Abstract: The present disclosure relates to a method performed by a deviation analyzing system (1) for black level drift assessment of a digital camera image sensor (21). The deviation analyzing system measures (1001) for pixels of an image captured by the image sensor, a respective luminance value and corresponding chromaticity value of each pixel. The deviation analyzing system further determines (1002) a respective average chromaticity value for differing luminance levels of the measured luminance values, based on for each luminance level averaging the corresponding measured chromaticity values. Moreover, the deviation analyzing system determines (1003), when the respective average chromaticity values of a range (4) of luminance levels indicate—to a predeterminable extent—chromaticity deviations (5) from the respective average chromaticity values (6) of other luminance levels (7), that a black level setting of the image sensor is drifted from a true black level.

Abstract: A method of encoding an image comprises establishing whether objects constituting one or more predefined object types or performing one or more predefined event types are visible in the image; in response to establishing that the objects are visible, encoding at least one region-of-interest of the image using a non-generative image model, thereby obtaining first image data; and encoding any remainder of the image using a generative image model, thereby obtaining second image data, wherein use of the non-generative image model enables decoding of the first image data without relying on information derived from images other than the encoded image or, if the image is a frame in a video sequence, enables decoding of the first image data without relying on information derived from images outside the video sequence.

Abstract: A method of activating an object-specific action comprises obtaining, based on image analysis of acquired images, a plurality of values of a movement characteristic, each value representing a moving object detected in the acquired images; receiving an input signal from a user input device, wherein the input signal represents a value of the movement characteristic for the user input device; comparing the value of the movement characteristic for the user input device with each value of the movement characteristics for the moving objects, and determining the moving object corresponding to the closest value of movement characteristic as a selected moving object; and activating the object-specific action for the selected moving object.

Abstract: A method in an access control system comprising a control unit connected to one or more mobile devices using radio-frequency signal communication. The control unit sends a motion status request to a connected mobile device out of the one or more connected mobile devices in response to the generated event. The method comprises determining an indication of a probability that the connected mobile device is associated with the event. Determining the indication is based on received signal strength data, measured by the connected mobile device on the radio-frequency signals transmitted by the control unit during a first predetermined period of time before the motion status request is received, and motion sensor data collected from a motion sensor comprised in the connected mobile device during a second predetermined period of time before the motion status request is received.

Abstract: A method for handling a radio-frequency connection between a control unit and a mobile device of an access control system. The mobile device is connected to the control unit using radio-frequency signal communication. The method comprises obtaining an indication of a first event generated in the access control system in response to a first request for the control unit to arrange to carry out an action. After a release of the connection by the control unit, the method further comprises obtaining an indication of whether or not a second event has been generated in the access control system in response to a second request for the control unit to arrange to carry out the action. The method further comprises determining, based on the indication of whether or not the second event has been generated, whether or not to allow the mobile device to re-connect to the control unit.

Abstract: A solid-state relay includes a semiconductor switch and a voltage boost block. The semiconductor switch has a control input, which causes the semiconductor switch to shift from an open, non-conducting position to a closed, conducting position when a voltage is applied to the control input. The voltage boost block includes a boost converter and a ground connector. A voltage output of the semiconductor switch is electrically connected to a voltage input of the boost converter. A voltage output of the boost converter is electrically connected to the control input. The ground connector of the boost converter is electrically connected to a voltage input of the semiconductor switch When the semiconductor switch is in the closed position, the semiconductor switch is maintained in a closed position in the absence of another control signal.

Abstract: There is provided a method for capturing a sequence of image frames in a thermal camera having a microbolometer detector comprising: capturing a first sequence and a second sequence of image frames with a shutter of the thermal camera being in a closed state and an open state, respectively. While capturing each of the first and the second sequence, an integration time of the microbolometer detector is switched between a plurality of integration times according to one or more repetitions of a temporal pattern of integration times. The method further comprises correcting image frames in the second sequence that are captured when the integration time is switched to a particular position within the temporal pattern of integration times using image frames in the first sequence that are captured when the integration time is switched to the same particular position within the temporal pattern of integration times.

Abstract: A method of encoding a video stream for the provision of prunable video data, comprising: receiving, in an encoder, a video stream in which each image frame of the video stream is divided into a number of subviews, providing each subview with an assigned category based on a content of the particular subview, monitoring the evolution of category assigned for each subview, and encoding the video stream using a hierarchical P-frame encoding structure, in such manner that each change in category for a subview starts a new hierarchical P-frame structure.

