 :-=-:-=-:-=-:-=-:-=-:
 Sixel Graphics News
 :-=-:-=-:-=-:-=-:-=-:

 //////////////////////////////////////////////////////////////////////////////

As of 2004-06-30, one way to convert old Sixel images to some more portable
image format is to run GraphicConverter, a shareware program for Mac OS X.

    http://www.graphicconverter.net/

 //////////////////////////////////////////////////////////////////////////////

Newsgroups: comp.os.vms
Path: cs.utk.edu!gatech!news.mathworks.com!mvb.saic.com!info-vax
Organization: Info-Vax<==>Comp.Os.Vms Gateway
Lines: 33
X-Gateway-Source-Info: Mailing List
Message-ID: <9505081119.AA25202@uu3.psi.com>
Date: Mon,  8 May 1995 07:05:38 EDT
From: Jerry Leichter <leichter@lrw.com>
Subject: RE: What is SIXEL?

	DECwindows Motif on VMS has a utility that can capture the screen and
	output it in any of several formats.  One of the choices is SIXEL.  I
	have captured a SIXEL file. It can then be displayed on my DECterm by
	simply TYPEing it.

	My question is what is the format, SIXEL? Is this a DEC format for
	VTxxx  terminals, an ANSII standard or some other thing?

	Also, where is this format supported for displaying files?

"Sixel" is a technique for encoding bitmaps using printable characters.  The
name comes from the fact that each printable character codes for 6 bits of
the bitmap image.

Sixel encoding was originally developed for DEC's older pin-head printers.  (I
know the LA50 supported it back around 1986 or so; I'm pretty sure it was not
the first sixel device.  One oddity of the sixel encoding is understandable
only based on this history:  A single sixel character encodes for 6 bit
positions arranged *vertically* on the page.  A whole bitmap image is thus
encoded by taking successive "graphic lines" - horizontal slices across the
image, each 6 bits high, and then written one after another.  Things were done
this way exactly so that a mechanical printer with little or no buffering
could print a sixel image.

Later versions of the sixel format support color printing, with successive
overstruck graphic lines encoding each color plane before moving on to the
next graphic line.

The format is very simple, and fully explained in the documentation of the
printers that support it.  I won't go into the details here - it's not clear
you care about this level of detail.

							-- Jerry

 //////////////////////////////////////////////////////////////////////////////

Newsgroups: comp.os.vms
Path: cs.utk.edu!gatech!news.mathworks.com!mvb.saic.com!info-vax
Message-ID: <9505091226.AA16263@uu3.psi.com>
Organization: Info-Vax<==>Comp.Os.Vms Gateway
Date: Tue,  9 May 95 07:57:29 EDT
From: Jerry Leichter <leichter@lrw.com>
Subject: Re: What is SIXEL?

	> Sixel is an old rather primitive graphics format used in some old
	> DEC hardware: VT340 terminals, LN03 printers etc..

	Remember the GIGI terminal?  I believe it did SIXELs.

Incorrect.  The GIGI used ReGIS.  (The sixel format is a bitmap encoding.
ReGIS is a geometric encoding, with primitives like "draw a line from x to
y".)

        I know that
	VT220 did, but it took weird stuff to use it.

Incorrect.  The VT220 was a text-only terminal.  (I suppose if you count
"unplug VT220, replace with [VT240], proceed to send sixel command stream" as
"weird stuff", your statement might be justified.  Of course, the [VT240] was
physically quite a bit bigger than a VT220 - it consisted of a box plus a
monitor, while the VT220 consisted of just a slightly bulkier monitor; so
you might have to make room....)

        Soft character sets
	were built out of SIXELs.

Incorrect.  The soft character set format is entirely different.

There *have* been hacks in which one uses soft character sets to build a set
of characters that can represent a bitmap.  This can be used to put an image
on a VT220's screen - a more sophisticated version of the classic "line
printer picture".  I've never seen this used for anything practical.

	He called VT340 "old hardware"!  <falls down>

The VT340 was around by the beginning of 1987.  I this business, I think that
counts as "old hardware"!
							-- Jerry


 //////////////////////////////////////////////////////////////////////////////

Newsgroups: comp.os.vms
Path: cs.utk.edu!cssun.mathcs.emory.edu!emory!news-feed-1.peachnet.edu!concert!ais.com!bruce
Message-ID: <1995May9.104223.7657@ais.com>
Date: 9 May 95 10:42:23 EST
References: <01HQ9Q9WLSIG8WWC52@kopc.hhs.dk> <hshubs-0805952339530001@denim.ultranet.com>
Organization: Applied Information Systems, Chapel Hill, NC
From: bruce@ais.com
Subject: Re: What is SIXEL?

