Chen Yaowu

A Novel Scene Change Detection Algorithm for H.264/AVC Bitstreams

In this paper, we present a novel scene change detection algorithm in the H.264/AVC compressed domain directly. Three major statistical features are used: (i) bit allocation for intra mode macroblocks (BIM), (ii) bit allocation for inter mode macroblocks (BPM), and (iii) the number of skip mode macroblocks in a frame. These features can be easily extracted from the H.264/AVC bitstreams. Besides the percent of skip macroblocks in a frame, an adaptive threshold based on the ratio of BIM to BPM is used to determine the abrupt and the gradual scene changes respectively. Experimental results indicate that the proposed algorithm achieves the good performance with a low computational complexity.

A No-Reference Perceptual Blur Metric by using OLS-RBF Network

This paper presents a new no-reference perceptual blur metric by using the radial basis function network which is based on the orthogonal least squares learning algorithm (OLS-RBF). It extracts the generalized local features of the edge points in structure-texture region and acquires the generalized image features by performing Principal Component Analysis (PCA) on the average of generalized local features. The Gaussian blurred image quality estimation involves making the function relationship between the generalized image features and subjective scores. This paper transforms the problem of quality estimation to a problem of function approximation and solves the problem by using OLS-RBF network. OLS-RBF network uses an orthogonal least squares learning algorithm to select suitable centers for the radial basis function, which makes the training procedure simpler. Experiments results on various Gaussian blurred images show that the new metrics performance is consistent with the subjective evaluation and outperforms other blur metrics.

A Component-based Framework for Embedded Digital Instrumentation Software with Design Patterns

The embedded digital instrumentations (EDI) software systems become diversified and more complex with variable requirements. Component-based frameworks (CBF) which are built on object-oriented (OO) technologies provide a better reuse. A CBF for EDI software systems is presented in this paper, and it will be demonstrated that it is convenient to reuse the components and to construct an EDI application. The system architecture and framework design of multimedia instrumentations will be presented as an example. For a maintainable, flexible and extensible design, design patterns are employed in the components and framework development; strategy, observer, command and composite patterns are discussed and implemented in examples.