In this paper we present a new algorithm for chroma prediction in YUV images, based on inter component correlation. Despite the YUV color space transformation for inter component decorrelation, some dependency still e...
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ISBN:
(纸本)9781424479948
In this paper we present a new algorithm for chroma prediction in YUV images, based on inter component correlation. Despite the YUV color space transformation for inter component decorrelation, some dependency still exists between the Y, U and V chroma components. This dependency has been previously used to predict the chrominance data from the reconstructed luminance. In this paper we show that a chrominance component can be more efficiently predicted by using the reconstructed data from both the luminance and the remaining chrominance signal. The proposed chroma prediction is implemented and tested using the Multidimensional Multiscale Parser (MMP) image encoding algorithm. It is shown that the new color prediction mode outperforms the originally proposed prediction methods. Furthermore, by using the new color prediction scheme, MMP is consistently better than the state-of-the-art H.264/AVC for coding both for the luminance and the chrominance image components.
In this paper, we propose a simple and efficient technique for embedded color image coding. The proposed algorithm exploits inter- and intra-subband correlations of the wavelet transformed luminance (Y) and chrominanc...
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ISBN:
(纸本)9781424404810
In this paper, we propose a simple and efficient technique for embedded color image coding. The proposed algorithm exploits inter- and intra-subband correlations of the wavelet transformed luminance (Y) and chrominance (U and V) planes as well as the interdependency among the coefficients of the three-color planes. The coefficients of the three-color planes are linked through the composite spatial orientation trees (CSOT) having root nodes in the Y-plane only. The CSOT is defined for blocks of coefficients rather than a single coefficient. Thus, the proposed algorithm combines the features of both zero-tree and zero-block based algorithm into a single algorithm due to the use of block-tree hierarchical structure. Simulation results show the improved performance of the proposed algorithm over other sate-of-the-art coders such as MPEG-4, color SPIHT (CSPIHT), color SPECK (CPECK), and JPEG-2000.
This paper considers an objective picture quality scale for colorimages (PQScolor). PQScolor approximates the mean opinion score satisfactorily, it takes into account the color perception by using color difference an...
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ISBN:
(纸本)0780331222
This paper considers an objective picture quality scale for colorimages (PQScolor). PQScolor approximates the mean opinion score satisfactorily, it takes into account the color perception by using color difference and the properties of visual perception for global features and for localized disturbances. There are two type systems, PQScolor1 is based on Godlove's color difference and PQScolor2 is based on H, V, C signal difference. The correlation coefficient between PQScolor (1, 2) and MOS is more than 0.9, which is very high compared to the value 0.34 obtained for the mean color difference scale.
This paper proposes an efficient extension of virtual set partitioning in hierarchical trees (VSPIHT) for color image coding. Our new scheme, color-Virtual-SPIHT (CVSPIHT) generates fully embedded bit stream similar t...
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ISBN:
(纸本)0780374029
This paper proposes an efficient extension of virtual set partitioning in hierarchical trees (VSPIHT) for color image coding. Our new scheme, color-Virtual-SPIHT (CVSPIHT) generates fully embedded bit stream similar to SPIHT. It combines the zerotrees of three color planes in two steps. First, zerotrees within the same color planes are joined to-gather by VSPIHT, then resulting longer zerotrees of three planes are combined through a novel composite tree. The simulation results show the improved performance of the proposed method compared to a SPIHT based colorcoding scheme.
This paper improves a colorization-based imagecoding using image segmentation and adaptive colorspaces. Recently, various approaches for color image coding based on colorization have been presented. These methods uti...
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ISBN:
(纸本)9781509041183
This paper improves a colorization-based imagecoding using image segmentation and adaptive colorspaces. Recently, various approaches for color image coding based on colorization have been presented. These methods utilize a YCbCr colorspace and transfer the luminance component by a conventional compression method. Then, the chrominance components are approximated from the luminance component using a colorization method. Our method segments a luminance component into small segments called superpixels, and reconstructs the chrominance of each superpixel as a linear combination of its luminance. For chrominance components, we introduce an adaptive color space transform optimized for liner combination. This is because YCbCr colorspace cannot always become a good approximation of the chrominance. In addition, we introduce an automatic selection for the number of superpixel segments from a given quality factor. The simulation with standard images shows that our method performs better result than conventional coding schemes.