In article <hshubs-0805952339530001@denim.ultranet.com>, hshubs@denim.ultranet.com (Howard S Shubs) writes:
> In article <01HQ9Q9WLSIG8WWC52@kopc.hhs.dk>, Arne Vajhoej <ARNE@ko.hhs.dk>
> wrote:
> 
>> Sixel is an old rather primitive graphics format used in some old
>> DEC hardware: VT340 terminals, LN03 printers etc..
> 
> Remember the GIGI terminal?  I believe it did SIXELs.  I know that VT220
> did, but it took weird stuff to use it.  Soft character sets were built
> out of SIXELs.
> 
> He called VT340 "old hardware"!  <falls down>

The VT220 only used SIXELs for defining the soft character set.  You
couldn't write to screen memory using SIXELs;  it didn't have a bitmap
screen memory.  The VT320, VT420 and VT520 also use SIXELs for this
purpose, but also don't allow you to write to screen memory (they have
no bitmap screen memory).  The VT240 and VT340 did allow you to write to
screen memory using SIXELs since they were/are true graphics terminals.

Bruce C. Wright


 //////////////////////////////////////////////////////////////////////////////

Newsgroups: comp.os.vms
Path: cs.utk.edu!nntp.memphis.edu!nntp.msstate.edu!gatech!howland.reston.ans.net!nntp.crl.com!pacbell.com!nntp-hub2.barrnet.net!news1.digital.com!pa.dec.com!nntpd.lkg.dec.com!extasy.enet.dec.com!fred
Message-ID: <3ookte$5fn@nntpd.lkg.dec.com>
References: <01HQ9Q9WLSIG8WWC52@kopc.hhs.dk>
Distribution: world
Organization: Digital Equipment Corporation
NNTP-Posting-Host: extasy.enet.dec.com
Reply-To: fred@extasy.enet.dec.com (Fred Kleinsorge)
X-Newsreader: mxrn 6.18-31
Date: 9 May 1995 20:56:14 GMT
Subject: Re: What is SIXEL?
From: fred@extasy.enet.dec.com (Fred Kleinsorge)


In article <01HQ9Q9WLSIG8WWC52@kopc.hhs.dk>, Arne Vajhoej
<ARNE@ko.hhs.dk> writes:
>>
>> DECwindows Motif on VMS has a utility that can capture the screen and
>> output it in any of several formats.  One of the choices is SIXEL.  I
>> have captured a SIXEL file. It can then be displayed on my DECterm by
>> simply TYPEing it.
>> 
>> My question is what is the format, SIXEL? Is this a DEC format for VTxxx
>> terminals, an ANSII standard or some other thing?
>> 
>> Also, where is this format supported for displaying files?
>
>Sixel is an old rather primitive graphics format used in some old
>DEC hardware: VT340 terminals, LN03 printers etc..
>
>It is still emulated by many newer DEC hardware/software.
>

  It is a encoded bitmap format designed for terminals.  It encodes
  the bitmap data into the ASCII range, and employes a simple run
  length encoding scheme.

  It's primitive, yes, as are terminals.  Most DEC terminal emulators,
  and terminals support it (the performance varies based on the skill
  of the implementor, and how much they felt it would be used... *mine*
  was pretty fast ;-).

-- 
                              +--------------------------------------+
Fred Kleinsorge               | All opinions expressed are mine, and |
kleinsorge@star.enet.dec.com  | may not reflect those of my employer |
                              +--------------------------------------+


 //////////////////////////////////////////////////////////////////////////////


Newsgroups: comp.os.vms
Path: cs.utk.edu!stc06.ctd.ornl.gov!fnnews.fnal.gov!uwm.edu!cs.utexas.edu!howland.reston.ans.net!gatech!concert!ais.com!bruce
Message-ID: <1995May9.163221.7658@ais.com>
Date: 9 May 95 16:32:20 EST
References: <9505091226.AA16263@uu3.psi.com>
Organization: Applied Information Systems, Chapel Hill, NC
From: bruce@ais.com
Subject: Re: What is SIXEL?

