# US 2019/0174160 A1 · Method of reading and generating a video stream containing compressed and encrypted images

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- Number: US 2019/0174160 A1
- Document ID: US20190174160A1
- Status: Published application
- Kind: A1
- Application number: 16/323,051
- Filed: 2017-07-28
- Published: 2019-06-06
- Earliest claimed: 2016-08-05
- Assignees: Viaccess
- Applicants: Viaccess
- Inventors: Vincent Hamon
- Web page: https://patentgrep.com/patent/US20190174160A1

## CPC

- H04N 21/23476: {by partially encrypting, e.g. encrypting the ending portion of a movie}
- H04N 13/344: with head-mounted left-right displays
- H04N 13/383: for tracking with gaze detection, i.e. detecting the lines of sight of the viewer's eyes
- H04N 21/2343: involving reformatting operations of video signals for distribution or compliance with end-user requests or end-user device requirements {(video transcoding H04N19/40; media packet handling at the source H04L65/762)}
- H04N 21/234327: {by decomposing into layers, e.g. base layer and one or more enhancement layers}
- H04N 21/234363: {by altering the spatial resolution, e.g. for clients with a lower screen resolution}
- H04N 21/23439: {for generating different versions}
- H04N 21/2347: involving video stream encryption
- H04N 21/42201: {biosensors, e.g. heat sensor for presence detection, EEG sensors or any limb activity sensors worn by the user (input arrangements for interaction with the human body based on nervous system activity detection G06F3/015)}
- H04N 21/4405: involving video stream decryption
- H04N 21/4728: for selecting a Region Of Interest [ROI], e.g. for requesting a higher resolution version of a selected region
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

This method of reading a video stream comprises: the reception (92) of a video stream which comprises, associated with each tile of an image, a high-quality variant and a degraded variant, this degraded variant being able to be decompressed independently of the degraded variants associated with other tiles which do not have the same coordinates and independently of the high-quality variant associated with the same tile, for each selected tile, the decryption (118) and the decompression (120) of the high-quality variant associated with this selected tile and, for each unselected tile, the decompression (126) of the degraded variant associated with this unselected tile, and then the construction (130) of the degraded version of each portion of the image situated inside an unselected tile on the basis of the degraded variant associated with this unselected tile.

## Claims

### Claim at position 1

1-10. (canceled)

### Claim 11

A method comprising reading a video stream, wherein said video stream comprises images, each of which is paved by a union of contiguous tiles such that a portion of said image is within each of said tiles, wherein each of said tiles is defined by coordinates within said image, wherein each of said images has been compressed and encrypted on a tile-by-tile basis, wherein each tile is associated with a high-quality variant and a degraded variant, wherein said high-quality variant is a compressed and encrypted first range of bits in said video stream, wherein said degraded variant is a second range of bits that has been compressed and that is distinct from said high-quality variant, wherein only said high-quality variant codes information necessary to construct a high-quality version of that portion of said image that is within said tile, wherein only said degraded variant contains information needed to construct a degraded version of that portion of said image that is within said tile, wherein said high-quality variant, when compressed and encrypted, is capable of being decrypted and decompressed independently of compressed and encrypted high-quality variants associated with other tiles, wherein said degraded variant, when compressed, is able to be decompressed independently of compressed degraded variants associated with other tiles, wherein said degraded variant, when compressed, is able to be decompressed independently of said compressed and encrypted high-quality variant associated with the same tile, wherein said degraded variant codes enough information representative of the content of the high-quality version of that portion of said image that is within said tile with which it is associated to construct a degraded version of said image but not a high-quality version of said image, wherein reading said video stream comprises receiving said video stream, for each image in said video stream that has been compressed and encrypted on a tile-by-tile basis, acquiring coordinates of said tiles, acquiring coordinates of a point-of-interest in said image, based on said coordinates of said tiles and said coordinates of said point-of-interest, defining selected tiles and unselected tiles, wherein said selected tiles are those tiles that are closest to said point-of-interest, wherein there exists at least one unselected tile, for each selected tile, decrypting and decompressing a high-quality variant associated with said selected tile, for each unselected tile, refraining from decrypting a compressed and encrypted high-quality variant associated with said unselected tile, constructing high-quality image portions, each of which is constructed from a high-quality version of each portion of said image that is within a selected tile, constructing degraded image portions, each of which is constructed from a degraded version of each portion of said image that is within an unselected tile, wherein constructing said degraded version is carried out without taking into account said compressed and encrypted high-quality variant associated with said unselected tile, assembling said degraded image portions and said high-quality image portions to form said video stream's decrypted and decompressed image, wherein only certain portions of said decrypted and decompressed image contain said high-quality image portions, said certain portions having been selected as a function of said coordinates of said point-of-interest, for each unselected tile, decompressing said compressed degraded variant associated with said unselected tile, and constructing said degraded version of those portions of said image that are within an unselected tile based on said decompressed degraded variant associated with said unselected tile.

