Embedded Block Coding With Optimized Truncation Research Articles

Secure and privacy-preserving data sharing in the cloud based on lossless image coding

Image and video processing in the encrypted domain has recently emerged as a promising research area to tackle privacy-related data processing issues. In particular, reversible data hiding in the encrypted domain has been suggested as a solution to store and manage digital images securely in the cloud while preserving their confidentiality. However, although efficiency has been claimed with reversible data hiding techniques in encrypted images (RDHEI), reported results show that the cloud service provider cannot add more than 1 bit per pixel (bpp) of additional data to manage stored images. This paper highlights the weakness of RDHEI as a suggested approach for secure and privacy-preserving cloud computing. In particular, we propose a new, simple, and efficient approach that offers the same level of data security and confidentiality in the cloud without the process of reversible data hiding. The proposed idea is to compress the image via a lossless image coder in order to create space before encryption. This space is then filled with a randomly generated sequence and combined with an encrypted version of the compressed bit stream to form a full resolution encrypted image in the pixel domain. The cloud service provider uses the created room in the encrypted image to add additional data and produces an encrypted image containing additional data in a similar fashion. Assessed with the lossless Embedded Block Coding with Optimized Truncation (EBCOT) algorithm on natural images, the proposed scheme has been shown to exceed the capacity of 3 bpp of additional data while maintaining data security and confidentiality.

FPGA-based Auxiliary Minutest MQ-coder architecture of JPEG2000

Embedded Block Coding with Optimized Truncation (EBCOT) used in JPEG2000 standard performs the sequential processing of code blocks for clear images. The employment of Matrix Quantizer (MQ) in EBCOT reduces the computational burden by generating the context decision pair from probabilistic estimation. But, it consumes huge devices and occupies large memory space that leads to the difficulties in hardware design. The bit truncation in MQ-coder reduces the computational complexities that lead to a reduction in the memory space occupation in the hardware platform. This paper proposes the Auxiliary Minutest MQ (AMMQ) architecture for bit truncation in the probability estimation of context decision pair making. The reduction in a number of bits minimizes the slice registers and lookup tables utilization that offers less flip-flop consumption to achieve the compact chip development for JPEG2000 compression. Besides, the reduction in computational steps effectively minimizes the time delay and hence the high operating frequency. The comparative analysis of proposed AMMQ-coder architecture with the existing architectures regarding the memory assures the effectiveness of new way of bit truncation scheme in the JPEG2000 compression.

Mutual information-based context template modeling for bitplane coding in remote sensing image compression

As remote sensing image applications are often characterized with limited bandwidth and high-quality demands, higher coding performance of remote sensing images are desirable. The embedded block coding with optimal truncation (EBCOT) is the fundamental part of JPEG2000 image compression standard. However, EBCOT only considers correlation within a sub-band and utilizes a context template of eight spatially neighboring coefficients in prediction. The existing optimization methods in literature using the current context template prove little performance improvements. To address this problem, this paper presents a new mutual information (MI)-based context template selection and modeling method. By further considering the correlation across the sub-bands, the potential prediction coefficients, including neighbors, far neighbors, parent and parent neighbors, are comprehensively examined and selected in such a manner that achieves a nice trade-off between the MI-based correlation criterion and the prediction complexity. Based on the selected context template, a high-order prediction model, which jointly considers the weight and the significance state of each coefficient, is proposed. Experimental results show that the proposed algorithm consistently outperforms the benchmark JPEG2000 standard and state-of-the-art algorithms in term of coding efficiency at a competitive computational cost, which makes it desirable in real-time compression applications, especially for remote sensing images.

An efficient hardware implementation of parallel EBCOT algorithm for JPEG 2000

With the augmentation in multimedia technology, demand for high-speed real-time image compression systems has also increased. JPEG 2000 still image compression standard is developed to accommodate such application requirements. Embedded block coding with optimal truncation (EBCOT) is an essential and computationally very demanding part of the compression process of JPEG 2000 image compression standard. Various applications, such as satellite imagery, medical imaging, digital cinema, and others, require high speed and performance EBCOT architecture. In JPEG 2000 standard, the context formation block of EBCOT tier-1 contains high complexity computation and also becomes the bottleneck in this system. In this paper, we propose a fast and efficient VLSI hardware architecture design of context formation for EBCOT tier-1. A high-speed parallel bit-plane coding (BPC) hardware architecture for the EBCOT module in JPEG 2000 is proposed and implemented. Experimental results show that our design outperforms well-known techniques with respect to the processing time. It can reach 70 % reduction when compared to bit plane sequential processing.

