A simple lossy-to-lossless bit-plane coding of still images is presented to integrate several functionality extension including selective tile partitioning, progressive transmission, ROI transmission, accuracy scalabi...
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A simple lossy-to-lossless bit-plane coding of still images is presented to integrate several functionality extension including selective tile partitioning, progressive transmission, ROI transmission, accuracy scalability, and others. The mean squared error between the original image and a decoded image at any progression level is known prior to encoding/decoding. The proposed bit-plane codec is competitive with JPEG-LS and JPEG 2000 in the lossless compression of 8-bit grayscale and 24-bit color images. The codec outperforms the existing standards in 8-bit color-quantized image compression.
A simple lossless color image compression scheme is proposed. It utilizes integer color transform and integer wavelet transform to ensure complete reversibility with fixed-point implementation. In the encoding process...
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A simple lossless color image compression scheme is proposed. It utilizes integer color transform and integer wavelet transform to ensure complete reversibility with fixed-point implementation. In the encoding process, the wavelet coefficients are divided into smaller block in order to increase the performance of arithmetic coding which is applied to the actual values of transform coefficients. Without any prediction or other model in the process, this very simple coder has low complexity along with promising compression efficiency in continuous tone image. The comparison with lossless JPEG 2000 and JPEG-LS reveals that it has almost the same performance as the state-of-the-art standards. With its fast and low complexity algorithm, the proposed coder is suitable to be used within wireless sensor nodes in wireless sensor network.
Panoramic video is efficient for user-driven interactive video application, so as the user can change his/her view angle. To achieve such interactivity, the efficient video coding method which supports high compressio...
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Panoramic video is efficient for user-driven interactive video application, so as the user can change his/her view angle. To achieve such interactivity, the efficient video coding method which supports high compression efficiency as well as key feature, such as spatially partial area decoding and smooth change of its position is proposed. In the proposed method, MVC video coding standard is used for compression, and the efficient control method of decoding and rendering of panoramic video is exploited.
The lossy compression performance of two different ordering schemes: dispersed dither type and clustered dither type, are studied and compared. For lossy coding of ordered dither images, two methods; multi-level lossy...
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The lossy compression performance of two different ordering schemes: dispersed dither type and clustered dither type, are studied and compared. For lossy coding of ordered dither images, two methods; multi-level lossy image coding (LML) with post-processing of ordered dithering and transmission of the number of black pixels in a block of bi-level pixels (BPN), with two kind of bit rates, corresponding to two block sizes (2 times 2 pixels and 4 times 4 pixels) are examined. Concerning dither types, not much difference was found in entropy and also in image quality for 4 times 4 lossy case, but Bayer dithering works slightly better than screen dithering for 2 times 2 cases. Concerning the comparison of LML and BPN, BPN shows subjectively better picture quality than LML in 2 times 2 cases and the PSNR of Inverse Halftone (IH) images of restored bi-level images to the IH images of lossless halftone images is found to well reflect the subjective impression.
Based on some simple arithmetic operation, an efficient lossless image compression technique is proposed. We use repeat reduction and arithmetic coding to improve the results of compression. We get better results than...
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Based on some simple arithmetic operation, an efficient lossless image compression technique is proposed. We use repeat reduction and arithmetic coding to improve the results of compression. We get better results than log-exp based compression and arithmetic modulo based compression. From the experimental results, it can be seen that the performance of proposed method is better for all standard images. The complexity of our proposed method with respect to compression ratio has also been analyzed. The proposed method is most applicable for those images where lossy compression is to be avoided.
Medical images have high spatial and high bit-depth resolution (12 bits per sample or more). These high resolutions allow computer-aided diagnosis, which are exploited by radiologists to identify relevant medical area...
