An Adaptive Coding Pass Scanning Algorithm for Optimal Rate Control in Biomedical Images

High-efficiency, high-quality biomedical image compression is desirable especially for the telemedicine applications. This paper presents an adaptive coding pass scanning (ACPS) algorithm for optimal rate control. It can identify the significant portions of an image and discard insignificant ones as early as possible. As a result, waste of computational power and memory space can be avoided. We replace the benchmark algorithm known as postcompression rate distortion (PCRD) by ACPS. Experimental results show that ACPS is preferable to PCRD in terms of the rate distortion curve and computation time

A New Texture Synthesis Algorithm Based on Wavelet Packet Tree

This paper presents an efficient texture synthesis based on wavelet packet tree (TSWPT). It has the advantage of using a multiresolution representation with a greater diversity of bases functions for the nonlinear time series applications such as fractal images. The input image is decomposed into wavelet packet coefficients, which are rearranged and organized to form hierarchical trees called wavelet packet trees. A 2-step matching, that is, coarse matching based on low-frequency wavelet packet coefficients followed by fine matching based on middle-high-frequency wavelet packet coefficients, is proposed for texture synthesis. Experimental results show that the TSWPT algorithm is preferable, especially in terms of computation time

An Efficient VLSI Linear Array for DCT/IDCT Using Subband Decomposition Algorithm

Discrete Cosine transform (DCT) and inverse DCT (IDCT) have been widely used in many image processing systems and real-time computation of nonlinear time series. In this paper, a novel lineararray of DCT and IDCT is derived from the data flow of subband decompositions representing the factorized coefficient matrices in the matrix formulation of the recursive algorithm. For increasing the throughput as well as decreasing the hardware cost, the input and output data are reordered. The proposed 8-point DCT/IDCT processor with four multipliers, simple adders, and less registers and ROM storing the immediate results and coefficients, respectively, has been implemented on FPGA (field programmable gate array) and SoC (system on chip). The linear-array DCT/IDCT processor with the computation complexity O(5N/8) and hardware complexity O(5N/8) is fully pipelined and scalable for variable-length DCT/IDCT computations

Nested Quantization Index Modulation for Reversible Watermarking and Its Application to Healthcare Information Management Systems

Digital watermarking has attracted lots of researches to healthcare information management systems for access control, patients' data protection, and information retrieval. The well-known quantization index modulation-(QIM-) based watermarking has its limitations as the host image will be destroyed; however, the recovery of medical images is essential to avoid misdiagnosis. In this paper, we propose the nested QIM-based watermarking, which is preferable to the QIM-based watermarking for the medical image applications. As the host image can be exactly reconstructed by the nested QIM-based watermarking. The capacity of the embedded watermark can be increased by taking advantage of the proposed nest structure. The algorithm and mathematical model of the nested QIM-based watermarking including forward and inverse model is presented. Due to algorithms and architectures of forward and inverse nested QIM, the concurrent programs and special processors for the nested QIM-based watermarking are easily implemented

Haar-Wavelet-Based Just Noticeable Distortion Model for Transparent Watermark

Watermark transparency is required mainly for copyright protection. Based on the characteristics of human visual system, the just noticeable distortion (JND) can be used to verify the transparency requirement. More specifically, any watermarks whose intensities are less than the JND values of an image can be added without degrading the visual quality. It takes extensive experimentations for an appropriate JND model. Motivated by the texture masking effect and the spatial masking effect, which are key factors of JND, Chou and Li (1995) proposed the well-known full-band JND model for the transparent watermark applications. In this paper, we propose a novel JND model based on discrete wavelet transform. Experimental results show that the performance of the proposed JND model is comparable to that of the full-band JND model. However, it has the advantage of saving a lot of computation time; the speed is about 6 times faster than that of the full-band JND model

JPEG2000-Based Image Features with Its Application to Texture Segmentation

In this paper, a context-based wavelet histogram (CBWH) is proposed to characterize image textures. A simple method is also developed to estimate bit-plane probabilities of the CBWH, which can be used as features to segment textured images. Based on the arithmetic coder of the JPEG2000 standard, the CBWH-derived image features can be obtained directly from the MQ table. As a result, images can be segmented in the JPEG2000 domain. The potential of this new scheme is shown by experimental results.APSIPA ASC 2009: Asia-Pacific Signal and Information Processing Association, 2009 Annual Summit and Conference. 4-7 October 2009. Sapporo, Japan. Oral session: Multimedia Analysis and Processing (7 October 2009)

Inverse texture synthesis in wavelet packet trees

Inverse texture synthesis (ITS) plays an important role in many computer vision applications. It aims at generating small compaction images to capture significant features of textures, from which arbitrarily large images with similar textures can be re‐synthesised. This study presents a fast approach to ITS with two algorithms developed in hierarchical wavelet packet (WP) trees: the modified inverse texture synthesis (MITS) algorithm, which extends the ITS algorithm into the WP domain, and the wavelet‐packet‐tree‐based cropping (WPTC) algorithm for the initialisation of MITS. Experimental results show that the combination of WPTC and MITS termed the image compaction in wavelet packet trees algorithm outperforms the ITS algorithm in terms of the ‘peak signal‐to‐noise ratio’ and computation time