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Documentation confusion, -filter

Posted: 2006-06-21T17:08:46-07:00
by ridera
The word "-filter" causes much confusion when it used to describe the resize algoritm.

A filter is a process to separate a wanted object from unwanted ones.

An algorithm is the process used for an operation, thus the -filter is really an algorithm type.

Ideally, the "filter" name should be an attribute of the resize command. e.g.,,

-resize 'Mitchell' 240x300

I'd suggest at least adding some text to -resize and -filter to clarify this point and certainly spell out that -filter must preceed -resize to work

Posted: 2006-06-21T18:23:05-07:00
by magick
In signal processing applications a filter modifies the harmonic content of signals. So -filter is an appropriate option name.

Posted: 2006-06-23T13:21:57-07:00
by ridera
It can; but not necessarily.

A simple case, and one of the first applications for electronic filters, about 1890, was to extract signals from noise. Had nothing to do with affecting the signal's harmonics. In fact, the filter bandwidth was wide enough so the signal's harmonics were not appreciably removed. Otherwise, the music and voice signals were distored.

Al Rider, EE