Radium wrote:
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.
That's just arm-waving words. Describe the result, not as an analogy,
but as a specification. If it turns out that you can't think critically
after all, I have no time for you.
#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.
Explain how everything can slow town without increasing the time to
complete a motion. Sounds have duration and pitch. motion has no analog
of pitch in that sense. Describe the result you want, not "something
like" the result.
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.
Tell me again how the crankshaft can take run one fifth speed without
using more time to make a turn.
#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"
Tell me again how everything in an image can be stretched to double size
without making the image twice as big.
My bad.
You betcha.
Anyways, this is an original pictu
http://www-dse.doc.ic.ac.uk/~nd/surp...ormalimage.jpg
OK
This is how the picture looks after low-pass filtering -- YUK!:
http://www-dse.doc.ic.ac.uk/~nd/surp...ort.lopass.jpg
Fine detail (and noise) is gone.
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
Justify why you think that images and sounds are subject to the same
transformations.
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?
Images have no visual equivalent of pitch. Pitch is temporal. Images are
spatial.
Here's the deal: From now on, I'll only answer your technical questions
if you make a good effort to state all the assumptions behind it. I'll
work with you to get the assumptions out into the open, but I won't
answer a question until the assumptions are clear. Most of your
questions are so far into fantasy that the assumptions, once made
explicit, will likely seem contradictory even to you, and the question
will go away. E.g.: Don't ask me to explain the meaning of life without
our first establishing that life has a meaning.
Jerry
--
Engineering is the art of making what you want from things you can get.
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