Wavelet based Image Coding Schemes: A Recent Survey

A variety of new and powerful algorithms have been developed for image compression over the years. Among them the wavelet-based image compression schemes have gained much popularity due to their overlapping nature which reduces the blocking artifacts that are common phenomena in JPEG compression and multiresolution character which leads to superior energy compaction with high quality reconstructed images. This paper provides a detailed survey on some of the popular wavelet coding techniques such as the Embedded Zerotree Wavelet (EZW) coding, Set Partitioning in Hierarchical Tree (SPIHT) coding, the Set Partitioned Embedded Block (SPECK) Coder, and the Embedded Block Coding with Optimized Truncation (EBCOT) algorithm. Other wavelet-based coding techniques like the Wavelet Difference Reduction (WDR) and the Adaptive Scanned Wavelet Difference Reduction (ASWDR) algorithms, the Space Frequency Quantization (SFQ) algorithm, the Embedded Predictive Wavelet Image Coder (EPWIC), Compression with Reversible Embedded Wavelet (CREW), the Stack-Run (SR) coding and the recent Geometric Wavelet (GW) coding are also discussed. Based on the review, recommendations and discussions are presented for algorithm development and implementation.

Area Efficient, High Speed EBCOT Architecture for Digital Cinema

Embedded block coding with optimised truncation (EBCOT) is a key algorithm in digital cinema (DC) distribution system. Though several high speed EBCOT architectures exist, all are not capable of meeting the DC specifications. To meet this challenge, the relationship between contents of a code block (CB) and context generation is studied. Our study reveals that it is difficult to predict number of contexts generated in a bit plane. Even the nature of number of contexts produced varies from CB to CB. In such a situation, it is difficult to ensure the frame rate requirement of DC. To avoid this uncertainty, a pass parallel, concurrent sample coding EBCOT architecture is proposed in this paper. It is capable of encoding one bit plane in 288 clock cycles under any circumstances. This design is prototyped on XC4VLX80-12 FPGA with multiple clock domains. After synthesizing, the bit plane coder (BPC) and MQ coder operate at 450 MHz and 123 MHz, respectively. In order to maintain synchronism among different clock domains, the BPC and MQ coder units are operated at 432 MHz and 108 MHz, respectively. This entails that the proposed design is capable of processing size 57 DC frames in a second.

Intelligent Image compression in Multi-agent system

When using wireless sensor networks for real-time data transmission, some critical points should be considered. Restricted computational power, memory limitations, narrow bandwidth and energy supplied present strong limits in sensor nodes. Therefore, maximizing network lifetime and minimizing energy consumption are always optimization goals. To reduce the energy consumption of the sensor network during image transmission, an energy efficient image compression scheme is proposed. The image compression scheme reduces the required memory. To address the above mentioned concerns, in this paper we describe an approach of image transmission in WSNs , taking advantage of JPEG2000 still image compression standard and using MATLAB . These features were achieved using techniques: the Discrete Wavelet Transform (DWT), and Embedded Block Coding with Optimized Truncation (EBCOT). Performance of the proposed image compression scheme is investigated with respect to image quality and energy consumption. Simulation results are presented and show that the proposed scheme optimizes network lifetime and reduces significantly the amount of required memory by analyzing the functional influence of each parameter of this distributed image compression algorithm.

Parallel-pass architecture for embedded block coding with optimal truncation in JPEG 2000

In this letter, we propose parallel-pass architecture for Embedded block coding with optimal truncation (EBCOT) entropy encoding in JPEG 2000. In the proposed method the time consuming sequential pass architecture is replaced with the parallel-pass approach. The experimental results show that the proposed method reduces the processing time by 22.6% as compared with the Taubman's Kakadu architecture of EBCOT.

