【摘要】 对几种常用的自动调焦算法进行了对比分析,并通过实验对各种调焦函数的灵敏度、一致性、稳定性、计算速度等指标进行测试和验证.理论分析和实验结果表明:灰度变化率之和函数具有较大的调焦范围,且近似为线性变化,同时计算速度适中,稳定性较好,因此适于大范围粗调焦;Laplacian函数和Tenengrad函数峰顶宽度相对较窄,灵敏度高,稳定性好,因此适合于小范围精确调焦,但是计算速度较慢;Roberts梯度函数的灵敏度居中,既有一定的调焦范围,在焦点附近又具有比较高的灵敏度,而且稳定性好,计算速度快,因此适于中等范围的自动调焦.更多还原

【Abstract】 In order to evaluate the practicality of multitudinous methods for auto-focusing, several methods were compared and analyzed. The parameters of sensitivity, consistency, stability and calculating speed were tested and validated through experiments. The experiments and analysis show that the sum of grad-change function has a large range of auto-focusing, moderate calculating speed, good stability, preferring to large-scale cursory focusing. The Laplacian function and the Tenengrad function both have sharp peaks near the focused regions, good sensitivity and stability, preferring to small-scale accurate focusing, but their calculating speeds are relatively low. The Roberts gradient function has not only moderate sensitivity and focusing scale, but also good stability, high calculating speed and high sensitivity in the vicinity of focus, preferring to moderate-scale auto-focusing.更多还原