Need help understanding offline slam tracker

[kmatzen]

I think I'm misunderstanding how to use the offline slam tracker. Here's some sample code that I wrote based on my understanding of the API. However, it always produces pure rotational transformations that are very close to the identity.

#include "ocean/base/PluginManager.h"
#include "ocean/media/FrameMedium.h"
#include "ocean/media/ImageFileSequence.h"
#include "ocean/media/ImageSequenceFrameProviderInterface.h"
#include "ocean/media/Manager.h"
#include "ocean/media/imageio/ImageIO.h"
#include "ocean/tracking/offline/SLAMTracker.h"

int main(int argc, char **argv) {
  auto tracker = std::make_shared<Ocean::Tracking::Offline::SLAMTracker>();

  Ocean::Media::ImageIO::registerImageIOLibrary();
  Ocean::PluginManager::get().loadPlugins(Ocean::PluginManager::TYPE_MEDIA);

  Ocean::Media::FrameMediumRef frameMedium =
      Ocean::Media::Manager::get().newMedium(
          "./output/C3464225073010_000000.png",
          Ocean::Media::Medium::Type::IMAGE_SEQUENCE, true);
  if (!frameMedium) {
    std::cerr << "no medium" << std::endl;
    Ocean::Media::ImageIO::unregisterImageIOLibrary();
    return -1;
  }

  int width = 960;
  int height = 540;
  float focal_x = 443.7213934872656;
  float focal_y = 443.7213934872656;
  float principal_x = width / 2;
  float principal_y = height / 2;

  Ocean::PinholeCamera pinholeCamera(width, height, focal_x, focal_y,
                                     principal_x, principal_y);

  auto frameProviderInterface = Ocean::CV::FrameProviderInterfaceRef(
      new Ocean::Media::ImageSequenceFrameProviderInterface(frameMedium));

  tracker->setFrameProviderInterface(frameProviderInterface);
  tracker->setTrackingFrameRange(0, 100, 0);
  tracker->setCamera(pinholeCamera, -1, false);
  tracker->setRegionOfInterest(Ocean::CV::SubRegion(0, 0, width, height),
                               false);
  tracker->setAbstractMotionType(Ocean::Tracking::Offline::OfflineTracker::
                                     AbstractMotionType::AMT_COMPLEX);

  tracker->start();
  frameMedium->start();

  while (tracker->running()) {
  }

  tracker->succeeded();

  auto poses = tracker->poses();

  for (const auto &pose : poses) {
    std::cerr << pose.transformation() << std::endl;
  }

  Ocean::Media::ImageIO::unregisterImageIOLibrary();
  return 0;
}