Basic sample code for freenect support for OpenCV.

freenectopencv.cpp

/* freenectopencv.cpp
Copyright (C) 2010 Arne Bernin
This code is licensed to you under the terms of the GNU GPL, version 2 or version 3;
see:
 
http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt
 
 
http://www.gnu.org/licenses/gpl-3.0.txt
 
*/
 
#include <stdio.h>
#include <string.h>
#include <math.h>
 
#include <libfreenect.h>
#include <pthread.h>
 
#define CV_NO_BACKWARD_COMPATIBILITY
 
#include <cv.h>
#include <highgui.h>
 
#define FREENECTOPENCV_WINDOW_D "Depthimage"
#define FREENECTOPENCV_WINDOW_N "Normalimage"
#define FREENECTOPENCV_RGB_DEPTH 3
#define FREENECTOPENCV_DEPTH_DEPTH 1
#define FREENECTOPENCV_RGB_WIDTH 640
#define FREENECTOPENCV_RGB_HEIGHT 480
#define FREENECTOPENCV_DEPTH_WIDTH 640
#define FREENECTOPENCV_DEPTH_HEIGHT 480
 
IplImage* depthimg = 0;
IplImage* rgbimg = 0;
IplImage* tempimg = 0;
IplImage* canny_img = 0;
IplImage* canny_temp = 0;
pthread_mutex_t mutex_depth = PTHREAD_MUTEX_INITIALIZER;
pthread_mutex_t mutex_rgb = PTHREAD_MUTEX_INITIALIZER;
pthread_t cv_thread;
 
// callback for depthimage, called by libfreenect
void depth_cb(freenect_device *dev, void *depth, uint32_t timestamp)
 
{
        cv::Mat depth8;
        cv::Mat mydepth = cv::Mat( FREENECTOPENCV_DEPTH_WIDTH,FREENECTOPENCV_DEPTH_HEIGHT, CV_16UC1, depth);
 
        mydepth.convertTo(depth8, CV_8UC1, 1.0/4.0);
        pthread_mutex_lock( &mutex_depth );
        memcpy(depthimg->imageData, depth8.data, 640*480);
        // unlock mutex
        pthread_mutex_unlock( &mutex_depth );
 
}
 
// callback for rgbimage, called by libfreenect
 
void rgb_cb(freenect_device *dev, void *rgb, uint32_t timestamp)
{
 
        // lock mutex for opencv rgb image
        pthread_mutex_lock( &mutex_rgb );
        memcpy(rgbimg->imageData, rgb, FREENECT_VIDEO_RGB_SIZE);
        // unlock mutex
        pthread_mutex_unlock( &mutex_rgb );
}
 
/*
 * thread for displaying the opencv content
 */
void *cv_threadfunc (void *ptr) {
        printf("cv_threadfunc\n");
        cvNamedWindow( FREENECTOPENCV_WINDOW_D, CV_WINDOW_AUTOSIZE );
        cvNamedWindow( FREENECTOPENCV_WINDOW_N, CV_WINDOW_AUTOSIZE );
        cvNamedWindow( "Canny Image", CV_WINDOW_AUTOSIZE );
        cvNamedWindow( "Depth Canny", CV_WINDOW_AUTOSIZE );
        depthimg = cvCreateImage(cvSize(FREENECTOPENCV_DEPTH_WIDTH, FREENECTOPENCV_DEPTH_HEIGHT), IPL_DEPTH_8U, FREENECTOPENCV_DEPTH_DEPTH);
        rgbimg = cvCreateImage(cvSize(FREENECTOPENCV_RGB_WIDTH, FREENECTOPENCV_RGB_HEIGHT), IPL_DEPTH_8U, FREENECTOPENCV_RGB_DEPTH);
        tempimg = cvCreateImage(cvSize(FREENECTOPENCV_RGB_WIDTH, FREENECTOPENCV_RGB_HEIGHT), IPL_DEPTH_8U, FREENECTOPENCV_RGB_DEPTH);
        canny_img = cvCreateImage(cvSize(FREENECTOPENCV_RGB_WIDTH, FREENECTOPENCV_RGB_HEIGHT), IPL_DEPTH_8U, 1);
        canny_temp = cvCreateImage(cvSize(FREENECTOPENCV_DEPTH_WIDTH, FREENECTOPENCV_DEPTH_HEIGHT), IPL_DEPTH_8U, FREENECTOPENCV_DEPTH_DEPTH);
        printf("images created\n");
        // use image polling
        while (1) {
                //lock mutex for depth image
                pthread_mutex_lock( &mutex_depth );
                // show image to window
                cvCanny(depthimg, canny_temp, 50.0, 200.0, 3);
                cvCvtColor(depthimg,tempimg,CV_GRAY2BGR);
                cvCvtColor(tempimg,tempimg,CV_HSV2BGR);
 
                cvShowImage(FREENECTOPENCV_WINDOW_D,tempimg);
                cvShowImage("Depth Canny", canny_temp);
                //unlock mutex for depth image
                pthread_mutex_unlock( &mutex_depth );
 
                //lock mutex for rgb image
                pthread_mutex_lock( &mutex_rgb );
                // show image to window
                cvCvtColor(rgbimg,tempimg,CV_BGR2RGB);
                cvCvtColor(tempimg, canny_img, CV_BGR2GRAY);
                cvShowImage(FREENECTOPENCV_WINDOW_N, tempimg);
 
                // Canny filter
                cvCanny(canny_img, canny_img, 50.0, 200.0, 3);
                cvShowImage("Canny Image", canny_img);
                //unlock mutex
                pthread_mutex_unlock( &mutex_rgb );
 
                // wait for quit key
                if( cvWaitKey( 15 )==27 )
                                break;
 
        }
        pthread_exit(NULL);
 
        return NULL;
 
}
 
int main(int argc, char **argv)
{
 
        freenect_context *f_ctx;
        freenect_device *f_dev;
 
        int res = 0;
        int die = 0;
        printf("Kinect camera test\n");
 
        if (freenect_init(&f_ctx, NULL) < 0) {
                        printf("freenect_init() failed\n");
                        return 1;
                }
 
                if (freenect_open_device(f_ctx, &f_dev, 0) < 0) {
                        printf("Could not open device\n");
                        return 1;
                }
 
        freenect_set_depth_callback(f_dev, depth_cb);
        freenect_set_video_callback(f_dev, rgb_cb);
        freenect_set_video_format(f_dev, FREENECT_VIDEO_RGB);
 
        // create opencv display thread
        res = pthread_create(&cv_thread, NULL, cv_threadfunc, (void*) depthimg);
        if (res) {
                printf("pthread_create failed\n");
                return 1;
        }
 
        printf("init done\n");
 
        freenect_start_depth(f_dev);
        printf("depth done\n");
        freenect_start_video(f_dev);
        printf("video done\n");
 
        while(!die && freenect_process_events(f_ctx) >= 0 );
 
}

Makefile

CXXFLAGS = -O2 -g -Wall -fmessage-length=0 `pkg-config opencv --cflags ` -I /usr/include/libusb-1.0
OBJS = freenectopencv.o 
LIBS = `pkg-config opencv --libs` -lfreenect
TARGET = kinectopencv
$(TARGET):$(OBJS)
	$(CXX) -o $(TARGET) $(OBJS) $(LIBS)
all:$(TARGET)
clean:
	rm -f $(OBJS) $(TARGET)

Hi,
after running this application I get a black window

Failed to submit isochronuis transfer 0....7 : -12

error
can you help me please ?
thankyou