Axis Ab

Dennis Nilsson

Björn Benderius

Johan Nyström

Simon Molin

Johan Nystrom

Johan Jeppsson

Johan NYSTRÖM

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

The present invention relates generally to auto focus algorithms for setting a focus of a camera. More specifically, the present invention relates to a method () and device for setting a focus of a camera wherein a camera motion level of the camera is continuously measured (S) during the read-out of pixel data by a rolling shutter image sensor and wherein the auto focus algorithm uses weighted focus measures which are calculated (S) using the continuously measured camera motion levels.

Method and device for setting a focus of a camera

A camera and a method for selecting a focus region in a camera view have a plurality of focus regions that are defined in the camera view. A focus distance of the camera is repeatedly set to focus at different distances by setting a lens distance of the camera to different lens distance values. A focus value is determined for each focus region at the set lens distance value. A function for a plurality of focus regions is estimated based on a plurality of determined focus value and lens distance value pairs. A local maximum point of the function is calculated for each focus region for which a function has been estimated, where the local maximum point has a lens distance value. Focus regions are grouped, rated and selected based on the lens distance value of the local maximum point of the focus regions and spatial distances between the focus regions.

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Malmo, Sweden

Dennis Nilsson