Codestream-Based Identification of JPEG 2000 Images with Different Coding Parameters

A method of identifying JPEG 2000 images with different coding parameters, such as code-block sizes, quantization-step sizes, and resolution levels, is presented. It does not produce false-negative matches regardless of different coding parameters (compression rate, code-block size, and discrete wavelet transform (DWT) resolutions levels) or quantization step sizes. This feature is not provided by conventional methods. Moreover, the proposed approach is fast because it uses the number of zero-bit-planes that can be extracted from the JPEG 2000 codestream by only parsing the header information without embedded block coding with optimized truncation (EBCOT) decoding. The experimental results revealed the effectiveness of image identification based on the new method.

Analysis Of Spiht Algorithm For Satellite Image Compression

Wavelets offer an elegant technique for representing the levels of details present in an image. When an image is decomposed using wavelets, the high pass component carry less information, and vice-versa. The possibility of elimination of the high pass components gives higher compression ratio in the case of wavelet based image compression. To achieve higher compression ratio, various coding schemes have been used. Some of the well known coding algorithms are EZW (Embedded Zero-tree Wavelet), SPIHT (Set Partitioning in Hierarchical Tree) and EBCOT (Embedded Block Coding with Optimal Truncation). SPIHT has been one of the popular schemes used for image compression. In this paper the performance of the SPIHT (Set Partitioning in Hierarchical Trees) compression technique for satellite images are studied. The satellite rural and urban images have been used for the present analysis. The standard Lena image is used for the purpose of comparison. For a given compression ratio, the PSNR (peak signal to noise ratio) values are computed to evaluate the quality of the reconstructed image. The analysis carried out clearly suggests that the PSNR values increases with the level of decomposition. For the satellite images the PSNR values achievable are less compared to that of Standard Lena Image and the SPIHT Algorithm are better suited for compression of Satellite urban Images.

Efficient JPEG 2000 Image Compression Scheme for Multihop Wireless Networks

When using wireless sensor networks for real-time data transmission, some critical points should be considered. Restricted computational power, reduced memory, narrow bandwidth and energy supplied present strong limits in sensor nodes. Therefore, maximizing network lifetime and minimizing energy consumption are always optimization goals. To overcome the computation and energy limitation of individual sensor nodes during image transmission, an energy efficient image transport scheme is proposed, taking advantage of JPEG2000 still image compression standard using MATLAB and C from Jasper. JPEG2000 provides a practical set of features, not necessarily available in the previous standards. These features were achieved using techniques: the discrete wavelet transform (DWT), and embedded block coding with optimized truncation (EBCOT). Performance of the proposed image transport scheme is investigated with respect to image quality and energy consumption. Simulation results are presented and show that the proposed scheme optimizes network lifetime and reduces significantly the amount of required memory by analyzing the functional influence of each parameter of this distributed image compression algorithm.

VLSI design of memory-efficient, high-speed baseline MQ coder for JPEG 2000

The embedded block coding with optimized truncation (EBCOT) algorithm is the heart of the JPEG 2000 image compression system. The MQ coder used in this algorithm restricts throughput of the EBCOT because there is very high correlation among all procedures to be performed in it. To overcome this obstacle, a high throughput MQ coder architecture is presented in this paper. To accomplish this, we have studied the number of rotations performed and the rate of byte emission in an image. This study reveals that in an image, on an average 75.03% and 22.72% of time one and two shifts occur, respectively. Similarly, about 5.5% of time two bytes are emitted concurrently. Based on these facts, a new MQ coder architecture is proposed which is capable of consuming one symbol per clock cycle. The throughput of this coder is improved by operating the renormalization and byte out stages concurrently. To reduce the hardware cost, synchronous shifters are used instead of hard shifters. The proposed architecture is implemented on Stratix FPGA and is capable of operating at 145.9 MHz. Memory requirement of the proposed architecture is reduced by a minimum of 66% compared to those of the other existing architectures. Relative figure of merit is computed to compare the overall efficiency of all architectures which show that the proposed architecture provides good balance between the throughput and hardware cost.

