HDTenEightyP/NetNews huggingface dataset:
From: loureiro@serss0 (Leonardo Loureiro)
Subject: Re: JPEG "Standard"
Organization: Florida International University.
Distribution: usa
Date: Sat, 9 Jan 1993 05:57:34 GMT

In article <C0K6wD.MH1@cs.columbia.edu> hee@cs.columbia.edu (Edward Hee) writes:

>In fact, ColorView uses the 8 bit image only when absolutely necessary,
>eg. for an 8-bit display, or for writing an 8 bit image such as GIF, or 
>8 bit BMP. All other processing is pefrformed on the original 24 bit image 
>for the highest output quality.
>
>As far as batch conversions of image files, ColorView version 2.1 is in beta 
>test and  will be released in a few days. The new features include batch 
>conversion from GIF/BMP/JPEG to any of the supported formats. The conversion
>utility operates completely in the text mode, and does not require a VGA/SVGA
>card, or a VESA driver.
>
>(NOTE: this message is from the authors of ColorView and not from the
>owner of this account)

And I hope this new version can read 24-bit DIB bitmaps, for I gave up the
current version (dos 2.0 & windows 0.95) because they couldn't. Also, I had
tested previous versions of CView with my SVGA card, and they DID work ok
on the 16 and 24 bit color modes, but version 2.0 for dos doesn't. 

--Leo
From: spl@szechuan.ucsd.edu (Steve Lamont)
Newsgroups: comp.graphics
Subject: Re: PCX Source including 24-bit, VGA...
Date: 4 Jan 93 14:53:24 GMT
Article-I.D.: network.1i9j14INNio
Organization: University of Calif., San Diego/Microscopy and Imaging Resource
NNTP-Posting-Host: szechuan.ucsd.edu

In article <C0C2KA.HB5@ocsmd.ocs.com> mark@ocsmd.ocs.com (Mark Wilson) writes:
>AUGH!  This is once again MY question, AND my NIGHTMARE!
>I have two editions of Rimmer's book and NEITHER one works for me!
>(Or some acquaintances, so it's not just me!)  And I don't have
>access to download files from most sites, because of my company's
>limited Internet access, so that doesn't help me.

There are FTP-by-mail services available.  See the comp.graphics FAQ
or the FTP FAQ that I believe is posted in news.answers for further
detail.

							spl
-- 
Steve Lamont, SciViGuy -- (619) 534-7968 -- spl@szechuan.ucsd.edu
UCSD Microscopy and Imaging Resource/UCSD Med School/La Jolla, CA 92093-0608
"Living alone is living in perpetual irony and thinking, more and more
frequently, Why not."   - Joyce Carol Oates, "The Boyfriend"
Newsgroups: comp.graphics
From: woo@tukey.Stanford.EDU (Alexander Woo)
Subject: DISSPLA replacement requested
Organization: Stanford University
Date: Wed, 6 Jan 93 18:29:55 GMT


As I recall, when Computer Associates bought DISSPLA,
several of the original authors left and wrote another package.
Can someone mail me the name of this package and the
address or phone number of the new company?  Does it
run on an Alpha machine?

Thanks.

Alex Woo
woo@playfair.stanford.edu
--
========================================================================
Alex Woo                         woo@playfair.stanford.edu
Disclaimer: These comments are not official statements of organization.
========================================================================
Newsgroups: comp.graphics,alt.graphics.pixutils,alt.binaries.pictures.utilities,alt.binaries.pictures.d
From: pfk@rz.uni-jena.de (Frank Klemm)
Subject: Re: JPEG "Standard"
Reply-To: pfk@rz.uni-jena.de (Frank Klemm)
Organization: University Jena, Germany
Date: Tue, 12 Jan 1993 16:51:52 GMT


