University of Konstanz
Graduiertenkolleg / PhD Program
Computer and Information Science

Guest Talks


Colour Fractal Analysis for Video Quality Assessment


Dr. Mihai Ivanovici, Transilvania University
Brasov, Romania

date & place

Thursday, 27.05.2010, 14:15 h
Room Z714


Vision is a complex process that integrates multiple aspects of an image: the spatial frequencies and the topology, as well as the colour - all the features used for the quality evaluation of images or the video signal. Unfortunately, so far all these elements were independently took into consideration for the development of image and video fidelity metrics, therefore we propose an approach that blends together all of them. Our approach allows for the analysis of the complexity of colour images in the RGB colour space, based on the probabilistic algorithm for the computation of the fractal dimension and lacunarity - the two most-known fractal measures. Given that all the existing approaches are defined only for binary and gray-scale images, we extend them to the colour domain. We show how these two colour fractal features are able to capture the multiple aspects that characterize the degradation of the video signal, based on the hypothesis that the quality degradation perceived by the user is directly proportional to the modification of the fractal complexity of the image. We emphasize the fact that the colour fractal dimension and lacunarity we defined can be used to objectively assess the quality of the video signal and how they can be used as metrics for the user-perceived video quality degradation for an MPEG-4 streaming application. We compare our results with the ones given by unanimously-accepted metrics and, for the ultimate validation, we present the results of our subjective tests.