Axis Ab

Axis Corporation

Durable Devices Ab

Stefan Lundberg

Carl-Axel Alm

Jonas Hjelmström

Björn Völcker

Per Kannermark

Gunnar Dahlgren

Song Yuan

Viktor Edpalm

Joacim Tullberg

Willy Sagefalk

Christian Gehrmann

Björn Ardö

Mikael Persson

Fredrik Hugosson

Ingemar Larsson

Viktor A Andersson

Kent Fransson

Anders Johannesson

Sven Svensson

Bjarne Rosengren

Andreas Karlsson Jägerman

Johan Wennersten

Stefan Sandstr&ouml;m

Tim Borglund

Anil Kumar Metla

Jonas Holmberg

Jon Hansson

Kajsa Larsson

Stefan Sandström

Fredrik Ternerot

Wilfried Rakow

Viktor Gustafsson

Patrik Madsen

Carl Axel Alm

There is provided techniques for providing digital signatures to a video stream encoded in layers. Each layer comprises encoded image frames. A digital signature for layer k=0 is provided by providing by generating signing data for layer k=0 and generating the digital signature for layer k=0. A respective digital signature for each layer k=1, . . . , K−1 is provided by, for each layer k=1, . . . , K−1 generating signing data, and generating the digital signature for layer k by encrypting the signing data, or a hash thereof, for layer k with the private key of the private-public key pair. The digital signatures for all the layers are provide to the video stream.

Validation of signatures of a video stream encoded in layers

A method and a video capturing system for controlling at least one infrared (IR) illumination source, illuminating an area captured by a camera, the method comprising modulating emission from the IR illumination source between first and second emission intensities at a first frequency during a first predetermined time period. Upon capturing images using an image sensor of the camera during the first predetermined time period, determining a radiation level indicator for each of a plurality of images captured by the image sensor. Further, evaluating a sequence of determined radiation level indicators to determine whether a frequency resulting from the modulated emission at the first frequency is detected in the sequence of radiation level indicators. If the frequency resulting from the modulated emission at the first frequency is determined as not detected in the sequence of radiation level indicators, the IR illumination source is stopped.

Method for controlling infrared illumination source

A device and a method of signing an encoded video sequence comprising: obtaining an encoded video sequence composed of encoded image frames; generating a set of one of more frame fingerprints for each encoded image frame; generating a document comprising a header of a supplemental information unit, and a representation of the generated sets of one or more frame fingerprints; generating a document signature by digitally signing the document; generating the supplemental information unit to only consist of the document, the document signature and an indication of an end of the supplemental information unit; and signing the encoded video sequence by associating the generated supplemental information unit with the encoded video sequence.

Method and device for signing an encoded video sequence

A transmitter and a method therein for enabling validation of a video sequence comprising encoded image frames by providing the sequence with a data structure and a digital signature. The method comprises: performing lossless compression of each encoded image frame to obtain a respective losslessly compressed (LC) encoded image frame; identifying small frames each having a data size that is smaller than a predefined number of bytes as small LC encoded image frames; generating a data structure comprising: the small LC encoded image frames; and individual hashes of either all encoded image frames lacking a respective small frame or all other obtained LC encoded image frames being different from the small frames; generating a digital signature; and providing the data structure and the digital signature to the video sequence.

Transmitter, a receiver and methods. therein for validation of a video sequence

A signed video bitstream obtained by prediction coding of a video sequence includes data units and associated signature units, wherein each data unit represents at most one macroblock in a video frame of the video sequence, and each signature unit includes a digital signature of a bitstring derived from fingerprints of exactly one associated data unit each. The bitstream is edited by: receiving a request to substitute a region; determining a first set of macroblocks, in which said region is contained, and a second set of macroblocks referring to macroblocks in the first set; adding an archive object that includes fingerprints of a first and a second set of data units, which represent the first and second set of macroblocks; editing the first set of data units in accordance with the request to substitute; and re-encoding the second set of data units.

Editable signed video data

A method for verifying a digital signature in a video data segment generated by a video delivery chain comprises: obtaining the video data segment comprising encoded image frames and a plurality of node device datasets associated with respective labels; wherein one or more node device datasets include respective digital signatures; wherein the one or more node device datasets comprises a first node device dataset which includes a first digital signature generated by a first node device based on a first number of node device datasets that have been last added to the video data segment before the first node device dataset; locating the labels; identifying, using the labels, the first number of node device datasets; and verifying the first digital signature. The application also discloses a method of adding a digital signature to a video data segment.

Methods of adding and validating a digital signature in a video data segment

A method of signing prediction-coded video data, comprising: obtaining a coded video sequence including at least one I-frame (I), which contains independently decodable image data, and at least one predicted frame (P1, P2, P3, P4), which contains image data decodable by reference to at least one other frame; generating a fingerprint (H) of each I-frame; generating a fingerprint (H) of each predicted frame by hashing a combination of data derived from the predicted frame and data derived from an I-frame to which the predicted frame refers directly or indirectly, wherein the fingerprint of the predicted frame is independent of any further predicted frame to which the predicted frame refers directly or indirectly; and providing a signature of the video sequence including the generated fingerprints.

