On Aug 19, 7:59 pm, Jerry Avins wrote:
Radium wrote:
2. Decreasing the spatial frequency of the images in the video-signal
without low-pass filtering the images or increasing their sizes. An
example of this would be making the sharp areas of an image look
duller without decreasing the "sharpness" setting [an example of low-
pass filtering] on the monitor or increasing the size of the image.
Normally, when the size of an image is decreased, its sharpness
increases [it's like compressing a lower-frequency sound wave into a
higher-frequency one]. Likewise, when the size of an image is
increased, it looks duller [like stretching a higher-frequency sound
wave into a lower-frequency one]. Low-pass filtering simply decreasing
the sharpness of an image while increasing its dull characteristics --
which is what I don't want.
That's a reasonable summary of what you don't want to do. What do you
think you might do instead?
The video-equivalent of changing the 'pitch' of audio recording
without changing the playback speed.
#1 Decreases the rate at which objects in the video move without
decreasing the video's playback speed or eliminating originally-
rapidly-moving objects [such as the rapidly flapping wings]
Something has to give. If the flapping of the wings is slowed, so is the
motion of everything else.
The motion of 'everything else' *is* slowed. However, the playback
speed remains constant.
Repetitive or cyclical motion (such as a ball bouncing, or a wagon
wheel rotating, or a bird-flapping its wings, or an exposed model of a
piston engine operating, or a flag waving in the wind) in the movie
are slowed without lengthening the clip.
#2 Decreases makes a still image less sharp by stretching everything
within the image without increasing the size of the image or
eliminating sharp portions of the original image
Huh?
Sorry that should read "makes a still image less sharp by stretching
everything within the image without increasing the size of the image
or eliminating sharp portions of the original image"
My bad.
Anyways, this is an original pictu
http://www-dse.doc.ic.ac.uk/~nd/surp...ormalimage.jpg
This is how the picture looks after low-pass filtering -- YUK!:
http://www-dse.doc.ic.ac.uk/~nd/surp...ort.lopass.jpg
I don't want low-pass filtering. I simply want all frequencies to be
downshifted similar to decreasing the pitch of audio without slowing
the playback speed. The analogy is lower the frequencies of all
components in the image w/out increasing the size of the image or
doing any low-pass filtering.
http://www-dse.doc.ic.ac.uk/~nd/surp...ab/report.html
Both #1 and #2 are visual-equivalents of decreasing the pitch of a
recorded audio signal without decreasing the audio's playback speed.
Says who? You're reasoning from false analogy again.
How is it false?