从焦点检测的历史背景出发，结合光学的成像原理，提出了以图像梯度为对焦评价函数的自动调焦技术。
Through studying the historical background of the focus detection and principles of optical imaging, the auto focusing system adopts image gradient as the auto focusing evaluation function.
此外文章还讨论了在可调焦范围内进行焦点自动搜索的方法，选用了逐次逼近法来进行本系统自动调焦的控制。
In addition, auto-searching in focusing field is also developed, and successive approximation approach was adopted as a method of auto-searching in this focusing system.
此外文章还讨论了在可调焦范围内进行焦点自动搜索的方法，选用了逐次逼近法来进行本系统自动调焦的控制。
In addition, auto-searching in focusing field is also developed, and successive approximation approach was adopted as a method of auto-searching in this focusing system.
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