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Video-equivalent of "pitch-shifting."

Started by Radium August 21, 2007
Hi:

I started a new thread because the previous one started to go into
tangent of digital vs. analog but was filled with emotions and
personal vendettas rather than science and logic. So I changed the
thread.

Anyways, Adobe Audition and voice-changers allow the frequencies of an
audio signal to be shifted w/out low-pass filtering or changing the
tempo. There are two video-equivalents of this because, while audio
has only one frequency component [temporal], video has two [temporal
and spatial].

The temporal video-equivalent would be changing the rate of back/
forth, up-down or other repetitive/cyclical movement [such as wing-
flapping or flickering of lights] of the video signal without high/low-
pass-filtering, separating any portion of the video signal, or
changing the speed at which the video-signal -- just as voice-changers
can lower the frequency of audio without changing the speed of the
audio. Using a voice-changer to decrease the pitch your voice will not
cause your speech to slow down.

The spatial video-equivalent would be changing the "sharpness" of a
still image without high/low-pass-filtering or changing the size of
the image.

Below is an example of low-pass-filtering in the spatial domain:

Here is an original picture:

http://www-dse.doc.ic.ac.uk/~nd/surprise_96/journal/vol4/sab/report.normalimage.jpg

Here is the picture after low-pass filtering:

http://www-dse.doc.ic.ac.uk/~nd/surprise_96/journal/vol4/sab/report.lopass.jpg

I obviously do not want this at all. Low-pass filtering involves
removing high-frequency components while preserving the low-frequency
components. Once again, this is not what I want. If a device cannot
handle high-frequencies, then I would like all the frequencies of the
signal to be down-shifted until the highest frequency is low-enough to
be acceptable to the device. This down-shifting should be done w/out
slowing the speed of the signal -- or in the case of spatial
frequency, w/out increasing the size of the image.


Thanks for your assistance, cooperation, and understanding,

Radium

If you play the tape or record faster, the pitch shifts up. If colors
are analogous to pitch, speeding up would be a shift to the blue,
slowing down would be a red shift.

Radium wrote:
> Hi: > > I started a new thread because the previous one started to go into > tangent of digital vs. analog but was filled with emotions and > personal vendettas rather than science and logic. So I changed the > thread. > > Anyways, Adobe Audition and voice-changers allow the frequencies of an > audio signal to be shifted w/out low-pass filtering or changing the > tempo. There are two video-equivalents of this because, while audio > has only one frequency component [temporal], video has two [temporal > and spatial].
A video signal consists of a succession of still images that follow one another at fixed intervals. What you call tempo is determined by how different each image id from the ones before and after it. That makes what you write next wrong.
> The temporal video-equivalent would be changing the rate of back/ > forth, up-down or other repetitive/cyclical movement [such as wing- > flapping or flickering of lights] of the video signal without high/low- > pass-filtering, separating any portion of the video signal, or > changing the speed at which the video-signal -- just as voice-changers > can lower the frequency of audio without changing the speed of the > audio. Using a voice-changer to decrease the pitch your voice will not > cause your speech to slow down. > > The spatial video-equivalent would be changing the "sharpness" of a > still image without high/low-pass-filtering or changing the size of > the image.
Sharpness is altered by applying a filter. There are sharpening and softening filters.
> Below is an example of low-pass-filtering in the spatial domain: > > Here is an original picture: > > http://www-dse.doc.ic.ac.uk/~nd/surprise_96/journal/vol4/sab/report.normalimage.jpg > > Here is the picture after low-pass filtering: > > http://www-dse.doc.ic.ac.uk/~nd/surprise_96/journal/vol4/sab/report.lopass.jpg > > I obviously do not want this at all. Low-pass filtering involves > removing high-frequency components while preserving the low-frequency > components. Once again, this is not what I want. If a device cannot > handle high-frequencies, then I would like all the frequencies of the > signal to be down-shifted until the highest frequency is low-enough to > be acceptable to the device. This down-shifting should be done w/out > slowing the speed of the signal -- or in the case of spatial > frequency, w/out increasing the size of the image.
But it together and be more specific. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
On Aug 21, 4:39 pm, Jerry Avins <j...@ieee.org> wrote:

