Please use this identifier to cite or link to this item: http://hdl.handle.net/10553/12385
Title: Discontinuity preserving in TV-L1 optical flow methods
Authors: Monzón López, Nelson
Salgado de la Nuez, Agustín Javier 
Sánchez, Javier 
Keywords: 12 Matemáticas
1206 Análisis numérico
33 Ciencias tecnológicas
Issue Date: 2014
Journal: CTIM Technical Report 
Abstract: We analyze the discontinuity preserving problem in TV-L1 optical flow methods. This type of methods typically creates rounded effects at flow boundaries, which usually do not coincide with object contours. A simple strategy to overcome this problem consists in inhibiting the diffusion at high image gradients. In this work, we first introduce a general framework for TV regularizers in optical flow and relate it with some standard approaches. Our survey takes into account several methods that use decreasing functions for mitigating the diffusion at image contours. Consequently, this kind of strategies may produce instabilities in the estimation of the optical flows. Hence, we study the problem of instabilities and show that it actually arises from an ill-posed formulation. From this study, it is possible to come across with different schemes to solve this problem. One of these consists in separating the pure TV process from the mitigating strategy. This has been used in another work and we demonstrate here that it has a good performance. Furthermore, we propose two alternatives to avoid the instability problems: (i) we study a fully automatic approach that solves the problem based on the information of the whole image; (ii) we derive a semi-automatic approach that takes into account the image gradients in a close neighborhood adapting the parameter in each position. In the experimental results, we present a detailed study and comparison between the different alternatives. These methods provide very good results, especially for sequences with a few dominant gradients. Additionally, a surprising effect of these approaches is that they can cope with occlusions. This can be easily achieved by using strong regularizations and high penalizations at image contours.
URI: http://hdl.handle.net/10553/12385
ISSN: 2254-2353
Source: CTIM: Technical report. Las Palmas de Gran Canaria: Centro de Tecnologías de la Imágen, 2014. Nº 5. 42 p. ISSN 2254-2353
Appears in Collections:Informe técnico

Files in This Item:
File Description SizeFormat 
CTIM_5_2014.pdfCTIM Technical Report10,19 MBAdobe PDFView/Open
Show full item record

Page view(s)

9
checked on Jul 14, 2019

Download(s)

4
checked on Jul 14, 2019

Google ScholarTM

Check


This item is licensed under a Creative Commons License Creative Commons