US 2010/0165174 A1 · AUTOMATIC FOCUSING METHOD AND DEVICE IN HIGH-NOISE ENVIRONMENT

Abstract

An automatic focusing method and device in a high-noise environment are used for determining a focusing distance between a digital imaging device and an object to be photographed. The automatic focusing method includes the steps of capturing M pre-photographed images at different object distances respectively; loading the pre-photographed images; superposing every N (N<M) pre-photographed images to create (M−N+1) composite images; redefining the object distances corresponding to the (M−N+1) composite images; calculating high-frequency signals in the focusing regions of the (M−N+1) composite images; determining an optimum focusing object distance based on the relation between the high-frequency signals and corresponding object distances; and adjusting an automatic focusing lens to the optimum focusing object distance and accomplishing focusing.

Claims8

Dependent claims

An automatic focusing method in a high-noise environment, applicable for determining a focusing object distance between a digital image device and at least one object to be photographed, comprising:

taking pre-photographed images at different object distances;
loading the pre-photographed images;
superposing the pre-photographed images respectively to generate a composite image;
calculating an object distance corresponding to the composite image;
calculating a high-frequency signal of at least part of pixels in the composite image;
and
determining the focusing object distance for the object to be photographed with the high-frequency signal and the corresponding object distance of the composite image as reference data.

4 more elements

A digital imaging device with automatic focusing in a high-noise environment, applicable for determining a focusing object distance for at least one object to be photographed, comprising:

a storage unit, for storing a plurality of pre-photographed images captured at different object distances;
a microprocessor, electrically connected to the storage unit, for loading the pre-photographed images;
an image superposition unit, arranged in the microprocessor, for superposing the pre-photographed images to generate a plurality of composite images under control of the microprocessor;
an object distance resetting unit, arranged in the microprocessor, for calculating an object distance corresponding to each of the composite images and deriving corresponding object distances of the same number as that of the composite images under control of the microprocessor;
and
a high-frequency signal calculation unit, arranged in the microprocessor, for calculating the high-frequency signal of at least part of pixels in each of the composite images and deriving the high-frequency signals of the same number as that of the composite images under control of the microprocessor;
wherein the microprocessor determines the focusing object distance for the object to be photographed by using the high-frequency signals and the corresponding object distances.

4 more elements

Dependencies are inferred from the claim text.

Automatic focusing method and device in high-noise environment

Life of this patent

Automatic focusing method and device in high-noise environment

Life of this patent

Abstract

Claims8