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Re: I have a small toy program...

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On Jan 21, 9:34 am, glen herrmannsfeldt <g...@ugcs.caltech.edu> wrote:
> Jim Leonard <mobyga...@gmail.com> wrote:
>
> (snip)
>
> > Why are you concerned about timing your code when you haven't verified
> > your decompression process works?  Shouldn't you be verifying that
> > first?
>
> One of the fun things you learn while writing a compressor for an
> existing decompressor is the ways things can go wrong.
>
> As noted previously, I am wrote a JBIG2 compressor, using Adobe reader
> to test it. Recently, after adding the ability to move the movable
> pixels in the context template, I thought it was working.
>
> It turned out to work for about 99 out of 100 pages that I tried it on.
> There weren't that many places to go wrong, and it didn't take long to
> find, but I can imagine how much harder it is when you are debugging
> both the compressor and decompressor at the same time.
>
> It turned out that I got the logic that says pixels outside the actual
> image should be zero wrong, such that they would wrap to the next line.
> Most pages have white on the left margin, but, it seems, a small number
> didn't.
>
> I presume that Adobe has well tested their implementation and that
> all bugs are mine, but one can never be sure. There can easily be
> corner cases that occur very rarely, and that real data has a
> tendency to avoid.
>
> -- glen


Their is so much mis-information in these posts.  I am awe struck at
the wrong-headedness.

First, I would have to trust someone before allowing them to sign an
NDA.  And, for various reasons no one who posts questions and
discussions will be asked to sign an NDA.  It's not you (well, not for
most of you.)  So don't think I'm attacking you or disrespecting you.
Absolutely not.   it's just not in my business interests, nothing
personal.

Oh, and another reason, (very practical!,) I don't have an NDA
prepared.  Very simply such a document doesn't exist.  The people I
deal with just get source code and I would never ask them to sign such
a document, it would just be a terrible insult.  No thank you!!  (I
only deliver source code, in "another life" -- an expression, I used
to distribute load modules and .EXE's.  Now, only C source code.)

Second, every single person who posts here can sleep soundly, as I
will never ask you to sign my NDA.  Relax.  I have a few friends here
but unless I'm about to get a Fed-Ex letter inviting me to negotiate
or (maybe!,) a buyout letter, I have no expectation that I have to put
such a document together.  Again, relax...

Third, about my simple 700 byte program.  It used the output of a PRNG
to fill a buffer.  The density of the buffer was controlled by a value
from 50 to 99, which designated the bit density ratio.  (Oh, that 700
bytes of C source turns into about 1100 bytes with the copyright's and
stuff.  And the email accompanying my attached source had a few
notes.  Do I count that text as well?)

Fourth, I put this simple program together so that people I'm talking
to will realize that random data CAN BE COMPRESSED.  Of course data,
at say, 60% density doesn't compress very well, (with zlib that's less
than one percent, in fact it's nearly zero,) that was another point my
program demonstrated.  Except my programs don't deliver 60% data to
the zlib "compress" buffer, the data presented is a minimum of 80%.
(Yes. I can turn client RAD from 50% dense to 80% dense without
storing additional information.  Isn't that nice.)

And fifth, I showed my best CLASS2 program to someone today.  He had
some criticisms.  So here it is...  I have at least a couple more
week's of work to do before I can say I'm really done.  And I know
this tune, really, I'm still months away from a completely finished
program.  But this is the method that has the potential to do
incredible things, the other two classes are just compressors.
CLASS2?, information theory was never so much fun!

