Frequently asked questions - weekly automated posting.
Jef Poskanzer
down on the repetitive junk in comp.graphics. If you have answers to
other frequently asked questions that you would like included in this
posting, please send me mail. If you don't want to see this posting
every week, please add the subject line to your kill file. Thank you.
---
Jef
Jef Poskanzer po...@well.sf.ca.us {ucbvax, apple, hplabs}!well!pokey
"...Is this a trick question?"
- - - - - - - - - -
1) How to convert from one image format to another. There are a number
of free toolkits for doing image format conversions and simple image
manipulations. Here are pointers to three of them:
Utah RLE Toolkit. Available via FTP on cs.utah.edu.
Fuzzy Pixmap Manipulation, by Michael Maulding. Available via FTP in
nl.cs.cmu.edu:/usr/mlm/ftp, and also in your nearest comp.sources.unix
archive.
PBMPLUS, by Jef Poskanzer. Current version was posted to alt.sources
on 13sep89. The latest version is always available via FTP as
expo.lcs.mit.edu:contrib/pbmplus.tar.Z.
For you MILNET folks who still don't have name servers, the IP addresses are:
cs.utah.edu 128.110.4.21
NL.CS.CMU.EDU 128.2.222.56
expo.lcs.mit.edu 18.30.0.212
Don't forget to set binary mode when you FTP tar files. Please do NOT
post or mail messages saying "I can't FTP, could someone mail this to me?"
If you bring one of these packages to someplace far away, such as the West
Coast or Europe, consider making it available for FTP from your site and
letting me know so I can add you to this posting.
Peter Schroeder
>This message is automatically posted every Sunday in an effort to cut
>down on the repetitive junk in comp.graphics. If you have answers to
>other frequently asked questions that you would like included in this
>posting, please send me mail. If you don't want to see this posting
>every week, please add the subject line to your kill file. Thank you.
>---
>Jef
Very good idea. I might suggest to add a line saying that if you have a
graphics question please check any of the following books first. If you
can't find an answer in them, that's when you want to ask the net.
Here is my short list:
David F. Rogers, Procedural Elements for Computer Graphics, McGraw Hill
J.D. Foley, A. van Dam, Fundamentals of Interactive Computer Graphics,
Addison Wesley
I've seen a lot of questions that could have been answered had the person
asking only bothered to go to their library...
Thank you!
Bill Davidson
>This message is automatically posted every Sunday in an effort to cut
>down on the repetitive junk in comp.graphics. If you have answers to
>other frequently asked questions that you would like included in this
>posting, please send me mail. If you don't want to see this posting
Wasn't someone already working on something like this? I can't
remember for sure. It's certainly about time that we did something
like this though. Jef is the logical person to have comment on
file format conversion too.
In article <9...@mit-amt.MEDIA.MIT.EDU> pe...@media-lab.media.mit.edu (Peter Schroeder) writes:
>Very good idea. I might suggest to add a line saying that if you have a
>graphics question please check any of the following books first. If you
>can't find an answer in them, that's when you want to ask the net.
This is also a good idea. We should probably include ISBN numbers for
those people who are trying to order books from a book dealer. It
makes these things a bit easier.
>David F. Rogers, Procedural Elements for Computer Graphics, McGraw Hill
ISBN 0-07-053534-5
>J.D. Foley, A. van Dam, Fundamentals of Interactive Computer Graphics,
> Addison Wesley
ISBN 0-201-14468-9 (I have the 1984 reprinted-with-corrections edition.
Anyone have the current edition?)
Newman and Sproul, _Principles of Interactive Computer Graphics_, McGraw Hill,
ISBN 0-07-046338-7
Bruce Artwick, _Applied Concepts in Microcomputer Graphics_, Prentice-Hall,
ISBN 0-13-039322-3
(I could add Salmon and Slater, Harrington, or Hearn and Baker but none
of these has any real advantages over the others and I'm getting tired of
looking these things up :-)
We could also have a comment like: "Each of these books has their strengths
and weaknesses but if I had to choose just one, it would be Rogers." :-)
I think we need to be careful to limit it to introductory books so we
avoid listing things like Ulichney or Hall's Color book (we want to keep
the list short).
There is another thing I am curious about. Why is it that we only
occasionally see highly Sun/Amiga/Macintosh specific questions but
we get deluged with VGA questions? Why can't these people use
comp.sys.ibm.pc? There are other groups for how to deal with your
particular graphics board, please use them.
