Master thesis

The final piece of my Master in Computer Science is the thesis “Monocular SLAM for Context-Aware Workflow Assistance”. The abstract is included below:

In this thesis, we propose the integration of contextual workflow knowledge into a
SLAM tracking system for the purpose of procedural assistance using Augmented Reality.
Augmented Reality is an intuitive way for presenting workflow knowledge (e.g. main-
tenance or repairing) step by step but requires sophisticated models of the scene appear-
ance, the actions to perform and the spatial structure. For the latter one we propose the
integration with SLAM (Simultaneous Localization And Mapping) operating on images of
a monocular camera.
We first develop a stand-alone SLAM system with a point cloud as map representation
which is continuously extended and refined by triangulations obtained from new view
points using a three-step keyframe insertion procedure. In a second step, we integrate
contextual knowledge which is automatically obtained from reference recordings in a so-
called offline mapping step. This allows the tracking not only to cope with but actively
adapt to changes in the environment by explicitly including them in the tracking model.
To aid the data acquisition and to merge multiple tracking models into a single one, we
propose a novel method for combining offline acquired maps which is independent of the
spatial structure as opposed to ICP (Iterative Closest Point).
We show typical tracking results and evaluate the single components of our system by
measuring their performance when exposed to noise.

I wrote my thesis in Prof. Stricker’s Augmented Vision group and was supervised by Nils Petersen.

Master Thesis

@mastersthesis{Hasper2014,
author = {Hasper, Philipp},
school = {TU Kaiserslautern},
title = {{Monocular SLAM for Context-Aware Workflow Assistance}},
type = {Masterthesis},
year = {2014}
}

Remote Execution vs. Simplification for Mobile Real-time Computer Vision

As part of my work at the DFKI Kaiserslautern, I published a paper at VISAPP 2014 dealing with Remote Execution for mobile Augmented Reality:

Remote Execution vs. Simplification for Mobile Real-time Computer Vision. Philipp Hasper, Nils Petersen, Didier Stricker. In Proceedings of the 9th International Conference on Computer Vision Theory and Applications (VISAPP) 2014. doi:10.5220/0004683801560161.

Mobile implementations of computationally complex algorithms are often prohibitive due to performance constraints. There are two possible solutions for this: (1) adopting a faster but less powerful approach which results in a loss of accuracy or robustness. (2) using remote data processing which suffers from limited bandwidth and communication latencies and is difficult to implement in real-time interactive applications. Using the example of a mobile Augmented Reality application, we investigate those two approaches and compare them in terms of performance. We examine different workload balances ranging from extensive remote execution to pure onboard processing.

@inproceedings{Hasper2014,
author = {Hasper, Philipp and Petersen, Nils and Stricker, Didier},
booktitle = {Proceedings of the 9th International Conference on Computer Vision Theory and Applications},
doi = {10.5220/0004683801560161},
isbn = {978-989-758-003-1},
pages = {156--161},
publisher = {SCITEPRESS - Science and and Technology Publications},
title = {{Remote Execution vs. Simplification for Mobile Real-time Computer Vision}},
year = {2014}
}

Indoor pedestrian navigation based on recursive filtering (Seminar Paper)

I decided to share my seminar with you which I did back in the summer semester 2013. It is a survey paper about indoor pedestrian navigation. The paper is a good starting point to introduce you to the topic and provides you with interesting literature.

While localization is most commonly associated with GPS, many use cases remain where satellite-based navigation is too inaccurate or fails completely. In this seminar, we will present techniques usable for indoor localization of pedestrians. We will introduce several approaches using Inertial Measurement Units attached to the subject. Due to the strong drifting behavior of those units, several steps are necessary to provide feasible accuracy: the use of filter techniques and the use of Zero Velocity Updates. We will explain the required state-space
model and its application in recursive Bayesian filters like the Extended Kalman Filter or the Particle Filter. The use of aiding techniques is discussed and a map-aided, WiFi-initialized Particle Filter is presented.

Kalman Filter

Figure from the seminar paper showing the steps of the Extended Kalman Filter (EKF).

@MISC{Hasper2013,
author = {Hasper, Philipp and Bleser, Gabriele},
title = {Indoor pedestrian navigation based on recursive filtering},
howpublished = {Seminar Paper},
year = {2013},
keywords = {Sensor fusion, Recursive Filtering, Kalman Filter, Particle Filter,
ZUPT, EKF, MCL}
}

Bachelor thesis

I finished my Bachelor in Computer Science with my thesis “Real-time mobile image processing using heterogeneous cloud computing”. I wrote it in German (the German title is “Mobile Echtzeit-Bildverarbeitung durch heterogenes Cloud-Computing”) but I also included an English abstract:

Providing real-time image processing with computationally intensive components to low-level mobile devices is a problem not yet fully solved.
We show that offloading complex computations elsewise done on a smartphone to a cloud system can result in a higher processing speed.
The tradeoff between computational and network footprint is from particular importance since smartphones are often used in mobile networks. It is shown to be unsuitable to use the mobile device solely for image retrieval and offloading all further calculations (which is referred to as thin-client).
To hide the delay caused by the remote execution the development of a so-called latency-hiding component is discussed and its effectiveness verified.

I wrote my thesis in Prof. Stricker’s Augmented Vision group and was supervised by Nils Petersen.
Bachelor thesis, Figure 4.3

@mastersthesis{Hasper2012,
author = {Hasper, Philipp},
school = {TU Kaiserslautern},
title = {{Mobile Echtzeit-Bildverarbeitung durch heterogenes Cloud-Computing}},
type = {Bachelorthesis},
year = {2012}
}