An Efficient Pass-Parallel Architecture for Embedded Block Coder in JPEG 2000

The embedded block coding with optimized truncation (EBCOT) is a key algorithm in JPEG 2000 image compression system. Various applications, such as medical imaging, satellite imagery, digital cinema, and others, require high speed, high performance EBCOT architecture. Though efficient EBCOT architectures have been proposed, hardware requirement of these existing architectures is very high and throughput is low. To solve this problem, we investigated rate of concurrent context generation. Our paper revealed that in an image rate of four or more context pairs generation is about 68.9%. Therefore, to encode all samples in a stripe-column, concurrently a new technique named as compact context coding is devised. As a consequence, high throughput is attained and hardware requirement is also cut down. The performance of the matrix quantizer coder is improved by operating renormalization and byte out stages concurrently. The entire design of EBCOT encoder is tested on the field programmable gate array platform. The implementation results show that throughput of the proposed architecture is 163.59 MSamples/s which is equivalent to encoding 1920p (1920 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">$\,\times\,$</tex></formula> 1080, 4:2:2) high-definition TV picture sequence at 39 f/s. However, only bit plane coder (BPC) architecture operates at 315.06 MHz which implies that it is 2.86 times faster than the fastest BPC design available so far. Moreover, it is capable of encoding digital cinema size (2048 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">$\,\times\,$</tex></formula> 1080) at 42 f/s. Thus, it satisfies the requirement of applications like cartography, medical imaging, satellite imagery, and others, which demand high-speed real-time image compression system.

On Accelerating Image Display for WAP Based on EBCOT

At present, because of the diversity of mobile devices and low bandwidth network, traditional internet application can not work efficiently on mobile devices. For example, it is very slow to download images from internet to a mobile phone. In order to overcome this problem, we propose a new method to design a wap application gateway based on embedded block coding with optimal truncation (EBCOT), which can modify images adaptively according to different types of mobile phones. Therefore we can quickly browse images with a mobile phone even in a low-bandwidth network.

An Improved Image Compression Algorithm Using Binary Space Partition Scheme and Geometric Wavelets

Geometric wavelet is a recent development in the field of multivariate nonlinear piecewise polynomials approximation. The present study improves the geometric wavelet (GW) image coding method by using the slope intercept representation of the straight line in the binary space partition scheme. The performance of the proposed algorithm is compared with the wavelet transform-based compression methods such as the embedded zerotree wavelet (EZW), the set partitioning in hierarchical trees (SPIHT) and the embedded block coding with optimized truncation (EBCOT), and other recently developed "sparse geometric representation" based compression algorithms. The proposed image compression algorithm outperforms the EZW, the Bandelets and the GW algorithm. The presented algorithm reports a gain of 0.22 dB over the GW method at the compression ratio of 64 for the Cameraman test image.

Optimization of Arithmetic Coding for JPEG2000

Embedded block coding with optimized truncation (EBCOT) employed in the JPEG2000 standard accounts for the majority of the processing time, because the EBCOT is full of bit operations that cannot be implemented efficiently in software. The block coder consists of a bit-plane coder (BPC) followed by a binary arithmetic coder (BAC), where the most up-to-date BPC architectures are capable of producing symbols at a much higher rate than the conventional BACs can handle. This letter proposes a novel pipelined BAC architecture that can encode input symbols at a much higher rate than the conventional BAC architectures. The proposed architecture can significantly reduce the critical path delay and can achieve a throughput of 400 Msymbols/s. The critical path delay synthesized with 0.18 ¿m CMOS technology is 2.42 ns, which is almost half of the delay taken in conventional BAC architectures.

A semi-fragile wavelet transform watermarking scheme for content authentication of images

A novel semi-fragile watermarking scheme for the content authentication of images using wavelet transform (WT) is presented in this paper. It is tolerant to the embedded wavelet image compression methods based on WT such as embedded zerotree wavelet (EZW), set partitioning in hierarchical trees (SPIHT) and embedded block coding with optimized truncation (EBCOT) in JPEG2000 to a pre-determined bit-plane, but is sensitive to all other malicious attacks. The image features are generated from the lowest-frequency (LF) subband of the original image as the embedded watermark. The watermark is embedded into the pre-determined bit-plane by adjusting the corresponding values in the given subband. In the process of watermarking authentication, we compare the image features generated from the LF subband of the received image with the embedded watermarking information (the image features of the original image) extracted from the pre-determined bit-plane in the given subband of the received image to decide whether the image is attacked maliciously or processed acceptably (the embedded wavelet compression). The most important advantage of our watermarking scheme is that the watermark information can be extracted from the watermarked image when detecting watermark, so the received image authentication needs no information about the original image or watermark. Experimental results prove the effectiveness of our proposed watermarking scheme.