In article <C0K6wD.MH1@cs.columbia.edu>, hee@cs.columbia.edu (Edward Hee) writes:
|> In article <C0JzJJ.Hup.2@cs.cmu.edu> tgl+@cs.cmu.edu (Tom Lane) writes:
|> >
|> >I'm guessing that you proceeded by loading and displaying the image, then
|> >using "Save".  This is a bad move since both programs will quantize the
|> >24-bit image down to 8 bits for display (assuming your display hardware is 8
|> >bits).  JPEG is intended for compressing 24-bit data, not 8-bit; your JPEG
|> >files are larger and of lower quality than they would be if you had made
|> >them directly from the Targa or BMP file.
|> ...
|> >The difference in file size is due to Colorview and WinJPEG using different
|> >quantization algorithms; hence the data fed to the JPEG compressor is not
|> >the same.  In particular, I'd bet you had dithering turned off in ColorView.
|> ...
|> >
|> >			regards, tom lane
|> >
|> 
|> 
|> This is incorrect. 
This is incorrect. Tom say that the human eye can distingues more than 256
gray scales and that correct. The number is about 400-600.
Some top level graphics systems are using 3x10 bit + 2 unused bits per pixel.
|> 
|> ColorView uses the best available image format for saving. If the original 
|> image was 24 bits, the save JPEG option will write from the original 24 bit 
|> source, even if an 8 bit quantized version was created for display. 
|>
For scaned pictures 24 bit is the best format, or JPEG, if you don't want to sharp
and proceed filters on the picture.
For comics and line art you can use less colors.
|> 
|> In fact, ColorView uses the 8 bit image only when absolutely necessary,
|> eg. for an 8-bit display, or for writing an 8 bit image such as GIF, or 
|> 8 bit BMP. All other processing is pefrformed on the original 24 bit image 
|> for the highest output quality.
|> 
|> This is the main reason the image saved with ColorView is smaller.
|> 
|> Dithering adds a lot of noise to an image. The file written by WinJPEG is 
|> bigger because it contains a lot of extraneous dithering information not 
|> necessary for writing the 24 bit JPEG.
|> 
|> As far as batch conversions of image files, ColorView version 2.1 is in beta 
|> test and  will be released in a few days. The new features include batch 
|> conversion from GIF/BMP/JPEG to any of the supported formats. The conversion
|> utility operates completely in the text mode, and does not require a VGA/SVGA
|> card, or a VESA driver.
|> 
Where can someone get Colorview?


Frank
Xref: sparky comp.graphics:13553 comp.sys.sgi:18595
From: aew@eosvcr.wimsey.bc.ca (Alan Walford)
Newsgroups: comp.graphics,comp.sys.sgi
Subject: Re: Controlling Lighting
Date: Thu, 7 Jan 93 08:21:45 -0800
Reply-To: aew@eosvcr.wimsey.bc.ca
Distribution: comp
Organization: Eos Systems Inc, Vancouver, B.C., Canada

In <C0DABM.16F.1@cs.cmu.edu> gleicher@CS.CMU.EDU (Michael Gleicher) writes:
>I'm looking for good ways to interactively control lighting. There's
>remarkably little in the literature - about all I know about is Poulin and
>Fournier's paper in last year's interactive 3D symposium. 

I saw a demo of a new Silcon Graphics modelling program that I felt had
a very nice way of adjusting, moving, and rotating light sources. I'm afraid
I do not remember the name of the program. Anybody know which one I am
refering to?  When you clicked on a light source in their view (which showed
the main object and the cameras and the light source) a set of 3 axes came up
and one manipulated the object (light or camera) along these axes. It is
too difficult to explain in words. You would have to see it for yourself. Very
slick!

Al

-- 
Alan Walford     Eos Systems Inc., Vancouver,B.C., Canada  Tel: 604-734-8655
aew@eosvcr.wimsey.bc.ca           OR        ...uunet!wimsey.bc.ca!eosvcr!aew
From: capelli@vnet.ibm.com (Ron Capelli)
Date: Tue, 12 Jan 93 10:58:31 EST
Newsgroups: comp.graphics
Subject: Re: Area of a parametric patch
Disclaimer: This posting represents the poster's views, not those of IBM
News-Software: UReply 3.1

In <gln.726347504@brutus> Glen Niebur writes:
>I have an application where i need to find the area of a bicubic Coons
>patch.  Is there a straight forward method to do this, or is it better
>to approximate it by subdividing the batch into rectangles, and finding
>the area of the rectangles?
>
>Any references to equations or algorithms would be appreciated.
>
An old but classic reference paper for this is:
G.J.Peters, "Interactive computer graphics application of the
bi-cubic parametric surface to engineering design problems",
1974 NCC, AFIPS Press, pp.491-511.

