Unformatted text preview: • First component of frequency is ‘fundamental’, the rest are ‘higher harmonics’ Contrast Sensitivity Function (CSF) • Contrast threshold: the minimum amount of contrast (on a sine grating) that is visible • Pick a frequency, “ f” , and measure the contrast threshold for that specific frequency • High threshold means low sensitivity, and visa-versa • Repeat procedure for many different frequencies • Highest sensitivity in the middle range (gets worse both for higher and lower ends of scale) • Cut-off frequency = 35 cycles per degree • CSF determines our window of visibility • Can use CSF to compare vision across different visual conditions. Selective Adaptation • Measure CSF of subject • Adapt the observer to a certain high-contrast grating of a given frequency, “ f ” • Measure CSF again...
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- Spring '07
- Joseph Fourier, Spatial frequency, grating