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In traditional fractal image coding schemes, domain blocks are constrained to be twice as large as range blocks in order to ensure the convergence of the iterative decoding stage. However, this constraint has limited the fractal e...
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In traditional fractal image coding schemes, domain blocks are constrained to be twice as large as range blocks in order to ensure the convergence of the iterative decoding stage. However, this constraint has limited the fractal encoder to exploit the self-similarity of the original image. In order to overcome the shortcoming, a novel scheme using same sized range and domain blocks is proposed in the letter. Experimental results show the remarkable improvement in compression ratio and image quality.
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摘要 :
In traditional fractal image coding schemes, domain blocks are constrained to be twice as large as range blocks in order to ensure the convergence of the iterative decoding stage. However, this constraint has limited the fractal e...
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In traditional fractal image coding schemes, domain blocks are constrained to be twice as large as range blocks in order to ensure the convergence of the iterative decoding stage. However, this constraint has limited the fractal encoder to exploit the self-similarity of the original image. In order to overcome the shortcoming, a novel scheme using same sized range and domain blocks is proposed in the letter. Experimental results show the remarkable improvement in compression ratio and image quality.
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This work launches a new variant of LBP Radial Median LBP (RM-LBP). Precisely, age invariant descriptor is proposed in different unconstrained conditions. In RM-LBP, the radial directional pixels are appended with center pixel for...
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This work launches a new variant of LBP Radial Median LBP (RM-LBP). Precisely, age invariant descriptor is proposed in different unconstrained conditions. In RM-LBP, the radial directional pixels are appended with center pixel for developing median value. For forming the code of RM-LBP, the comparison of medians with mean is done. By computing code of RM-LBP in every place forms RM-LBP image and from this the size developed is 256. Further compression and matching steps are achieved by using FLDA and SVMs. The age dataset used for the evaluation is FG-NET. Apart from RM-LBP, the five other descriptors are also evaluated for comparison. RM-LBP conquers accuracy of all compared descriptors. RM-LBP also conquers several literature methods. These numerous literature methods are tested on different settings/protocols. The objective of the proposed work is to introduce the novel age invariant descriptor in the unconstrained conditions. The achieved results proves the effectiveness of the developed method. The novelty of the proposed work is the development of the local descriptor RM-LBP.
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Intra prediction is an effective tool for coding still images and intra pictures in video. The H.264/AVC video compression standard uses extrapolation of the reconstructed pixels surrounding the target block to be coded to form th...
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Intra prediction is an effective tool for coding still images and intra pictures in video. The H.264/AVC video compression standard uses extrapolation of the reconstructed pixels surrounding the target block to be coded to form the sample predictor block. Our previous paper augmented this conventional intra prediction method with sample predictor blocks generated using pixel based texture synthesis by template matching methods. This paper describes further improvements and refinements of the sample predictor block creation method. Multiple candidate sample predictor blocks were created using template matching. A weighted average of the multiple candidates then formed the final sample predictor block. Improvements in coding efficiency by more than 15% in bitrates were achieved by this refined method compared to the conventional intra prediction. The impact of the search window and the different template shapes used in the template matching method was also studied and presented.
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In this paper, we present a new contour point distortion measurement, called accurate distortion measurement for B-spline-based shape coding (ADMBSC). Different from existing distortion measurements containing approximation, quant...
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In this paper, we present a new contour point distortion measurement, called accurate distortion measurement for B-spline-based shape coding (ADMBSC). Different from existing distortion measurements containing approximation, quantization or parameterization, our distortion is defined as the shortest distance from the original B-spline to the associated contour point. This is in line with the subjective-based objective quality metric. Geometric relationships are introduced to simplify computation, followed by a hybrid admissible distortion checking algorithm to reduce execution time. Theoretical analysis and experimental results demonstrate that when the operational rate-distortion optimal shape coding framework under the minimum-maximum criterion is applied, the ADMBSC can lead to the smallest bit-rate among all the distortion measurements that can guarantee the admissible distortion. Moreover, if the original contour has NC points, it takes only O(NC) time for segment distortion measuring paradigms, whose computational complexity is the same as the lowest one among the existing distortion measurements.
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In this paper, we present a new contour point distortion measurement, called accurate distortion measurement for B-spline-based shape coding (ADMBSC). Different from existing distortion measurements containing approximation, quant...
