Abstract: A method for detecting an object in a first distorted image using a sliding window algorithm, comprising: receiving an inverse of a mathematical representation of a distortion of the first distorted image; wherein the detection of an object comprises sliding a sliding window over the first distorted image, the sliding window comprising a feature detection pattern, and for each position of a plurality of positions in the first distorted image: transforming the sliding window based on the inverse of the mathematical representation of the distortion at the position, wherein the step of transforming the sliding window comprises transforming the feature detection pattern of the sliding window such that a resulting distortion of the feature detection pattern of the transformed sliding window corresponds to the distortion of the first distorted image at the position; and using the transformed sliding window comprising the transformed feature detection pattern in the sliding window algorithm.

Abstract: A method for training an alarm system to classify audio of an event, wherein the alarm system is connected to a neural network trained to classify audio as an event type, the method comprising the steps of: receiving audio recorded during a first period of time; transmitting the audio to an external unit; receiving data from the external unit indicating a sub-period of time of the audio and data indicating an event type of the indicated sub-period of time of the audio; and re-training the neural network by inputting a sub-period of the audio corresponding to the indicated sub-period of time of the audio and using the indicated event type as a correct classification of the sub-period of the audio.

Abstract: A method for verifying a digital signature in a video data segment generated by a video delivery chain comprises: obtaining the video data segment comprising encoded image frames and a plurality of node device datasets associated with respective labels; wherein one or more node device datasets include respective digital signatures; wherein the one or more node device datasets comprises a first node device dataset which includes a first digital signature generated by a first node device based on a first number of node device datasets that have been last added to the video data segment before the first node device dataset; locating the labels; identifying , using the labels, the first number of node device datasets; and verifying the first digital signature. The application also discloses a method of adding a digital signature to a video data segment.

Abstract: A method of enabling a remote access to a first network device from a second network device includes the second device generating a data item signed by a network service trusted by the first device, and including a fingerprint of a public key of the second device. The signed data item is sent to the first device via a signalling service, SIGS, as part of a negotiation of terms for a peer-to-peer connection. The first device uses the received signed data item to verify that the terms it receives from the SIGS has not been tampered with by the SIGS, in order to prevent the SIGS from performing a Man-In-The-Middle attack. Various network devices and a network system are also provided.

Abstract: Mechanisms are provided for retraining a pre-trained object classifier. A method comprises obtaining a stream of image frames of a scene. Each of the image frames depicts an instance of a tracked object. The method comprises classifying, with a level of confidence, each instance of the tracked object to belong to an object class. The method comprises verifying that the level of confidence for at least one of the instances of the tracked object is higher than a threshold confidence value. The method comprises, when so, annotating all instances of the tracked object in the stream of image frames as belonging to the object class, yielding annotated instances of the tracked object. The method comprises retraining the pre-trained object classifier with at least some of the annotated instances of the tracked object.

Abstract: A device and a method of signing an encoded video sequence comprising: obtaining an encoded video sequence composed of encoded image frames; generating a set of one of more frame fingerprints for each encoded image frame; generating a document comprising a header of a supplemental information unit, and a representation of the generated sets of one or more frame fingerprints; generating a document signature by digitally signing the document; generating the supplemental information unit to only consist of the document, the document signature and an indication of an end of the supplemental information unit; and signing the encoded video sequence by associating the generated supplemental information unit with the encoded video sequence.

Abstract: Storing and retrieving media recordings in an object comprises a first method of storing a media recording comprising the following steps performed at an ingest component of a system: assigning a recording ID to the media recording; storing media data in one or more data objects in an object store, each carrying the recording ID; storing media metadata in an attribute object carrying the recording ID; computing a hash of the metadata; and storing the hash, the recording ID, a recording interval and a recording source in an index object. The first method further comprises concatenating the index object with an existing index object using a maintenance component. A second method is suitable for retrieving a media recording stored in an object store using the first method. A third method is suitable for performing maintenance on the object store by concatenating specific groups of index objects.

Abstract: The present disclosure generally relates to the field of camera surveillance, and in particular to a method and control unit for controlling a bitrate of a video stream captured with an image acquisition device.

