Supercomputing and Algorithms Group, CSIC-UAL Associated Unit, University of Almeria, 04120 Almeria, Spain.
Sensors (Basel). 2011;11(9):8412-29. doi: 10.3390/s110908412. Epub 2011 Aug 29.
Images from high dynamic range (HDR) scenes must be obtained with minimum loss of information. For this purpose it is necessary to take full advantage of the quantification levels provided by the CCD/CMOS image sensor. LinLog CMOS sensors satisfy the above demand by offering an adjustable response curve that combines linear and logarithmic responses. This paper presents a novel method to quickly adjust the parameters that control the response curve of a LinLog CMOS image sensor. We propose to use an Adaptive Proportional-Integral-Derivative controller to adjust the exposure time of the sensor, together with control algorithms based on the saturation level and the entropy of the images. With this method the sensor's maximum dynamic range (120 dB) can be used to acquire good quality images from HDR scenes with fast, automatic adaptation to scene conditions. Adaptation to a new scene is rapid, with a sensor response adjustment of less than eight frames when working in real time video mode. At least 67% of the scene entropy can be retained with this method.
从高动态范围（HDR）场景获取的图像必须以最小的信息损失获得。为此，有必要充分利用 CCD/CMOS 图像传感器提供的量化水平。LinLog CMOS 传感器通过提供结合线性和对数响应的可调节响应曲线来满足上述要求。本文提出了一种快速调整控制 LinLog CMOS 图像传感器响应曲线的参数的新方法。我们建议使用自适应比例-积分-微分控制器来调整传感器的曝光时间，并结合基于图像饱和度和熵的控制算法。通过这种方法，可以使用传感器的最大动态范围（120dB）从 HDR 场景中获取高质量的图像，并快速、自动适应场景条件。对新场景的适应速度很快，在实时视频模式下，传感器响应调整不到八帧。通过这种方法可以保留至少 67%的场景熵。