Abstract: An image processor and a method therein to provide a target image for evaluation with an object detector. The method comprises: obtaining a source image captured by a camera and depicting an object, and applying an inverse pixel transform to each target pixel of a target image to determine one or more source pixels located at a position in the source image corresponding to a position of each target pixel in the target image. The method further comprises assigning, to each target pixel, a target pixel value determined based on one or more source pixel values of the determined one or more source pixels located at the corresponding position, thereby is a size c in the target image of the depicted object of a specific object type normalized in at least one size dimension. Thereafter, the target image is fed to an object detector for evaluation.

Abstract: A method for encoding a video stream for the provision of prunable video data, comprising identifying, in the video stream, a first event-generating occurrence in one or more frames of the video stream, and, in an encoder, using the event-generating occurrence to initiate a hierarchical branch extending from a base-layer when encoding the video stream.

Abstract: A method of masking or marking an object in an image stream is provided, including: generating one or more output image streams by processing an input image stream capturing a scene, including discarding pixel information about the scene provided by pixels of the input image stream, such that the discarded pixel information about the scene is not included in any output image stream; and detecting an object in the scene using the discarded pixel information, wherein generating the one or more output image streams includes masking or marking the detected object in at least one output image stream once deciding that the object is at least partially visible within this at least one output image stream. A corresponding device, computer program and computer program product are also provided.

Abstract: A method of masking in an output image stream includes receiving an input image stream capturing a scene, processing the input image stream to generate the output image stream, including using a detector to detect objects in the scene and a tracker to track objects in the scene based on information provided by the detector, and further including to generate a particular output image of the output image stream by checking whether there exists a particular area in the scene in which an evaluation of a historical performance of the detector and/or tracker fulfills at least one condition, and to, if confirming that such a particular area exists, mask the particular area of the scene in the particular output image. A corresponding device, computer program, and computer program product are also provided.

Abstract: A method for image stabilization of a video stream captured by a panable and/or tiltable video camera the method comprising: generating a motor position signal, Y1, of a pan/tilt motor of the video camera; generating a gyro signal, Y2, of a gyroscopic sensor of the video camera; generating a reference signal from a predetermined movement curve of the pan/tilt motor of the video camera, the reference signal is a reference on how a pan/tilt operation of the video camera is made without shaking of the video camera; from the motor position signal, Y1, and the gyro signal, Y2, generating a combined signal, Y, according to: Y=F1*Y1+F2*Y2, wherein F1 is a low pass filter and F2 is a high pass filter; and performing image stabilization on the video stream based on a difference between the combined signal, Y, and the reference signal.

Abstract: A wearable form factor wireless camera may include an image sensor, coupled to an infrared detection module, which captures infrared video. The wearable form factor wireless camera may attach to clothing worn on a user and be ruggedized. A storage device may store the captured infrared video at a first fidelity. The stored infrared video may be capable of being transmitted at the first fidelity and at a second fidelity, with the first fidelity providing a higher frame rate than the second fidelity. A burst transmission unit may transmit the stored infrared video at the second fidelity via a cellular network. The infrared detection module, the image sensor, the storage device and the burst transmission unit may be powered by a battery. The image sensor, the infrared detection module, the battery, the storage device and the burst transmission unit may be internal to the wearable form factor wireless camera.

Abstract: A method of transfer learning an object recognition neural network comprises acquiring a set of image frames; determining, by a first object recognition algorithm implementing an object recognition neural network, a plurality of object recognitions in the set of image frames; determining verified object recognitions by evaluating the plurality of object recognitions by a second, different from the first, object recognition algorithm, wherein an object recognition with a positive outcome in said evaluating forms a verified object recognition; forming a training set of annotated images comprising image frames associated with the verified object recognitions; performing transfer learning of the object recognition neural network based on the training set of annotated images.

Abstract: The present invention relates to the field of video encoding. In particular, it relates to a method 300 of encoding images captured by a camera and to an image processing device. An image sequence captured with an image sensor of the camera is obtained S310, and an oscillation frequency of a periodic movement of the camera during capturing of the image sequence is determined S320. A base subset of images of the image sequence corresponding to the oscillation frequency is identified S330 and the base subset of images are encoded S340 into an encoded video stream comprising intra frames and inter frames.

Abstract: There is provided techniques for setting frame rates of a camera. The camera comprises a plurality of image sensors arranged to capture images to be stitched into a panorama image of a scene. Information of a respective angle between the optical axis of each of the plurality of image sensors and a direction along which a straight path structure, to be monitored by the camera, extends through the scene is obtained. The plurality of image sensors are divided into at least two groups as a function of the angles. All the angles of the image sensors within each of the at least two groups are part of its own continuous angle interval. One frame rate is set per each of the at least two groups. The frame rate decreases from the group with highest continuous angle interval towards the group with lowest continuous angle interval.