In article <9505091226.AA16263@uu3.psi.com>, Jerry Leichter <leichter@lrw.com>
writes:
> 	> Sixel is an old rather primitive graphics format used in some old
> 	> DEC hardware: VT340 terminals, LN03 printers etc..
> 
> 						       Soft character sets
> 	were built out of SIXELs.
> 
> Incorrect.  The soft character set format is entirely different.

The soft character set format is different from the format to write
bits in graphics memory using SIXELs, but it's not all _that_ different.
Both formats encode the bits in the same way;  the DEC documentation 
usually refers to this bit encoding as a `sixel encoding' -- eg, the
VT330/VT340 Programmer Reference Manual, Volume 1 (Text programming),
p. 84 (soft character sets):  "The terminal receives the code for a
soft character in sections, called _sixels_."  Now the soft character
set is loaded with a different starting escape sequence, and the SIXELs
used have fewer options (for example, no color or repeat specifiers),
and the characters used to advance to the next row of sixels are
different (/ instead of $-), but the formats are very closely related
and are both referred to in the DEC documentation as `sixel formats'.

You still won't get very far trying to make the VT220 into a graphics
terminal though :-)

Bruce C. Wright


 //////////////////////////////////////////////////////////////////////////////


Path: cs.utk.edu!stc06.ctd.ornl.gov!fnnews.fnal.gov!uwm.edu!vixen.cso.uiuc.edu!howland.reston.ans.net!gatech!news.mathworks.com!mvb.saic.com!info-vax
From: Jerry Leichter <leichter@lrw.com>
Newsgroups: comp.os.vms
Subject: Re: What is SIXEL?
Message-ID: <9505100239.AA29266@uu3.psi.com>
Date: Tue,  9 May 95 22:11:30 EDT
Organization: Info-Vax<==>Comp.Os.Vms Gateway
X-Gateway-Source-Info: Mailing List
Lines: 40

	[I wrote:]
	>
	> Soft character sets were built out of SIXELs.
	> 
	> Incorrect.  The soft character set format is entirely different.

	[Bruce C. Wright replies:]
	The soft character set format is different from the format to write
	bits in graphics memory using SIXELs, but it's not all _that_
	different.  Both formats encode the bits in the same way;  the DEC
	documentation  usually refers to this bit encoding as a `sixel
	encoding' -- eg, the VT330/VT340 Programmer Reference Manual, Volume 1
	(Text programming), p. 84 (soft character sets):  "The terminal
	receives the code for a soft character in sections, called _sixels_."
	Now the soft character set is loaded with a different starting escape
	sequence, and the SIXELs used have fewer options (for example, no
	color or repeat specifiers), and the characters used to advance to the
	next row of sixels are different (/ instead of $-), but the formats
	are very closely related and are both referred to in the DEC
	documentation as `sixel formats'.

Given all the things that are *different* let's see what's left to be the
same.  Hmm.  Six bits of information are encoded as a printable character
by adding them to the value 63.  Thus, 0 maps to ?, 1 to @, all the way up
to 63, which maps to ~.  Seems a bit obvious, no?  (uuencode also encodes
arbitrary binary data in groups of six bits.  It happens to add 32 rather
than 64, so the encoded characters are SPACE (a bad choice) through _, but
the principle is the same.)

The term "sixel" is actually used in several different ways.  The quoted
reference talks about a "sixel" as a group of 6 vertically-arrayed pixels.
But there's also the "sixel encoding" - adding 63; and the "sixel data format"
used in the sixel DCS.  Soft fonts and the sixel DCS share the first two
uses of the word, but not the last - which is the real guts of things.

	You still won't get very far trying to make the VT220 into a graphics
	terminal though :-)

100% agreement there!
							-- Jerry


 //////////////////////////////////////////////////////////////////////////////

Path: cs.utk.edu!cssun.mathcs.emory.edu!swrinde!cs.utexas.edu!news.cs.utah.edu!cc.usu.edu!jrd
Newsgroups: comp.protocols.kermit.misc
Message-ID: <1995Nov26.114622.67753@cc.usu.edu>
References: <49a6er$lr5@panix.com>
Organization: Utah State University
Date: 26 Nov 1995 11:46:22 MDT
From: jrd@cc.usu.edu (Joe Doupnik)
Subject: Re: Sixel graphics

In article <49a6er$lr5@panix.com>, mgflax@panix.com (Marshall G. Flax) writes:
>
> Other than SAS, are there any applications out there (say, in the Unix world)
> which use Kermit's Sixel graphics features?
> 
> marshall
> -- 
>                   [Marshall G. Flax -- mgflax@panix.com]

	WordPerfect for VMS and for Unix systems, by design.
	Joe D.


