December 2022
Intermediate to advanced
488 pages
16h 2m
English
After the image has been transformed into the frequency or sequency domain, we may want to modify the resulting spectrum. Filtering modifies the frequency or sequency spectrum by selectively retaining, removing or scaling various components of the spectrum. High-frequency information can be removed with a lowpass filter, which will have the effect of blurring an image, or low-frequency information can be removed with a highpass filter, which will tend to sharpen the image by emphasizing rapid changes. We may want to extract the frequency information in specific parts of the spectrum by bandpass filtering. Alternately, ...