Automatic focusing method for digital image pickup device

Abstract

The auto focusing method for a digital image acquisition device comprises: A. selecting the initial movement direction for lens, let it move to a position; let r = 0 and s = 1; B. calculating and recording corresponding boundary information of current lens position; C. deciding whether it has found out the maximal value of information value; if yes, determining current lens position as the accurate focus position, the process ends; D. if meeting lens deflecting condition, let lens movement direction as the inverse one for current movement, let s = 0 and r = r+1; E. if r>1, taking lens position with known maximal boundary information value as the focusing position, the process ends; F. moving lens along preset direction, let s = s+1, and turning to step B.

Description

technical field

[0001] The invention relates to an automatic focusing method of an image capture device, in particular to an automatic focus method of a digital image capture device. Background technique

[0002] A patent document whose publication number is CN1794032 discloses an autofocus method, comprising the following steps: a) acquiring the image data of the initial position of the lens and extracting the edge of the image, counting the pixel values ​​of each point on the edge to obtain the boundary and store the information value, and store the corresponding lens position at the same time; b) move the lens, and obtain the boundary information value of the image corresponding to the current lens position according to the method described in step a); c) compare the boundary information value of the current image with the above For the boundary information values ​​stored once, save the larger value and its corresponding lens position, and then perform steps b) and c) in...

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