Scalable image registration with JPEG2000

We present a scalable registration algorithm for aligning large-frame imagery compressed with the JPEG2000 coding standard. Unlike traditional approaches, the proposed method registers the images in the compressed domain, which eliminates the need to reconstruct the full image prior to performing registration. Two forms of scalability are exploited during registration: resolution and quality. Resolution scalability results from the native multiresolution image representation of the discrete wavelet transform utilized as a building block in JPEG2000. Quality scalability relates to the embedded block coding with optimal truncation (EBCOT) used for compressing the wavelet coefficients. This combination allows registration on selectable resolution levels and quality layers, which enables registration of large-frame imagery at low bit rates over constrained bandwidth channels. Furthermore, the hierarchical nature of the algorithm provides a trade-off between registration accuracy and computational complexity. Experimental results show that the proposed algorithm exhibits consistent registration performance across a range of quality levels (3.5 to 0.5 bpp) for frames sizes of 2 K×4 K. We present simulation results with imagery collected from a prototype persistent surveillance system to demonstrate the feasibility of the proposed algorithm in real-world scenarios.

AN EFFICIENT DESIGN FOR MOTION-JPEG2000 SYSTEM IN REAL-TIME VIDEO ENCODING

Motion-JPEG2000 is derived from Part 1 of the JPEG2000 standard and provides high quality image compression in video coding system. This paper presents a real-time Motion-JPEG2000 encoding which is built on a fixed-point digital signal processor (DSP) as a single-chip implementation. The design addresses on the system-level design considerations. Among several modules in JPEG2000, Embedded Block Coding with Optimized Truncation (EBCOT) algorithm contains the highest computation complexity and also becomes the bottleneck of JPEG2000. Two speed-improved methods are proposed to significantly reduce the processing time of EBCOT. The fast algorithm is used by processing the three coding passes in sequential and is very suitable to the execution on programming-based processor. For Motion-JPEG2000 implementation, a real-time encoding system is built on the single-chip DSP processor without any extra hardware support. The optimization techniques are also applied to enhance the performance. Due to the contribution on algorithm and implementation issue, the complexity of Motion-JPEG2000 is largely reduced. Simulation results show that the proposed system can process 30 frames per second in CIF size (352 × 288 pixels) with 4:2:0 video sequences. For SDTV size resolution (760 × 480 pixels), the system can achieve near 20 frames per second.

Automatically-Determined Region of Interest in JPEG 2000

This work presents an automatically-determined region of interest (ROI) scheme embedded in JPEG 2000. The proposed scheme analyzes the image content and then determines the probable ROI masks by examining the significant states of high-frequency subbands generated from embedded block coding with optimized truncation (EBCOT). Additionally, probable ROI masks are constructed in all bit planes of subbands by categorizing sub-blocks as either interesting or uninteresting, smoothing subblocks of interest, and grouping these subblocks based on an or no initial point. The rate-distortion (RD) pairs corresponding to all probable ROI masks are then estimated from the RD distribution during the Tier-2 coding process of EBCOT. Based on these estimations, the Lagrangian multiplier method is employed in the RD function to obtain the optimized ROI mask from the probable masks by minimizing the distortion of the ROI-encoded image at a given bit-rate constraint. ROI-encoded images obtained using the proposed scheme outperform ROI-encoded images obtained via the conventional schemes using fixed-square and object-segmentation masks, as judged by subjective visual perception and objective measurement in terms of peak signal-to-noise ratio. Particularly, the proposed scheme can easily adapt the ROI region with varied sizes and shapes according to the bit-rate constraint whereas the conventional schemes only adopt the fixed-square region and fixed segmented objects. Furthermore, when the proposed scheme is applied to motion JPEG 2000 for video compression, the centroid of the ROI mask in the previous frame can be used as an initial point for merging the subblocks of interest in the current frame to track the ROI masks in a video sequence. Therefore, the proposed scheme can easily be employed to improve the perceptual and objective performance in the ROI coding associated with JPEG 2000 and motion JPEG 2000.