Axis Ab

Telefonaktiebolaget Lm Ericsson (publ)

Song Yuan

Viktor Edpalm

Johan Förberg

Axel Keskikangas

Ludvig Hassbring

Hampus Linse

Harald Gustafsson

Björn Ardö

Johan Nyström

Toivo Henningsson

Raphael Teller

Stefan Lundberg

Johan Eker

Alexandre Martins

Tim Borglund

Jessica Nilsson

Johan Stening

Giovanni Mumolo

Magnus Norberg Olsson

Carl-Axel Alm

Niclas Danielsson

Joakim Ericson

Xing Danielsson Fan

Per Persson

Björn Johansson

Håkan Ardö

Alexander Toresson

Patrik Persson

Carl Von Platen

John Rehn

Martin Santesson

Johan Palmaeus

Jan Patrik Persson

Erik Andersson

Tor Nilsson

Charles Chen Xu

Mingchao Shao

Viktors Jakovels

Mikael Murstam

Lars Branzén

Adnan Saleem

Rodrigo Such

Fan Xing Danielsson

Viktor Yakovel

A method of encoding a video stream is provided, including obtaining a first image with a first FOV; encoding the first image as part of a first encoded video frame; obtaining a second image with a second FOV different from the first FOV; generating a first additional video frame referencing the first video frame, including motion vectors transforming image content of the first image to a FOV closer to the second FOV than the first FOV, wherein the motion vectors are formed based on a difference between the first and second FOVs; inserting the first additional video frame into the encoded video stream as a no-display frame, and encoding the second image as part of a second video frame of the encoded video stream referencing the first additional video frame. A corresponding device, computer program and computer program product are also provided.

Encoding of video stream during changing camera field-of-view

A method for rendering a text string in a digital raster image suitable for block-wise transform coding, the method comprising: obtaining a partition of an image area into coding blocks for the block-wise transform coding; representing the text string as a plurality of graphical elements from a typeface which are arranged according to a tentative layout in the image area, wherein the tentative layout defines at least a position, orientation and size of each graphical element; modifying the tentative layout by applying a spectrum sparsening operation to at least one nonempty coding block, thereby obtaining a modified layout; and rendering a digital raster image of the graphical elements arranged according to the modified layout.

Encoder-optimized text rendering

A method for identifying stationary regions in frames of a video sequence comprises receiving an encoded version of the video sequence, wherein the encoded version of the video sequence includes an intra-coded frame followed by a plurality of inter-coded frames; reading coding-mode information in the inter-coded frames of the encoded version of the video sequence, wherein the coding-mode information is indicative of blocks of pixels in the inter-coded frames being skip-coded; finding, using the read coding-mode information, one or more blocks of pixels that each was skip-coded in a respective plurality of consecutive frames in the encoded version of the video sequence; and designating each found block of pixels as a stationary region in the respective plurality of consecutive frames.

Method for identifying stationary regions in frames of a video sequence

A method of encoding a video stream including an overlay is provided, including: capturing a first image; adding an overlay to the first image at a first position, and encoding the first image in a first frame of a video stream; capturing a second image of the scene; determining a desired position of the overlay in the second image; encoding the second image in a second frame marked as a no-display frame, and generating and encoding a third frame including temporally predicted macroblocks at the desired position of the overlay referencing the first frame with motion vectors based on a difference between the desired position and the first position, and skip-macroblocks outside of the desired position of the overlay referencing the first frame. A corresponding device, computer program and computer program product are also provided.

Video stream overlay encoding using no-display frames and motion vectors calculated based on known position-differences between frames

A method of distortion correction in an image captured by a non-rectilinear camera includes obtaining multiple images of a scene captured by the camera over time, determining where bottom portions of objects having moved over a horizontal surface in the scene are located in the images, determining a boundary of the horizontal surface in the scene based on the determined locations of the bottom portions, generating a three-dimensional model of the scene by defining one or more vertical surfaces around the determined boundary of the horizontal surface of the scene, and correcting a distortion of at least one of the images by projecting the image onto the three-dimensional model of the scene. A corresponding device, computer program and computer program product are also provided.

Self-learning distortion correction

The present disclosure relates to methods, systems and non-transitory computer-readable storage mediums for detecting an object of a first object type in a video sequence. A first algorithm is used to detect areas or objects in the scene as captured in the video stream that have an uncertain object type status. A second algorithm is used to provide a background model of the video sequence. For areas or objects having the uncertain object type status, the background model is used to check if the area or object is considered to be part of the background or the foreground in the video sequence. If the area or object is determined to belong to the foreground, the area or object is classified as the first object type. If the area or object is determined to not belong to the foreground, the area or object is not classified as the first object type.

