46424681
Fast face detection via morphology-based pre-processing
Abstract An efficient face detection algorithm which can detect multiple faces oriented in any directions in a cluttered environment is proposed. In this paper, a morphology-based technique is first devised to perform eye-analogue segmentation. Next, the previously located eye-analogue segments are used as guides to search for potential face regions. Then, each of these potential face images is normalized to a standard size and fed into a trained backpropagation neural network for identification. In this detection system, the morphology-based eye-analogue segmentation process is able to reduce the background part of a cluttered image by up to 95%. This process significantly speeds up the subsequent face detection procedure because only 5–10% of the regions of the original image remain for further processing. Experiments demonstrate that an approximately 94% success rate is reached, and that the relative false detection rate is very low.
35793047
A message-based cocktail watermarking system
Abstract A noise-type Gaussian sequence is most commonly used as a watermark to claim ownership of media data. However, only a 1-bit information payload is carried in this type of watermark. For a logo-type watermark, the situation is better because it is visually recognizable and more information can be carried. However, since the sizes and shapes of logos for different organizations are different, the flexibility of use of a logo-type watermark will certainly be degraded. In this paper, a more flexible type of watermark, i.e., a message, is designed. Since a message is composed of a finite number of ASCII-type characters, it is by nature vulnerable to attacks. Therefore, we propose to choose a set of nonlinear Hadamard-codes that has the maximum Hamming distance between any two constituent codes to replace the original ASCII-type inputs. This design will make our system much more fault-tolerant in comparison with ASCII-code based systems under direct attack. To recover an attacked Hadamard code, we use a trained backpropagation neural network to perform inexact matching. The proposed Hadamard code-based message is embedded using the cocktail-watermarking scheme (IEEE Trans. Multimedia 2 (4) (2000) 209–224) for copyright protection. Experimental results demonstrate that our message-based cocktail watermarking system is superb in terms of robustness and flexibility.
16804646
Mean quantization blind watermarking for image authentication
The objective of this paper is to propose an image authentication scheme, which is able to detect malicious tampering of images even they have also been incidentally distorted. By modeling incidental and malicious distortions as Gaussian distributions with small and large variances, respectively, we propose to embed a watermark in the wavelet domain by a mean quantization technique. Due to the various probabilities of tamper response at each scale, these responses are integrated to make a decision on the tampered areas. Statistical analysis is conducted and experimental results are given to demonstrate that our watermarking scheme is able to detect malicious attacks while tolerating incidental distortions.
2266632
Fast Face Detection via Morphology-Based Pre-processing
An e$cient face detection algorithm which can detect multiple faces oriented in any directions in a cluttered environment is proposed. In this paper, a morphology-based technique is "rst devised to perform eye-analogue segmentation. Next, the previously located eye-analogue segments are used as guides to search for potential face regions. Then, each of these potential face images is normalized to a standard size and fed into a trained backpropagation neural network for identi"cation. In this detection system, the morphology-based eye-analogue segmentation process is able to reduce the background part of a cluttered image by up to 95%. This process signi"cantly speeds up the subsequent face detection procedure because only 5}10% of the regions of the original image remain for further processing. Experiments demonstrate that an approximately 94% success rate is reached, and that the relative false detection rate is very low. ( 2000 Published by Elsevier Science Ltd on behalf of Pattern Recognition Society.
10243856
A new LDA-based face recognition system which can solve the small sample size problem
A new LDA-based face recognition system is presented in this paper. Linear discriminant analysis (LDA) is one of the most popular linear projection techniques for feature extraction. The major drawback of applying LDA is that it may encounter the small sample size problem. In this paper, we propose a new LDA-based technique which can solve the small sample size problem. We also prove that the most expressive vectors derived in the null space of the within-class scatter matrix using principal component analysis (PCA) are equal to the optimal discriminant vectors derived in the original space using LDA. The experimental results show that the new LDA process improves the performance of a face recognition system signi"cantly. ( 2000 Pattern Recognition Society. Published by Elsevier Science Ltd. All rights reserved.
2240592
An extremal problem for H-linked graphs
We introduce the notion of H-linked graphs, where H is a fixed multigraph with vertices w1; . . . ;wm. A graph G is H-linked if for every choice of vertices v1; . . . ; vm in G, there exists a subdivision of H in G such that vi is the branch vertex representing wi (for all i). This generalizes the notions of k -linked, k -connected, and k-ordered graphs. Given k and n 5k þ 6, we determine the least integer d such that, for every loopless graph H with k edges and minimum degree at least two, every n-vertex graph with minimum degree at least d is H-linked. This value D1(k; n) appears to equal the least integer d 0 such that every n-vertex graph with minimum degree at least d 0 is k -connected. On the way to the proof, we extend a theorem by Kierstead et al. on the least integer d 00 such that every n-vertex graph with minimum degree at least d 00 is k-ordered. 2005 Wiley Periodicals, Inc. J Graph Theory 50: 321–339, 2005