In this paper, we introduce a novel framework for lossless/near-lossless (LS/NLS) color image coding assisted by an inverse demosaicing. Conventional frameworks are typically based on prediction (and quantization for ...
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ISBN:
(纸本)9781479928941
In this paper, we introduce a novel framework for lossless/near-lossless (LS/NLS) color image coding assisted by an inverse demosaicing. Conventional frameworks are typically based on prediction (and quantization for NLS coding) followed by entropy coding, such as the JPEG-LS for bit rate saving. The approach of this work is totally different from the conventional ones. Basically, colorimages are created by demosaicing Bayer-pattern color filter array (CFA) whose operator can be expressed as square matrices. By using the (pseudo) inverse matrix of a joint demosaicing and color-to-gray conversion, the proposed decoder can recover the colorimage from its corresponding gray image data which is losslessly transmitted by the proposed encoder. Thus, LS/NLS colorimage reconstruction can be achieved while saving a bit rate significantly. In addition, using the same framework of color image coding, LS/NLS CFA coding can be realized by a comparable bit rate with JPEG-LS.
We present a method for ordering the wavelet coefficient information in a compressed bitstream that allows an image to be sequentially decoded, with lower memory requirements than conventional wavelet decompression sc...
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We present a method for ordering the wavelet coefficient information in a compressed bitstream that allows an image to be sequentially decoded, with lower memory requirements than conventional wavelet decompression schemes. We also introduce a hybrid filtering scheme that uses different horizontal and vertical filters, each with different depths of wavelet decomposition. This reduces decoder memory requirements by reducing the instantaneous number of wavelet coefficients needed fbr inverse filtering.
We propose an embedded, block-based, image wavelet transform coding algorithm of low complexity. It uses a recursive set-partitioning procedure to sort subsets of wavelet coefficients by maximum magnitude with respect...
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We propose an embedded, block-based, image wavelet transform coding algorithm of low complexity. It uses a recursive set-partitioning procedure to sort subsets of wavelet coefficients by maximum magnitude with respect to thresholds that are integer powers of two. It exploits two fundamental characteristics of an image transform-the well-defined hierarchical structure, and energy clustering in frequency and in space. The two partition strategies allow for versatile and efficient coding of several image transform structures, including dyadic, blocks inside subbands, wavelet packets, and discrete cosine transform (DCT). We describe the use of this coding algorithm in several implementations, including reversible (lossless) coding and its adaptation for colorimages, and show extensive comparisons with other state-of-the-art coders, such as set partitioning in hierarchical trees (SPIHT) and JPEG2000. We conclude that this algorithm, in addition to being very flexible, retains all the desirable features of these algorithms and is highly competitive to them in compression efficiency.
With the increasing use of multimedia technologies, image compression requires higher performance as well as new features. To address this need in the specific area of still image encoding, a new standard is currently...
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With the increasing use of multimedia technologies, image compression requires higher performance as well as new features. To address this need in the specific area of still image encoding, a new standard is currently being developed, the JPEG2000. It is not only intended to provide rate-distortion and subjective image quality performance superior to existing standards, but also to provide features and functionalities that current standards can either not address efficiently or in many cases cannot address at all. Lossless and lossy compression, embedded lossy to lossless coding, progressive transmission by pixel accuracy and by resolution, robustness to the presence of bit-errors and region-of-interest coding, are some representative features. It is interesting to note that JPEG2000 is being designed to address the requirements of a diversity of applications, e.g. Internet, color facsimile, printing, scanning, digital photography, remote sensing, mobile applications, medical imagery, digital library and E-commerce.
color image coding by inverse demosaicing, which exploits the implicit Bayer structure in colorimages, has a potential to achieve superior performance compared to conventional color image coding methods. The previous...
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ISBN:
(纸本)9781479983391
color image coding by inverse demosaicing, which exploits the implicit Bayer structure in colorimages, has a potential to achieve superior performance compared to conventional color image coding methods. The previous framework of inverse demosaicing was limited to lossless and near-lossless data compression, while this paper explores its adaptation to lossy compression. To cope with distortions due to lossy compression, we propose a regularization approach using side color information for the Bayer recovery problem in the decoder. Thanks to careful design of the regularization, the resulting Bayer recovery problem becomes an unconstrained quadratic programming problem, and thus several efficient solvers can be used. A numerical example demonstrates the efficacy of our approach. It can significantly reduce distortions in the recovery of the Bayer data and keep the total bit rate.
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