Methods, systems and non-transitory computer-readable storage mediums for detecting an object of a first object type in a video sequence

A system and method trigger a second camera in a camera system to perform an action prior to an object appearing in the field of view of the second camera. The camera system includes the second camera for which a location and a field of view is known, and at least a first device for which a location is known. The method comprises receiving, in the second camera, information indicating that the object is approaching the field of view of the second camera. The received information indicates a location and a direction of movement of the object, and, in response to the received information, triggers the second camera to action prior to the object appearing in the field of view of the second camera by: generating an intra frame or initiating an intra refresh procedure, adjusting one or more image processing parameters, or adjusting an exposure time.

Camera information handover

A method for determining a lens distortion correction comprising:

Method and image-processing device for determining a lens distortion correction for an interchangeable camera lens

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.

Image processing device and a method for encoding a view area within an image frame of a video into an encoded video area frame

An image processing device, a camera system, a non-transitory computer-readable storage medium, and methods for encoding two video image frames captured by one of two image sensors, wherein each of the video image frames depicts a respective portion of a scene. A respective overlapping area is identified in each of the video image frames, which overlapping areas both depict a same sub-portion of the scene, and a video image frame of the video image frames is selected. Compression levels are then set for the image frames, wherein respective compression levels are set for pixel blocks in the selected video image frame based on a given principle. Respective compression levels for pixel blocks in the overlapping area in the selected video image frame are selectively set higher or lower than respective compression levels that would have been set based on the given principle. The video image frames are then encoded.

Camera system and method for encoding two video image frames captured by a respective one of two image sensors

An image processing device, a non-transitory computer-readable storage medium and a method for dividing an array of pixels into slices and tiles, and a system for encoding the slices and tiles into a video stream by means of a first encoder arranged in a first image processing circuitry and a second encoder arranged in a second image processing circuitry are disclosed. The array of pixels consists of a first subset of pixels having pixel data stored in a first buffer arranged in the first image processing circuitry and a second subset of pixels having pixel data stored in a second buffer arranged in the second image processing circuitry, wherein a first border between the first subset of pixels and the second subset of pixels is tilted at a tilt angle in relation to the array of pixels. The array of pixels is divided into two or more slices, and each slice is divided into two or more tiles. The two or more tiles of each slice consists of a first subset of tiles and a second subset of tiles, wherein the first subset of tiles and the second subset of tiles are disjunct and the first subset of tiles is to be encoded by the first encoder and the second subset of tiles is to be encoded by the second encoder. Dividing each slice into two or more tiles comprises setting a second border between the first subset of tiles and the second subset of tiles at an offset between two adjacent slices of the two or more slices, wherein the offset is based on the tilt angle.

Method, an image processing device for dividing an array of pixels into slices and tiles, and a system for encoding the slices and tiles into a video stream

A method of generating an output video stream is provided, including receiving a first input video stream from at least one first camera capturing a scene, receiving a second input video stream from a second camera only partially capturing the scene, and generating an output video stream from the first input video stream, including, in response to determining that a particular area of the output video stream depicts a part of the scene depicted in the second input video stream, refraining from, or at least reducing a level of, a masking of the particular area of the output video stream. A corresponding device, camera monitoring system, computer program and computer program product are also provided.

PTZ masking control

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.

Method for controlling a bitrate of a video stream captured with an image aquisition device

A method for masking of objects in a video stream, the method comprising: acquiring a video stream; detecting an object in the video stream; determining whether the detected object belongs to a foreground of the video stream indicative of moving objects or to a background of the video stream indicative of static objects; classifying the detected object to be of a specific type using a first classifier if the detected object is determined to belong to the foreground, and using a second classifier if the detected object is determined to belong to the background, the first classifier being different from the second classifier, and if the detected object is classified as being of the specific type of object, masking the object in the video stream.

Masking of objects in a video stream

A method includes detecting a first object in a first area of a scene; determining, based on characteristics of the first object, a first probability value indicating a first probability that the detected first object; detecting a second object in a second area of the scene captured in a second stream of image frames by a second camera of the camera system different from the first camera, wherein the second area at least partly overlaps the first area; determining, based on characteristics of the second object, a second probability value indicating a second probability that the detected second object; and when the second probability value is below a second threshold value and the first probability value is above a first threshold value determining an updated second probability value by increasing the second probability value.

Method and image-processing device for determining a probability value indicating that an object captured in a stream of image frames belongs to an object type

Growing community of inventors

Lund, Sweden

Song Yuan