Patent ID: 9706189
Date: 2017-07-11
CPC Classifications: G02B,G03B,G06K,G06T,H04N

Claim:
1. A method for calibrating image defection, adapted to an image capturing device having a first lens, a second lens, a focusing actuator, and a pre-stored first focusing step-to-focusing distance relation ratio, comprising: capturing a plurality of image sets by utilizing the first lens and the second lens, wherein each of the image sets comprises a first image corresponding to the first lens and a second image corresponding to the second lens, and the image sets comprise a reference image set including a first reference image corresponding to the first lens and a second reference image corresponding to the second lens; detecting whether the reference image set is out of focus by determining whether clarity values of the first reference image and the second reference image are not greater than a predetermined clarity value, wherein the reference image set is detected out of focus when at least one of the first reference image and the second reference image is out of focus; and when the reference image set is detected to be out of focus and when a focusing condition of the image capturing device is a far focusing condition: recording a focusing step corresponding to a focused target in each of the image set, wherein the focusing step corresponding to the focused target in each of the image sets is a number of steps that the focusing actuator is required to move the first lens and the second lens to a focusing position to provide maximum clarity to a focused target in each of the image sets; when the focusing step corresponding to the focused target in each of the image sets reaches a convergent value, obtaining a minimum focusing step and calculating a difference value between the minimum focusing step and the convergent value; and calibrating the first focusing step to focusing distance ratio according to the difference value; and when the reference image set is detected to be deformed and when a focusing condition of the image capturing device is a near focusing condition: performing a three-dimensional depth estimation on each of the image sets to generate depth information of the focused target in each of the image sets; obtaining the focusing distance corresponding to the focused target in each of the image sets according to each of the depth information; performing a regression according to the focusing distance and the focusing step corresponding, to the focused target in each of the image sets; and calibrating the first focusing step-to-focusing distance ratio according to a result of the regression.