Abstract: Techniques for Long Term Reference (LTR) frame updating in a video encoding process are performed by an image processing device as part of the video encoding process. The method comprises encoding a first LTR frame. The method comprises encoding a plurality of frames referencing directly or indirectly to the first LTR frame. The method comprises sequentially updating the first LTR frame by evaluating a cost for encoding a block of image data in one of the plurality of frames and by updating an image area in the first LTR frame when the cost fulfils a cost criterion. The image area is updated based on the block of image data in at least one of the plurality of frames. The method comprises encoding the sequentially updated first LTR frame as a second LTR frame.

Abstract: A method of detecting a change of ratio of occlusion of a tracked object in a video sequence. For each of a plurality of image frames, a bounding box of the tracked object is determined and for each pair of successive image frames, an intersection over union (IoU) of a first bounding box in a first image frame and a second bounding box in a second image frame is calculated. Similarly, for a further pair of successive image frames, a further IoU of a first bounding box in a first image frame of the further pair of successive image frames and a second bounding box in a second image frame of the further pair of successive image frames is calculated. If the further IoU differs from the calculated IoUs by more than a threshold amount, the ratio of occlusion of the tracked object has changed.

Abstract: A method for encoding lidar data where subsequent frames of lidar data to be encoded are received. Each frame of lidar data comprises a number of lidar return signals for each of a plurality of rays emitted at a respective elevation and azimuth angle by a lidar, and each lidar return signal includes lidar measurement values. Each frame of lidar data is then represented as an image frame of a video sequence, wherein, for each ray of the plurality of rays of the frame of lidar data, lidar measurement values of different lidar return signals are represented in different image portions of the image frame. The different image portions are stacked after each other in a row direction or a column direction of the image frame. The video sequence is then encoded using video encoding.

Abstract: The present disclosure relates to a method of background modelling for a video stream acquired by a camera having movement capabilities. The method comprises: acquiring a video stream; repeatedly updating a background model for the video stream by analyzing changes in the sequence of image frames and categorizing image areas in the image frames which do not change over time as background; detecting camera movement; performing a reset of the background model by: applying an image segmentation and/or object detection algorithm to identify at least foreground objects; after having performed the reset of the background model, returning to repeatedly updating the background model for the video stream by analyzing changes in the sequence of image frames and categorizing image areas in the image frames which do not change over time as background. The disclosure further relates to an image processing system.

Abstract: A camera arrangement comprises a camera head, a holder ring and a holder base. The camera head has an imaging unit and an interaction portion with constant cross section. The camera holder ring has an inner surface configured to fit onto the interaction portion of the camera head, and the camera holder base has a receptacle orifice dimensioned to receive the camera holder ring fitted onto the interaction portion of the camera head and grip an outer surface of the holder ring. The receptacle orifice has reduced dimensions due to a tightening function to fixate the camera holder ring and the camera head in relation to the camera holder base, and thereby to fixate an orientation of the camera in relation to the camera holder base. The camera holder ring is movable along a length of the interaction portion until the tightening function of the receptacle orifice has been actuated.

Abstract: A system includes a mounting bracket configured for attachment to the surface, a plastic clamp having a base part and a connection part. The mounting bracket is provided with an opening into which the base part of the plastic clamp is insertable with a snap fit and the connection part of the plastic clamp is configured for snap fit engagement with an object attachable to the mounting bracket. The base part comprises two legs, each comprising a guide surface and an L-shaped corner section, the guide surface being configured to engage the mounting bracket in response to insertion of the base part into the opening and the L-shaped corner section being configured to face an edge portion of the opening when the base part has been received by the opening. The legs deflect in response to guide surfaces engaging the mounting bracket so the base part is insertable into opening.

Abstract: A method of encoding an input video including a sequence of video frames as a hybrid video stream, comprises downsampling the input video from an original spatial resolution to a reduced spatial resolution and an intermediate spatial resolution; providing the input video at the reduced spatial resolution to a base encoder to obtain a base encoded stream; providing a first enhancement stream based on first residuals at the intermediate spatial resolution; and providing a second enhancement stream based on second residuals based at the original spatial resolution, which is at least partially encoded using temporal prediction. The method further comprises detecting at least one non-motion region in a video frame, and causing the set of first residuals but not the set of second residuals to vanish throughout the non-motion region.

Abstract: A cable retention arrangement for an electronic device, such as a surveillance camera, comprises a base member and an attachment member releasably attachable to the base member. The base member is provided with a channel configured to receive a cable and arranged in a surface of the base member configured to face the attachment member in an assembled state of the cable retention arrangement in which the attachment member is attached to the base member. The channel extends between a cable entry and a cable exit and the attachment member is provided with a slit which, in the assembled state of the cable retention arrangement, is configured to extend in a direction traversing the channel such that the cable exit of the channel is defined at the intersection of the channel and the slit. The disclosure further relates to an electronic device comprising such a cable retention arrangement.

Abstract: A method, system and software for searching for an object in a forensic search application comprises: determining a plurality of static areas in the scene; obtaining a first image depicting the scene comprising an object; determining a plurality of candidate color transforms; determining a plurality of candidate color values of the object by applying each of the plurality of candidate color transform to third pixel data from the first image, said third pixel data depicting the object in the first image; searching for an object in a forensic search application using a search request comprising a first color value; determining that the first color value matches one or more candidate color values; and returning a search response based at least in part on the object.

