Abstract: A device, a non-transitory computer-readable storage medium, and a method of signing a metadata frame corresponding to an image frame of a sequence of image frames are disclosed. The metadata frame comprises metadata of one or more detected objects in the image frame, and the metadata of each detected object comprises coordinates defining a location in the image frame of the detected object. A digital signature is generated based on at least a subset of the metadata in the metadata frame, and additional metadata are added to the metadata frame. The additional metadata comprise the digital signature and predefined coordinates which define that the additional metadata comprise the digital signature. Furthermore, a device, a non-transitory computer-readable storage medium, and method of authenticating a digitally signed metadata frame corresponding to an image frame of a sequence of image frames are disclosed.

Abstract: A method and a device for setting a value of an object property in a sequence of metadata frames corresponding to a sequence of video frames is provided. An object is detected in a plurality of video frames. For a temporally first video frame a first value of an object property is determined and the object property is set to have the first value in a metadata frame corresponding to the first video frame. For each subsequent video frame, a subsequent value of the object property is determined and a deviation is calculated with respect to a value of the object property that was last set in a metadata frame. If the deviation exceeds a non-zero threshold, the object property is set to have the subsequent value in a metadata frame corresponding to the subsequent video frame. Otherwise no value of the object property is set in that metadata frame.

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: Methods, systems and computer program products, for producing streams of image frames. Image frames in streaming video are segmented into background segments and instance segments. A background image frame containing the background segments is created. At least some of the instance segments are classified into movable objects of interest and movable objects of non-interest. During a background update time period, the background image frame is updated when a movable object of non-interest has moved to reveal a background area, to include the revealed background area in the background image frame. A foreground image containing the movable objects of interest is created. Blocks of pixels of the updated background and foreground image frames are encoded. A stream of encoded foreground image frames having a first frame rate is produced. A stream of encoded updated background image frames a second, lower frame rate is produced.

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: A method of transmitting an image stream together with color metadata is disclosed. The method comprises capturing image frames of a first image stream, capturing image frames of a second image stream, using camera settings for prioritizing color capture, detecting an object in a first image frame of the first image stream and determining color information associated with the object based on the second image stream. The method further comprises adding the color information as color metadata to the first image stream, encoding the first image stream, and transmitting the encoded first image stream together with the color metadata. A corresponding device is also disclosed.

Abstract: A method, a computer program product, an encoder and a monitoring device for encoding an audio signal with variable bitrate, wherein: an audio signal comprising a plurality of successive audio frames is received; and for each successive audio frame of the audio signal: the audio frame is represented in a frequency domain with respect to a plurality of frequency sub-bands; the audio frame is classified in each frequency sub-band as either background or foreground using a background model specific to the frequency sub-band; each successive audio frame of the audio signal is encoded, wherein a number of bits is allocated for each frequency sub-band of the audio frame, wherein the number of bits allocated for a frequency sub-band is higher if the audio frame is classified as foreground in the frequency sub-band than if the audio frame is classified as background in the frequency sub-band.

Abstract: Methods, systems and computer program products, for producing streams of image frames. Image frames in streaming video are segmented into background segments and instance segments. A background image frame containing the background segments is created. At least some of the instance segments are classified into movable objects of interest and movable objects of non-interest. During a background update time period, the background image frame is updated when a movable object of non-interest has moved to reveal a background area, to include the revealed background area in the background image frame. A foreground image containing the movable objects of interest is created. Blocks of pixels of the updated background and foreground image frames are encoded. A stream of encoded foreground image frames having a first frame rate is produced. A stream of encoded updated background image frames a second, lower frame rate is produced.

Abstract: Video encoding, and specifically to a method and an encoder which can adapt the probability of intra refresh of image frame subdivisions based on a count of image frames since a previous refresh and modulated through convex or concave shaped distribution functions are set forth herein.

Abstract: A method of controlling output bitrate of a video encoder encoding a video sequence comprises: setting an allowable average bitrate, gathering encoding data by encoding video during a first time period and for each of a plurality of time intervals, storing a respective output bitrate, and a quantisation parameter used for encoding during the respective time interval. For each time interval, the output bitrate is normalised by calculating a corresponding normalised bitrate estimated for a predetermined nominal quantisation parameter as a function of the output bitrate and the quantisation parameter. An average normalised bitrate is calculated by averaging the normalised bitrates of the plurality of time intervals. A new quantisation parameter is calculated based on a comparison of the average normalised bitrate and the allowable average bitrate. The video sequence is encoded using the new quantisation parameter during a second time period subsequent to the first time period.

Abstract: A method and a controller for controlling a video processing unit to facilitate detection of newcomers in a first environment. The method comprises: capturing a thermal image of a human object in the first environment, the first environment being associated with a first climate; calculating, based on the thermal image, a thermal signature of a portion of the human object; determining that the human object has entered the first environment from a second environment when the thermal signature of the portion of the human object deviates from a predetermined thermal signature associated with the first environment, wherein the second environment is associated with a second, different, climate; and controlling the video processing unit to prioritize the human object over other human objects when processing video frames depicting the human object together with the other human objects.

