Monitoring animals’ movements using digitized video images

Abstract

An animal’s movements can be monitored continuously using video digitization techniques. We outline the differences between video frame-grabbers and column-scan digitizers, and describe two applications using column-scanners: detecting episodes of spontaneous locomotion and tracking the position of a moving appendage. Strategies are discussed for increasing the speed of software and for compressing the information in the video images into an analog motion signal to be displayed and stored for later analysis. Finally, the advantages and limitations of frame-grabbers and column-scan digitizers are assessed.

Margaret C. Thompson was supported by a grant for undergraduate research to Smith College from the Merck Foundation. Her present address is Department of Computer and Information Sciences, University of Massachusetts, Amherst, MA 01003. The manuscript was prepared while Richard F. Olivo was a visiting scientist at the Eaton-Peabody Laboratory, Massachusetts Eye & Ear Infirmary, Boston; he thanks the members of the laboratory and its director, Nelson Kiang, for hospitality. We are grateful to Carrie Fischer, Dennis Freeman, and Ishmael Stefanov-Wagner for their comments on the manuscript.