);
+
+       pthread_mutex_unlock(&mutex);   //Close the mutex
+       return true;
 }
+

diff --git a/server/image.h b/server/image.h
index 3c1ab69..7f4271d 100644 (file)
--- a/server/image.h
+++ b/server/image.h
@@ -7,10 +7,12 @@
 #define _IMAGE_H
 
 #include "common.h"
+#include "cv.h"
 
 extern void Image_Init();
 extern void Image_Handler(FCGIContext * context, char * params); 
 extern void Image_Cleanup();
+extern bool Camera_GetImage(int num, int width, int height,  CvMat * image);
 
 #endif //_IMAGE_H
 

diff --git a/server/sensors/dilatometer.c b/server/sensors/dilatometer.c
index 0bbda6b..10b2e61 100644 (file)
--- a/server/sensors/dilatometer.c
+++ b/server/sensors/dilatometer.c
@@ -11,6 +11,10 @@
 // test positions
 static double test_left, test_right;
 
+// Remembers the last position to measure rate of expansion
+static double lastPosition;
+
+
 // Canny Edge algorithm variables
 int blur = 5;
 int lowThreshold = 30;
@@ -23,8 +27,8 @@ 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
+//static CvCapture * g_capture = NULL;
+//static IplImage * frame  = NULL;     // This is required as you can not use capture with CvMat in C
 
 
 /**
@@ -70,10 +74,11 @@ void Dilatometer_TestImage()
  */
 bool Dilatometer_Cleanup(int id)
 {
-       if (g_capture != NULL)
-               cvReleaseCapture(&g_capture);
-       if (frame != NULL)
-               cvReleaseImageHeader(&frame);
+       //if (g_capture != NULL)
+       //      cvReleaseCapture(&g_capture);
+       //if (frame != NULL)
+       //      cvReleaseImageHeader(&frame);
+
        //if (g_srcRGB != NULL)
        //      cvReleaseMat(&g_srcRGB);        // Causing run time error in cvReleaseMat
        if (g_srcGray != NULL)
@@ -84,9 +89,9 @@ bool Dilatometer_Cleanup(int id)
 }
 
 /**
- * Get an image from the Dilatometer
+ * Get an image from the Dilatometer. Replaced by Camera_GetImage in image.c
  */
-static bool Dilatometer_GetImage()
+/*static bool Dilatometer_GetImage()
 {      
        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
@@ -118,10 +123,13 @@ static bool Dilatometer_GetImage()
        cvCvtColor(g_srcRGB,g_srcGray,CV_RGB2GRAY);
        
        return result;
-}
+}*/
 
 void CannyThreshold()
 {
+       // Convert the RGB source file to grayscale
+       cvCvtColor(g_srcRGB,g_srcGray,CV_RGB2GRAY);
+
        if ( g_edges == NULL)
        {
                g_edges = cvCreateMat(g_srcGray->rows,g_srcGray->cols,CV_8UC1);
@@ -152,7 +160,7 @@ void CannyThreshold()
 }
 
  /**
- * Read the dilatometer image. The value changed will correspond to the new location of the edge.
+ * Read the dilatometer image. The value changed will correspond to the rate of expansion. If no edge is found then 
  * @param val - Will store the read value if successful
  * @param samples - Number of rows to scan (increasing will slow down performance!)
  * @returns true on successful read
@@ -162,11 +170,12 @@ bool Dilatometer_GetEdge( double * value, int samples)
        bool result = false; 
        double average = 0;
        // Get the image from the camera
-       result = Dilatometer_GetImage();
+       result = Camera_GetImage( 0, 1600, 1200 ,&g_srcRGB); // Get a 1600x1200 image and place it into src
+
        // If an error occured when capturing image then return
        if (!result)
                return result;
-       
+
        // Apply the Canny Edge theorem to the image
        CannyThreshold();
 
@@ -180,7 +189,7 @@ bool Dilatometer_GetEdge( double * value, int samples)
        }
        
        int sample_height;
-       int num_edges = 0;      // Number of edges. if each sample location has an edge, then num_edges = samples
+       int num_edges = 0;      // Number of edges found. if each sample location has an edge, then num_edges = samples
 
        for (int i=0; i<samples; i++)
        {
@@ -211,11 +220,19 @@ bool Dilatometer_GetEdge( double * value, int samples)
        }
        if (num_edges > 0)
                average /= num_edges;
+       else
+               return result;  // As no edges were found
        
        if( average > 0)
        {       
-               result = true; //Successfully found an edge
-               *value = average;
+               result = true; // Successfully found an edge
+               // If the experiment has already been initialised
+               if( lastPosition > 0)
+               {       
+                       // Find the rate of expansion and convert to mm. Will give a negative result for compression.
+                       *value = (average - lastPosition) * SCALE;
+                       lastPosition = average; // Current position now becomes the last position
+               }
        }
        return result;
 }
@@ -238,8 +255,9 @@ bool Dilatometer_Init(const char * name, int id)
 {
        // Make an initial reading (will allocate memory the first time only).
        double val;
-       Dilatometer_GetEdge(&val, 1); 
-       return true;
+       lastPosition = 0;  // Reset the last position
+       bool result = Dilatometer_GetEdge(&val, 1); 
+       return result;
 }
 
 // Overlays a line over the given edge position

diff --git a/server/sensors/dilatometer.h b/server/sensors/dilatometer.h
index 2c683d6..e8be7d1 100644 (file)
--- a/server/sensors/dilatometer.h
+++ b/server/sensors/dilatometer.h
@@ -11,6 +11,9 @@
 //Number of samples of the image to take
 #define SAMPLES 600
 
+//Scaling factor required to change from pixels to mm
+#define SCALE 1 // Note camera has not been calibrated yet so result will be in pixels
+
 extern bool Dilatometer_Init(const char * name, int id); // Initialise the dilatometer
 extern bool Dilatometer_Cleanup(int id); // Cleanup
 extern bool Dilatometer_Read(int id, double * value); // Read the Dilatometer