Abstract: A video capturing device configured to capture video data, the image capturing device comprising: an image processing pipeline configured to generate a video stream from the captured video data; an encryption key activating module configured to, upon request, activate an encryption key and deactivate any previously activated encryption key used for encrypting the video stream, such that only one encryption key is activated to be used for encryption of the video stream at each instance in time; an encryption scheduler module configured to, at a predetermined time interval, instruct the encryption key activating module to activate an encryption key; an event handling module configured to, as a response to receiving indications of a detected event, instruct the encryption key activating module to activate an encryption key; an encryption module configured to encrypt the video stream using the one activated encryption key.
Abstract: A method and crystal oscillator circuit match a supply voltage with a drive level of a crystal. The crystal oscillator circuit is based on a Pierce oscillator circuit which further includes a capacitor Cd. The capacitor Cd together with the load capacitor act as a capacitive voltage divider and the capacitance of this capacitor may be selected to reduce the supply voltage to match the drive level of the crystal oscillator without affecting the oscillation margin of the crystal.
Abstract: A method, video server, and system for playing back recorded video based on comparing the encoder frame rates at temporal positions of a received video sequence to a predetermined threshold and changing the playback frame rate to a playback frame rate greater than the encoder frame rate if the encoder frame rate is below the predetermined threshold and changing the playback frame rate to the encoder frame rate if the encoder frame rate is greater than the predetermined threshold. The recorded video is thereby played back in a time efficient manner, decreasing the total time period for video playback, and assisting a security operator in finding parts of the recorded video that may be of interest.
Abstract: A method and an alert discriminator for converting alerts in a video monitoring operation. The method comprises: triggering a candidate alert, in response to detecting, in a stream of thermal images of a scene, a stationary foreground object in the scene; evaluating an intensity of the detected stationary foreground object in relation to a background intensity; and in response to the intensity of the detected stationary foreground object being above the background intensity, converting the candidate alert to an actual alert.
Abstract: A method for setting a motion trigger level is used in detection of motion in a video stream depicting a scene which includes receiving data pertaining to a video stream depicting the scene; dividing the scene into a plurality of specific portions; wherein each image frame of the video stream comprises multiple blocks of pixels, wherein each specific portion of the scene is associated with one or more block of pixels; and for each specific portion of the scene: evaluating, over time, statistical features of bitrate associated with an encoding of block of pixels pertaining to the specific portion of the scene; determining a motion base level based on the evaluated statistical features of bitrate associated with the encoding of block of pixels pertaining to the specific portion of the scene; and setting a motion trigger level based on the motion base level.
Abstract: A method and a system for filtering thermal image data. The method comprises: capturing thermal image data by a thermal image detector; forming a signal distribution of intensity values; identifying a first part in the signal distribution of intensity values, the first part being a peak having an intensity width equal to or smaller than a predetermined intensity span being based on a resolution parameter of the thermal image detector; identifying a second part having an intensity width larger than the predetermined intensity span; determining an intensity range between the first part and the second part; and filtering, if the intensity range is larger than a predetermined minimum intensity range, the thermal image data by excluding thermal image data forming part of the first part.
Type:
Application
Filed:
September 6, 2019
Publication date:
March 12, 2020
Applicant:
Axis AB
Inventors:
Thomas Winzell, Jesper Bengtsson, Anthony Hawkins
Abstract: A method and apparatus are disclosed. The method may include determining a current zoom value of a camera and determining a first modulation transfer function of a transparent dome of the camera. The method may include applying a first low-pass filter to an image captured by the camera based on the current zoom value and the first modulation transfer function of the transparent dome.
Abstract: A method, device, and computer program product related to the field of image encoding. In particular, the method, device, and computer program product uses multiple image sensors and multiple encoders for outputting a single encoded image, where image data captured by a first image sensor is added to the encoded image as a first tile or slice, and where image data captured by a second image sensor is added to the encoded image as a second tile or slice.
Type:
Application
Filed:
August 21, 2019
Publication date:
February 27, 2020
Applicant:
Axis AB
Inventors:
Björn Ardö, Stefan Lundberg, Stefan Sandström
Abstract: A method of controlling output bitrate of a video encoder encoding a video sequence. The method comprises setting a long-term bit budget for a time period of at least one day for output of the video encoder, and determining a first allowable bitrate based on the long-term bit budget. The method further comprises determining an instantaneous bit restriction for output of the video encoder, and determining a second allowable bitrate based on the instantaneous bit restriction. Output bitrate is controlled based on the first allowable bitrate and the second allowable bitrate, such that the long-term bit budget, the first allowable bitrate and the second allowable bitrate are complied with. The method may be performed in a non-transitory computer-readable medium having instruction stored thereon. The method may also be performed by a bitrate controller. The bitrate controller may be found in a camera and a network video recorder.
Type:
Grant
Filed:
April 23, 2018
Date of Patent:
February 25, 2020
Assignee:
Axis AB
Inventors:
Viktor Edpalm, Alexander Toresson, Alexandre Martins