In TV broadcasting deaf people are not able to get information from the audio content. In public television, some programs may be accompanied by a sign language interpreter as a part of the broadcasted signal. As a su...
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In TV broadcasting deaf people are not able to get information from the audio content. In public television, some programs may be accompanied by a sign language interpreter as a part of the broadcasted signal. As a supplementary service, it would enable more programs to be accessible with a sign language interpreter to assist in comprehension. To be able to transmit such data flow separately, we define the parameters of compression of sign language interpreter image to ensure intelligibility and quality while maintaining low bitrate. This paper deals with specific video compression of Czech sign language interpreter based on regions of interest implemented to the x264 open source library. The results of this approach are verified in subjective tests with the deaf and hearing evaluators. The experiments examine the intelligibility of sign language expressions containing minimal pairs for different levels of image compression and also evaluate the subjective quality of the final image.
We present an efficient content-based image coding called Locally Adaptive Resolution (LAR) offering advanced scalability at different semantic levels, i.e., pixel, block, and region. A local analysis of image activit...
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We present an efficient content-based image coding called Locally Adaptive Resolution (LAR) offering advanced scalability at different semantic levels, i.e., pixel, block, and region. A local analysis of image activity leads to a nonuniform block representation supporting two layers of image description. The first layer provides global information encoded in the spatial domain enabling a low bit rate while preserving contours. The second layer holds texture information encoded in the spectral domain, enabling scalable bitstream in accordance with the required quality. This basic LAR coding leads to an efficient progressive compression, evaluated through subjective quality tests. Its nonuniform block representation also allows a hierarchical region representation providing higher semantic functionalities. More precisely, the segmentation process can be simultaneously performed at both the coder and the decoder from only the luminance component highly compressed by the first coding layer. This solution provides a representation at a region level while avoiding any contour encoding overhead. region enhancement can then be realized through the second layer. Furthermore, very high compression of the chromatic components is achieved thanks to this region representation. In this scheme, a low-cost chromatic control, which was first introduced during the segmentation process, increases the consistency of region representation in terms of color.
Reducing the algorithmic complexity of image compression techniques is a major challenge in wireless image sensor networks (WISNs). Many image compression standards, such as JPEG and JPEG2000, are unsuitable for imple...
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Reducing the algorithmic complexity of image compression techniques is a major challenge in wireless image sensor networks (WISNs). Many image compression standards, such as JPEG and JPEG2000, are unsuitable for implementation in WISNs because of their high energy consumption. In this paper, a solution to this problem is proposed. It consists of a region-of-interest (ROI) based image compression using the discrete Tchebichef transform (DTT).The main idea is about compressing only the ROI instead of the whole image. The DTI' is used as an alternative to the discrete cosine transform (DCT) due to its low complexity and good energy compaction. Simulation results have shown that the proposed method reduces the number of arithmetic operations, the processing/transmission energy consumption and the amount of transmitted data. The savings obtained generally exceed 50%. Furthermore, it has a competitive compression efficiency compared with the state-ofthe-art image compression techniques. (C) 2018 Elsevier Ltd. All rights reserved.
Objective estimators for video are expected to estimate accurately subjective ratings provided by humans. This work presents a subjective experiment designed to acquire intelligibility ratings for a collection of comp...
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ISBN:
(纸本)9781424479948
Objective estimators for video are expected to estimate accurately subjective ratings provided by humans. This work presents a subjective experiment designed to acquire intelligibility ratings for a collection of compressed ASL videos. The distortions present in the experimental database are analyzed in terms of their impact on the performance of objective estimators. Distortions that do not significantly vary across space or time cannot adequately challenge traditional objective estimators, such as PSNR and RMS distortion contrast, and an objective intelligibility measure designed specifically for ASL video provides negligible improvements in prediction accuracy. Distortions that vary across space and time, affecting only localized regions in the video, are considered spatially and temporally diverse. When the distortions present in the experimental database are sufficiently diverse, the objective intelligibility measure estimates subjective ratings more accurately than PSNR and RMS distortion contrast.
In this paper, we present an automated region-of-interest-based video coding system for use in ultra-low-bandwidth applications. region-of-interest (ROI) coding methodology specifies that targets or ROIs be coded at h...
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ISBN:
(纸本)9781424452385
In this paper, we present an automated region-of-interest-based video coding system for use in ultra-low-bandwidth 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 fewer 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 are specified automatically by a video target detection and tracking algorithm that continuously monitors the incoming video stream for the presence of targets. When targets appear in the scene, the detection/tracking stage feeds the target position and size information to the video compression stage, which applies a greater percentage of available bits to these areas, thereby preserving their appearance relative to the non-target or background portion of the scene. In the proposed system, position information is updated in real time and is efficiently exchanged between the transmitter and receiver. coding examples are presented for infrared (IR) video sequences to demonstrate the outstanding performance of the proposed system.
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