Using Gauss-Legendre quadrature, a numerical solution for the area
of a bi-cubic patch can be found more accurately and efficiently
than tiling the patch into rectangles or triangles.

The area of a parametric surface patch is, precisely:

        /1 /1                           /
    A = \  \  |N(u,v)| du dv            \ is attempt at integral sign.
        /  /                            /
         0  0

where N(u,v) is the surface normal at parametric coordinates (u,v),
typically from the cross-product of the partial derivative vectors
of the surface function with respect to u and with respect to v at
the point.  |N(u,v)| is the magnitude of the normal vector.

Using an M-point quadrature, the area can be approximated using:

         M   M
    A = SUM SUM ( gi * hj * |N(ui,vj)| )
        i=1 j=1

where gi and hj are the M-point quadrature formula weights, and
ui and vj are the Gaussian roots.

Many books on numerical methods cover Gaussian quadrature, providing
Tables of roots and weights, or definition of Legendre polynomials
from which the roots and weights are derived.
_______________________________________________________________________

...Ron Capelli                 IBM Corp.  Dept. C13,  Bldg. 703-2
   capelli@vnet.ibm.com        PO Box 950
   (914) 435-1673              Poughkeepsie, NY  12602
Newsgroups: comp.graphics
From: megardi@watserv1.uwaterloo.ca (Michael Gardi)
Subject: Re: 2D bitmap to arbitrary positioned 3D (3 or 4)-gon. how or where?
Organization: University of Waterloo
Date: Tue, 5 Jan 1993 11:36:28 GMT

In article <C0DE7r.Kqr@rahul.net> wilsont@rahul.net (Timothy Wilson) writes:
>I'd like to know where to get info on how to take a bitmap and stick it on
>to a polygon. 
>
>this is also known as texture mapping correct?
>Timothy Wilson <wilsont@rahul.net>

In Dr. Dobb's Journal (Sept. and Oct. 92) Michael Abrash has done a very nice
job of explaining and demonstrating (with source) a two-stage DDA texture
mapper.

Mike
Newsgroups: comp.graphics
From: amjad@wam.umd.edu (Amjad A. Soomro)
Subject: Video Test Sequences
Followup-To: amjad@wam.umd.edu 
Keywords: Video Image Sequences Test
Organization: University of Maryland, College Park
Date: Mon, 4 Jan 1993 22:21:25 GMT
Expires: Mon, 1 Feb 1993 05:00:00 GMT

I am currently searching for 'standard' test sequences for video compression
comparison purposes. Specifically, if somebody could help me in finding
sources, in analog or digital form, for any of the following sequences I 
would appreciate it. The sequences are :

1. ALEXIS
2. MISS AMERICA
3. CINDY
4. DUO
5. QUAD
6. ZOOM/PAN 

Thanks in advance.

Amjad A. Soomro
Computer Science Center
U. of Maryland at College Park
College Park , MD 20742
Email: amjad@wam.umd.edu


Newsgroups: comp.graphics
From: Timothy.Parker <Timothy.Parker@mixcom.mixcom.com>
Subject: Stereoptic Pictures?
Organization: Milwaukee Internet Xchange BBS, Milwaukee, WI U.S.A.
Distribution: usa
Date: Tue, 05 Jan 1993 06:27:27 GMT


Mike,
 
I don't know if this is exactly what you had in mind but ...
 
The USGS - EROS Data Center in Sioux Falls, SD can provide photos
from the National Aerial Photography Program covering at least the
48 continental states.  This includes color and B&W photos of
different scales as well as other misc subjects.  The point I am
getting to here is that they take the aerial photos in a continuous
strip and in the N-S direction they overlap by more than 50%, there-
fore they can be viewed as stereo pairs of the overlapping area.  I
not sure I explained that well but you probably get the idea.
 