--Bill Davidson
Harold E Mueller
> ISBN 0-07-053534-5
Might as well include the companion:
David F. Rogers and J. Alan Adams, Mathematical Elements for Computer
Graphics, McGraw-Hill 1976, ISBN 0-07-053527-2
Hal Mueller hmue...@cssun.tamu.edu
Grad Student, CS Dept. n270ca@tamunix (Bitnet)
Texas A&M University, College Station, TX 77843
Patrick J. Flynn
>>>David F. Rogers, Procedural Elements for Computer Graphics, McGraw Hill
>> ISBN 0-07-053534-5
>
>Might as well include the companion:
>
>David F. Rogers and J. Alan Adams, Mathematical Elements for Computer
> Graphics, McGraw-Hill 1976, ISBN 0-07-053527-2
>
Might as well use the new edition:
David F. Rogers and J. Alan Adams, Mathematical Elements for Computer
Graphics (2nd ed.), McGraw-Hill 1990, ISBN 0-07-053529-9 (hard),
ISBN 0-07-053530-2 (soft).
\begin{plug}
In terms of useful information per dollar, I don't think you can do any
better than the 'Dynamic Duo':
softcover copies of _Procedural Elements_ and _Mathematical Elements_.
\end{plug}
--
Pat Flynn, CS, Mich. State U. fl...@cps.msu.edu
Peter Schroeder
Reply-To: pe...@media-lab.media.mit.edu (Peter Schroeder)
Followup-To:
Distribution:
Organization: MIT Media Lab, Cambridge MA
Keywords:
In article <52...@cps3xx.UUCP>
fl...@pixel.cps.msu.edu (Patrick J. Flynn) writes:
>In terms of useful information per dollar, I don't think you can do any
>better than the 'Dynamic Duo':
>softcover copies of _Procedural Elements_ and _Mathematical Elements_.
>\end{plug}
YES! The first books I give someone to look at if they want to find out
about some `classic' algorithm. Comes ready with pseudo code which can
be typed in almost as is.
Peter
Jef Poskanzer
down on the repetitive junk in comp.graphics. If you have answers to
other frequently asked questions that you would like included in this
posting, please send me mail. If you don't want to see this posting
---
Jef
Jef Poskanzer po...@well.sf.ca.us {ucbvax, apple, hplabs}!well!pokey
"...Is this a trick question?"
- - - - - - - - - -
0) General references for graphics questions:
Fundamentals of Interactive Computer Graphics, J. D. Foley and A. van Dam,
Addison Wesley, ISBN 0-201-14468-9
Principles of Interactive Computer Graphics, Newman and Sproul, McGraw
Hill, ISBN 0-07-046338-7
Procedural Elements for Computer Graphics, David F. Rogers, McGraw Hill,
ISBN 0-07-053534-5
Mathematical Elements for Computer Graphics, David F. Rogers and J. Alan
Adams, McGraw Hill, ISBN 0-07-053527-2
Applied Concepts in Microcomputer Graphics, Bruce Artwick, Prentice-Hall,
ISBN 0-13-039322-3
1) Quantizing 24 bit images down to 8 bits. Find a copy of "Color
Image Quantization for Frame Buffer Display" by Paul Heckbert, SIGGRAPH
'82 Proceedings, page 297. There are other algorithms, but this one
works well and is fairly simple.
2) Converting color into grayscale. The NTSC formula is:
luminosity = .299 red + .587 green + .114 blue
3) Quantizing grayscale to black&white. The only reference you need
for this stuff is:
Digital Halftoning, Robert Ulichney, MIT Press, ISBN 0-262-21009-6
4) How to convert from one image format to another. There are a number
of free toolkits for doing image format conversions, simple image
manipulations such as size scaling, plus the above-mentioned 24 -> 8,
color -> gray, gray -> b&w conversions. Here are pointers to three of
them:
Utah RLE Toolkit. Available via FTP on cs.utah.edu.
Fuzzy Pixmap Manipulation, by Michael Mauldin. Version 0.9 was posted
to comp.sources.unix, and is available from c.s.u archives. The latest
version is always available via FTP in nl.cs.cmu.edu:/usr/mlm/ftp.
PBMPLUS, by Jef Poskanzer. Version of 13sep89 was posted to
alt.sources. The latest version is always available via FTP as
expo.lcs.mit.edu:contrib/pbmplus.tar.Z.
Don't forget to set binary mode when you FTP tar files. For you MILNET
folks who still don't have name servers, the IP addresses are:
cs.utah.edu 128.110.4.21
NL.CS.CMU.EDU 128.2.222.56
expo.lcs.mit.edu 18.30.0.212
Please do *not* post or mail messages saying "I can't FTP, could
someone mail this to me?" There are a number of sites that archive the
sources newsgroups and make the contents available through an automated
mail query system.