US Patent No. 9,258,622

METHOD OF ACCESSING A SPATIO-TEMPORAL PART OF A VIDEO SEQUENCE OF IMAGES


Patent No. 9,258,622
Issue Date February 09, 2016 
Title Method Of Accessing A Spatio-temporal Part Of A Video Sequence Of Images
Inventorship Fablet Youenn, La Dominelais (FR)
Denoual Franck, Saint Domineuc (FR)
Assignee Canon Kabushiki Kaisha, Tokyo (JP)

Claim of US Patent No. 9,258,622

1. A method of accessing a spatio-temporal part of a video sequence of images compressed using a coding format implementing
a spatial-unit-based prediction, the method comprising, at a client terminal of a communication network, the steps of:
defining a target spatial region corresponding to said spatio-temporal part to access;
obtaining compressed data corresponding to a selection spatial region in at least one first image of the video sequence, said
selection spatial region including said target spatial region;

decoding the compressed data corresponding to the selection spatial region in the first image to obtain a decoded part of
the first image corresponding to the target spatial region in the first image;

identifying, based on said decoding step, spatial unit or units missing in the compressed data to decode the whole target
spatial region in the first image, and projecting the location of the missing spatial unit or units on the same image;

identifying, based on said decoding step, non-useful spatial unit or units of the decompressed data that are not used to obtain
the decoded part corresponding to the target spatial region in the first image;

generating, based on the identified missing and non-useful spatial unit or units, at least one item of updating information
for updating the selection spatial region before it is used for at least one next image of the video sequence, the item of
updating information being configured to add the projected missing spatial unit or units to the selection spatial region and
to delete the identified non-useful spatial unit or units from the selection spatial region;

transmitting the item of updating information to a remote server storing the compressed video sequence, for the client terminal
to obtain next compressed data corresponding to the updated selection spatial region in the next image of the video sequence.