AXIS AB

A method for determining a status of a microphone comprises inducing a piezoelectric component, located in a vicinity of and in mechanical connection with the microphone, to emit a predetermined impulse waveform; determining whether a response signal waveform from the microphone corresponds to the predetermined impulse waveform; and upon the response signal waveform from the microphone corresponding to the predetermined impulse waveform, determining that the status of the microphone is operational.

A method and control unit for object detection in a video stream captured with an image acquisition device, especially for the purpose of anonymizing objects in the video stream.

An apparatus and a method for tracking a temporarily occluded object in image frames of objects and associating detected instances into tracks. An active first track of a first object and an active second track of a second object are identified, which objects are moving together. Upon determination that the first track, but not the second track, has become inactive connecting it to the second track. Thereafter, a detected object instance is associated with an inactive track when a similarity score between the detected instance and the inactive track fulfills a similarity requirement. The requirement is less strict when the instance is spatially proximate to the second track and when the detected instance is compared to the inactive first track connected to the second track as compared to when the detected instance is compared to an unconnected inactive track.

Controlling a camera includes determining a first camera setting for monitoring a scene under a first lighting condition, and a second camera setting for monitoring the scene under a second lighting condition. The method further includes obtaining a reference image that represents the scene under the second lighting condition, as captured in the first camera setting. While monitoring the scene in the first camera setting, detecting a change in the scene from the first to the second lighting condition. The detecting the change includes performing a comparison between first image feature data derived from a first image of the scene captured with the camera set to the first camera setting, after the change from the first to the second lighting condition, and reference image feature data derived from the reference image, to determine that the first image feature data matches the reference image feature data.

A device for monitoring a heap of material, comprises circuitry for executing a plurality of functions. A region of interest function, in a thermal video stream captured by a thermal video camera, defines a region of interest covering the heap of material. A reference spatial property setting function, from pixels within a video frame of the thermal video stream, determines a spatial property of the heap of material; and sets the determined spatial property as a reference spatial property. A region of interest adjusting function determines a respective sample spatial property for regions in the thermal video stream; and adjusts the region of interest such that regions exhibiting a sample spatial property above a threshold are included by the region of interest. A temperature monitoring function over time and within the region of interest, monitors a temperature measure; and if it exceeds a predetermined threshold, generates an alarm event.

A method for object detection (post-processing) in an image is provided, and includes obtaining, from one or more artificial neural network (ANN) entities trained to localize objects and one or more subparts of such objects in images, a plurality of object proposals and one or more subpart proposals in a same image; performing a first filtering of the object proposals; matching subpart proposals with corresponding object proposals remaining after the first filtering, and performing a second filtering of the unmatched object proposals remaining after the first filtering. The first and second filtering are based on classification confidence scores and proximity scores of the object proposals, and the second filtering is statistically more aggressive than the first filtering. A corresponding device, computer program and computer program product are also provided.

A method of controlling a guard tour of a thermal camera, wherein the thermal camera is a pan-tilt camera or a pan-tilt-zoom camera, comprises the steps of: obtaining a guard tour comprising a plurality of views of an area or facility and a sequence of movements and/or view times of the thermal camera for traversing the plurality of views; controlling the thermal camera to traverse the plurality of views according to the sequence of movements and view times of the guard tour; for each view: extracting a temperature profile based on thermal images from the thermal camera; based on the temperature profile, estimating whether an increased risk of overheating or overcooling exists for the view; and if so, adjusting the sequence of movements and view times of the thermal camera to show the view having an increased risk of overheating or overcooling more frequently.

A method for encoding an image frame, performed by an image processing device, comprising obtaining image data, and identifying an image area in an image frame based on that the image area fulfilling an identification criterion. The method further comprises determining a bit depth reduction factor for the identified image area by analyzing the image data in the identified image area, and replacing some of the bit values of the pixel values in the identified image area with dummy values. How many of the bit values that are replaced with dummy values is defined by the bit depth reduction factor. The method comprises encoding the image frame upon said some of the bit values having been replaced in the identified image area.