中央/對焦之測光方法應用於自動曝光

Abstract

照片拍出來的亮暗，主要是由自動曝光來控制。實際生活中，我們要拍的景都非常不同，很難用一種簡單的測光方式去符合各種景。Nikon提出一種AMP的測光方式，使用表格對照的方式來解決各種景的分析，再藉由分析天氣和對比的情況來選擇適合的演算法。C. C. Yu使用模糊控制、主體擴張、多重參考表格的方式來改善AMP的效能。我們新的演算法使用了對焦的資訊，並用更精簡的測光演算法達到更好的效果。 另外，Yu也提出最佳曝光照片選擇演算法，主要目的是選出人眼最喜歡的照片。我們修改了演算法，使得選出來的照片會有更大的機率符合大部份的人喜好。

Automatic exposure (AE) controls the light intensity of pictures. In real life, the scenes are too many and diverse to analyze. The common AE metering methods do not work for all scenes, so Nikon’s Automatic Multiple Pattern (AMP) metering algorithm [2] solves these problems. It analyzes large image data, and constructs reference tables. AMP chooses a better metering method by considering weather and contrast conditions. C. C. Yu’s AE metering algorithm [3] solves some problems of AMP method with fuzzy control, subject growing, and multiple reference tables. Our new metering algorithm utilizes the focus information and is simpler and smaller than AMP and C. C. Yu’s algorithms. Moreover, C. C. Yu proposes an optimal exposure selector (OES) to choose one of pictures with different exposures and to satisfy people preference. We modify the OES factors to achieve precise results.