The region of Interest (ROI) coding is an important application of region-based still imagecoding and can encode these significant regions with higher quality than others (background). In this paper, we present a new...
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ISBN:
(纸本)1424400600
The region of Interest (ROI) coding is an important application of region-based still imagecoding and can encode these significant regions with higher quality than others (background). In this paper, we present a new region-based image coding method called Partial Subbands Maximum Bitplanes Shift (PSMBShift). The new method applies different scaling strategies for the different frequency subbands of wavelet image. In low and mediate frequency subbands, the Maxshift method recommended by JPEG2000 standard is used to scale all bitplanes of the ROI coefficients. In high frequency subbands, only the partial most significant bitplanes of the ROI coefficients are scaled and the other bitplanes of the ROI coefficients are obtained in original position. The experiments show that the PSMBShift method can not only combine the advantages of the two standard methods of JPEG2000, but also can control efficiently the quality between the ROIs and BG by adjusting scaling values of high frequency subbands.
The region of Interest (ROI) coding is an important application of region-based still imagecoding and can encode these significant regions with higher quality than others (background). In this paper, we present a new...
详细信息
The region of Interest (ROI) coding is an important application of region-based still imagecoding and can encode these significant regions with higher quality than others (background). In this paper, we present a new region-based image coding method called Partial Subbands Maximum Bitplanes Shift (PSMBShift). The new method applies different scaling strategies for the different frequency subbands of wavelet image. In low and mediate frequency subbands, the Maxshift method recommended by JPEG2000 standard is used to scale all bitplanes of the ROI *** high frequency subbands, only the partial most significant bitplanes of the ROI coefficients are scaled and the other bitplanes of the ROI coefficients are obtained in original position. The experiments show that the PSMBShift method can not only combine the advantages of the two standard methods of JPEG2000, but also can control efficiently the quality between the ROIs and BG by adjusting scaling values of high frequency subbands.
This paper presents a progressive imagecoding technique in which a rough preview image is enhanced with the zerotree encoding of the residual image in the wavelet domain. The preview image is achieved with a region b...
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This paper presents a progressive imagecoding technique in which a rough preview image is enhanced with the zerotree encoding of the residual image in the wavelet domain. The preview image is achieved with a regionbased approach that gives a basic description of the scene with a very high compression ratio. As a second stage, the residual between the original image and the preview is decomposed using a wavelet transform, and it is encoded for a progressive transmission. The wavelet coefficients are selected from the coarsest to the finest level of resolution, using a mask obtained from the image preview. Such a mask sets the importance of the coefficients on the basis of their distance from the contours of the regions of the preview. A modified zerotree approach is used to progressively encode the weighted coefficients until significant texture is introduced in the image and the required quality is achieved. Moreover, if it is required an image with very good quality, the resulting reconstruction error is encoded by means of vector quantization and transmitted over the channel. The proposed method is compared to progressive JPEG, and it obtains similar results at low compression ratios and far better at higher ones.
To get the high compression ratio as well as the high-quality reconstructed image, an effective image compression scheme named irregular segmentation regioncodingbased on spiking cortical model（ISRCS） is presented...
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To get the high compression ratio as well as the high-quality reconstructed image, an effective image compression scheme named irregular segmentation regioncodingbased on spiking cortical model（ISRCS） is presented. This scheme is region-based and mainly focuses on two issues. Firstly, an appropriate segmentation algorithm is developed to partition an image into some irregular regions and tidy contours, where the crucial regions corresponding to objects are retained and a lot of tiny parts are eliminated. The irregular regions and contours are coded using different methods respectively in the next step. The other issue is the coding method of contours where an efficient and novel chain code is employed. This scheme tries to find a compromise between the quality of reconstructed images and the compression ratio. Some principles and experiments are conducted and the results show its higher performance compared with other compression technologies, in terms of higher quality of reconstructed images, higher compression ratio and less time consuming.
We present a new vertex selection scheme for polygon-based contour coders. When contour coding is used for imagecoding applications, it is argued that partitioning a contour into partial segments and then approximati...