> A video signal consists of a succession of still images that follow one > another at fixed intervals. What you call tempo is determined by how > different each image id from the ones before and after it. That makes > what you write next wrong.
Okay. How would you correct it?
"Radium" <glucegen1@gmail.com> wrote in message 
news:1187738038.538439.164520@i38g2000prf.googlegroups.com...
> Hi: > > I started a new thread because the previous one started to go into > tangent of digital vs. analog but was filled with emotions and > personal vendettas rather than science and logic. So I changed the > thread. > > Anyways, Adobe Audition and voice-changers allow the frequencies of an > audio signal to be shifted w/out low-pass filtering or changing the > tempo. There are two video-equivalents of this because, while audio > has only one frequency component [temporal], video has two [temporal > and spatial]. > > The temporal video-equivalent would be changing the rate of back/ > forth, up-down or other repetitive/cyclical movement [such as wing- > flapping or flickering of lights] of the video signal without high/low- > pass-filtering, separating any portion of the video signal, or > changing the speed at which the video-signal -- just as voice-changers > can lower the frequency of audio without changing the speed of the > audio. Using a voice-changer to decrease the pitch your voice will not > cause your speech to slow down. > > The spatial video-equivalent would be changing the "sharpness" of a > still image without high/low-pass-filtering or changing the size of > the image. > > Below is an example of low-pass-filtering in the spatial domain: > > Here is an original picture: > > http://www-dse.doc.ic.ac.uk/~nd/surprise_96/journal/vol4/sab/report.normalimage.jpg > > Here is the picture after low-pass filtering: > > http://www-dse.doc.ic.ac.uk/~nd/surprise_96/journal/vol4/sab/report.lopass.jpg > > I obviously do not want this at all. Low-pass filtering involves > removing high-frequency components while preserving the low-frequency > components. Once again, this is not what I want. If a device cannot > handle high-frequencies, then I would like all the frequencies of the > signal to be down-shifted until the highest frequency is low-enough to > be acceptable to the device. This down-shifting should be done w/out > slowing the speed of the signal -- or in the case of spatial > frequency, w/out increasing the size of the image. > > > Thanks for your assistance, cooperation, and understanding, > > Radium >
So basically you want software that analyzes each frame the way mpeg coverts video and instead of eliminating file size by compressing the images, you want to have it eliminate most of the static images and thus reduce file duration instead. Is this correct? So if a scene has movement and talking you want that left alone but if the person is just standing still or not much action going on in the scene have it eliminated and blended so it shortens the duration but not affecting the movement speed thus making the scene shorter in length. I don't know of anything that would do this to video but I could see a use for it. DVD player software can speed up movement by say 10% and allow the sound to not be effected as far a pitch goes, this is useful for watching say a 2 hour and 15 minute movie on a flight that is 2 hours long. Is this what you are trying to find? AnthonyR.
Radium wrote:
> On Aug 21, 4:39 pm, Jerry Avins <j...@ieee.org> wrote: > >> A video signal consists of a succession of still images that follow one >> another at fixed intervals. What you call tempo is determined by how >> different each image id from the ones before and after it. That makes >> what you write next wrong. > > Okay. How would you correct it?
I would leave out the rest of the paragraph. It's based on a false assumption. Jerry -- Engineering is the art of making what you want from things you can get. &macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;
Radium wrote:

(snip)

> The temporal video-equivalent would be changing the rate of back/ > forth, up-down or other repetitive/cyclical movement [such as wing- > flapping or flickering of lights] of the video signal without high/low-
It would be reasonably similar to a cyclical intensity of a lamp, or something similar. A moving object is different.
> pass-filtering, separating any portion of the video signal, or > changing the speed at which the video-signal -- just as voice-changers > can lower the frequency of audio without changing the speed of the > audio. Using a voice-changer to decrease the pitch your voice will not > cause your speech to slow down.
-- glen
"BobG" <bobgardner@aol.com> wrote in message 
news:1187739471.037333.144590@x40g2000prg.googlegroups.com...
> If you play the tape or record faster, the pitch shifts up. If colors > are analogous to pitch, speeding up would be a shift to the blue, > slowing down would be a red shift. >
Sound is physical - Light is electromagnetic radiation That would make a great Sci-Fi effect to depict 'beings' in a different temporal dimension co-existing with us but what you describe is the effect of motion linking the audio analogy to video which is not valid. Sound is an air-pressure wave whose speed changes depending on the medium whereas light is part of the electromagnetic spectrum whose speed is fixed to the speed of light and except for some very high-end academic experiments never changes. Never-the-less it's a good special effects used in a modified way in the BBC production Ultra Violet.
Stuart wrote:
> "BobG" <bobgardner@aol.com> wrote in message > news:1187739471.037333.144590@x40g2000prg.googlegroups.com... >> If you play the tape or record faster, the pitch shifts up. If colors >> are analogous to pitch, speeding up would be a shift to the blue, >> slowing down would be a red shift. >> > > Sound is physical - Light is electromagnetic radiation > > That would make a great Sci-Fi effect to depict 'beings' in a different > temporal dimension co-existing with us but what you describe is the effect > of motion linking the audio analogy to video which is not valid. Sound is an > air-pressure wave whose speed changes depending on the medium whereas light > is part of the electromagnetic spectrum whose speed is fixed to the speed of > light and except for some very high-end academic experiments never changes. > Never-the-less it's a good special effects used in a modified way in the BBC > production Ultra Violet.
You have very little influence on the speed of sound in the medium in which you live. The speed of light depends on the medium it travels through and sometimes on the frequency. Consider a prism's dispersion. Jerry -- Engineering is the art of making what you want from things you can get. &macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;
On Aug 21, 5:19 pm, "AnthonyR." <nos...@nospam.please.com> wrote:

> So basically you want software that analyzes each frame the way mpeg coverts > video and instead of eliminating file size by compressing the images, you > want to have it eliminate most of the static images and thus reduce file > duration instead. Is this correct?
I don't think so. Any thing in the video with a temporal/spatial frequency component that is too high for a low-bandwidth device to accept, should have all of its frequencies downshifted until the highest frequency is low-enough for the low-bandwidth device to accept without any aliasing or other artifacts associated with a frequency exceeding the limits.
> So if a scene has movement and talking you want that left alone but if the > person is just standing still or not much action going on in the scene have > it eliminated and blended so it shortens the duration but not affecting the > movement speed thus making the scene shorter in length.
No. The length of any parts of the movie should not be affected at all.
> DVD player software can speed up movement by say 10% and allow the sound to > not be effected as far a pitch goes, this is useful for watching say a 2 > hour and 15 minute movie on a flight that is 2 hours long. > Is this what you are trying to find?
Not really. This change in video-frequency has nothing to do with speeding up a video. The movie should remain exactly the same length. Two hours should stay two hours.