389 results about "Objective quality" patented technology

The present invention relates to a method and system for evaluating the quality of encoded video data without gaining access to the source data or the compressed video bitstream. The system is configured to decode compressed video data using an MPEG decoder to produce decompressed video data. The decoded data is analyzed to determine whether the decompressed video data is intra-coded. If so, a discrete cosine transform (DCT) is performed to produce a set of DCT coefficients for at least one AC frequency band in the decompressed video data. At the same time, quantization matrix data of a frame of the decompressed video data as well as a quantizer scale for each block of the decompressed video data are extracted. Thereafter, the variance of the converted DCT coefficients is obtained, and then an average quantization error for each set of said DCT coefficients is determined based on the variance, the quantization matrix, and the quantizer scale. Lastly, a peak signal to noise ratio (PSNR) is calculated based on the resultant average quantization error.

The invention discloses an H.264/AVC video information hiding method based on a predictive mode. For a macro block whose coding mode is Intra_4*4 in an I chip, a predictive mode of a 4*4 luma block is modulated to a suboptimal predictive mode from an optimal predictive mode under the circumstance that the predictive mode of the 4*4 luma block needs to be changed, and for macro blocks whose coding modes are marked not by 0 in a P chip and a B chip, a coding mode of a macro block is modulated to a suboptimal predictive mode from an optimal predictive mode under the circumstance that the predictive mode of the macro block needs to be changed; the impact on the objective quality of a video, caused by the change of the predictive mode or the coding mode, can be reduced as much as possible under the circumstance of ensuring that the secret information can be effectively hidden at the same time; on the other hand, due to the fact that the secret information not only can be embedded in the macro block whose coding mode is Intra_4*4 in the I chip but also can be embedded in the macro blocks whose coding modes are marked not by 0 in the P chip and the B chip, the higher hiding capacity can be obtained.

The invention discloses a method for evaluating the objective quality of a full-reference image based on structure similarity, comprising the following steps: firstly, utilizing the space domain visual characteristic to obtain a visual perceptual map of an original image and solve for a position at which visual perception is remarkable; secondly, utilizing an evaluating method based on the structure similarity to solve for a structure similarity drawing SSIM (i, j) between the original image and a distorted image, calculating relative quality of the distorted image, and solving for a position of severe distortion; thirdly, defining the principle of visual attention focus transfer, ensuring a new visual attention focus, and producing a new visual perceptual map after the visual attention focus transfer; and fourthly, obtaining the objective evaluation of the image quality by using the weighted structure similarity of the produced visual perceptual map. The method is suitable for design of various image coding and treating algorithm as well as comparison of different algorithm effects, more accords with a human subjective evaluation on the aspect of an evaluating result of the image, and has a wide application prospect.

A no-reference estimation of video quality in streaming video is provided on a macroblock basis. Compressed video is being deployed in video in streaming and transmission applications. MB-level no-reference objective quality estimation is provided based on machine learning techniques. First the feature vectors are extracted from both the MPEG coded bitstream and the reconstructed video. Various feature extraction scenarios are proposed based on bitstream information, MB prediction error, prediction source and reconstruction intensity. The features are then modeled using both a reduced model polynomial network and a Bayes classifier. The classified features may be used as feature vector used by a client device assess the quality of received video without use of the original video as a reference.

A method is provided which is suitable for implementation in a switched digital video content-based network, wherein a head end obtains a first group of program streams and sends to a client only a subset of the program streams selected by subscribers in a neighborhood of the client. At least one of imminence and presence of a condition of inadequate bandwidth is determined. Responsive to the determining of the at least one of imminence and presence of the condition of inadequate bandwidth, a bit rate of at least one of the subset of the program streams selected by the subscribers in the neighborhood of the client is dynamically decreased by adjusting encoding thereof, while maintaining adequate quality for the at least one of the subset of the program streams selected by the subscribers in the neighborhood of the client, based on an objective quality measure, in order to address the at least one of imminence and presence of the condition of inadequate bandwidth.

The invention discloses a method for partial reference evaluation of wireless videos based on space-time domain feature extraction, which relates to a method for evaluating video quality. On the basis of performing profound understanding and detailed analysis on the existing video objective quality evaluation model, by combining visual characteristics of human eyes, the invention provides the method for the partial reference evaluation of the wireless videos based on the space-time domain feature extraction to improve the conventional SSIM model. The method takes the fluency of the time domain and the structural similarity and the definition of the space domain of the videos as main evaluation indexes, and under the condition of ensuring the evaluation accuracy, the method extracts characteristic parameters of ST domains (the space domain and the time domain), establishes a new evaluation model, reduces the reference data needed by the evaluation and lowers the computational complexity to ensure that the evaluation model is suitable for evaluating the quality of wireless transmission videos in real time.

In a method of generating a measure of video quality, a set of weightings (160) for a plurality of objective quality metrics is obtained. The objective quality metrics have themselves been calculated from a plurality of measurable objective properties (120) of video data files (100). The weightings (160) have been determined by fitting the objective quality metrics to a set comprising a ground-truth quality rating of each of the video data files coming from human scoring of quality (100). The method includes receiving a target video data file (180), the quality of which is to be measured. Values are calculated for the objective quality metrics (220) on the target video data file (180). The measure of video quality (240) is generated by combining the values for the objective quality metrics (220) on the target video data file (180) using the obtained set of weightings (160).

