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US 7,480,452 B2Granted
System and method for image capturing
AssigneeWinbond Electronics Corp.
InventorKazuya Matsumoto
Life of this patent
Estimating the term…
Abstract
Methods and related computer program products, systems, and devices for auto-focusing in an image-capturing system includes sampling output signals from an auto-focusing circuit in a first interval of lens distances and determining a first lens distance and a second lens distance corresponding to the two highest values of the sampled output signals in the first interval of lens distances.
Claims19
A method for auto-focusing in an image-capturing system, the method comprising:
- performing pre-gamma correction on received image signals to generate pre-gamma corrected image signals;
- processing the pre-gamma corrected image signals to generate output signals of an auto-focusing circuit;
- sampling the output signals from the auto-focusing circuit in a first interval of lens distances;
- determining a first lens distance and a second lens distance corresponding to the two highest values of the sampled output signals in the first interval of lens distances;
- and
- sampling the output signals from the auto-focusing circuit in a second interval between the first lens distance and the second lens distance.
3 more elements
An image-capturing system comprising:
- a focus lens;
- an auto-focusing circuit, the auto-focusing circuit being configured to:
- perform pre-gamma correction on received image signals to generate pre-gamma corrected image signals;
- and
- process the pre-gamma corrected image signals to generate output signals;
- and
- a processing unit, the processing unit being configured to:
- sample the output signals from the auto-focusing circuit in a first interval of lens distances;
- determine a first lens distance and a second lens distance corresponding to the two highest values of the sampled output signals in the first interval of lens distances;
- and
- sample the output signals in a second interval between the first lens distance and the second lens distance, the second interval being smaller than the first interval.
8 more elements
A method comprising:
- providing a pre-gamma function having a first region, a second region, and a third region, the derivative of the function in the second region being greater than the derivative of the function in the first and third regions;
- receiving image signals from an imaging device;
- and
- performing pre-gamma correction on the received image signals using the pre-gamma function to generate a pre-gamma corrected image signal.
1 more element
An image-capturing system comprising:
- a circuit configured to:
- provide a pre-gamma function having a first region, a second region, and a third region, the derivative of the function in the second region being greater than the derivative of the
- function in the first and third regions;
- receive image signals from an imaging device;
- and
- perform pre-gamma correction on the received image signals by multiplying the received image signals by the derivative of the pre-gamma function in a region of the pre-gamma function corresponding to an illumination level of the received signal using the pre-gamma function to generate a pre-gamma corrected image signal.
3 more elements
Dependencies are inferred from the claim text.