Abstract: Techniques for encoding a video utilize a reduced range of pixel values, and comprise defining a first pixel value range within the reduced range that leads to exaggerated differences when converted to a full range; identifying blocks where a threshold portion of pixels fall within this first pixel value range; determining basic compression values for all blocks; determining lowered compression values for the identified blocks by applying a predetermined offset to the basic values; and encoding the image frame using the lowered compression for the identified blocks and the basic compression for all other blocks.

Abstract: A system and a method for visualizing movement of a detected object in a scene are disclosed. For each image of a sequence of images captured by a camera and depicting the scene: information is obtained indicating a location in horizontal direction in the image of the detected object, and a graphical shape is displayed on a display in a 2-dimensional graphical representation of a field of view of the camera in a horizontal plane, wherein the graphical shape has a location in the 2-dimensional graphical representation representing the location in horizontal direction in the image of the detected object.

Abstract: A method of stabilizing bounding boxes for objects in a video stream includes receiving a video stream having 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. An image processing system is also disclosed.

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. For each of the subarrays, a frequency spectrum is computed of those elements of the compensated virtual array signal which correspond to consecutive virtual antenna elements generated by physical receivers belonging to the same row. Next, an amplitude-peak frequency is identified jointly for the frequency spectra of the subarrays. Next, a residual phase shift between a pair of the subarrays is determined by comparing, at the amplitude-peak frequency, the respective phases of the frequency spectra.

Abstract: A speaker system comprises a main unit and passive units connected by control voltage signal, reference voltage signal and audio signal connections to form a daisy chain. The main unit generates a control voltage through the control voltage signal connection; a reference voltage through the reference voltage signal connection; and an audio signal through the audio signal connection. The system further comprises a voltage regulation unit between passive units on the reference voltage signal connection; each voltage regulation unit providing a local reference voltage to each passive unit, wherein the local reference voltages to the passive units gradually increase or decrease between subsequent passive units along the daisy chain. Each passive unit comprises: a speaker; a comparator unit for comparing the control voltage to first and second voltage thresholds from the local reference voltage to generate an audio enable signal enabling the speaker unit to play the audio signal.

Abstract: A cable sealing assembly to be used in a housing of an electronic device is provided. The assembly comprises a first sealing block and a second sealing block, each sealing block comprises an elongated cable receiving groove. The sealing blocks are configured to be arranged to sealingly abut each other, whereby the two cable receiving grooves together define a cable receiving channel. A housing using such an assembly is provided.

Abstract: A signed video bitstream obtained by prediction coding of a video sequence includes data units and associated signature units, wherein each data unit represents one macroblock in a video frame. Each signature unit includes a digital signature of a bitstring derived from fingerprints, and each fingerprint has been computed from a macroblock reconstructed from one data unit associated with the signature unit. The bitstream is edited by: receiving a request to substitute a region; reconstructing 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 the first set of macroblocks; editing the first set of data units and encoding them; re-encoding the second set of macroblocks; and adding the new data units to the signed video bitstream.

Abstract: A method for encoding a video stream includes obtaining images of a scene captured by a camera at a first resolution; identifying regions of interest (ROIs) in an image; adding, as part of an encoded video stream, a first video frame encoding at least part of the image at a second resolution lower than the first resolution; adding a second video frame marked as a no-display frame, and being an inter-frame referencing the first video frame with motion vectors for upscaling of the ROIs; adding a third video frame encoding the ROIs at a third resolution higher than the second resolution, and being an inter-frame referencing the second video 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: Methods and apparatus, including computer program products, implementing and using techniques for controlling the display of an overlay in a video. An overlay to be displayed in a video is defined. An overlay area is defined, which includes the overlay. At least one foreground object in the video is defined. A spatial overlap between the foreground object and the overlay area is determined. In response to determining that a size of the spatial overlap exceeds a first threshold, the entire overlay is stopped from being displayed within the overlay area.

Abstract: An AC-DC power converter includes: a rectification circuit configured to convert an input AC voltage to a rectified AC voltage; a power factor correction boost converter circuit configured to convert the rectified AC voltage to a first boosted DC voltage, wherein the first boosted DC voltage has AC ripple; a switched mode power supply output stage having a transformer; a buck and/or boost converter having two input voltage terminals, wherein a first voltage input terminal is connected to the first boosted DC voltage or to a secondary side of the transformer, and wherein a second input voltage terminal is connected to a second DC voltage, wherein the second DC voltage is higher than the voltage on the first voltage input terminal within a predefined voltage range, and wherein the buck and/or boost converter uses pulse width modulation to generate an output DC voltage with reduced AC ripple.

Abstract: A method for tracking an object in a scene is provided, including receiving a first image frame of a first image stream capturing a scene; detecting or tracking a first object in the first image frame, and determining that the first object is in a first part of the first image frame; determining, using object detection, that the first object belongs to a first object class; determining, based on multiple values of a tracking parameter each specific for different parts of the first image frame and for different object classes, a first value of the tracking parameter for the first part of the first image and for the first object class, and tracking the first object in a second image frame of the first image stream subsequent to the first image frame, based on the first value of the tracking parameter.

Abstract: A method for detecting objects in a scene comprises capturing video of the scene, segmenting a first image in into first and second scene areas whereby detection conditions are expected to differ between the scene areas. A first object detection threshold is set for the first scene area. A first object in the first image is detected, a first confidence value for the detection of the first object being above the first object detection threshold. In a plurality of images subsequent to the first image, the first object is tracked as it moves into the second scene area. A second confidence value for a detection of the first object in the second scene area is determined. A second object detection threshold for the second scene area is set such that the second confidence value is above the second object detection threshold.

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.