Several years ago the B&W photos were quite reasonable, $6.00 each.
Now if you meant that you wanted a pair of stereoptic pictures already
digitized then you'll have to find a friend with a digitizer :).  I
would be interested to hear if you persue this idea.
 
Tim 
-- 
Tim Parker
Timothy.Parker@mixcom.com
From: gelinas@CAM.ORG (Daniel Gelinas)
Newsgroups: comp.graphics
Subject: Screen problems
Summary: help
Date: 4 Jan 93 03:40:13 GMT
Organization: Communications Accessibles Montreal, Quebec Canada

I was wondering if someone in this newsgroup could help me out with a problem
that I am having with my graphics card.  I have had an ati vga wonder for many
years now, and I am starting to see some problems with some games I play.

In these particular games it seems that the program only draws every second
line.  It looks to me like there are black lines running down the screen.  Only
certain games like lab3d.zip(shareware) do this, but it is really starting to
get on my nerves.  It seems that I am the only one with these problems.

This only happends in 320*200. (At least for now).

Any info would be appreciated.

thanks.

Daniel Gelinas
Newsgroups: comp.graphics
From: fisher@tinton.ccur.com (Greg Fisher)
Subject: Re: ASCII "graphics" and text displays used by newsreaders.
Summary: font differences make ascii pics difficult to exchange
Keywords: ASCII graphics text aspect-ratio
Organization: Concurrent Computer Corp., Oceanport, NJ
Date: Fri, 8 Jan 1993 16:00:26 GMT

Robert P Munafo writes:
> I have developed software that converts black-and-white bitmap images of
> the Mandelbrot Set into text-oriented ASCII                         -,
> graphics, like the little example shown here.  In                  ._7/,
> order for the algorithm to work well, an                        ._.-" '-_..
> assuption must be made concerning the "aspect            :_ ,, :r`       `\_
> ratio" (height-to-width ratio) of the text              ,a7~^~\/          ]`
> characters in the final display format....
I have done something similar, and I am not sure
if "aspect ratio" is really key.  The real problem with the interchange
of ascii pics is that the font used in the rendering process may bear
little resemblance to that used by other people's displays.

I have settled on a simple 9x7 font, which is approximated by most dumb
terminals (and printers, dont forget), and is available to X terminals.
I suppose the right thing to do is to let the user of the rendering
program select a font description in rendering which matches his current
display - but I don't know how best to do that :-{

> Because                                           -----*(%,   .          -:
>I am interested in using these text images to            `:)/_/~\          'c
>illustrate my messages on the Internet, I have            '  `  '",_     _,/^
>decided that it would be a good idea to survey                   '^'^r.:^^''
>USENET readers and collect data concerning aspect                    ^)\`
>ratios and types of equipment/software/etc that                      ^`
>are used.
>Please let me know if you think a survey would be a *bad* idea.  
As I said, I'm not sure if it will help that much.

Nice pic, by the way - how many characters in the set do you use?
>mrob's .sig #4 |                                            '^`^` T_,       .-`
>collect all 5! |    Internet: mrob@world.std.com

Greg



-- 

Greg Fisher @ fisher.tinton.ccur.com
From: williams@casbah.acns.nwu.edu (Gus Williams)
Subject: Particle tracing
Organization: Northwestern University, Evanston, Illinois, USA
Date: Mon, 11 Jan 1993 22:39:28 GMT

Does anyone know of any example routines for moving
a particle through a 3D velocity field?

What is the best method, linear interpolation of x,y,z
components then move the particle accordingly for some
small time step? or is there a better way? 

The velocity field is irregular (from the results of
a FEM calculation).

