Axis Ab

Johan Nyström

Song Yuan

Johan Förberg

Björn Ardö

Björn Benderius

Ludvig Hassbring

Kent Fransson

Johan Jeppsson

Toivo Henningsson

Can Xu

Dennis Nilsson

Tim Borglund

Jessica Nilsson

Tor Nilsson

Michael Barnes

A controller interacts with an image processing chain configured to process a video stream captured by a video camera and including an object detection algorithm which outputs a frame-wise detection score for each image region, and a masking function which applies a privacy mask in dependence of the detection score. When the controller detects a sudden change in luminance of a scene which is being imaged the video camera, it maintains or expands, for a period while the video camera is imaging the scene, the privacy mask which was applied at the detected sudden change. The maintaining or expanding of the privacy mask may be achieved by locally reducing a masking threshold applied by the masking function. The expansion of the privacy mask may be gradual over time and related to an estimated speed of a moving object in the scene.

Video monitoring with robust privacy masking

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, Y, of a pan/tilt motor of the video camera; generating a gyro signal, Y, 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, Y, and the gyro signal, Y, generating a combined signal, Y, according to: Y=F*Y+F*Y, wherein Fis a low pass filter and Fis 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.

Image stabilization of a video stream captured by a panable and/or tiltable video camera

Image encoding within a pixelated privacy mask area is adapted in order to reduce flickering during movement of a camera. Motion vectors are set equal to the movement of the camera, and residuals are set to zero, thereby encoding pixel blocks within the privacy mask area as copies of corresponding pixel blocks in a reference image.

Method of encoding an image including a privacy mask

Methods and apparatus, including computer program products, for selecting a cropping area in a sequence of images captured by a camera. First external motion data including data of external factors affecting movement of the camera is correlated with internal motion data describing a movement of the camera. The first external motion data and the internal motion data are obtained during a first time interval. Second external motion data is obtained during a second time interval subsequent to the first time interval. A sequence of images being captured during a third time interval is stabilized by selecting a cropping area based on the correlation and the second external motion data. The cropping area remains constant and maximized in size with respect to the field of view of the images during the third time interval. The third time interval is subsequent to, or partly overlapping with, the second time interval.

Statistics-based electronic image stabilization

A power control system for controlling operation of a first battery-powered device positioned at a remote location from a camera. The power control system includes a receiving module, a retrieving module, a comparison module, and a transmission module. The receiving module is configured to receive at least one of a pan angle and a tilt angle of the camera indicative of a field of view. The retrieving module is configured to retrieve a position of the first battery-powered device. The comparison module is configured to compare the pan angle and the tilt angle with the position of the first battery-powered device, and determine whether the first battery-powered device is positioned within the field of view of the camera based on the comparison. The transmission module is configured to transmit instructions to control power consumption of the first battery-powered device, based on the determination.

Operation control of battery-powered devices

A method for determining a local contrast value for a digital image captured by an image sensor in a camera comprising: applying an edge detection algorithm to image data of the digital image, thereby obtaining a data set pertaining to edges in the digital image; calculating, based on said data set, an edge occurrence value for the digital image; estimating, based on image data of the digital image and a noise model of the image sensor, an estimated image sensor noise for the digital image; and computing the local contrast value as a relationship between the edge occurrence value of the digital image and the expected edge occurrence value for the digital image. A method for adjusting a focus setting of a camera using the local contrast value for images captured by the camera.

Determination of a contrast value for a digital image

Methods and devices for protecting personal privacy in captured image data by controlling privacy masking of an image, where the degree of blurring to be applied to a privacy area of the image depends on a threshold distance from the image capturing device, and the spatial resolution of content of the scene at this distance in the image.

Method, device and system for a degree of blurring to be applied to image data in a privacy area of an image

The invention relates to a method for moving a maneuverable part of a pan-tilt camera from a first pan-tilt position, having a first pan coordinate and a first tilt coordinate, to a second pan-tilt position, having a second pan coordinate and a second tilt coordinate. The maneuverable part is moved by inverting the maneuverable part of the camera and panning to the second pan coordinate. The first pan coordinate is part of a pan-tilt coordinate system and the second pan coordinate is part of a complementary pan-tilt coordinate system, which represents positions of the inverted maneuverable part. The maneuverable part is moved from the first tilt coordinate to the second tilt coordinate. The first tilt coordinate is part of the pan-tilt coordinate system and the second tilt coordinate is part of the complementary pan-tilt coordinate system. The invention also relates to a corresponding device and a corresponding computer program.

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Lund, Sweden

Johan Nyström