 //////////////////////////////////////////////////////////////////////////////

Article 5157 of comp.terminals:
Path: cs.utk.edu!gatech2!news.sprintlink.net!paperboy.ids.net!usenet
Newsgroups: comp.terminals
Organization: Cormack Planetarium
Lines: 62
Message-ID: <49fg7c$8n1@paperboy.ids.net>
References: <49cfbe$o5r@nz12.rz.uni-karlsruhe.de>
NNTP-Posting-Host: ids.net
Date: Tue, 28 Nov 1995 12:17:29 +500
From: cormack_pl@ids.net (Michael Umbricht)
Subject: RE: Q: ReGIS Graphics on VT ?

In Article <49cfbe$o5r@nz12.rz.uni-karlsruhe.de>
uhb0@rzstud2.rz.uni-karlsruhe.de (Axel Probst) writes:
>
> Does anybody can tell me about applications that
> use this Graphics Interface.

Try:

    http://www.cs.utk.edu/~shuford/terminal/gifregis.zip

		[OLD: ftp://cs.utk.edu/pub/shuford/terminal/gifregis.zip]

This has executables that run on VMS.  But, the source is there too:

	gif_regis_src_zip.uue

>Especially applications that can display DVI-Files
>or PostScript on the screen.

I've never seen anything that can do PS.  Let me know if you find anything.

>Any other applications are too welcome. Perhaps I
>find something else useful.

In general you can check out:

	http://www.cs.utk.edu/pub/shuford/terminal/dec.html

Look for items that mention Sixel and Regis

Below is something I pulled off of another newsgroup.

-mike

===================================================================
From: pmoreau@cenaath.cena.dgac.fr (Patrick MOREAU, CENA Athis, Tel: (1) 69.57.70.40)
Subject: Re: Graphics viewers? (Gif,JPG,MPG?)
Date: 10 Nov 95 17:04:16 +0100

In article <47qd3b$gqn@hptemp1.cc.umr.edu>, dharding@saucer.cc.umr.edu (David Harding) writes:
> I'm working in a vax/vms v6.1 enviornment.  I only have a monochrome 
> display but I would like to preview graphics before I download them to a 
> PC.  Does anyone know where I can find a GIF and/or JPG viewer for DCL 
> v6.1 on a terminal that can emulate VT100,VT200,VT220?

Ooops, if you only have VTxxx displays, you can only view GIF files, using the
interesting GIFSIXEL product (available at ada.cenaath.cena.dgac.fr into [.VMS]
directory:

Directory CENA10:[ANONYMOUS.VMS]

GIFSIXEL.ZIP;1                     553  25-MAR-1994 17:33:04.01

You also need to have a Sixel/Regis emulation (works well on a VT320)

Patrick
-- 
===============================================================================
pmoreau@cena.dgac.fr  (CENA)     ______      ___   _           (Patrick MOREAU)
moreau_p@decus.decus.fr(DECUS)  / /   /     / /|  /|
CENA/Athis-Mons FRANCE         / /___/     / / | / |   __   __   __   __  
BP 205                        / /         / /  |/  |  |  | |__| |__  |__| |  |
94542 ORLY AEROGARE CEDEX    / /   ::    / /       |  |__| | \  |__  |  | |__|
===============================================================================


 //////////////////////////////////////////////////////////////////////////////

Newsgroups: comp.protocols.kermit.misc
Path: cs.utk.edu!stc06.ctd.ornl.gov!fnnews.fnal.gov!uwm.edu!vixen.cso.uiuc.edu!newsfeed.internetmci.com!inet-nntp-gw-1.us.oracle.com!news.caldera.com!park.uvsc.edu!news.cc.utah.edu!news.cs.utah.edu!cc.usu.edu!jrd
Message-ID: <1996Feb3.082727.73114@cc.usu.edu>
Date: 3 Feb 96 08:27:27 MDT
References: <4ergge$leo@omni2.voicenet.com> <4ev5s1$j1n@omni1.voicenet.com>
Organization: Utah State University
From: jrd@cc.usu.edu (Joe Doupnik)
Subject: Re: Is sixel vesa 16 colors?

