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Textual image compression at low bit rates based on region-of-interest coding

INTERNATIONAL JOURNAL ON DOCUMENT ANALYSIS AND RECOGNITION 2016年第1期19卷 65-81页

作者： Grailu, Hadi Univ Shahrood Elect & Robot Engn Dept Shahrood Iran

In this paper, we deal with those applications of textual image compression where high compression ratio and maintaining or improving the visual quality and readability of the compressed images are of main concern. In textual images, most of the information exists in the edge regions;therefore, the compression problem can be studied in the framework of region-of-interest (ROI) coding. In this paper, the Set Partitioning in Hierarchical Trees (SPIHT) coder is used in the framework of ROI coding along with some image enhancement techniques in order to remove the leakage effect which occurs in the wavelet-based low-bit-rate compression. We evaluated the compression performance of the proposed method with respect to some qualitative and quantitative measures. The qualitative measures include the averaged mean opinion scores (MOS) curve along with demonstrating some outputs in different conditions. The quantitative measures include two proposed modified PSNR measures and the conventional one. Comparing the results of the proposed method with those of three conventional approaches, DjVu, JPEG2000, and SPIHT coding, showed that the proposed compression method considerably outperformed the others especially from the qualitative aspect. The proposed method improved the MOS by 20 and 30%, in average, for high- and low-contrast textual images, respectively. In terms of the modified and conventional PSNR measures, the proposed method outperformed DjVu and JPEG2000 up to 0.4 dB for high-contrast textual images at low bit rates. In addition, compressing the high contrast images using the proposed ROI technique, compared to without using this technique, improved the average textual PSNR measure up to 0.5 dB, at low bit rates.

关键词： Textual image Compression region-of-interest coding SPIHT Image enhancement

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Wavelet-based compression of medical images: Protocols to improve resolution and quality scalability and region-of-interest coding

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FUTURE GENERATION COMPUTER SYSTEMS 1999年第2期15卷 171-184页

作者： Schelkens, P Munteanu, A Cornelis, J Free Univ Brussels Dept Elect & Informat Proc ETRO B-1050 Brussels Belgium

The paper describes a methodology to improve the scalability support of an embedded bit stream, generated with a wavelet-based compression algorithm, and a generic protocol to handle multiple regions-of-interest (ROIs). The generic scheme, illustrated for embedded zero-tree wavelet (EZW) coding, exploits the inherent graceful degradation capabilities of wavelet-based compression methods and ensures an optimal trade-off between the image reconstruction quality and the compression ratio. Additionally, an efficient protocol is proposed to handle multiple ROIs in an interactive client-server set-up for telemedicine applications. The processing of the ROIs takes place in the wavelet domain. (C) 1999 Elsevier Science B.V. All rights reserved.

关键词： wavelet-based image compression region-of-interest coding telemedicine resolution and quality scalability

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Compression of digital mammograms with region-of-interest coding evaluated on a CAD system

Compression of digital mammograms with region-of-interest co...

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Medical Imaging 2005 Conference

作者： Engan, K Lillo, MR Gulsrud, TO Univ Stavanger Dept Elect & Comp Engn N-4036 Stavanger Norway

ISBN: (纸本)0819457213

Screening programs produce large amount of mammographic data, and good compression schemes would be beneficial for both storage and transmission purposes. In medical data it is crucial that diagnostic important information is preserved. In this work we have implemented two different region-of-interest (ROI) coding methods to,ether with a Set Partitioning in Hierarchical Trees (SPIHT) scheme to be used for compression of mammograms. Reuion-of- interest coding allows a region of the image to be compressed with higher fidelity than the rest of the image. This is useful in medical data to be able to compress a region containing a possibly cancer area with very high fidelity, but still manage an overall good compression ratio. Both the ROI methods, the basic SPIHT method as well as JPEG compression standard, the latter two without possibility of ROI coding, are evaluated by studying the results from a Computer Aided Detection (CAD) system for microcalcifications tested on the original and the compressed mammograms. In addition a visual inspection is performed as well as Peak Signal-to-Noise-Ratio (PSNR) calculations. from the MIAS database is used. We show that mammograms can be compressed to less than 0.5 (0.3) bpp without any visual degradation and without significantly influence on the performance of the CAD system.

关键词： mammogram compression Computer Aided Detection (CAD) region-of-interest coding ROI SPHIT

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Memory-efficient contour-based region-of-interest coding of arbitrarily large images

Memory-efficient contour-based region-of-interest coding of ...