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ISBN:
(纸本)9781424458257
Medical images have high spatial and high bit-depth resolution (12 bits per sample or more). These high resolutions allow computer-aided diagnosis, which are exploited by radiologists to identify relevant medical areas, known as Regions of Interest (ROI). In image compression, ROI coding allows to recover the ROI earlier than the rest of the image. In JPEG2000, ROI coding may be provided through two different mechanisms: either by modifying wavelet coefficients, or by rate-distortion optimization techniques. The former obtains an excellent accuracy to delimit ROIs, but, in some cases, the ROI and the background can not be encoded losslessly; the latter is usually not able to achieve the intended fine-grain accuracy, but it overcomes the lossless encoding shortcoming. This article introduces a ROI coding method based on rate-distortion optimization techniques that recovers the ROI and the background losslessly, regardless of the high bit-depth resolution, and that yields an accuracy equivalent to MaxShift and Scaling, the two compliant JPEG2000 ROI coding methods based on modifying wavelet coefficients. The proposed method is JPEG2000 compliant.
In video coding standards like H.264 / MPEG-4 AVC, the encoder performs motion estimation in order to utilise temporal dependencies within a sequence. In addition to the rate of the residue, the encoder has to allocat...
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ISBN:
(纸本)9781424438273
In video coding standards like H.264 / MPEG-4 AVC, the encoder performs motion estimation in order to utilise temporal dependencies within a sequence. In addition to the rate of the residue, the encoder has to allocate bits for motion vectors required to compensate the motion at the decoder. This bit rate increases for smaller block sizes, since more motion vectors need to be transmitted. Therefore, motion compensation using dense motion vector field is not feasible for such an architecture. This paper proposes to estimate motion for coding of B frames at the decoder. Using this decoder-side motion estimation, the transmission of the motion vectors is not necessary and the bit rate is reduced. Furthermore, prediction quality is higher in many cases resulting in a coding gain of up to 1.7 dB at low bit rates and 0.2 dB at higher bit rates.
A wavelet subdivision surfaces based multiple description 3D model coding with optimal reconstruction filtering approach is proposed in this paper to transmit 3D models over mediums with possible packet loss with high...
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A wavelet subdivision surfaces based multiple description 3D model coding with optimal reconstruction filtering approach is proposed in this paper to transmit 3D models over mediums with possible packet loss with higher quality. The proposed method is based on the wavelet subdivision surfaces strategy for 3D model coding and introduces optimal reconstruction filtering. Initially, remeshing is performed for any 3D model to obtain a semi-regular mesh structure which includes an irregular base mesh and regular wavelet (detail) coefficients of finer levels. Next, multiple descriptions of detail coefficients are obtained using Multiple Description Scalar Quantization (MDSQ) to be encoded using SPIHT. In the proposed approach, reconstructed multiple descriptions are applied to optimal filters, that are obtained at the encoder so as to reduce the reconstruction error between the original model and encoded model. Each transmitted description therefore includes encoded 3D data as well as optimal reconstruction filter coefficients. Experimental results show that the optimal reconstruction filtering approach reduces the distortion of standard MDSQ based 3D model coding.
Audio transform coding methods generally employ an assumption of locally stationary signals. However, as demands on coding efficiency increase, the assumption of stationarity becomes increasingly challenging. In this ...
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Audio transform coding methods generally employ an assumption of locally stationary signals. However, as demands on coding efficiency increase, the assumption of stationarity becomes increasingly challenging. In this article we study a parametric method for modeling variability in an audio signal, especially with voiced speech in mind. Namely, we model modulation in fundamental frequency and amplitude, with the objective of allowing normalization of the signal to satisfy the stationarity requirements of transform based coders.
In image compression and image processing applications, region of interest (ROI) of images are hoped to get better compression results compares with region of back ground. Combining the advantages of general scaling b...
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In image compression and image processing applications, region of interest (ROI) of images are hoped to get better compression results compares with region of back ground. Combining the advantages of general scaling based method (SBM) for the processing region of interest in JPEG2000, a novel ROI image coding method using multiwavelet-based set partitioning in hierarchical (SPIHT) algorithm is proposed. By using this coding method, the compressed bit stream are all embedded and suited for progressive transmission. Experimental results show that at the same compression ratio, although the whole image's PSNR performance of the proposed algorithm is inferior to the original multiwavelet-based SPIHT algorithm, ROI can get better reconstructed quality, especially for low bit rate compression condition.
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