Freenect.cc

#include "Freenect.h"

#include <cmath>
#include <string.h>

Freenect::Freenect()
    : context(NULL)
    , device(NULL)
    , tiltAngle(0)
{
    // default rgb camera parameters
    rgbCameraParameters.cx = 3.2894272028759258e+02;
    rgbCameraParameters.cy = 2.6748068171871557e+02;
    rgbCameraParameters.fx = 5.2921508098293293e+02;
    rgbCameraParameters.fy = 5.2556393630057437e+02;
    rgbCameraParameters.k[0] = 2.6451622333009589e-01;
    rgbCameraParameters.k[1] = -8.3990749424620825e-01;
    rgbCameraParameters.k[2] = -1.9922302173693159e-03;
    rgbCameraParameters.k[3] = 1.4371995932897616e-03;
    rgbCameraParameters.k[4] = 9.1192465078713847e-01;

    // default depth camera parameters
    depthCameraParameters.cx = 3.3930780975300314e+02;
    depthCameraParameters.cy = 2.4273913761751615e+02;
    depthCameraParameters.fx = 5.9421434211923247e+02;
    depthCameraParameters.fy = 5.9104053696870778e+02;
    depthCameraParameters.k[0] = -2.6386489753128833e-01;
    depthCameraParameters.k[1] = 9.9966832163729757e-01;
    depthCameraParameters.k[2] = -7.6275862143610667e-04;
    depthCameraParameters.k[3] = 5.0350940090814270e-03;
    depthCameraParameters.k[4] = -1.3053628089976321e+00;

    // relative rotation/translation between cameras with depth camera as reference
    transformMatrix = QMatrix4x4(9.9984628826577793e-01, 1.2635359098409581e-03,
                                 -1.7487233004436643e-02, 1.9985242312092553e-02,
                                 -1.4779096108364480e-03, 9.9992385683542895e-01,
                                 -1.2251380107679535e-02, -7.4423738761617583e-04,
                                 1.7470421412464927e-02, 1.2275341476520762e-02,
                                 9.9977202419716948e-01, -1.0916736334336222e-02,
                                 0.0, 0.0, 0.0, 1.0);

    // relative rotation/translation between cameras with rgb camera as reference
    transformMatrix = transformMatrix.transposed();

    // populate gamma lookup table
    for (int i = 0; i < 2048; ++i)
    {
        float v = static_cast<float>(i) / 2048.0f;
        v = powf(v, 3.0f) * 6.0f;
        gammaTable[i] = static_cast<unsigned short>(v * 6.0f * 256.0f);
    }

    // populate depth projection matrix
    for (int i = 0; i < FREENECT_FRAME_H; ++i)
    {
        for (int j = 0; j < FREENECT_FRAME_W; ++j)
        {
            QVector2D originalPoint(j, i);
            QVector2D rectifiedPoint;
            rectifyPoint(originalPoint, rectifiedPoint, depthCameraParameters);

            QVector3D rectifiedRay;
            projectPixelTo3DRay(rectifiedPoint, rectifiedRay, depthCameraParameters);

            depthProjectionMatrix[i * FREENECT_FRAME_W + j] = rectifiedRay;

            rectifyPoint(originalPoint, rectifiedPoint, rgbCameraParameters);
            rgbRectificationMap[i * FREENECT_FRAME_W + j] = rectifiedPoint;
        }
    }
}

Freenect::~Freenect()
{
    if (device != NULL)
    {
        freenect_stop_depth(device);
        freenect_stop_rgb(device);
    }

    freenect_close_device(device);

    freenect_shutdown(context);
}

bool
Freenect::init(int userDeviceNumber)
{
    if (freenect_init(&context, NULL) < 0)
    {
        return false;
    }

    freenect_set_log_level(context, FREENECT_LOG_DEBUG);

    if (freenect_num_devices(context) < 1)
    {
        return false;
    }

    if (freenect_open_device(context, &device, userDeviceNumber) < 0)
    {
        return false;
    }

    freenect_set_user(device, this);

    memset(rgb, 0, FREENECT_RGB_SIZE);
    memset(depth, 0, FREENECT_DEPTH_SIZE);

    // set Kinect parameters
    if (freenect_set_tilt_degs(device, tiltAngle) != 0)
    {
        return false;
    }
    if (freenect_set_led(device, LED_RED) != 0)
    {
        return false;
    }
    if (freenect_set_rgb_format(device, FREENECT_FORMAT_RGB) != 0)
    {
        return false;
    }
    if (freenect_set_depth_format(device, FREENECT_FORMAT_11_BIT) != 0)
    {
        return false;
    }
    freenect_set_rgb_callback(device, rgbCallback);
    freenect_set_depth_callback(device, depthCallback);

    if (freenect_start_rgb(device) != 0)
    {
        return false;
    }
    if (freenect_start_depth(device) != 0)
    {
        return false;
    }

    thread.reset(new FreenectThread(device));
    thread->start();

    return true;
}

bool
Freenect::process(void)
{
    if (freenect_process_events(context) < 0)
    {
        return false;
    }