Abstract: An encoding device and a method for encoding an image frame comprising a plurality of pixel blocks are provided. A respective offset compression value is set for each of the plurality of pixel blocks based on an interest level associated with the pixel block, wherein each offset compression value defines an offset in relation to a reference compression value set for the image frame. In the image frame, one or more low contrast regions having a contrast which is below a predefined contrast threshold are identified. For pixel blocks within the one or more low contrast regions having set offset compression values based on the associated interest levels higher than a predefined offset compression threshold, the set offset compression values are selectively restricted to be at most equal to the predefined offset compression threshold. The image frame is then encoded using the set offset compression values.

Abstract: A method for determining whether or not a transparent protective cover of a video camera comprising a lens-based optical imaging system is partly covered by a foreign object is disclosed. The method comprises: obtaining (402) a first captured image frame captured by the video camera with a first depth of field; obtaining (404) a second captured image frame captured by the video camera with a second depth of field which differs from the first depth of field; and determining (406) whether or not the protective cover is partly covered by the foreign object by analysing whether or not the first and second captured image frames are affected by presence of the foreign object on the protective cover such that the difference between the first depth of field and the second depth of field results in a difference in a luminance pattern of corresponding pixels of a first image frame and a second image frame.

Abstract: A and method encode a view area within a current image frame of a video into an encoded video area frame. The view area is a respective subarea of each image frame, each image frame comprising first and second image portions, and between previous and current image frames, the view area moves across a boundary between the first and second image portions. First and second encoders are encode image data of the first and second image portions, respectively. First, second and third portions of the view area are identified based on their respective location in the previous and current image frames. Image data of the first and third portions are inter-coded as first and third encoded slices/tiles. Image data of the second portion of the view area in the current image frame are intra-coded as a second encoded slice/tile. The encoded slices/tiles are merged into the encoded video area frame.

Abstract: A method of controlling an operating temperature of a data storage device is disclosed. A threshold temperature for the storage device is set. Over time, during operation of the data storage device, an operating temperature of the storage device is measured at a plurality of points in time. A plurality of temperature measurements as a function of time are thereby obtained. Above threshold temperature measurements are accumulated over time to form a high temperature accumulation value (Vhigh), and below threshold temperature measurements are accumulated to form a low temperature accumulation value (Vlow). The low temperature accumulation value (Vlow) and the high temperature accumulation value (Vhigh) are compared. If an outcome of the comparison is that the high temperature accumulation value (Vhigh) is too high in relation to the low temperature accumulation value (Vlow), an operating temperature lowering action is initiated.

Abstract: An exposure time controller for controlling an exposure time (ET) variable of a video camera, which is associated with an auto-exposure algorithm configured to reduce an exposure mismatch (?E) by incrementing and decrementing the ET variable, which comprises: a memory for recording ET values applied while the video camera is imaging a scene and the algorithm is active; and processing circuitry configured to: determine that the exposure mismatch exceeds a threshold while the video camera is imaging the scene; estimate a distribution of the recorded ET values; based on the estimated distribution, identify multiple relatively most frequent ET values; and, in reaction to determining that the exposure mismatch exceeds the threshold, assign one of the identified ET values to the ET variable.

Abstract: A method of configuring a camera comprising: collecting a video data with the camera, providing a plurality of imaging profiles, each imaging profile being associated with a set of scene characteristics, for each imaging profile, generating a spatial output data in dependence on the video data and the set of scene characteristics of the imaging profile, wherein the spatial output data is indicative of spatial locations of events detected in the video data matching one or more of the scene characteristics, performing a comparison of the spatial output data of each of the plurality of imaging profiles, selecting a preferred imaging profile in dependence on the comparison, configuring the camera to operate according to the preferred imaging profile.

Abstract: A method for suppressing chromatic aberration, especially blue or red fringing, in a digital image with multiple color channels is disclosed. The method comprises negatively correcting a first color channel by subtracting an overshoot component of the first color channel. The subtraction is subject to a lower threshold, which is dependent on a local value of at least one further color channel.