NUI Galway – UL Alliance First Annual ENGINEERING AND - ARAN ...

Real-time depth map generation using an FPGA-implemented stereo camera
Istvan Andorko, Dr. Peter Corcoran, Dr. Petronel Bigioi
College of Engineering and Informatics, NUI Galway; Tessera (Ireland) Ltd.
i.andorko1@nuigalway.ie; peter.corcoran@nuigalway.ie; petronel.bigioi@nuigalway.ie
Abstract
An FPGA-implemented stereo camera based system is
proposed whose aim is to generate real-time accurate
depth maps at VGA resolution.
1. Introduction and progress of current
research
The aim of our current research is to generate realtime
accurate depth maps. There are two main types of
depth map generation algorithms. In case of the first
one, the resulting depth maps are not accurate enough
and they have a lot of noise, but they can be
implemented in hardware for real-time applications [1].
The second types of algorithms are computationally
expensive, but they can generate very accurate depth
maps [2].
Based on our study so far, almost all the researchers
have created scenes for testing that are the most suitable
for their algorithms and that cannot be found in the
“real-life” environment. Some of these pictures can be
found in figure 1.
Figure 1. Tsukuba stereo pair
Our idea was to create setups for testing that are very
likely to be found when the user will be trying to create
depth maps using the handheld stereo camera. An
example of this can be seen in figure 2.
Figure 2. Stereo image of a face for the “real-life” scenario
The tests that we carried out were done with the less
computationally expensive algorithms. For each setup
we have taken pictures from four different distances and
four different illumination conditions. In figure 3 a, b, c
the difference between different algorithms and setup
conditions can be seen.
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Figure 3.a. Difference between SAD and NCC algorithms
Figure 3.b. SAD algorithm, different illumination
Figure 3.c SAD algorithms, similar illumination and different distance
2. Future work
Regarding our future work, the plans are to find an
algorithm that works well and gives similar results
under different conditions (illumination, distance). The
second step will be to make it work well when using
human faces. The reason for this is that in the
Consumer Electronics industry, most of the camera
features are developed for faces. In the end, the
algorithm will be implemented in a SoC and it will be
optimized to work in real-time (30 fps) at VGA
(640x480) resolution.
3. Acknowledgement
The project is financed by the Irish Research Council
for Science, Engineering and Technology (IRCSET)
and Tessera (Ireland) Ltd.
4. References
[1] C. Georgulas et al, “Real-time disparity map computation
module”, Microprocessors and Microsystems, vol. 32, pp.
159-170, 2008.
[2] V. Kolmogorov, R. Zabih, “Computing visual
correspondence with occlusions via graph cuts”, International
Conference on Computer Vision, pp. 508-515, 2001.