Auto-focus system for a digital imaging device and method
AssigneesSK hynix Inc., Chungang University Industry Academic Cooperation Foundation
InventorsJoon Ki Paik, Yoon Jong Yoo, Jin Beum Jang, Jong Heon Kim, Jae Hyun Im, Jae Hwan Jeon, Wan Hee Jo
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Abstract
The present invention relates to an auto-focus system and method based on a sensor, using hierarchical extraction and motion estimation for an image. The auto-focus method may include the steps of: (a) extracting a phase difference image from a sensed image; (b) extracting a robust feature image which satisfies a preset reference with respect to noise and out-of-focus blur, from the phase difference image; and (C) estimating a motion vector for lens shift from the feature image.
Claims19
An auto-focus system for a digital electronic device that adjust focus by lens shift comprising:
- a sensing unit suitable for sensing an image;
- and
- an auto-focus control unit suitable for extracting first and second phase images having a phase difference from the image sensed by the sensing unit, extracting a strong feature image from the first and second phase images, and estimating a motion vector used for the lens shift to adjust focus from the feature image,
- wherein the auto-focus control unit comprises:
- a feature extraction unit suitable for acquiring a first difference image and a second difference image by applying a Difference of Gaussian scheme and a difference scheme between images reconstructed by a pyramid method to any one of the first and second phase images, acquiring coordinate of a predefined area by summing the first and second difference images, and extracting the feature image corresponding to the coordinate from the first and second phase images.
An auto-focus method for a digital electronic device that adjust focus by lens shift comprising:
- extracting first and second phase images having a phase difference from an image sensed by a sensing unit;
- extracting a strong feature image from the first and second phase images;
- estimating a motion vector used for the lens shift to adjust focus from the feature image;
- and
- performing the lens shift to adjust focus using the motion vector,
- wherein the extracting of the feature image comprises:
- acquiring a first and difference images by applying a Difference of Gaussian scheme and a difference scheme between images reconstructed by a pyramid method to any one of the first and second phase images;
- acquiring coordinate of a predefined area by summing the first and second difference images;
- and
- extracting the feature image corresponding to the coordinate from the first and second phase images.
Dependencies are inferred from the claim text.