    //libfreenect changed some access functions in one of the new revisions
    freenect_raw_device_state state;
    freenect_get_mks_accel(&state, &ax, &ay, &az);
    //tiltAngle = freenect_get_tilt_degs(&state);

    //these are the old access functions
    //freenect_get_raw_accel(device, &ax, &ay, &az);
    //freenect_get_mks_accel(device, &dx, &dy, &dz);

    return true;
}

QSharedPointer<QByteArray>
Freenect::getRgbData(void)
{
    QMutexLocker locker(&rgbMutex);
    return QSharedPointer<QByteArray>(
            new QByteArray(rgb, FREENECT_RGB_SIZE));
}

QSharedPointer<QByteArray>
Freenect::getRawDepthData(void)
{
    QMutexLocker locker(&depthMutex);
    return QSharedPointer<QByteArray>(
            new QByteArray(depth, FREENECT_DEPTH_SIZE));
}

QSharedPointer<QByteArray>
Freenect::getColoredDepthData(void)
{
    QMutexLocker locker(&coloredDepthMutex);
    return QSharedPointer<QByteArray>(
            new QByteArray(coloredDepth, FREENECT_RGB_SIZE));
}

QVector<QVector3D>
Freenect::get3DPointCloudData(void)
{
    QMutexLocker locker(&depthMutex);

    QVector<QVector3D> pointCloud;

    unsigned short* data = reinterpret_cast<unsigned short*>(depth);
    for (int i = 0; i < FREENECT_FRAME_PIX; ++i)
    {
        if (data[i] <= 2048)
        {
            // see www.ros.org/wiki/kinect_node for details
            double range = 1.0f / (-0.00307f * static_cast<float>(data[i]) + 3.33f);

            if (range > 0.0f)
            {
                QVector3D ray = depthProjectionMatrix[i];
                ray *= range;

                pointCloud.push_back(QVector3D(ray.x(), ray.y(), ray.z()));
            }
        }
    }

    return pointCloud;
}

QVector<Freenect::Vector6D>
Freenect::get6DPointCloudData(void)
{
    QVector<QVector3D> rawPointCloud = get3DPointCloudData();

    QVector<Freenect::Vector6D> pointCloud;

    for (int i = 0; i < rawPointCloud.size(); ++i)
    {
        Vector6D point;

        point.x = rawPointCloud[i].x();
        point.y = rawPointCloud[i].y();
        point.z = rawPointCloud[i].z();

        QVector4D transformedPoint = transformMatrix * QVector4D(point.x, point.y, point.z, 1.0);

        float iz = 1.0 / transformedPoint.z();
        QVector2D rectifiedPoint(transformedPoint.x() * iz * rgbCameraParameters.fx + rgbCameraParameters.cx,
                                 transformedPoint.y() * iz * rgbCameraParameters.fy + rgbCameraParameters.cy);

        QVector2D originalPoint;
        unrectifyPoint(rectifiedPoint, originalPoint, rgbCameraParameters);

        if (originalPoint.x() >= 0.0 && originalPoint.x() < FREENECT_FRAME_W &&
            originalPoint.y() >= 0.0 && originalPoint.y() < FREENECT_FRAME_H)
        {
            int x = static_cast<int>(originalPoint.x());
            int y = static_cast<int>(originalPoint.y());
            unsigned char* pixel = reinterpret_cast<unsigned char*>(rgb)
                                   + (y * FREENECT_FRAME_W + x) * 3;

            point.r = pixel[0];
            point.g = pixel[1];
            point.b = pixel[2];

            pointCloud.push_back(point);
        }
    }

    return pointCloud;
}

int
Freenect::getTiltAngle(void) const
{
    return tiltAngle;
}

void
Freenect::setTiltAngle(int angle)
{
    if (angle > 30)
    {
        angle = 30;
    }
    if (angle < -30)
    {
        angle = -30;
    }

    tiltAngle = angle;
}

Freenect::FreenectThread::FreenectThread(freenect_device* _device)
{
    device = _device;
}

void
Freenect::FreenectThread::run(void)
{
    Freenect* freenect = static_cast<Freenect *>(freenect_get_user(device));
    while (1)
    {
        freenect->process();
    }
}

void
Freenect::rectifyPoint(const QVector2D& originalPoint,
                       QVector2D& rectifiedPoint,
                       const IntrinsicCameraParameters& params)
{
    double x = (originalPoint.x() - params.cx) / params.fx;
    double y = (originalPoint.y() - params.cy) / params.fy;

    double x0 = x;
    double y0 = y;