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We present a new vertex selection scheme for polygon-based contour coders. When contour coding is used for imagecoding applications, it is argued that partitioning a contour into partial segments and then approximating these segments with a variable accuracy is required to efficiently handle their relative significance. Accordingly, a decision rule for the allowable maximum distortion (d(max)) is derived based on interregion contrasts, and an adaptive vertex selection method is proposed based on the derived rule. Experimental results are presented to show the superiority of the proposed method over conventional methods. (C) 2004 Society of Photo-Optical Instrumentation Engineers.
This paper presents a new morphological spatiotemporal segmentation algorithm, The algorithm incorporates luminance and motion information simultaneously and uses morphological tools such as morphological filters and ...
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This paper presents a new morphological spatiotemporal segmentation algorithm, The algorithm incorporates luminance and motion information simultaneously and uses morphological tools such as morphological filters and watershed algorithm, The procedure toward complete segmentation consists of three steps: joint marker extraction, boundary decision, and motion-basedregion fusion, First, the joint marker extraction identifies the presence of homogeneous regions in both motion and luminance, where a simple joint marker extraction technique is proposed. Second, the spatio-temporal boundaries are decided by the watershed algorithm, For this purpose, a new joint similarity measure is proposed, Finally, an elimination of redundant regions is done using motion-basedregion fusion. By incorporating spatial and temporal information simultaneously, we can obtain visually meaningful segmentation results. Simulation results demonstrates the efficiency of the proposed method.
Recently, a new technique for the lossless encoding of contour maps was introduced, based on the concept of "transition points." in this paper we show that by using a simple representation for the transition...
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Recently, a new technique for the lossless encoding of contour maps was introduced, based on the concept of "transition points." in this paper we show that by using a simple representation for the transition points, i.e., the map of transition points, the problem of encoding arbitrary contour maps can be easily converted into a problem of lossless imagecoding. Experimental results show that the joint bilevel image experts group (JBIG) imagecoding standard can be used successfully For encoding maps of transition points, outperforming, in most cases, differential chain-coding. Moreover, if we take into account that JBIG codecs are available as "off the shelf" components, then the effort required to implement the proposed method is small.
An efficient technique for encoding arbitrary contours is presented. It is based on the concept of transition point of a contour map and relies on a new four-symbol adaptive context-based arithmetic encoder (CAE) that...
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An efficient technique for encoding arbitrary contours is presented. It is based on the concept of transition point of a contour map and relies on a new four-symbol adaptive context-based arithmetic encoder (CAE) that calculates contexts in the (binary) domain of the contour map. The results obtained with this new technique applied to the compression of image partitions are substantially better than those previously attained, showing a clear superiority over adaptive CAE-based differential chain coding and also over the MPEG-4 shape coder.
This paper presents a solution for image partition encoding, usable for region-basedimage or video compression. This solution consists of several elements which can eventually be used separately in other contexts suc...
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ISBN:
(纸本)0819424358
This paper presents a solution for image partition encoding, usable for region-basedimage or video compression. This solution consists of several elements which can eventually be used separately in other contexts such as the recent VOP contour encoding defined withing the ISO-MPEG-4 standardization effort. Namely, these elements are the graph representation of the contour network topology on the one hand, and the B-spline approximation of the contour geometry, approximation carried out on a purely geometric criterion on the other hand. The role of the graph repesentation is two-fold;to enable the regeneration of region labels at the decoder side, without needing to send them along with the contour geometry, which could be jeopardized otherwise by contour approximation errors, and to save the coding of the contours starting points. Such label regeneration is based on the extraction of the list of consecutive arcs corresponding to the external region boundary only from the graph structure. The algorithm for such an extraction is given as well as the encoding of the graph structure. Compression of the geometric information is obtained through contour approximation by B-spline curves. Such an approximation combines a Least Mean Squares curve fitting and a gradient-based geometric curve evolution from this first approximation. Finally, a solution is proposed for the encoding of the resulting B-spline control points.
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