1. Maximum Response Experimentation
Senior Project – Electrical Engineering Motion Detection Using MATLAB Laura DeMar, Jin Han Advisor: Prof. Rudko
Objectives
Model a lizard’s visual perception of movements in natural scenes
Use an elementary motion detector of the correlation type
In the correlation-type movement detector two mirror subunits have a delay and multiplication. The spatially filtered input is correlated at a given distance with the imprint of the preceding frames given by the temporal filtered output.
Maximum Response Experimentation
Calculated the size of the maximum response for various object sizes, speeds, and memory time constants.
Input Simulation
Movie with several frames, in which an object moves with constant velocity n0 from frame to frame.
Filtering
Results
There is a shift in the desired peak of the maximum response for large object sizes with different tau. Thus, the peak of the maximum response does not occur when its velocity is equal to the correlation distance
Large objects are not tuned for different memory time constants
For a small correlation distance and a small tau, the maximum response is broader
Tuning of the motion detector depends on tau because there were more maximum response peaks for a small tau
Gain is inversely proportional to the time constant
Program can be tested further for varying speeds between frames
Results need to be correlated with lizard physiological data
Temporal Filter
Lowpass filter
Time constant tau determines memory of the filter
The larger tau, the longer the memory of the filter
Filtered signals mimic those that would appear in lizard’s retinal image
Spatial Filter
Symmetric Gaussian filter
Enhances the edges of the object