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In this paper, we present a new contour point distortion measurement, called accurate distortion measurement for B-spline-based shape coding (ADMBSC). Different from existing distortion measurements containing approximation, quantization or parameterization, our distortion is defined as the shortest distance from the original B-spline to the associated contour point. This is in line with the subjective-based objective quality metric. Geometric relationships are introduced to simplify computation, followed by a hybrid admissible distortion checking algorithm to reduce execution time. Theoretical analysis and experimental results demonstrate that when the operational rate-distortion optimal shape coding framework under the minimum-maximum criterion is applied, the ADMBSC can lead to the smallest bit-rate among all the distortion measurements that can guarantee the admissible distortion. Moreover, if the original contour has NC points, it takes only O(NC) time for segment distortion measuring paradigms, whose computational complexity is the same as the lowest one among the existing distortion measurements.
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Intra prediction is an effective method for reducing the coded information of an image or an intra frame within a video sequence. The conventional method today is to create a sample predictor block by extrapolating the reconstruct...
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Intra prediction is an effective method for reducing the coded information of an image or an intra frame within a video sequence. The conventional method today is to create a sample predictor block by extrapolating the reconstructed pixels surrounding the target block to be coded. The sample predictor block is subtracted from the target block and the resulting residual coded using transformation, quantization and entropy coding. This is an effective method for sample predictor block creation in most sequences. However the extrapolation method is not able to represent sample prediction blocks with complex texture. Furthermore, pixels that are far from the surrounding pixels are usually badly predicted. In this paper, a new method for sample predictor creation by template matching in a region of reconstructed pixels is presented. Improvements in coding efficiency by more than 11% in bitrate were achieved.
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Existing vertex-based shape coding algorithms use a number of different distortion measurement techniques including the shortest absolute distance (SAD), distortion band (DB) or tolerance band (TB), accurate distortion measurement...
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Existing vertex-based shape coding algorithms use a number of different distortion measurement techniques including the shortest absolute distance (SAD), distortion band (DB) or tolerance band (TB), accurate distortion measurement technique for shape coding (ADMSC) and distortion measurement based on chord-length-parameterisation (DMCLP). Among these techniques DMCLP is computationally the fastest. It however, is a relaxed measurement technique and does not fully utilise the admissible distortion within the rate-distortion optimisation. This paper presents a novel distortion measurement technique based on arc-length-parameterisation (DMALP) within the vertex-based shape coding framework. Experimental results vindicate its superior performance over the existing geometric distortion measurement techniques.
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摘要 :
Existing vertex-based shape coding algorithms use a number of different distortion measurement techniques including the shortest absolute distance (SAD), distortion band (DB) or tolerance band (TB), accurate distortion measurement...
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Existing vertex-based shape coding algorithms use a number of different distortion measurement techniques including the shortest absolute distance (SAD), distortion band (DB) or tolerance band (TB), accurate distortion measurement technique for shape coding (ADMSC) and distortion measurement based on chord-length-parameterisation (DMCLP). Among these techniques DMCLP is computationally the fastest. It however, is a relaxed measurement technique and does not fully utilise the admissible distortion within the rate-distortion optimisation. This paper presents a novel distortion measurement technique based on arc-length-parameterisation (DMALP) within the vertex-based shape coding framework. Experimental results vindicate its superior performance over the existing geometric distortion measurement techniques.
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An improved SPIHT algorithm that combines the SPIHT and the sub bands threshold calculation to reduce the number of comparison operations, without sacrificing the reconstructed image quality, is proposed. After applying discrete w...
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An improved SPIHT algorithm that combines the SPIHT and the sub bands threshold calculation to reduce the number of comparison operations, without sacrificing the reconstructed image quality, is proposed. After applying discrete wavelet transform to the image, the threshold of each independent sub band is calculated. The scanning of the sets inside a sub band is determined by the magnitude of the thresholds that establish a hierarchical scanning not only for the set of coefficients with large magnitude, but also, for the sub bands. The proposed algorithm uses the set partitioning technique to sort the transformed coefficients. Results show that the proposed algorithm significantly reduces the number of comparison operations in the sorting passes while maintaining the visual quality and PSNR of the recovered image.
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