    // eliminate lens distortion iteratively
    for (int i = 0; i < 4; ++i)
    {
        double r2 = x * x + y * y;

        // tangential distortion vector [dx dy]
        double dx = 2 * params.k[2] * x * y + params.k[3] * (r2 + 2 * x * x);
        double dy = params.k[2] * (r2 + 2 * y * y) + 2 * params.k[3] * x * y;

        double icdist = 1.0 / (1.0 + r2 * (params.k[0] + r2 * (params.k[1] + r2 * params.k[4])));
        x = (x0 - dx) * icdist;
        y = (y0 - dy) * icdist;
    }

    rectifiedPoint.setX(x * params.fx + params.cx);
    rectifiedPoint.setY(y * params.fy + params.cy);
}

void
Freenect::unrectifyPoint(const QVector2D& rectifiedPoint,
                         QVector2D& originalPoint,
                         const IntrinsicCameraParameters& params)
{
    double x = (rectifiedPoint.x() - params.cx) / params.fx;
    double y = (rectifiedPoint.y() - params.cy) / params.fy;

    double r2 = x * x + y * y;

    // tangential distortion vector [dx dy]
    double dx = 2 * params.k[2] * x * y + params.k[3] * (r2 + 2 * x * x);
    double dy = params.k[2] * (r2 + 2 * y * y) + 2 * params.k[3] * x * y;

    double cdist = 1.0 + r2 * (params.k[0] + r2 * (params.k[1] + r2 * params.k[4]));
    x = x * cdist + dx;
    y = y * cdist + dy;

    originalPoint.setX(x * params.fx + params.cx);
    originalPoint.setY(y * params.fy + params.cy);
}

void
Freenect::projectPixelTo3DRay(const QVector2D& pixel, QVector3D& ray,
                              const IntrinsicCameraParameters& params)
{
    ray.setX((pixel.x() - params.cx) / params.fx);
    ray.setY((pixel.y() - params.cy) / params.fy);
    ray.setZ(1.0);
}

void
Freenect::rgbCallback(freenect_device* device, freenect_pixel* rgb, uint32_t timestamp)
{
    Freenect* freenect = static_cast<Freenect *>(freenect_get_user(device));

    QMutexLocker locker(&freenect->rgbMutex);
    memcpy(freenect->rgb, rgb, FREENECT_RGB_SIZE);
}

void
Freenect::depthCallback(freenect_device* device, void* depth, uint32_t timestamp)
{
    Freenect* freenect = static_cast<Freenect *>(freenect_get_user(device));
    freenect_depth* data = reinterpret_cast<freenect_depth *>(depth);

    QMutexLocker depthLocker(&freenect->depthMutex);
    memcpy(freenect->depth, data, FREENECT_DEPTH_SIZE);

    QMutexLocker coloredDepthLocker(&freenect->coloredDepthMutex);
    unsigned short* src = reinterpret_cast<unsigned short *>(data);
    unsigned char* dst = reinterpret_cast<unsigned char *>(freenect->coloredDepth);
    for (int i = 0; i < FREENECT_FRAME_PIX; ++i)
    {
        unsigned short pval = freenect->gammaTable[src[i]];
        unsigned short lb = pval & 0xFF;
        switch (pval >> 8)
        {
        case 0:
            dst[3 * i] = 255;
            dst[3 * i + 1] = 255 - lb;
            dst[3 * i + 2] = 255 - lb;
            break;
        case 1:
            dst[3 * i] = 255;
            dst[3 * i + 1] = lb;
            dst[3 * i + 2] = 0;
            break;
        case 2:
            dst[3 * i] = 255 - lb;
            dst[3 * i + 1] = 255;
            dst[3 * i + 2] = 0;
            break;
        case 3:
            dst[3 * i] = 0;
            dst[3 * i + 1] = 255;
            dst[3 * i + 2] = lb;
            break;
        case 4:
            dst[3 * i] = 0;
            dst[3 * i + 1] = 255 - lb;
            dst[3 * i + 2] = 255;
            break;
        case 5:
            dst[3 * i] = 0;
            dst[3 * i + 1] = 0;
            dst[3 * i + 2] = 255 - lb;
            break;
        default:
            dst[3 * i] = 0;
            dst[3 * i + 1] = 0;
            dst[3 * i + 2] = 0;
            break;
        }
    }
}