Thanks for any help.
Newsgroups: comp.graphics
Subject: Depth Sorting
From: news@massey.ac.nz (USENET News System)
Date: Fri, 8 Jan 93 03:29:01 GMT
Organization: DSIR, Palmerston North, New Zealand

I need to be able to display a very complicated three dimensional structure
consisting of a lot of small unconnected polygons, a whole heap of line
segments, a few very small ellipsoids, which are probably small enough to
be approximated by a single polygon each.  I have no problems in performing
the 3D transformations etc, but I'm having trouble figuring out what exactly
is the best way of displaying this data.  For a first attempt I'll probably
just sort the objects in order from back to front and plot them like that,
but this is not really a good solution.  What I would like is a fairly nice
algorithm (understandability is preferable to efficiency) that will allow
me to draw polygons and line segments without objects being drawn over the
top of objects on front of them.

Does anyone have any such algorithms, (or better still, C code), or know
where I can look to find something suitable.

Any help will be deeply appreciated.
Xref: sparky comp.graphics:13621 alt.graphics.pixutils:2886 alt.binaries.pictures.utilities:2431 alt.binaries.pictures.d:6105 alt.binaries.pictures.erotica.d:10764 news.answers:5055
From: cyberman@exucom.com (Stephen R. Phillips)
Newsgroups: comp.graphics
Subject: Re: JPEG --> GIF Converter
Date: 9 Jan 93 16:38:15 GMT
Organization: ExuCom Multimedia Inc.
X-Newsreader: TIN [version 1.1 PL8]

Sean Myers (smmyers@foghorn.srv.pacbell.com) wrote:

: Does anyone know of an FTP site that would carry a JPEG to GIF converter
: to be used on an RS6K?

Yes. :)

Read/find the JPEG FAQ it tells you WHERE to get these things.  I don't
have it handy so I can't divulge this information.  But it includes the
source code to compress and decompress jpeg files from targa/GIF/PPM and
to targa/GIF/PPM.

Cyberman
-- 
This is my sig file!
Read rec.games.programer!
Xref: sparky comp.graphics:13459 alt.graphics.pixutils:2836
From: jk87377@cc.tut.fi (Kouhia Juhana)
Newsgroups: comp.graphics,alt.graphics.pixutils
Subject: Re: Your one stop GRAPHICS shop!
Date: 6 Jan 1993 19:23:25 +0200
Organization: Tampere University of Technology
Distribution: world
NNTP-Posting-Host: cc.tut.fi

In article <1993Jan6.145125.24519@a.cs.okstate.edu>
jmccorm@a.cs.okstate.edu (MCCORMICK JOSHUA C) writes:
>
>Actually, the experience is just the reverse here for me. After searching a 
>GIFLITE picture carefully, it is very difficult to tell _any_ damage to the
>picture. When comparing commonly available JPG's to the originals, the
>damage is more than obvious.

Do you write about misconverted JPEG's or properly converted?

I have recently converted few tiff files to jpeg
with 'tifftopbm image.tiff | cjpeg -Q 90 (or 95) > image.jpg'
and then compared 'tiff to 8bit' and 'tiff to jpeg to 8bit'
images due the lack of 24bit screen.

I have got very good results even by zooming the image to pixel
level -- only bad place is when the image is scanned and
overilluminated; that is cured by using Q=95 quality level.

However, the overilluminated images are rare.

Juhana Kouhia
From: M16302@mwvm.mitre.org
Newsgroups: comp.graphics
Subject: Problems with font sizing when going McDraw --> CGM
Date: 6 Jan 93 21:43:26 GMT
Organization: The MITRE Corporation, McLean VA 22102

I am using Graph Porter to go from McDraw 2.1 to CGM.  The conversion works
fine except for font sizes.  Does anyone sucessfully done this conversion and
preserved font sizes.  Also, does anyone know where I can FTP a CGM spec?
Robert B. Shain                              EMAIL: RSHAIN @MITRE.ORG
The MITRE Corporation                        Voice: (703)883-5592
Center for Intellignence & Special Programs  FAX: (703)883-6991
Mailstop W955
7525 Colshire Drive                    "My other computer is a Cray"
McLean, VA. 22102                      "My other car is a bike"
                                       "My other sport is ping pong"
From: jwhitnell@cup.portal.com (Jerry D Whitnell)
Newsgroups: comp.graphics
Subject: Re: Touch Screens
Date: Thu,  7 Jan 93 22:33:59 PST
Organization: The Portal System (TM)
  <1993Jan5.232216.6435@desire.wright.edu>

In article <1993Jan2.195959.21840@spang.Camosun.BC.CA>, morley@suncad.camosun.b
c.ca (Mark Morley) writes:
> ... If anyone out there has any info on
> this or similar products, I'd be most interested in getting it.  Also, if
> you have ideas for other touch screens or alternatives I'd like to hear them.
> 

SuperMac Technology has a line of touchscreen monitors.  For more info, give
them a call at 408-245-2202.