Signed video data with linked hashes

The present application relates to detecting if video images captured by a camera are depicting a live scene or a recorded video played on a monitor, display or computer screen, which is setup to hide the scene from the camera. Metadata regarding the mapping operation used to transform image data between different intensity ranges, or bit depths, is included with the video and evaluated in order to determine if a video replay attack has taken place.

Video replay attack detection

A device, and method of signing a video segment comprising one or more groups of pictures, GOPs, wherein each GOP comprises a header and one or more frames, are disclosed. For each of the one or more GOPs a GOP hash is produced and the GOP hash is digitally signed by means of a digital signature to produce a signed GOP hash. For each GOP except a last GOP of the one or more GOPs the respective signed GOP hash is saved in the header of a subsequent GOP. An additional GOP is added to the video segment after the last GOP of the one or more GOPs, wherein the additional GOP comprising a header and one or more frames. The signed GOP hash of the last GOP of the one or more GOPs is saved in the header of the additional GOP.

Device and a method for signing a video segment comprising one or more groups of pictures

A signed media bitstream comprises data units and signature units. Each signature unit is associated with one or more nearby data units and include at least one fingerprint derived from the associated data units and a digital signature of the at least one fingerprint. A storing method comprises: receiving a segment of the media bitstream; identifying N≥2 instances of a repeating data unit in the received segment; pruning up to N−1 of the identified instances of the repeating data unit; and storing the received segment after pruning. A validation method comprises: receiving a segment of the media bitstream stored in accordance with the storing method; and validating a signature unit using a digital signature contained therein. Despite the pruning of the repeating data unit, the received associated data units can be successfully validated, either directly or indirectly, by means of different embodiments herein.

Methods and devices for compressing signed media data

An image processing device a camera and a method for of encoding images captured by a camera are disclosed. For each image of an image sequence captured by the camera, the image is pre-processed by filtering the image by applying a privacy filter, the privacy filter being configured to distort the image in such a way that privacy is achieved in the filtered image, and, for at least a subset of the filtered images, by colour revising the filtered image by changing colour of pixels of a plurality of scattered areas of the filtered image such that a respective colour of one or more pixels of each area of the plurality of scattered areas represents one or more original colours of one or more pixels before filtering at a location of that area in the filtered image. The pre-processed images are then encoded into an encoded video stream.

Device and a method of encoding images including a privacy filter

There is provided a camera and a method therein for facilitating installation of the camera. The method comprises capturing a video stream of a scene when the camera is installed with a first FOV, which scene comprises an object. A size in the video stream of at least one part of the object is estimated. As long as the estimated size is above a first threshold and below a second threshold, providing a first, edge-filtered, version of the video stream to secure privacy of the object. In response to the estimated size being above the second threshold indicating that the privacy is at risk of being revealed, entering an enhanced secure privacy mode comprising generating an alert to prompt an installer to re-install the camera with a second FOV different from the first FOV, and disabling provision of the first, edge-filtered, version of the video stream.

Camera and a method therein for facilitating installation of the camera

A method of activating an object-specific action comprises obtaining, based on image analysis of acquired images, a plurality of values of a movement characteristic, each value representing a moving object detected in the acquired images; receiving an input signal from a user input device, wherein the input signal represents a value of the movement characteristic for the user input device; comparing the value of the movement characteristic for the user input device with each value of the movement characteristics for the moving objects, and determining the moving object corresponding to the closest value of movement characteristic as a selected moving object; and activating the object-specific action for the selected moving object.

Method of activating an object-specific action

The present disclosure relates to a method performed by a background blurring system () for provision of a video compression stream from a video camera () adapted for capturing a scene. The background blurring system identifies () in a first image of the scene, at a first point in time, at least a first pixel comprised in a background of the first image. The background blurring system further determines () a blurred pixel value for the at least first pixel. Moreover, the background blurring system provides (), subsequent the first point in time, the blurred pixel value in the video compression stream. The background blurring system furthermore identifies () in a second image of the scene, at a subsequent second point in time, that the at least first pixel has altered to be comprised in a foreground of the second image. Moreover, the background blurring system provides () in the video compression stream, subsequent the second point in time&#x2014;continuously and/or intermittently&#x2014;identified non-blurred pixel values for the at least first pixel. The background blurring system further identifies () in a third image of the scene, at a subsequent third point in time, that the at least first pixel has altered to be comprised in a background of the third image, wherein a value of the at least first pixel has remained unchanged from an intermediate point in time up to the third point in time. Furthermore, when the third point in time is within a predeterminable background merge time period from the intermediate point in time, the background blurring system provides (), subsequent the third point in time, the blurred pixel value in the video compression stream. The disclosure also relates to a background blurring system in accordance with the foregoing, a video camera comprising such a background blurring system, and a respective corresponding computer program product and non-volatile computer readable storage medium.

Video compression stream

Methods and apparatus, including computer program products, for determining a presence of an object located close to a lens () of a camera monitoring a scene. A first infrared illumination source () arranged to illuminate the scene from a first angle is activated. A first image () is acquired by the image capturing device (). The first infrared illumination source () is deactivated, and a second infrared illumination source () arranged to illuminate the scene from a second angle is activated. A second image () is acquired by the image capturing device (). Intensity information of the first image () and the second image () is compared to determine the presence of an object located close to the lens ().

Growing community of inventors

Lund, Sweden

Stefan Lundberg