Tools for Investigating the Perception of Natural Scenes

Research on the perception of complex half-tone images and images of natural scenes requires accurate quantitative control of the characteristics of the stimuli. The tools consist of the hardware and the software for stimulation and processing. Our hardware for stimulation includes a CCD, an IBM PC with implementing Frame Grabber, the display, and a device for photometric control. We present programs for image processing allowing control of the brightness scale, reformation, changing the number of discretisation levels, addition and subtraction, programs for convolution operations including frequency filtration approximations, the means of different methods, programs for generation of test images and for generation of noise added to these, and programs for measuring statistical and geometrical characteristics of images. We also present software for use in electrophysiological experiments.