### Claim 12 (depends on 11)

The method of claim 11, wherein acquiring coordinates of a point-of-interest comprise using a sensor to measure displacement of a user and using said measured displacement as a basis for acquiring said coordinates.

### Claim 13 (depends on 12)

The method of claim 12, further comprising displaying said decrypted and decompressed images of said video stream on a screen with respect to which a position of the user is known, wherein using a sensor to measure displacement of a user comprises measuring a physical quantity that is representative of at least one physical quantity representative of a direction of said user's gaze, said method further comprising determining coordinates of an intersection between said screen and a line extending along said direction of said user's gaze, wherein said intersection defines coordinates of said point-of-interest.

### Claim 14 (depends on 11)

The method of claim 11, wherein said degraded version has a first spatial-resolution and said high-quality version has a second spatial-resolution, wherein said second spatial-resolution is greater than said first spatial-resolution.

### Claim 15 (depends on 11)

The method of claim 11, wherein said degraded version has a first temporal-resolution and said high-quality version has a second temporal-resolution, wherein said second temporal-resolution is greater than said first temporal-resolution.

### Claim 16 (depends on 11)

The method of claim 11, wherein said degraded version has a first colorimetric-resolution and said high-quality version has a second colorimetric-resolution, wherein said second colorimetric-resolution is greater than said first colorimetric-resolution.

### Claim 17 (depends on 11)

The method of claim 11, further comprising composing, based solely on said high-quality versions, a right image for a user's right eye and a left image for a user's left eye and displaying said left and right images on corresponding left and right screens of a pair of stereoscopic vision spectacles worn by a user.

### Claim 18 (depends on 11)

The method of claim 11, wherein said compressed and encrypted images encode views taken in all directions contained within a cone of vision whose vertex angle is greater than 100°.

### Claim 19

A method comprising generating a video stream that contains compressed and encrypted images, wherein generating said video stream comprises receiving an initial video stream that is to be compressed and encrypted, said initial video stream comprising images that are to be encrypted and compressed, for each of said images, acquiring coordinates of contiguous tiles that, when joined, pave said image, for each of said tiles, acquiring a first range of bits, said first range of bits defining a high-quality variant that alone codes information needed to construct a high-quality version of a portion of said image that is within said tile, said high-quality variant being a range of bits, compressing said high-quality variant without taking into account high-quality variants acquired for other tiles, thereby forming a compressed high-quality variant, encrypting said compressed high-quality variant, without taking into account high-quality variants acquired for other tiles associating said compressed-and-encrypted high-quality variant with said tile in said video stream in such a way as to obtain a compressed and encrypted high-quality variant that is able to be decrypted and decompressed independently of other, compressed and encrypted high-quality variants acquired for other tiles, acquiring a second range of bits, said second range of bits defining a degraded variant that is distinct from said high-quality variant, wherein only said degraded variant codes information necessary to construct a degraded version of said portion of said image that is within said tile, wherein said information necessary to construct a degraded version is insufficient to construct a corresponding high-quality version, compressing said degraded variant without taking into account high-quality or degraded variants acquired for other tiles and without taking into account said high-quality variant acquired for said tile, and encrypting said compressed degraded variant for said tile without taking into account high-quality and degraded variants acquired for other tiles and without taking into account said high-quality variant acquired for said tile.

### Claim 20 (depends on 19)

The method of claim 19, wherein said compressed and encrypted images encode views taken in all directions contained within a cone of vision whose vertex angle is greater than 100 °.

### Claim 21 (depends on 11)

A non-transitory computer-readable medium having encoded thereon instructions for causing an apparatus comprising an electronic reader to carry out the method recited in claim 11.

### Claim 21 (depends on 11)

An apparatus comprising an electronic reader configured to read a video stream containing compressed and encrypted images, said reader comprising a programmable microprocessor that is configured to carry out the method recited in claim 11.

### Claim 22 (depends on 19)

An apparatus comprising a generator of a video stream containing compressed and encrypted images, said generator comprising a programmable microprocessor that is configured to carry out the method recited in claim 19.