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Thread

I have a small toy program... jules Gilbert <jules.stocks@gmail.com> - 2012-01-12 13:50 -0800
  Re: I have a small toy program... Earl_Colby_Pottinger <earlcolby.pottinger@sympatico.ca> - 2012-01-12 17:21 -0800
  Re: I have a small toy program... Jim Leonard <mobygamer@gmail.com> - 2012-01-13 08:22 -0800
    Re: I have a small toy program... jules Gilbert <jules.stocks@gmail.com> - 2012-01-15 10:30 -0800
    Re: I have a small toy program... Noob <root@127.0.0.1> - 2012-01-16 10:29 +0100
      Re: I have a small toy program... jules Gilbert <jules.stocks@gmail.com> - 2012-01-16 10:16 -0800
        Re: I have a small toy program... Jim Leonard <mobygamer@gmail.com> - 2012-01-16 11:08 -0800
        Re: I have a small toy program... Sebastian <s.gesemann@gmail.com> - 2012-01-16 15:34 -0800
        Re: I have a small toy program... stan <smoore@exis.net> - 2012-01-17 21:07 -0500
          Re: I have a small toy program... jules Gilbert <jules.stocks@gmail.com> - 2012-01-19 17:27 -0800
            Re: I have a small toy program... Jim Leonard <mobygamer@gmail.com> - 2012-01-20 07:36 -0800
              Re: I have a small toy program... jules Gilbert <jules.stocks@gmail.com> - 2012-01-20 19:05 -0800
                Re: I have a small toy program... Thomas Richter <thor@math.tu-berlin.de> - 2012-01-21 11:02 +0100
                Re: I have a small toy program... Sebastian <s.gesemann@gmail.com> - 2012-01-21 01:55 -0800
                Re: I have a small toy program... jules Gilbert <jules.stocks@gmail.com> - 2012-01-27 21:30 -0800
                Re: I have a small toy program... Sebastian <s.gesemann@gmail.com> - 2012-01-28 06:59 -0800
                Re: I have a small toy program... Jim Leonard <mobygamer@gmail.com> - 2012-01-23 11:09 -0800
                Re: I have a small toy program... jules Gilbert <jules.stocks@gmail.com> - 2012-01-23 19:18 -0800
                Re: I have a small toy program... pfraser <pete_fraser@comcast.net> - 2012-01-23 19:53 -0800
                Re: I have a small toy program... glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-01-24 11:33 +0000
                Re: I have a small toy program... Earl_Colby_Pottinger <earlcolby.pottinger@sympatico.ca> - 2012-01-24 06:30 -0800
                Re: I have a small toy program... glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-01-24 15:35 +0000
                Re: I have a small toy program... Earl_Colby_Pottinger <earlcolby.pottinger@sympatico.ca> - 2012-01-24 13:00 -0800
                Re: I have a small toy program... jacko <jackokring@gmail.com> - 2012-01-24 13:37 -0800
                Re: I have a small toy program... pfraser <pete_fraser@comcast.net> - 2012-01-24 07:55 -0800
                Re: I have a small toy program... jules Gilbert <jules.stocks@gmail.com> - 2012-01-28 11:03 -0800
                Re: I have a small toy program... Jim Leonard <mobygamer@gmail.com> - 2012-01-30 10:01 -0800
                Re: I have a small toy program... stan <smoore@exis.net> - 2012-01-30 18:59 -0500
                Re: I have a small toy program... Jim Leonard <mobygamer@gmail.com> - 2012-01-24 07:31 -0800
              Re: I have a small toy program... glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-01-21 14:34 +0000
                Re: I have a small toy program... jules Gilbert <jules.stocks@gmail.com> - 2012-01-27 21:22 -0800
                Re: I have a small toy program... pfraser <pete_fraser@comcast.net> - 2012-01-28 07:00 -0800
                Re: I have a small toy program... jules Gilbert <jules.stocks@gmail.com> - 2012-01-28 11:06 -0800
  Re: I have a small toy program... Thomas Richter <thor@math.tu-berlin.de> - 2012-01-13 20:03 +0100
    Re: I have a small toy program... jules Gilbert <jules.stocks@gmail.com> - 2012-01-14 17:13 -0800
      Re: I have a small toy program... Thomas Richter <thor@math.tu-berlin.de> - 2012-01-15 11:28 +0100
        Re: I have a small toy program... glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-01-15 11:53 +0000
          Re: I have a small toy program... Thomas Richter <thor@math.tu-berlin.de> - 2012-01-15 13:24 +0100
            Re: I have a small toy program... glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-01-15 13:48 +0000
              Re: I have a small toy program... jules Gilbert <jules.stocks@gmail.com> - 2012-01-15 10:43 -0800
                Re: I have a small toy program... Thomas Richter <thor@math.tu-berlin.de> - 2012-01-15 20:44 +0100
        Re: I have a small toy program... stan <smoore@exis.net> - 2012-01-15 21:31 -0500
      Re: I have a small toy program... Sebastian <s.gesemann@gmail.com> - 2012-01-15 03:32 -0800

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