On Aug 20, 6:42 pm, Jerry Avins <j...@ieee.org> wrote:> The video analog of acoustic pitch is color. Both are our biological > response to frequency.True. Maybe I am just using the wrong words. Instead of "pitch-shift", I should say "frequency-shift" because that is what I really mean.
Questions about equivalents of audio/video and digital/analog.
Started by ●August 19, 2007
Reply by ●August 20, 20072007-08-20
Reply by ●August 20, 20072007-08-20
Radium wrote:> On Aug 20, 7:15 pm, glen herrmannsfeldt <g...@ugcs.caltech.edu> wrote: > >> For video the modulation (wing flapping) is not separate from >> the source frequency. If you know you are trying to separate >> wing flapping, it could be done by cutting out whole flap >> cycles, assuming only one bird is in the scene, and is doing >> most of the motion. Otherwise, I don't think there is anything >> you could do. > > I don't want to separate the wing-flapping or anything from the video. > I want all temporal components of the video signal to be slowed > without changing the length or speed of the video. Just like Adobe > Audition and certain voice-changers allow the pitch of the audio > signal to be decreased without changing the length or speed of the > audio.He wants to walk the same distance at half speed and complete the trip in the same time as before. I give up! Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
Reply by ●August 20, 20072007-08-20
Jerry Avins <jya@ieee.org> wrote:>Floyd L. Davidson wrote: >> Jerry Avins <jya@ieee.org> wrote: > > ... > >>> I can >>> demonstrate a circuit using analog components that >>> transforms a continuous ramp input into a staircase >>> output. Moreover, the output levels can be individually >>> adjusted. Is the output digital? (We're discussing an >>> arbitrary definition here. There is no wrong answer.) >> The output is apparenlty analog. At least you have >> said >> *nothing* that indicates otherwise. > >Apparently analog but actually digital? That would be in >keeping with your assertion that quantizing an otherwise >analog signal digitizes it.You *didn't* quantize it. Or at least nothing you said assures that it has been quantized, and given "levels can be individually adjusted" is high suggests that it is not quantized.>> Do you think all digital signals are square waves and >> anything that has square waves is digital? Your example >> above suggests that you might, but it simply isn't true. > >By old vacuum-tube signal generator was certainly >analog. It produced square waves among other wave shapes.Hot damned, you *are* aware of that. Amazing... -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
Reply by ●August 20, 20072007-08-20
Jerry Avins <jya@ieee.org> wrote:>Floyd L. Davidson wrote: >> Jerry Avins <jya@ieee.org> wrote: > >>> ... A signal can be >>> quantized without any need to measure it or describe it >>> with a number. >> That isn't true. In order to quantize it you *must* >> decide on non-overlapping ranges of *values*, and a >> specific quantity value that equates to those values. >> >>> An example is the signal being measured >>> in a quantum Hall-effect experiment. >> Explain. > >http://www.warwick.ac.uk/~phsbm/qhe.htmWhy don't you tell us what you think this means. I have no need to spend my time tracking down your comments. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
Reply by ●August 20, 20072007-08-20
On Aug 20, 6:40 pm, Radium <gluceg...@gmail.com> wrote:> I want all temporal components of the video signal to be slowed > without changing the length or speed of the video. Just like Adobe > Audition and certain voice-changers allow the pitch of the audio > signal to be decreased without changing the length or speed of the > audio.But pitch changing software does change the speed of all the details in the audio. Instead of 200 vibrations per phoneme, you might get only 100 after the pitch changer does its distortion. The onset of the phoneme will be 5 mS less accurate. I suppose the equivalent in the temporal component of a video scan line would be taking a picture of a house with 6 or 8 windows and changing the house to be about the same width but only having 3 or 4 windows across, and maybe moving the house so that it is an even number of window widths from the house next door. An artist could probably do this kind kind of caricature for you before storing a lower data rate description of the resulting picture. You could also shift the all colors down into infrared, but couldn't see the result anymore, although you might be able to use it as a hand warmer on a cold day. And just how do you that this reply was not generated somehow involving an escaped AI experiment?
Reply by ●August 20, 20072007-08-20
On 8/20/07 5:43 PM, in article 876439hg3o.fld@apaflo.com, "Floyd L. Davidson" <floyd@apaflo.com> wrote:> nospam@nospam.com (Don Pearce) wrote: >> On 20 Aug 2007 21:42:18 GMT, Scott Seidman >> <namdiesttocs@mindspring.com> wrote: >> >>> floyd@apaflo.com (Floyd L. Davidson) wrote in >>> news:87zm0mjrfy.fld@apaflo.com: >>> >>>>> quantized - a sampled signal, but with the possible levels constrained >>>>> to a limited set of values >>>> >>>> That is by definition a digital siganl. As soon as the possible values >>>> are "constrained to a limited set", it is by definition digital data. >>>> >>>> >>> >>> Wouldn't this make the output of a D/A converter digital by definition? >> >> It certainly would. But apparently there are those that can't see the >> difference between a limited set of values, and a set of numbers >> describing those values. > > You don't appear to understand that the limited set of values makes > it digital, by definition. PERIOD. > > Of course if you then run that digital PAM signal through virtually > any analog channel, it no longer has a limited set of values...Including a two foot piece of cable, or two inches with a small cap.
