Heng-Ming Tai

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This paper presents results of our work in development of a genetic algorithm based path-planning algorithm for local obstacle avoidance (local feasible path) of a mobile robot in a given search space. The method tries to find not only a valid path but also an optimal one. The objectives are to minimize the length of the path and the number of turns. The(More)
In this paper, we present a new two-dimensional (2-D) direction-of-arrival (DOA) angle estimation method for coherent or highly correlated narrowband signals using L-shape arrays. The proposed method decorrelates the coherent incident signals and reconstructs the signal subspace using the cross-correlation matrix. Then the shift invariance property of the(More)
This paper proposes a self-embedding watermarking scheme that reduces the watermark payload significantly while maintaining good recovery quality and security. The embedded watermark contributes to the tamper detection and content recovery and is composed of only the compression codes of the image content. The compression codes with variable length are(More)
This paper proposes a wavelet-based fragile watermarking scheme for secure image authentication. In the proposed scheme, the embedded watermark is generated using the discrete wavelet transform (DWT), and then the improved security watermark by scrambling encryption is embedded into the least significant bit (LSB) of the host image. The proposed algorithm(More)
In this paper, we present the performance analysis of a self-recovery fragile watermarking scheme using block-neighbor- hood tamper characterization. This method uses a pseudorandom sequence to generate the nonlinear block-mapping and employs an optimized neighborhood characterization method to detect the tampering. Performance of the proposed method and(More)
A novel iterative algorithm for estimating the frequency of a single complex sinusoid in the complex white Gaussian noise is proposed. Inspired by the works of Fitz, L&R, and the ILP approaches, the algorithm is based on the repeated use of an autocorrelation-based frequency estimator. This approach is different from the iterative linear prediction (ILP)(More)
This paper proposes a function-controlled variable step size least mean square (VSLMS) algorithm for channel estimation in low-SNR or colored input signals. The proposed method aligns the step size update with the steady-state error and alleviates the impact of high-level noise. It improves the filter performance in terms of fast convergence rate and low(More)
This paper proposes a color-direction patch-sparsity-based image inpainting method to better maintain structure coherence, texture clarity, and neighborhood consistence of the inpainted region of an image. The method uses super-wavelet transform to estimate the multi-direction features of a degraded image, and combines with color information to construct(More)