bool PyramidRegionTracker::Track(const Image<float> &image1,
const Image<float> &image2,
double x1, double y1,
double *x2, double *y2) const {
// Shrink the guessed x and y location to match the coarsest level + 1 (which
// when gets corrected in the loop).
*x2 /= pow(2., num_levels_);
*y2 /= pow(2., num_levels_);
// Create all the levels of the pyramid, since tracking has to happen from
// the coarsest to finest levels, which means holding on to all levels of the
// pyraid at once.
std::vector<Image<float>> pyramid1(num_levels_);
std::vector<Image<float>> pyramid2(num_levels_);
MakePyramid(image1, num_levels_, &pyramid1);
MakePyramid(image2, num_levels_, &pyramid2);
for (int i = num_levels_ - 1; i >= 0; --i) {
// Position in the first image at pyramid level i.
double xx = x1 / pow(2., i);
double yy = y1 / pow(2., i);
// Guess the new tracked position is where the last level tracked to.
*x2 *= 2;
*y2 *= 2;
// Save the previous best guess for this level, since tracking within this
// level might fail.
double x2_new = *x2;
double y2_new = *y2;
// Track the point on this level with the base tracker.
notify(INFO) << "Tracking on level " << i;
bool succeeded = tracker_->Track(pyramid1[i], pyramid2[i], xx, yy,
&x2_new, &y2_new);
if (!succeeded) {
if (i == 0) {
// Only fail on the highest-resolution level, because a failure on a
// coarse level does not mean failure at a lower level (consider
// out-of-bounds conditions).
notify(INFO) << "Finest level of pyramid tracking failed; failing.";
return false;
}
notify(INFO) << "Failed to track at level " << i << "; restoring guess.";
}
else {
// Only save the update if the track for this level succeeded. This is a
// bit of a hack; the jury remains out on whether this is better than
// re-using the previous failed-attempt.
*x2 = x2_new;
*y2 = y2_new;
}
}
return true;
}
///////////////////////////////////////////////////////////////////////////////
// This function does any needed initialization on the rendering context.
// This is the first opportunity to do any OpenGL related tasks.
void SetupRC()
{
// Black background
glClearColor(0.7f, 0.7f, 0.7f, 1.0f );
shaderManager.InitializeStockShaders();
glEnable(GL_DEPTH_TEST);
glGenTextures(1, &textureID);
glBindTexture(GL_TEXTURE_2D, textureID);
LoadTGATexture("stone.tga", GL_LINEAR, GL_LINEAR, GL_CLAMP_TO_EDGE);
MakePyramid(pyramidBatch);
cameraFrame.MoveForward(-7.0f);
}
