Interdigital Vc Holdings, Inc.

Thomson Licensing

Mikael Le Pendu

Dominique Thoreau

Christine Guillemot

Ronan Boitard

Martin Alain

Mehmet Turkan

To encode High Dynamic Range (HDR) images, the HDR images can be converted to Low Dynamic Range (LDR) images through tone mapping operation, and the LDR images can be encoded with an LDR encoder. The present principles formulates a rate distortion minimization problem when designing the tone mapping curve. In particular, the tone mapping curve is formulated as a function of the probability distribution function of the HDR images to be encoded and a Lagrangian multiplier that depends on encoding parameters. At the decoder, based on the parameters indicative of the tone mapping function, an inverse tone mapping function can be derived to reconstruct HDR images from decoded LDR images.

Method and apparatus for encoding and decoding HDR images

The present disclosure generally relates to a method for predicting at least one block of pixels of a view () belonging to a matrix of views () obtained from light-field data belong with a scene, According to present disclosure, the method is implemented by a processor and comprises for at least one pixel to predict of said block of pixels: &#x2014;from said matrix of views (), obtaining () at least one epipolar plane image (EPI) belong with said at least one pixel to predict, &#x2014;among a set of bidirectional prediction modes, determining () at least one optimal bidirectional prediction mode from a set of previous reconstructed pixels neighbouring said at least one pixel to predict in said at least one epipolar plane image, &#x2014;extrapolating () a prediction value of said at least one pixel to predict by using said at least one optimal bidirectional prediction mode.

Method and apparatus for encoding and decoding light field based image, and corresponding computer program product

A method for encoding and decoding an image block, an encoder, and a decoder are provided. The method for encoding an image block comprises: determining a local dynamic range of the block; adaptively precision-extending pixel values of the block based on the local dynamic range of the block; and encoding the block with an adaptively extended precision. The method for decoding an image block comprises: determining a minimum pixel value of the block and an indicating value for indicating a precision extension factor according to precision extension information; decoding the block according to the indicating value; and de-extending precision of the decoded block based on the minimum pixel value of the block and the precision extension factor. The precision of the intermediate calculations may be improved without increasing an original intermediate bit depth used in intermediate calculations.

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Rennes, France

Mikael Le Pendu