Optimum detectors for artificial object recognition

Current digital cameras have a linear response and are only really suitable for simple picture imaging under controlled light conditions. In fact compared to human vision these cameras have two critical and debilitating limitations, a limited dynamic range and variability in object colour. The first of these limitations causes saturation when the dynamic range of a scene is larger than that of the camera. The second limitation is subtler and means that unlike human vision it is difficult to use colour information from linear cameras in artificial object recognition systems. Both these limitations can be overcome using pixels with a relatively narrow spectral response and an output that is proportional to the logarithm of the detected photocurrent. We intend to overcome these limitations by developing a new camera technology based upon organic photodiodes and a logarithmic response.