Method and apparatus for adjusting exposure in digital imaging
AssigneeNokia Corporation
InventorsJarno Nikkanen, Ossi Kalevo
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Abstract
The invention relates to electronic equipment for performing imaging, including a camera (CAM) for forming image frames (FRp, FRc), using set exposure parameters (ET, AG, DG), and a unit for determining the total exposure level (EV), from at least some of the image frames, and a unit for adjusting the said exposure parameters on the basis of the determined total exposure level of the exposure. In addition, the equipment also includes a motion-detection for detecting movement from at least some of the image frames. In the equipment the exposure parameters are arranged to be adjusted on the basis of the said total exposure level of the exposure and the detected movement.
Claims17
An apparatus comprising:
- a camera configured to capture a first image frame and a second image frame,
- a determiner configured to determine a required total exposure level from a captured image frame,
- a motion detector configured to detect movement from said first image frame and said second image frame, and
- an adjustor configured to adjust exposure time of said camera for a third image frame, wherein said apparatus is configured to:
- determine a first statistical number of a block of said first image frame,
- determine a second statistical number of a corresponding block of said second image frame,
- detect movement by comparing said first statistical number with said second statistical number
- define specific criterion values for exposure time and an analog gain, wherein at least part of the criterion values of at least the exposure time depends on the detected amount of the movement,
- define a first value range of the total exposure level and a second value range of the total exposure level based on the specific criterion values for the exposure time and the analog gain, and
- adjust the exposure time of the camera, at a value corresponding to the required total exposure level when the required total exposure level is in the first value range of the total exposure level, for capturing the third image frame.
A method comprising,
- capturing a first image frame and a second image frame using a camera used for digital imaging,
- determining a required total exposure level from a captured image frame,
- detecting movement by determining a first statistical number of a block of said first image frame, by determining a second statistical number of a corresponding block of said second image frame, and by comparing said first statistical number with said second statistical number,
- defining specific criterion values for exposure time and an analog gain, wherein at least part of the criterion values of at least the exposure time depends on the detected amount of the movement,
- defining a first value range of the total exposure level and a second value range of the total exposure level based on the specific criterion values for the exposure time and the analog gain, and
- adjusting the exposure time of a camera, at a value corresponding to the required total exposure level when the required total exposure level is in the first value range of the total exposure level, for capturing a third image frame.
A program storage medium comprising a storage and a program code written on said storage, said program code when executed by processor being configured to:
- capture a first image frame and a second image frame,
- determine a required total exposure level from a captured image frame,
- detect movement by determining a first statistical number of a block of said first image frame, by determining a second statistical number of a corresponding block of said second image frame, and by comparing said first statistical number with said second statistical number,
- define specific criterion values for exposure time and an analog pain, wherein at least part of the criterion values of at least the exposure time depends on the detected amount of the movement,
- define a first value range of the total exposure level and a second value range of the total exposure level based on the specific criterion values for the exposure time and the analog gain, and
- adjust the exposure time of a camera, at a value corresponding to the required total exposure level when the required total exposure level is in the first value range of the total exposure level, for capturing a third image frame.
Dependencies are inferred from the claim text.