Thomson Licensing

Interdigital Vc Holdings, Inc.

Centre National De La Recherche Scientifique

Université De Nantes

Patrick Le Callet

Olivier Le Meur

Dominique Barba

Sebastien Lasserre

Saurabh Puri

Dominique Thoreau

Alexandre Ninassi

Edouard Francois

Philippe Salmon

Sébastien Lasserre

Matthieu Perreira Da Silva

Manish Narwaria

Oliver Le Meur

Coding of the last coded coefficient position is performed by basing the coding of the y coordinate of the position of the last coded coefficient on knowledge of the size of the partial transform used to generate a block of coefficients from a block of video pixels. This enables a context adaptive coding of the last coded coefficient parameter to be performed much more efficiently.

Last coefficient coding for adaptive transform based video compression

A decoding method is disclosed. The decoding method comprises: In a specific embodiment, determining the index comprises:

Method and a device for picture encoding and decoding

Coding of the last coded coefficient position is performed by basing the coding of they coordinate of the position of the last coded coefficient on knowledge of the size of the partial transform used to generate a block of coefficients from a block of video pixels. This enables a context adaptive coding of the last coded coefficient parameter to be performed much more efficiently.

A method for decoding a bitstream representative of a picture is disclosed. Information representative of at least one encoding precision is first determined. A transform is then decoded responsive to the determined information. Finally, the picture is decoded using the decoded transform. A method for encoding a bitstream representative of a picture, as well as encoding devices and decoding devices are also disclosed.

Encoding and decoding method and corresponding devices

A method for determining objectively a visual quality index of at least one high dynamic range video sequence, referred to as an HDR sequence, distorted by image processing operations and issued from a reference high dynamic range video sequence, referred to a reference sequence or a reference HDR sequence. The method is based on signal pre-processing, transformation, and subsequent frequency based decomposition. Video quality is then computed based on a spatio-temporal analysis that relates to human eye fixation behavior during video viewing. One advantage of this method is that it does not involve expensive computations.

Method for determining a visual quality index of a high dynamic range video sequence

A method for assessing the quality of a distorted version of a frame sequence includes the steps of determining a last spatial distortion by comparing a block of a last frame (I) of the sequence with a corresponding block of the distorted version of the last frame, determining, in a last-but-one frame, a best-matching block matching said block of the last frame best, determining a last-but-one spatial distortion by comparing the determined best-matching block of the last-but-one frame with a corresponding block of the distorted version of the last-but-one frame, determining a spatio-temporal perceptual distortion value associated with said block using said determined distortions and using the determined spatio-temporal perceptual distortion value for assessing the quality.

Method for assessing the quality of a distorted version of a frame sequence

Detection of the salient points in an image enable the improvement of further steps such as coding or image indexing, watermarking, video quality estimation. The methods rely on the fact that a model is fully based on the human visual system (HVS) such as the computation of early visual features, and the methods compute a saliency map for video images taking into account motion and the velocity of the eye.

Device and method for creating a saliency map of an image

A method of obtaining a saliency map from a plurality of saliency maps created from different visual quantities. Initially the saliency maps are normalized based on a theoretical maximum of each visual quantity. An intra-competition step selects the main saliency areas in each saliency map. An inter-competition step is then performed based on a sum of the intra-map competition with an inter-map redundancy term that is a function of the product of the intra-map competitions and of the probability of a site appearing on the saliency maps.

Method of obtaining a saliency map from a plurality of saliency maps created from visual quantities

A method for assessing image quality between a reference image and an impaired image is disclosed. The method comprises the steps of The subband decomposition is based on a wavelet transform adapted to decompose each of the luminance components into L levels of decomposition, with L a positive integer determined as a function of the image height and of the distance of visualization.

Method for assessing image quality

The invention is a method for assessing image quality value of a distorted image with respect to a reference image. The method comprises the following steps:

The invention concerns a device and a method for creating a saliency map of an image. It comprises the steps of:

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Le Pallet, France

Patrick Le Callet