Abstract: Methods and apparatus, including computer program products, implementing and using techniques for reducing bitrate from a monitoring camera. A first input is received that identifies first regions of an image representing a camera field of view. The first regions contribute significantly to the bitrate. A second input is received that identifies second regions of the image. The second regions contain information that is deemed to be of little visual interest to a user of the monitoring camera. Third regions of the image are determined. The third regions are regions where the first and second regions overlap at least in part. Video encoder settings are applied to force skip blocks in at least some of the third regions, thereby reducing contributions to the bitrate from the third regions.

Abstract: Video encoding, and specifically to a method and an encoder which can adapt the probability of intra refresh of image frame subdivisions based on a count of image frames since a previous refresh and modulated through convex or concave shaped distribution functions are set forth herein.

Abstract: Methods and apparatus, including computer program products, implementing and using techniques for reducing bitrate from a monitoring camera. A first input is received that identifies first regions of an image representing a camera field of view. The first regions contribute significantly to the bitrate. A second input is received that identifies second regions of the image. The second regions contain information that is deemed to be of little visual interest to a user of the monitoring camera. Third regions of the image are determined. The third regions are regions where the first and second regions overlap at least in part. Video encoder settings are applied to force skip blocks in at least some of the third regions, thereby reducing contributions to the bitrate from the third regions.

Abstract: A method, a computer program product, an encoder and a monitoring device for encoding an audio signal with variable bitrate, wherein: an audio signal comprising a plurality of successive audio frames is received; and for each successive audio frame of the audio signal: the audio frame is represented in a frequency domain with respect to a plurality of frequency sub-bands; the audio frame is classified in each frequency sub-band as either background or foreground using a background model specific to the frequency sub-band; each successive audio frame of the audio signal is encoded, wherein a number of bits is allocated for each frequency sub-band of the audio frame, wherein the number of bits allocated for a frequency sub-band is higher if the audio frame is classified as foreground in the frequency sub-band than if the audio frame is classified as background in the frequency sub-band.

Abstract: A method of controlling output bitrate of a video encoder encoding a video sequence comprises: setting an allowable average bitrate, gathering encoding data by encoding video during a first time period and for each of a plurality of time intervals, storing a respective output bitratet, and a quantisation parameter used for encoding during the respective time interval. For each time interval, the output bitrate is normalised by calculating a corresponding normalised bitrate estimated for a predetermined nominal quantisation parameter as a function of the output bitrate and the quantisation parameter. An average normalised bitrate is calculated by averaging the normalised bitrates of the plurality of time intervals. A new quantisation parameter is calculated based on a comparison of the average normalised bitrate and the allowable average bitrate. The video sequence is encoded using the new quantisation parameter during a second time period subsequent to the first time period.

Abstract: The present invention relates to a system and a method for encoding a video stream. The encoding includes determining a level of relevance for areas in an image frame to be included in the video stream, determining a block size value for coding blocks in the image frame, the block size value is depending on the level of relevance determined for the area including each coding block, respectively, encoding the image frame using coding block sizes based on the determined block size values for each of the coding blocks.

Abstract: A method, system, and computer program product of encoding a digital image comprising a privacy mask. Information representative of pixels in the digital image is received. The pixels are grouped into encoding units. Information representative of a privacy mask area in which a privacy mask is to be applied on the image is also received. All encoding units that at least partially are located within the privacy mask area are identified, and the privacy mask area is extended to be aligned with the identified encoding units. For each encoding unit, a respective quantization parameter to be used for encoding the image is determined. The privacy mask is applied in the extended privacy mask area of the image, and the image with the applied privacy mask is encoded using the determined quantization parameters. The digital image encoding system may be included in a camera.

Abstract: A method, video server, and system for playing back recorded video based on comparing the encoder frame rates at temporal positions of a received video sequence to a predetermined threshold and changing the playback frame rate to a playback frame rate greater than the encoder frame rate if the encoder frame rate is below the predetermined threshold and changing the playback frame rate to the encoder frame rate if the encoder frame rate is greater than the predetermined threshold. The recorded video is thereby played back in a time efficient manner, decreasing the total time period for video playback, and assisting a security operator in finding parts of the recorded video that may be of interest.

Abstract: A method for controlling a video camera which is configured to capture and process image frames prior to encoding. The method comprises determining whether the video camera is going to encode an image frame as an intra-frame or an inter-frame. If the image frame is going to be encoded as an inter-frame, the video camera is controlled to capture and process the image frame using first settings prior to encoding. If the image frame is going to be encoded as an intra-frame, the video camera is controlled to capture and process the image frame using second settings prior to encoding, wherein the second settings are modified in relation to the first settings to further reduce a level of noise in the image frame.