To provide an initial feature information extracting device for a mobile body detection element, employing a photoelectric conversion protein analogous to visual pigment that can extract initial feature information required for image information processing, from a time series signal outputted from the mobile body detection element, employing the photoelectric conversion protein analogous to visual pigment.

The initial feature information extraction device is provided with an initial feature information extracting means that extracts initial feature information by each time series signal of a differential response type outputted, from each pixel electrode of the mobile body detection element employing the photoelectric conversion protein similar to visual pigment, and the initial feature information extraction means respectively extracts information about a time, when a differential response takes place, a time constant of the differential response and a maximum value of the differential response sequentially from the time series signal of the differential response type for a prescribed time region, outputted from pixel electrodes by using a wavelet transform method.