Motion Detection Using Colour Templates

The Horridge template model1 is an empirical motion detection model inspired by insect vision. This model has been successfully implemented on several micro-sensor VLSI chips26 using greyscale pixels. The template model is based on movement of detected edges rather than whole objects, which facilitates simple tracking techniques. Simple tracking algorithms developed by Nguyen7 have been successful in tracking coherent movement of objects in a simple environment. Due to the inherent edge detection nature of the template model, two closely spaced objects moving at the same speed relative to the template model sensor will appear to have a common edge and hence be interpreted as one object. Hence when the two objects separate, the tracking algorithm will be upset by the detection of two separate edges, resulting in a loss of tracking. This paper introduces a low-cost insect vision prototype, based on a colour CMOS camera. Although this approach sacrifices auto gain control (AGC) at each pixel, results are valid for controlled lighting conditions. We demonstrate working results, for indoor conditions, by extension of the template model using the colour CMOS sensor to form colour templates. This enables the detection of colour boundaries or edges of closely moving objects by exploiting the difference in colour contrast between the objects. This paper also discusses the effectiveness of this technique in facilitating the independent tracking of multiple objects.