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Conference on Mobile Multimedia/Image Processing for Military and Security Applications

作者： Sadaka, Nabil G. Abousleman, Glen P. Karam, Lina J. Arizona State Univ Dept Elect Engn Tempe AZ 85287 USA Gen Dynam C4 Syst Video Compress & Exploitat Lab Tempe AZ 85287 USA

ISBN: (纸本)9780819467010

In this paper, we present a memory-efficient, contour-based, region-of-interest (ROI) algorithm designed for ultra-low-bit-rate compression of very large images. The proposed technique is integrated into a user-interactive wavelet-based image coding system in which multiple ROIs of any shape and size can be selected and coded efficiently. The coding technique compresses region-of-interest and background (non-ROI) information independently by allocating more bits to the selected targets and fewer bits to the background data. This allows the user to transmit large images at very low bandwidths with lossy/lossless ROI coding, while preserving the background content to a certain level for contextual purposes. Extremely large images (e.g., 65000 X 65000 pixels) with multiple large ROIs can be coded with minimal memory usage by using intelligent ROI tiling techniques. The foreground information at the encoder/decoder is independently extracted for each tile without adding extra ROI side information to the bit stream. The arbitrary ROI contour is down-sampled and differential chain coded (DCC) for efficient transmission. ROI wavelet masks for each tile are generated and processed independently to handle any size image and any shape/size of overlapping ROIs. The resulting system dramatically reduces the data storage and transmission bandwidth requirements for large digital images with multiple ROIs.

关键词： region-of-interest coding differential chain coding wavelet-based coding lossy/lossless coding

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Automatic face detection and tracking for H.263 compatible region-of-interest coding

Automatic face detection and tracking for H.263 compatible r...

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Conference on Image and Video Communications and Processing 2000

作者： Menser, B Wien, M Rhein Westfal TH Aachen Inst Elekt Nachrichtentech D-52056 Aachen Germany

ISBN: (纸本)0819435929

In this paper a H.263 compatible region-of-interest coding system is presented. A face detection and tracking algorithm is applied to find the region-of-interest (ROI). The input image is filtered by a region-adaptive lowpass filter which blurs the image outside the facial region. This region-adaptive lowpass filtering leads to a graceful degradation of the image quality outside the ROI, whereas the ROI remains unchanged. Since no modification is necessary at the encoder, the ROI preprocessing step is compatible to any existing implementation of the H.263 encoder. For face detection, color information is integrated into a detection algorithm based on principal components analysis. Once a face is detected, tracking is based on color information. The ROI filter can be combined with any video sequence coder. Simulation results are given using the H.263 standard. The bitrate can be significantly reduced while retaining a high perceptual quality.

关键词： region-of-interest coding low bitrate video coding face detection face tracking

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A new JPEG2000 region-of-interest image coding method: Partial significant bitplanes shift

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IEEE SIGNAL PROCESSING LETTERS 2003年第2期10卷 35-38页

作者： Liu, LJ Fan, GL Oklahoma State Univ Dept Elect & Comp Engn Stillwater OK 74078 USA

In this letter, we propose a new region-of-interest (ROI) coding method called partial significant bitplanes shift (PSBShift) that combines the advantages of the two standard ROI coding methods defined in JPEG2000. The PSBShift method not only supports arbitrarily shaped ROI coding without coding the shape, but also enables the flexible adjustment of compression quality in ROI and background. Additionally, the new method can efficiently code multiple ROIs with different degrees of interest in an image.

关键词： image coding JPEG2000 region-of-interest coding

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Scalable Wavelet-Based coding of Irregular Meshes With Interactive region-of-interest Support

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 2019年第7期29卷 2067-2081页

作者： Khalil, Jonas El Sayeh Munteanu, Adrian Lambert, Peter Univ Ghent Elect & Informat Syst Dept IMEC B-9000 Ghent Belgium Vrije Univ Brussel Dept Elect & Informat B-1050 Brussels Belgium

This paper proposes a novel functionality in wavelet-based irregular mesh coding, which is interactive region-of-interest (ROI) support. The proposed approach enables the user to define the arbitrary ROIs at the decoder side and to prioritize and decode these regions at arbitrarily high-granularity levels. In this context, a novel adaptive wavelet transform for irregular meshes is proposed, which enables: 1) varying the resolution across the surface at arbitrarily fine-granularity levels and 2) dynamic tiling, which adapts the tile sizes to the local sampling densities at each resolution level. The proposed tiling approach enables a rate-distortion-optimal distribution of rate across spatial regions. When limiting the highest resolution ROI to the visible regions, the fine granularity of the proposed adaptive wavelet transform reduces the required amount of graphics memory by up to 50%. Furthermore, the required graphics memory for an arbitrary small ROI becomes negligible compared to rendering without ROI support, independent of any tiling decisions. Random access is provided by a novel dynamic tiling approach, which proves to be particularly beneficial for large models of over 10(6) similar to 10(7) vertices. The experiments show that the dynamic tiling introduces a limited lossless rate penalty compared to an equivalent codec without ROI support. Additionally, rate savings up to 85% are observed while decoding ROIs of tens of thousands of vertices.

