Axis

A device, a non-transitory computer, and a method for adapting encoding of image frames of a video are provided. The image frames are arranged in a sequence of groups of pictures, GOPs, and each GOP contains an intra frame and a plurality of successive inter frames. A start is determined of a second GOP subsequent to a first GOP in the sequence of GOPs, and encoding is adapted of each of, or a subset of, a predetermined number of inter frames of the first GOP which immediately precede the determined start of the second GOP. The encoding is adapted such that the total size of the predetermined number of inter frames of the first GOP with adapting encoding is smaller than the size of the predetermined number of inter frames of the first GOP would have been without adapting encoding.

Methods and a device for updating a track of an object in relation to a current image frame are disclosed. A first track of an object in a sequence of image frames preceding the current image frame is determined using a first computer implemented tracker. The first tracker is updated in at least a first subset of image frames of the sequence of image frames based on an object detection from a computer implemented object detector using an object detection algorithm. The first track includes a respective estimated location of the object in each image frame of the first subset of image frames of the sequence of image frames. A location of the object in the current image frame is predicted using a motion model of the first tracker, and determined respective locations of detected motion areas in the current image frame are received from a computer implemented motion detector using a motion detection algorithm. Using the first tracker, and based on the predicted location of the object in the current image frame and the determined respective locations of the detected motion areas, it is determined that a detected motion area of the detected motion areas is associated with the object in the current image frame. The predicted location of the object in the current image frame is updated using the first tracker and based on the determined location of the detected motion area determined to be associated with the object in the current image frame. Thereby an estimated location of the object in the current image frame is determined.

A TDM MIMO FMCW radar comprises at least one row of physical receivers with a first spacing in a first direction, and further comprises a plurality of physical transmitters arranged with a second spacing in said first direction. To determine whether a peak in an angle spectrum corresponds to a direct reflection or a first-order multipath artefact, a full-array angle spectrum (901) based on all elements of a virtual array signal, and a single-subarray angle spectrum (902) based on one subarray are computed. If a peak in the full-array angle spectrum and a corresponding baseline peak in the single-subarray angle spectrum are co-located, it is concluded that the peak represents a direct reflection in the scene. Otherwise, if the peak and the baseline peak are not co-located, it is concluded that the peak represents a first-order multipath artefact.

There is provided a method, device, and system for tracking an object in a sequence of video frames by using a tracking filter. In the method, costs are assigned for associating each object detection in a received set of object detections to the tracked object. The cost assigned to an object detection is a measure of deviation between a motion associated with the object detection and both of a first motion of the object estimated by the tracking filter and a second motion of the object indicated by motion vectors from a video encoder which encodes the sequence of video frames.

A method is disclosed for adapting a stream of image frames for display. A first stream of image frames acquired by a pan tilt zoom, PTZ, camera arranged to monitor a scene are obtained, a first criterion related to pan or tilt motion of the PTZ camera is evaluated, and a second stream of image frames generated based on a background model of the monitored scene is obtained. On condition that the first criterion is not met, image frames from the first stream of image frames are injected in the stream of image frames for display. On condition that the first criterion is met, image frames from the second stream of image frames are injected in the stream of image frames for display.

A dome camera arrangement comprising one or more camera heads, arranged in a transparent dome is disclosed. Each camera head comprises an optics unit (118), a panning device, for moving the camera head in a panning movement, and a tilting device (110) for moving the camera head (104) in a tilting movement. The tilting device (110) has a pivot portion (116) and a cradle portion (112). The camera head further has a roll device (124) for rotating the optics unit (118) in a roll movement. A compensation lens (122) is arranged in a compensation lens fitting (120) in front of the optics unit, and the compensation lens fitting is connected to the panning device and the tilting device (110), such that the compensation lens (122) will move with the camera head in panning movement and tilting movement. However, the compensation lens fitting is disconnected from the same features such that the compensation lens (122) will not follow the optics unit (118) in roll movement, thus enabling an adequate optical compensation by means of the compensation lens.

This disclosure relates to a method (500), software and device for encoding a video sequence into an encoded video stream having a target resolution, comprising: encoding (S502) a first image frame of the video sequence using the base layer to encode the image frame in a first resolution being lower than the target resolution, and using the enhancement layer to encode at least a portion of image data of the first image frame to reach the target resolution; detecting (S504) an encoding scenario from a set of one or more predefined encoding scenarios; and encoding (S506) a second image frame of the video sequence using the base layer to encode the second image frame in the target resolution, and indicating in the encoded video stream that the second image frame is decodable in the target resolution using only the base layer.

A method and a device for stitching images and blending pixel data of respective images from each of at least three image sensors during a time period when an object passes through a combined view of the at least three image sensors. The combined view is a combination of a respective view of each of the at least three image sensors, and comprises a first region in which at least three of the views of the at least three image sensors overlap and through which the track passes. The method comprises obtaining a respective sequence of images from each of the at least three image sensors, detecting the object in the combined view, determining a location of the detected object, predicting a track of the object, identifying a minimal view set covering all portions of the track, and stitching and blending images captured at a same point in time from each of the sequences of images to a combined image corresponding to the combined view. The stitching and blending is such that, in a major proportion of a first portion of the combined image corresponding to the first region of the combined view, blending is performed using pixel data only from respective images from at most two image sensors and only from image sensors having views comprised in the minimal view set.

The present invention generally relates to a computer-implemented method for enabling video recreation, comprising: acquiring (S102), by a camera control unit (112), a video stream (300) comprising a set of image data packages (302, 303) each comprising coded image frames; transmitting (S104), by the control unit (112), at least a portion of the video stream to a client (116) across a communication network (114), receiving (S106), by the control unit (112), an acknowledgement message (306) for each image data package (303) that was successfully received by the client (116), storing (S108), in a digital memory (108) accessible to the control unit (112), the image data packages (303) for which an acknowledgement message (306) is received, and indications of successful receipt (308) at the client (116) of the corresponding image data packages (303).

A tracked state of a tracked object in a sequence of images is determined. A region of interest, ROI, is determined (210) in a current image. Based on at least one previous image from the sequence of images, motion information data of the current image is aggregated (220) to obtain an estimated current motion of the ROI. A predicted current state of the ROI is predicted, based on a previous state of the ROI, a plurality of object tracking models, and the estimated current motion of the ROI. The predicting (230) comprises selecting (232) at least one of the plurality of object tracking models to be used for predicting the predicted current state. The predicted current state of the ROI is associated (240) with the observed current state of the ROI to determine the tracked state of the tracked object.