In article <4ev5s1$j1n@omni1.voicenet.com>, cmosley@voicenet.com (Christopher Mosley) writes:
> Christopher Mosley (cmosley@voicenet.com) wrote:
> :    I have an svga card but only have a vga monitor, so I have
> : only been able to use vga tek/vt340 graphics. It seems
> : that if the allowable <= 256 colors are defined at the beginning
> : of a sixel file they are mapped to the 16 predefined colors.
> : As is the case with ega resolution. I believe this would also be
> : the case for vesa? I have been able to convert gifs to sixel files
> : using portable bit map utilities. If the images use simple colors
> : they are fine but photographs using many and subtle colors are not
> : rendered well in sixteen colors. I can dither the images but the
> : results are not great. ~ 800 x 600 and only 16 colors - is this
> : correct? 
> :                                                Thanks 
> :                                                cmosley
> 
> p.s. In msdos dos kermit: Does HLP have the same 16 color
> constraint as RGB, if not would anyone know how to convert
> sixel RGB to sixel HLS? What vga mode is selected when
> set term graphics vga is used? I would think the one with 256 
> colors - even though cga colors are used.   
------------
	HLS (hue, lightness, saturation) is a logical mapping to
RGBi (red, greeen, blue, intensity). Standard VGA 256 color is video 
mode 13h, which has the crude resolution of 320x200. Kermit does not use
that mode, though many games do, because it is unsuitable for technical
graphics.
	You can read more about it, as they say, in source file msgibm.asm
(see kermit.columbia.edu).
        Joe D.


 //////////////////////////////////////////////////////////////////////////////

Newsgroups: comp.os.vms
Path: utkcs2!utkux1.utk.edu!darwin.sura.net!spool.mu.edu!yale.edu!ira.uka.de
      !news.belwue.de!news.uni-ulm.de!news
Message-ID: <1992Oct6.100706.18129@wega.rz.uni-ulm.de>
X-News-Reader: VMS NEWS 1.24
Organization: Chaos Computer Club Ulm
Sender: news@wega.rz.uni-ulm.de (News Net)
Date: Tue, 6 Oct 1992 10:07:06 GMT
From: CCC_KARG@rzmain.rz.uni-ulm.de (ComRam)
Subject: Solution: Displaying GIFs on a VT330

Some days ago I posted a question here, how to display GIFs or similar
common graphics formats on a DEC VT330 Terminal. After a while I got an
solution. As some people asked me to forward them any answers to my
question I will explain how it works.

Actually I don't have a specific GIF-Viewer , but I found a nice way to
show GIFs on a VT330 anyway. All You need is the PBM+ Graphics Package.
Then you just have to execute a statement like this:
(for this solution you need something like Unix-Pipe, otherwise use Temp-Files)

giftoppm GIFNAME | pnmdither | ppmscale .5 | ppmquant 4 | ppmtosixel >OUTFILE

Then a simple type OUTFILE will show the Pic in a rather good quality.

PS: In my VMS-PBM+ Package the ppmtosixel seem to have a bug.
    When I use a Unix Version of PBM+ everything works fine.


 //////////////////////////////////////////////////////////////////////////////

Newsgroups: comp.terminals
References: <tWoN9.2903$LY2.151490@newsc.telia.net>
Message-ID: <8%p%9.1107$B33.957953@reader1.news.jippii.net>
Organization: Saunalahti Customer
Date: Mon, 3 Feb 2003 10:42:55 +0200
From: Jukka Aho <jukka.aho@iki.fi>
Subject: Re: Character set graphics

Raz A Mattazz wrote:

> In the manual for my VT220 Tandberg there is some mention 
> of loading custom character sets. Does this mean that I'd
> be able to compose some kind of character sets that would
> produce what would in reality be perceived as bitmap graphics?
> 
> Has someone already tried this?

Yes, I wrote such a program back in my Amiga days. It displayed
2-color bitmap graphics on by redefining the character set on 
an Ampex A220 (which is a VT220 compatible character-cell based
text-terminal.) Of course, the area which you can cover with 
redefined characters is relatively smallish.

I could try digging out the source code for you if you're
interested. It was written in C, and could probably be easily
adapted to other environments.

-- 
znark

 //////////////////////////////////////////////////////////////////////////////