Reply by ●August 20, 20072007-08-20
On Aug 20, 7:05 pm, "Ron N." <rhnlo...@yahoo.com> wrote:> On Aug 20, 6:40 pm, Radium <gluceg...@gmail.com> wrote:> > I want all temporal components of the video signal to be slowed > > without changing the length or speed of the video. Just like Adobe > > Audition and certain voice-changers allow the pitch of the audio > > signal to be decreased without changing the length or speed of the > > audio.> But pitch changing software does change the speed of > all the details in the audio. Instead of 200 vibrations > per phoneme, you might get only 100 after the pitch > changer does its distortion. The onset of the phoneme > will be 5 mS less accurate.I am fine with that.> I suppose the equivalent > in the temporal component of a video scan line would > be taking a picture of a house with 6 or 8 windows and > changing the house to be about the same width but only > having 3 or 4 windows across, and maybe moving the house > so that it is an even number of window widths from the > house next door. An artist could probably do this kind > kind of caricature for you before storing a lower > data rate description of the resulting picture.I still think a more precise example of an equivalent is the wing- flapping I described. In the video signal containing the flapping-wings, all temporal components of the video [including the flap-rate] are slowed without increasing the length of the video. The video clip remains just as short.
Reply by ●August 20, 20072007-08-20
Floyd L. Davidson wrote: (snip)> Analog signals are by *definition* continous.> You have misunderstood what that means though. The > analog value of a signal is continuous, but that does > not imply that the signal continuously exists or that > it even changes at all.There needs to be a way to describe sampled but not quantized signals. They are not continuous in time, but the function can take on any value at each sample point. It does occur to me that you could have quantized but not sampled data. It works best gray coded so that there isn't a problem at transitions. This is sometimes done for rotational encoders, where the rotation angle can be continuous such that transitions can occur at any time. -- glen
Reply by ●August 21, 20072007-08-21
Don Bowey <dbowey@comcast.net> wrote:>On 8/20/07 5:43 PM, in article 876439hg3o.fld@apaflo.com, "Floyd L. >Davidson" <floyd@apaflo.com> wrote: > >> nospam@nospam.com (Don Pearce) wrote: >>> On 20 Aug 2007 21:42:18 GMT, Scott Seidman >>> <namdiesttocs@mindspring.com> wrote: >>> >>>> floyd@apaflo.com (Floyd L. Davidson) wrote in >>>> news:87zm0mjrfy.fld@apaflo.com: >>>> >>>>>> quantized - a sampled signal, but with the possible levels constrained >>>>>> to a limited set of values >>>>> >>>>> That is by definition a digital siganl. As soon as the possible values >>>>> are "constrained to a limited set", it is by definition digital data. >>>>> >>>>> >>>> >>>> Wouldn't this make the output of a D/A converter digital by definition? >>> >>> It certainly would. But apparently there are those that can't see the >>> difference between a limited set of values, and a set of numbers >>> describing those values. >> >> You don't appear to understand that the limited set of values makes >> it digital, by definition. PERIOD. >> >> Of course if you then run that digital PAM signal through virtually >> any analog channel, it no longer has a limited set of values... > >Including a two foot piece of cable, or two inches with a small cap.Nope. It would take a fair sized cap. Keep in mind that that is *exactly* what a V.90 modem puts on a regular twisted pair telephone cable, and it works just fine for a couple miles at least, sometimes even much farther. And that signal is digital, and is processed as a digital signal by the receiving modem. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
Reply by ●August 21, 20072007-08-21
glen herrmannsfeldt <gah@ugcs.caltech.edu> wrote:>Floyd L. Davidson wrote: > >(snip) > >> Analog signals are by *definition* continous. > >> You have misunderstood what that means though. The >> analog value of a signal is continuous, but that does >> not imply that the signal continuously exists or that >> it even changes at all. > >There needs to be a way to describe sampled but not quantized >signals. They are not continuous in time, but the function >can take on any value at each sample point.Exactly.>It does occur to me that you could have quantized but not >sampled data. It works best gray coded so that there isn't >a problem at transitions. This is sometimes done for rotational >encoders, where the rotation angle can be continuous such >that transitions can occur at any time.-- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
