Abstract: Methods and a device for updating a track of an object include first tracking of the object across a sequence of image frames preceding the current image frame using a first computer-implemented tracker. The tracker is updated based on object detections generated by a computer-implemented object detector executing an object detection algorithm. The first track includes an estimated object location for each frame in the subset. Using a motion model of the first tracker, a location of the object in the current image frame is predicted. Motion areas detected in the current image frame by a computer-implemented motion detection algorithm are then received. Based on the predicted location and the detected motion areas, the first tracker determines that a detected motion area corresponds to the object. The predicted location is updated based on the corresponding motion area, thereby determining an estimated location of the object in the current image frame.

Abstract: Adapting encoding of image frames of a video is performed. The image frames are arranged in a sequence of groups of pictures (GOPs) and each GOP contains an intra-frame and a plurality of inter-frames. A start is determined of a second GOP after a first GOP and encoding is adapted of a predetermined number of inter frames of the first GOP which immediately precede the determined start of the second GOP. The encoding is such that the size of the 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 without adapting encoding. The method further comprises enabling cancellation of quantized transform coefficients when encoding inter-frames of the first GOP. Adapting encoding of inter-frames of the second GOP which immediately succeed the intra-frame of the second GOP further comprises disabling cancellation of quantized transform coefficients.

Abstract: 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.

Abstract: Signing of an encoded video stream using a first device and second device, wherein the first device provides the original signatures of a first encoded video stream, wherein the second device applies video processing to the first encoded video stream to modify the image frames thereof and include the modified image frames into a second encoded video stream. The second device determines difference data corresponding to the video processing and includes the difference data in the second encoded video stream. On a decoder side, the decoder can authenticate the received second encoded video stream by validating the original signatures using the difference data.

Abstract: 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 based on all elements of a virtual array signal, and a single-subarray angle spectrum 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.

Abstract: A method, device, and system track 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.

Abstract: A method for attaching an image sensor to an optics unit of an imaging device, wherein an attachment part is releasably attached to a sensor attachment surface of the optics unit and the image sensor is releasably attached to a sensor holder. Using an active alignment method, a position of at least one of the image sensor and the optics unit is adjusted, such that the image sensor is positioned at a desired angle in relation to an optical axis of the optics unit and in a desired position in relation to the optics unit, thereby positioning the image sensor in an aligned position. The sensor holder is permanently attached to the attachment part, such that the image sensor is fixed in the aligned position. The image sensor is releasable from the sensor holder when the sensor holder has been permanently attached to the attachment part.

Abstract: A TDM MIMO FMCW radar comprises at least one row of physical receivers with a first spacing (dr) in a first direction, and further comprises a plurality of physical transmitters arranged with a second spacing (dt) in said first direction. To determine whether a peak in an angle spectrum corresponds to a direct reflection or a first-order multipath artefact, an inverse phase-shift vector corresponding to a phase ({circumflex over (?)}1) of the peak is applied and a constant signal with the amplitude of the peak is subtracted. To the thus obtained intermediate signal (v), a further inverse phase-shift vector—now corresponding to an offset phase (?{circumflex over (?)}) of the two leading peaks of the angle spectrum—after which a constant signal is subtracted. It is then detected whether the thus obtained test signal (w) has any non-noise content. If yes, the peak corresponds to a multipath artefact, and otherwise to a direct reflection.

Abstract: A device and a method mask an object in a video stream. The camera is arranged in a system including the camera and another device. A location and field of view is known for the device and the camera. Furthermore, the field of view of the device and the camera are non-overlapping. Information indicating that an object is approaching the field of view of the camera is obtained. The obtained information is determined from the device indicating a location and a direction of movement of the object and the known locations and fields of view of the camera and the device. In response to the information, a threshold for detecting objects to be masked in the video stream captured by the camera is reduced. An object to be masked in the video stream is detected using the reduced threshold, and masking of the object in the video stream is inserted.

Abstract: A dome camera arrangement comprises one or more camera heads arranged in a transparent dome Each camera head comprises an optics unit, a panning device and a tilting device for moving the camera head in panning and tilting movements, respectively. The tilting device has a pivot portion and a cradle portion. The camera head further has a roll device for rotating the optics unit in a roll movement. A compensation lens is arranged in a compensation lens fitting in front of the optics unit, and the compensation lens fitting is connected to the panning and tilting device, such that the compensation lens will move with the camera head in panning and tilting movements. However, the compensation lens fitting is disconnected from the same features such that the compensation lens will not follow the optics unit in roll movement, thus enabling an adequate optical compensation by the compensation lens.

Abstract: A method , software and device for encoding a video sequence into an encoded video stream having a target resolution, comprises: encoding 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 an encoding scenario from a set of one or more predefined encoding scenarios; and encoding 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.

Abstract: A method and device are provided for stitching images and blending pixel data from at least three image sensors while an object moves through their combined field of view. The combined view includes a first region where the views of at least three sensors overlap and through which the object’s track passes. The method includes obtaining time-synchronized image sequences from each sensor, detecting the object in the combined view, determining its location, and predicting its track. Based on the predicted track, a minimal set of sensor views that fully covers the track is identified. Images captured at the same time from sensors in this minimal view set are stitched and blended to form a combined image. In most of the portion of the combined image corresponding to the overlapping region, pixel blending uses data from no more than two sensors at any location.

Abstract: A computer-implemented method for enabling video recreation, comprising: acquiring, by a camera control unit, a video stream comprising a set of image data packages each comprising coded image frames; transmitting, by the control unit, at least a portion of the video stream to a client across a communication network, receiving, by the control unit, an acknowledgement message for each image data package that was successfully received by the client, storing, in a digital memory accessible to the control unit, the image data packages for which an acknowledgement message is received, and indications of successful receipt at the client of the corresponding image data packages.

Abstract: Methods, software, devices and systems encode an image frame in a video stream, such that a decoded version of the encoded image frame is provided with a first masked region. A block-aligned mask is applied to the image frame being encoded, and a pre-generated encoded image frame is used to transform the block-aligned masked region during decoding. The pre-generated encoded image frame contains motion vectors but no residual data, enabling efficient transformation of a block-aligned masked region into the first masked region with an edge that cuts across coding blocks.