[PD]Creating noise in Gem

[IOhannes zmoelnig]

? wrote:
 >> [Rory Walsh]->[Re: [PD]Creating noise in Gem]->[02-05-31 17:22]
 >>
 >> |I can't seem to find the sig2pix~ object? Is this an
 >> |extern? I'm using windows 95, thanks again for the
 >> |help.
 >>
 >> got it from
 >> ftp://iem.at/pd/Externals/GEMEE/
 >There is a pix_sig2pix~ in the new gem release, I am not sure
 >if it is the same one that was in the gemee ....

pix_sig2pix~ (from GEM>0.87) is not exactly the same thing as sig2pix~ 
from GEMEE:::
  GEMEE's version uses a per-line interpretation of signals (this is: 
signal vector n is used as pixel-line k; in the next dsp-cycle, the same 
signal-vector n will be used as pixel-line k+1 (at least, that is, how i 
understood it)
  GEM's object is a per-image interpretation: (thus signal vector n will 
be interpreted as y consecuting lines if pixel-data; in the next 
dsp-cycle, the old signal-vector will not be re-used) this is the same 
approach as in the SOLVE-library by Michael Droettboom.

in practical terms this means:
GEMEE's object will eventually have scrolling images (which might be no 
problem when generating noise) because the signal-vectors are reused.
i thought this somehow unpractical, especially, when converting images 
to signals, doing some manipulation (in dsp-domain) and converting the 
signals back to images.
images created by GEM's object will always stay synched to some external 
clock and therefore will not scroll. however you can obtain a scrolling 
effect by delaying the signals.
the major drawback is, that you will need large blocksizes if you want 
high resolution. eg: for a 128x128-image, you need a [block~ 16384] 
somewhere, else only a part of the image might get drawn (for example: 
only 64 samples, which would equal to half of the first-line)
of course you might want to set an overlap-factor (or upsampling ???) to 
get more than 4 images per second.


mfg.cdsa.dr
IOhannes

PS: there seems to be a bug in the reverse pix_pix2sig~ object, which 
keeps crashing my machine...(have had no time yet)