Jerry
Newsgroups: comp.graphics,news.answers
From: h8915726@hkuxb.hku.hk (Medusa de NetHack)
Subject: Partitioning
Reply-To: h8915726@hkuxa.hku.hk
Organization: University of Hong Kong
X-Newsreader: Tin 1.1 PL4
Date: Tue, 5 Jan 1993 18:09:28 GMT

Hi,

	I'm quite interested in polygon partitioning.
	Can anyone give me a brief intro for me?

	BTW, is there an algorithm that determine a polygon is concave
	or convex _AND_ partition it at the same time? I know how to
	determine polygon is convex (discussed some-time ago in this newsgp),
	but is it possible to integrate partitioning into it so 
	partitioning can be determined (faster or) at the same time.

--
Medusa
University of Hong Kong
H8915726@hkuxa.hku.hk

Newsgroups: comp.graphics
From: kal@lems.brown.edu (Kaleem Siddiqi)
Subject: contour filling/tracing ?
Keywords: filling, tracing
Organization: Laboratory for Engineering Man/Machine Systems
Date: Tue, 5 Jan 1993 17:10:22 GMT

Hi all,
I was just wondering if anyone has or
knows of general purpose contour tracing and
contour filling software in C or Lisp
(such as efficient implementations of 
the algorithms in Pavlidis).

I'm interested in the following 2 problems:
a) Given a 2D array with several binary shapes
   I'd like to be able obtain a separate list of contour
   points for each contour that is ordered
   according to a CW or CCW trace of that contour.

b) Given an array with several contours I'd like to
   be able to selectively fill each contour with a
   binary value.
      
Please send replies to kal@lems.brown.edu
thanks!
-Kaleem

-- 
Kaleem Siddiqi
Laboratory for Engineering Man/Machine Systems
Brown University
Providence RI 02912

e-mail: kal@lems.brown.edu
Newsgroups: comp.graphics
From: mrob@world.std.com (Robert P Munafo)
Subject: Re: ASCII "graphics" and text displays used by newsreaders.
Summary: Here's the chart of characters I use in my algorithm
Keywords: ASCII graphics text aspect-ratio algorithm
Organization: The World Public Access UNIX, Brookline, MA
Date: Sun, 10 Jan 1993 16:37:19 GMT

> Nice pic, by the way - how many characters in the set do you use?
 
Table 1 shows the assignment of binary values of the 6 dots within a
character cell.  Table 2 shows the ASCII characters used for each of the 64
combinations:
 
Tbl. 1    Table 2: Character corresponding to each pattern value
 32 16              1    1    2    2    3    3    4    4    5    5    6
  8  4    0    5    0    5    0    5    0    5    0    5    0    5    0
  2  1     .,_-:/a-\ce-vrm':/d']//~(/("(/d`\;L~\))`\[L"\)b^7F%"T)$"(FC*#F@
-- 
mrob's .sig #1 |____                                      RF(1/3B1) -> '\-
collect all 5! |\RM/ Robert P. Munafo                              _,_'F']_, ,
Newsgroups: comp.graphics
From: orourke@sophia.smith.edu (Joseph O'Rourke)
Subject: Attendance at SIGGRAPH
Organization: Smith College, Northampton, MA, US
Date: Fri, 8 Jan 1993 20:22:56 GMT

Can anyone tell me the attendance at the last SIGGRAPH conference,
say to the nearest thousand?  Thanks!
Xref: sparky comp.graphics:13561 comp.graphics.visualization:1988 comp.multimedia:4015 comp.org.acm:1042 alt.graphics.pixutils:2864 comp.graphics.animation:1526