Abstract: A method for prioritizing feature extraction for object re-identification in an object tracking application. Region of interests (ROI) for object feature extraction is determined based on motion areas in the image frame. Each object detected in an image frame and which is at least partly overlapping with a ROI is associated with the ROI. A list of candidate objects for feature extraction is determined by, for each ROI associated with two or more objects: adding each object of the two or more objects that is not overlapping with any of the other objects among the two or more objects with more than a threshold amount. From the list of candidate objects, at least one object is selected, and image data of the image frame depicting the selected object is used for determining a feature vector for the selected object.

Abstract: There are provided encoding and decoding methods, and corresponding systems which are beneficial in connection to performing a search among regions of interest, ROIs, in encoded video data. In the encoded video data, there are independently decodable ROIs. These ROIs and the encoded video frames in which they are present are identified in metadata which is searched responsive to a search query. The encoded video data further embeds information which associates the ROIs with sets of coding units, CUs, that spatially overlap with the ROIs. In connection to independently decoding the ROIs found in the search, the embedded information is used to identify the sets of CUs to decode.

Abstract: A TDM MIMO FMCW radar comprises an array of physical receivers with a first spacing in a first direction and a plurality of physical transmitters arranged with a second spacing in said first direction. A virtual array signal of a range-Doppler bin relating to a scene with a moving object is processed by a phase compensation method, which introduces a phase ambiguity between the subarrays. A positive or negative spatial phase change rate with respect to the first direction is computed based on elements of the compensated virtual array signal corresponding to one subarray at a time. From this, based on the spacings, a spatial phase change between a pair of the subarrays is predicted. Next, a residual phase shift between said pair of subarrays is determined by comparing an actual phase shift of the compensated virtual array signal and the predicted spatial phase shift.

Abstract: 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.

Abstract: The present disclosure relates to a method performed by a monitoring camera (100) for handling a first and a second video stream (201a, 201b). The monitoring camera (100) obtains a first video stream (201a) from a first image sensor (103a) and a second video stream (201b) from a second image sensor (103b). A field of view of the first video stream (201a) partly overlaps with the second video stream (201b). The monitoring camera (100) identifies a moving object (205) in the overlap area (203). The monitoring camera (100) divides the moving object (205) into a plurality of sub objects (210). The monitoring camera (100) performs a hard handover of the sub objects (210) from the first to the second video stream (201a, 201b) when the sub object (210) is within the overlap area (203) and when a point of the sub object (210) passes a border (208).

Abstract: A method of stabilizing bounding boxes for objects in a video stream comprises: receiving a video stream comprising a sequence of image frames; detecting an object in the image frames and generating a bounding box surrounding the object; measuring a noise level for the video stream; and temporally filtering the bounding box over a plurality of image frames based on the measured noise level, thereby stabilizing the bounding box in the video stream. The disclosure further relates to an image processing system.

Abstract: A method includes aligning a first image frame of a first stream of images from a first image sensor and a further first image frame of a second stream of images from a second image sensor according to a first alignment, aligning a second image frame of the first stream of images and a further second image frame of the second stream of images according to the first alignment, obtaining a first stitched image frame by blending the aligned first image frame and further first image frame in a first blending area according to a first blending function, obtaining second stitched image frame by blending the aligned second image frame and the further second image frame in a second blending area according to a second blending function, and evaluating the first alignment from a difference pattern calculated from pixel values of the first stitched frame and the second stitched frame.

Abstract: An arrangement for attachment of devices to a surface, such as a wall, comprises at least one device, and for each device, at least two mounting brackets. Each device has a rear side provided with a recess for each mounting bracket, wherein each mounting bracket has a male connector end and a female connector end, the male connector end being configured to be received by the female connector end of an adjoining mounting bracket associated to a neighbouring device. Each male connector end is provided with a through hole for receiving an attachment means, such as a screw. Each mounting bracket is insertable into its associated recess with an orientation in which the male connector end extends beyond a periphery of the device, and each mounting bracket is insertable into its associated recess with an orientation in which the female connector end is accessible from the periphery of the device.

Abstract: A method of generating a segmentation outcome which indicates individual instances of one or more object classes for an image in a sequence of images is disclosed.

Abstract: The present disclosure relates to methods, systems and non-transitory computer-readable storage mediums for detecting an object of a first object type in a video sequence. A first algorithm is used to detect areas or objects in the scene as captured in the video stream that have an uncertain object type status. A second algorithm is used to provide a background model of the video sequence. For areas or objects having the uncertain object type status, the background model is used to check if the area or object is considered to be part of the background or the foreground in the video sequence. If the area or object is determined to belong to the foreground, the area or object is classified as the first object type. If the area or object is determined to not belong to the foreground, the area or object is not classified as the first object type.

Abstract: A method and a device associate an object detection in a first frame with an object detection in a second frame using a convolutional neural (CNN) network trained to determine feature vectors such that object detections relating to separate objects are arranged in separate clusters. The CNN determines a reference set of feature vectors associated with the object detection in the first frame, and candidate sets of feature vectors associated with a respective one of identified areas corresponding to object detections in the second frame. A set of closest feature vectors is determined, and then measure of closeness to the reference set of feature vectors is determined for each candidate. A respective weight is determined for each object detection in the second frame. The object detection in the first frame is associated with one of the object detections in the second frame based on the assigned weights.