An exposure control system of video cameras based on fuzzy logic using color information

Auto exposure (AE) is an important function of video cameras to adjust the image luminance. In this paper, an exposure control system of the AE using color information is discussed. Current AE systems detect special image conditions such as backlighting and excessive frontlighting in which the luminance of a main object deteriorates, and compensate the exposure in order to obtain the appropriate luminance of the main object. The compensation is determined according to the degree of backlighting and excessive frontlighting, regardless of the the background. The exposure control system proposed in this paper uses "hue" and "chroma" of pixels to derive the importance of the background, and determines the amount of compensation required by fuzzy reasoning. Simulations of AE were carried out using both the conventional system and proposed method. Results showed that the proposed system was more efficient for AE than the conventional method.