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US 9,426,351 B2Granted
Auto-focusing system and method
AssigneeHanwha Techwin Co., Ltd.
InventorsKyungeun Lee, Youngseo Park, Dongseuk Park, Chunwon Lee, Youngsang Kwon, Daebong Kim
Life of this patent
Estimating the term…
Abstract
An auto-focusing method includes dividing an image into a plurality of blocks, performing discrete cosine transform (DCT) on image data of the plurality of blocks to output a plurality of DCT blocks each comprising DCT coefficients, generating a DCT mask for selecting DCT coefficients corresponding to a selected frequency range in a DCT block among the plurality of DCT blocks, and calculating a focus value of the image by applying the generated DCT mask to the DCT block.
Claims18
An auto-focusing method comprising:
- dividing an image into a plurality of blocks;
- performing discrete cosine transform (DCT) on image data of the plurality of blocks to output a plurality of DCT blocks each comprising DCT coefficients;
- generating a DCT mask for selecting DCT coefficients corresponding to a selected frequency range in a DCT block among the plurality of DCT blocks;
- and
- calculating a focus value of the image by applying the DCT mask to the DCT block;
- wherein the DCT block comprises a plurality of alternating current (AC) components divided into at least one low frequency component, at least one medium frequency component, and at least one high frequency component, and
- wherein the generating the DCT mask comprises generating:
- a first DCT mask for selecting DCT coefficients corresponding to the low frequency component and a first medium frequency component adjacent to the low frequency component;
- and
- a second DCT mask for selecting DCT coefficients corresponding to the high frequency component and a second medium frequency component adjacent to the high frequency component.
7 more elements
An auto-focusing system comprising:
- a divider configured to divide an image into a plurality of blocks;
- a discrete cosine transform (DCT) processor configured to perform DCT on image data of the plurality of blocks to output a plurality of DCT blocks each comprising DCT coefficients;
- a mask generator configured to generate a DCT mask for selecting DCT coefficients corresponding to a selected frequency range in a DCT block among the plurality of DCT blocks;
- and
- a focus value calculator configured to calculate a focus value of the image by applying the DCT mask to the DCT block,
- wherein the mask generator is configured to divide a plurality of alternating current (AC) components of the DCT block into at least one low frequency component, at least one medium frequency component, and at least one high frequency component, and
- wherein the mask generator is further configured to generate:
- a first DCT mask for selecting DCT coefficients corresponding to the low frequency component and a first the medium frequency component adjacent to the low frequency component;
- and
- a second DCT mask for selecting DCT coefficients corresponding to the high frequency component and a second medium frequency component adjacent to the high frequency component.
7 more elements
Dependencies are inferred from the claim text.