The invention discloses a three-dimensional image objective quality evaluation method, which comprises the following steps: respectively carrying out wavelet transformation on left view point images and right view point images of undistorted three-dimensional images and distorted three-dimensional images; extracting characteristic values of each sub band; carrying out similarity measurement on the characteristic values; determining the weight factors of each sub band by contrast sensitive functions; then, realizing the evaluation on the three-dimensional sensing quality through evaluating the absolute difference image similarity of left images and right images of the undistorted three-dimensional images and the distorted three-dimensional images; and finally, combining the quality of the left images and the right images and the three-dimensional sensing quality to obtain the final evaluation results of the three-dimensional image quality. The invention has the advantages that the human eye visual characteristics such as human visual sensitivity bandpass, the multi-channel effect, the three-dimensional sensation and the like are utilized, the three-dimensional sensation is simultaneously evaluated on the basis of the evaluation on the quality of the left view point images and the right view point images, the influence of the three-dimensional sensation in the three-dimensional images on the final three-dimensional image quality is merged into an evaluation model, and the correlativity of the objective evaluation results and the subjective sensation is improved.

The invention discloses a method for video or image deblocking filter and the device thereof. According to the block types of the two sides of a boundary and a motion vector, whether to perform deblocking filter is judged, and a needed filter strength when deblocking filter is needed is selected, and then deblocking filter is carried out in accordance with the filter strength and image content. Compared with current deblocking filter method, the deblockign filter method can improve the objective quality and the subjective quality of an image and the adaptability of filter without increase of calculation complexity and storage complexity.

The invention discloses an adaptive video transcode method based on contents, and the method comprises the steps: obtaining a minimum quantitative value which meets a preset objective quality standard and is used for representing the complexity degree of to-be-transcoded video contents; setting the value of a transcode parameter according to the minimum quantitative value of the complexity degree of to-be-transcoded video contents and a video parameter value of a to-be-transcoded video; and transcoding the to-be-transcoded video according to the set transcode parameter and generating a target video. The invention also provides an adaptive video transcode device based on contents. The method provided by the invention can avoid the unnecessary consumption of bandwidth while guaranteeing video quality after transcoding.

A process and system for providing objective quality measurement of a target audio signal. Reference and target signals are processed by a peripheral ear processor, and compared to provide a basilar degradation signal. A cognitive processor employing a neural network then determines an objective quality measure from the basilar degradation signal by calculating certain key cognitive model components.

This invention relates to the field of multi-objective workflow optimization. Certain exemplary embodiments of the invention are applicable in cases where workflow descriptions contain choice variables relating for instance to the selection of a specific service provider out of several service providers that provide similar services, to the selection of human workers, or to the selection between alternative subworkflows. A binding represents a combination of choices, binding the choice variables to specific values. Bindings induce specific cost and/or quality properties to the workflow, a binding being Pareto-optimal if no other binding exists that is at least as good for every cost and/or quality property and better for at least one property. Certain exemplary embodiments relate to a system and/or computer-implemented method for computing an approximation of the set of Pareto-optimal bindings such that the computed approximation satisfies specified minimum precision requirements

In a method of quality assessment for a multimedia signal comprising video telephony media in a video telephony system, the multimedia signal is received SlO, a plurality of parameters of said multimedia signal are extracted S20, and an objective quality measure is determined S30 for the video telephony media based on representations of at least two of the extracted parameters.

A user's content presentation device automatically measures the technical objective quality of an Internet video stream and/or estimates the perceived subjective quality of the stream, and provides feedback to the user regarding one or both of these estimates.

PCT No. PCT/EP96/01143 Sec. 371 Date Sep. 5, 1997 Sec. 102(e) Date Sep. 5, 1997 PCT Filed Mar. 13, 1996 PCT Pub. No. WO96/28950 PCT Pub. Date Sep. 19, 1996A device for determining the quality of an output signal to be generated by a signal processing circuit with respect to a reference signal. The device is provided with a first series circuit for receiving the output signal and a second series circuit for receiving the reference signal. The device generates an objective quality signal through a combining circuit which is coupled to the two series circuits. Poor correlation between the objective quality and subjective quality signals, the latter which will be assessed by human observers, can be considerably improved by a differential arrangement present in the combining circuit. This arrangement determines a difference between the two series circuit signals and reduces this difference by a certain value, preferably one that is a function of a series circuit signal. Poor correlation can be improved further by disposing a scaling circuit, between the two series circuits, for scaling at least one series circuit signal. Furthermore, the quality signal can also be scaled as a function of the scaling circuit.

The invention discloses an objective evaluation method for quality of VoIP non-reference video communication based on a neural network, is mainly applicable to monitoring the quality of the VoIP video communication under a real-time communication scene, and belongs to the field of objective evaluation of video quality. The method provided by the invention is implemented by the following steps of extracting a network parameter during a VoIP video communication process, meanwhile performing an objective test to score the video, performing standardization treatment and dimension reduction treatment on the extracted network parameter, using acquired dimension-reduced data as an input of the neural network, and using an objective test score as a reference output of the neural network to perform neural network training, thus acquiring a weight and a threshold of each neural node, that is so say building of the neural network is completed, wherein the output of the neural network is the objective quality score acquired through mapping according to the input parameter, and the objective quality score is used for objectively evaluating the quality of the VoIP non-reference video communication. According to the method provided by the invention, the quality of the VoIP video can be accurately evaluated in real time.