Abstract:
Because of the encoding, decoding, and/or transmitting characteristic, the blocks affected by packet defect usually gather in a small spatial / temporal area. The viewers perception of each affected block will influence by other affected block in this small area. The invention proposes using processing means for clustering blocks affected by the packet loss into at least one cluster, for using at least one of spatial and temporal characteristics of the at least one cluster for determining a visibility value of the at least one cluster, for classifying the at least one cluster as belonging into one of at least two different class candidates, wherein each class candidate is associated with a different weight; for weighting the determined visibility value with the weight associated with the class of the at least one cluster, and for assessing the degradation of the video using a sum of the weighted visibility value.
Abstract:
A system (100) for encoding an input video frame (1005), for transmitting or storing the encoded video and for decoding the video is disclosed. The system (100) includes an encoder (1000) and a decoder (1200) interconnected through a storage or transmission medium (1100). The encoder (1000) includes a turbo encoder (1015) for forming parity bit data from the input frame (1005) into a first data source (1120), and a sampler (1020) for down-sampling the input frame (1005) followed by intraframe compression (1030) to form a second data source (1110). The decoder (1200) receives data from the second data source (1110) to form an estimate for the frame (1005). The decoder (1200) also receivers the parity bit data from the first data source (1120), and corrects errors in the estimate by applying the parity bit data to the estimate. Each bit plane is corrected in turn by a turbo decoder (1260). The decoder determines how reliably a pixel value was decoded, too. Frame reconstruction module (1290) takes advantage of this and discards unreliably decoded pixels and replaces them with predicted pixel values.
Abstract:
A particular implementation receives a bitstream and derives parameters from the bitstream. The parameters include quantization parameters, content unpredictability parameters, ratios of lost blocks, ratios of propagated blocks, error concealment distances, motion vectors, durations of freezing, and frame rates. Using these parameters, a compression distortion factor, a slicing distortion factor, and a freezing distortion factor are estimated respectively for distortions resulting from video compression, a slicing mode error concealment, and a freezing slicing mode error concealment. The distortion factors are then mapped to a composite video quality score. For applications with limited computational power, the estimation of distortion factors can be simplified. In particular, the compression distortion factor, the slicing distortion factor, and the freezing distortion factor can be predicted from quantization parameters, ratios of lost blocks, and durations of freezing, respectively.
Abstract:
Procédé d'estimation du débit et de la distorsion d'au moins une image compressée à l'aide d'au moins une opération de transformée en ondelettes délivrant au moins une sous-bande b contenant des coefficients, ladite sous- bande étant subdivisée en au moins un paquet (106) de coefficients associé à une couche de qualité de la compression, ledit paquet (106) comportant en plus un entête (101,102,103,104,107) de paquet et étant transmis à travers un canal de propagation, ledit procédé étant caractérisé en ce qu'il comprend au moins les étapes suivantes: o une étape d'estimation de la distorsion formule (I) liée à la compression des coefficients dudit paquet (106), o une étape d'estimation de la distorsion formule (II) liée à la corruption ou à la perte dudit paquet (106), o une étape d'estimation du débit L b de compression, o une étape d'estimation de la sensibilité formule (III) dudit paquet (106) en fonction de formule (I) et formule (II) et du débit L b , o une étape d'estimation de la distorsion de ladite image liée à la décompression dudit paquet (106) à partir de formule (III).
Abstract:
Methods and systems may provide for using an adaptive entropy encoder to generate a compressed video signal based on an input video signal. Additionally, a compressed state signal can be generated based on the internal state of the adaptive entropy encoder. In one example, the compressed state signal is selectively incorporated into a data stream containing the compressed video signal.
Abstract:
A method of transmitting a complex content packet in a broadcasting and communication system is provided. The method includes creating an Forward Error Correction(FEC) source block by using at least one MMT Processing Unit(MPU) included in at least one MPEG Media Transport(MMT) asset, and transmitting the FEC source block, wherein the FEC source block is generated so that a boundary of the at least one MPU and a boundary of the FEC source block do not deviate.
Abstract:
A system for correcting non-uniformity in a video detector. In one embodiment, a system for correcting non-uniformity in a video detector having an array of sensors referred to as pixels stores compressed gain terms and compressed offset terms in a non-uniformity memory (105). These gain terms and offset terms are generated in a calibration procedure, and are calculated to correct for non-uniformity in the video detector. The gain terms and offset terms are decompressed by a decompression block (125) and used to correct raw video data generated by the detector, forming corrected video. The storage of the gain terms and correction terms in compressed form reduces both the memory capacity requirements and the data bus bandwidth required.
Abstract:
Various arrangements for testing video decoder device functionality are presented. A video frame decoded by a video decoder device under test may be received. The received video frame may be segmented into a plurality of blocks. A first value may be calculated for a first block of the plurality of blocks of the received video frame using pixel values of pixels present within the first block. The first value may be compared to a first reference value. The first reference value may correspond to a first reference block of one or more reference frames. Video decoder functionality of the video decoder device may be determined to be functional at least partially based on comparing the first value to the first reference value.