关键词： Irregular mesh coding region-of-interest coding wavelet coding random access

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region-of-interest-based ultra-low-bit-rate video coding

Region-of-interest-based ultra-low-bit-rate video coding

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Conference on Visual Information Processing XVII

作者： Chien, Wei-Jung Sadaka, Nabil G. Abousleman, Glen R. Karam, Lina J. Arizona State Univ Dept Elect Engn Tempe AZ 85287 USA Gen Dynam C4 Syst Video Compress & Exploitat Lab Scottsdale AZ 85257 USA

ISBN: (纸本)9780819471697

In this paper, we present a region-of-interest-based video coding system for use in real-time applications. region-of-interest (ROI) coding methodology specifies that targets or ROIs be coded at higher fidelity using a greater number of available bits, while the remainder of the scene or background is coded using a fewer number of bits. This allows the target regions within the scene to be well preserved, while dramatically reducing the number of bits required to code the video sequence, thus reducing the transmission bandwidth and storage requirements. In the proposed system, the ROI contours can be selected arbitrarily by the user via a graphical user interface (GUI), or they can be specified via a text file interface by an automated process such as a detection/tracking algorithm. Additionally, these contours can be specified at either the transmitter or receiver. Contour information is efficiently exchanged between the transmitter and receiver and can be adjusted on the fly and in real time. coding results are presented for both electro-optical (EO) and infrared (IR) video sequences to demonstrate the performance of the proposed system.

关键词： ultra-low-bit-rate video coding region-of-interest coding JPEG2000

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Cascaded differential and wavelet compression of chromosome images

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IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING 2002年第4期49卷 372-383页

作者： Liu, ZM Xiong, ZX Wu, Q Wang, YP Castleman, K Texas A&M Univ Dept Elect Engn College Stn TX 77843 USA Adv Digital Imaging Res LLC League City TX 77573 USA

This paper proposes a new method for chromosome image compression based on an important characteristic of these images: the regions of interest (ROIs) to cytogeneticists for evaluation and diagnosis are well determined and segmented. Such information is utilized to advantage in our compression algorithm, which combines lossless compression of chromosome ROIs with lossy-to-lossless coding of the remaining image parts. This is accomplished by first performing a differential operation on chromosome ROIs for decorrelation, followed by critically sampled integer wavelet transforms on these regions and the remaining image parts. The well-known set partitioning in hierarchical trees (SPIHT) (Said and Perlman, 1996) [1] algorithm is modified to generate separate embedded bit streams for both chromosome ROIs and the rest of the image that allow continuous lossy-to-lossless compression of both (although lossless compression of the former is commonly used in practice). Experiments on two sets of sample chromosome spread and karyotype images indicate that the proposed approach significantly outperforms current compression techniques used in commercial karyotyping systems and JPEG-2000 compression, which does not provide the desirable support for lossless compression of arbitrary ROIs.

关键词： chromosome spread and karyotype images differential operations integer wavelet transform JPEG-2000 lossy and lossless compression region-of-interest coding SPIHT

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Content-based compression of mammograms with fractal-based segmentation and a modified JPEG2000

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OPTICAL ENGINEERING 2004年第12期43卷 2986-2993页

作者： Chan, HY Sari-Sarraf, H Grinstead, BI Gleason, SS Texas Tech Univ Dept Elect & Comp Engn Lubbock TX 79409 USA Univ Tennessee Dept Elect & Comp Engn Knoxville TN 37996 USA Oak Ridge Natl Lab Oak Ridge TN 37831 USA

We describe a strategy for the content-based compression of mammograms. In this two-step strategy, the clinically important structures are first identified via a fractal-based segmentation method. Then, a modified version of JPEG2000 is applied in such a way that lossless compression is applied to the extracted structures from the first step, while a lossy compression is applied to the remaining regions. Preliminary results demonstrate that this strategy can achieve high compression ratios (up to 50:1) without compromising the diagnostic quality of the mammograms. (C) 2004 Society of Photo-Optical Instrumentation Engineers.

关键词： content-based compression mammograms JPEG2000 fractal-based segmentation region-of-interest coding

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