Part1 - Part2

JPEG image compression FAQ, part 2/2


From: (Tom Lane)

Subject: JPEG image compression FAQ, part 2/2

Message-ID: <>


Summary: System-specific hints and program recommendations for JPEG images

Keywords: JPEG, image compression, FAQ, JPG, JFIF

Supersedes: <>


Organization: Independent JPEG Group

References: <>

Date: Mon, 29 Mar 1999 02:24:34 GMT

Expires: Mon, 26 Apr 1999 02:24:20 GMT


Archive-name: jpeg-faq/part2

Posting-Frequency: every 14 days

Last-modified: 28 March 1999

This article answers Frequently Asked Questions about JPEG image compression.

This is part 2, covering system-specific hints and program recommendations

for a variety of computer systems.  Part 1 covers general questions and

answers about JPEG.  As always, suggestions for improvement of this FAQ are


New since version of 14 March 1999:

  * Added entries for PIE (Windows digicam utility) and Cameraid (Macintosh

    digicam utility).

  * New version of VuePrint (7.3).

This article includes the following sections:

General info:

[1] What is covered in this FAQ?

[2] How do I retrieve these programs?

Programs and hints for specific systems:

[3] X Windows

[4] Unix (without X)

[5] MS-DOS

[6] Microsoft Windows

[7] OS/2

[8] Macintosh

[9] Amiga

[10] Atari ST

[11] Acorn Archimedes

[12] NeXT

[13] Tcl/Tk

[14] Other systems

Source code for JPEG:

[15] Freely available source code for JPEG


[16] Which programs support progressive JPEG?

[17] Where are FAQ lists archived?

This article and its companion are posted every 2 weeks.  If you can't find

part 1, you can get it from the news.answers archive at

(see "[17] Where are FAQ lists archived?"). This article changes frequently;

get a new copy if the one you are reading is more than a couple months old.


Subject: [1] What is covered in this FAQ?

This list describes programs that are of particular interest to JPEG users.

For the most part, I concentrate on viewers, since a viewer program is the

first thing you'll need.  Some general image-editing programs are listed

too, especially if they are useful as plain viewers (meaning that they can

load and display an image as quickly and easily as a dedicated viewer).

Programs that convert JPEG to and from other image file formats are also


I list only freeware and shareware programs that are available on the

Internet by FTP.  Commercial products are intentionally excluded, to keep

the list to a reasonable size and to avoid any appearance of advertising.

Also, I try to list only programs that are popular among Usenet users, as

indicated by comments and recommendations in news articles.  I have no

access to many of the types of systems covered here, so I have to rely on

what other people say about a program to decide whether to list it.  If you

have an opinion pro or con on any program, I'd appreciate hearing it.

This FAQ also includes a few hints that are specific to a machine or

program, and thus don't belong in the general discussion of part 1.


Subject: [2] How do I retrieve these programs?

Almost all the files mentioned in this FAQ are available by standard

Internet FTP.  If you don't know how to use FTP, please read the article

"Anonymous FTP FAQ List", which you can get by sending e-mail to with the single line "send faqs/ftp-list/faq"

in the body.  (See also "[17] Where are FAQ lists archived?")  This section

gives some quick reminders which are not meant as a substitute for reading

the FTP FAQ.

If you use a WWW browser such as Netscape or Lynx, it will do FTP for you.

To retrieve a file described here as "", tell the

browser to open the URL "".  (If you are reading

this FAQ in the WWW FAQ archive, the file names should appear as links that

you can just click on.)  Depending on your browser, you may have to shift-

click or take some other special action to instruct the browser to save the

file to disk, rather than trying to display the file to you.

If you do not have direct access to FTP, you can use an "ftpmail" server to

obtain files by e-mail.  See the FTP FAQ for details.

Many of the pointers given here refer to popular central archive sites,

such as for DOS software or for Mac.

These sites are often overloaded, and are likely to refuse your connection

request when they are busy.  You can try again at a less popular time of

day, or you can look for a "mirror site".  Most central archive sites have

groups of mirror sites that keep copies of their files.  Find out the name

of the mirror site closest to you, and visit that site instead; it's good

net citizenship and you'll get faster response.  Check the FAQs for the

newsgroups specific to your system type to find lists of mirror sites.

(The archive site may list some mirror sites in its connection-refused error

message.  Unfortunately, some FTP programs won't show you the whole message.

WWW browsers are often bad about this.)

If you are able to reach the archive site, but the file you want doesn't

exist, most likely it's been replaced by a newer version.  Get a directory

listing of the directory that's supposed to contain the file, and look for

a file with a similar name but a higher version number.  In a WWW browser,

you can get a directory listing by removing the file name, that is opening

the URL consisting of everything up to and including the last slash.  (If

you find an out-of-date reference in a *current* version of the JPEG FAQ,

I'd appreciate hearing about it by e-mail.)

Practically all of the files listed here are compressed archive files.

This means you need to retrieve them in binary mode.  (WWW browsers do this

automatically, but many older FTP programs must be told to use binary mode.)

Once you've got the archive file, you'll need a decompressor/dearchiver

to extract the program and documentation files inside it.  Check the FAQs

for your system type to find out where to get dearchiver programs.


Subject: [3] X Windows

XV is an excellent viewer for JPEG, GIF, and many other image formats.

It can also do format conversion and some simple image manipulations.

Current release is 3.10a, available from or from  Shareware, $25.  HINT: if you have an 8-bit

display then you need to "lock 8-bit mode" to get decent display of JPEG

images.  (But do NOT do this if you intend to resave the image, because

it'll be written from the 8-bit version, thus costing you image quality.)

You can set this mode to be default by adding "xv.force8: true" to your

.Xdefaults file.  To override that default for editing, say "xv -24".

Another excellent choice is John Cristy's free ImageMagick package, currently

at release 4.1; see

This software handles many image processing and conversion tasks.  The

ImageMagick package provides a C/C++-callable library and a set of command

line processing/display programs.  Perl and Python interfaces to the

ImageMagick library are also available.

Both of the above are large, complex packages.  If you just want a simple

image viewer, try xloadimage or xli.  xloadimage views and converts many

image file types including JPEG.  Version 4.1 has better JPEG support than

prior versions and is easier to install.  xloadimage is free and available

from  xli is a variant version

of xloadimage; xli is slightly better as an interactive viewer, but it can't

be used as a converter, and it supports fewer file formats.  xli is also

free and available from


Subject: [4] Unix (without X)

If you want a command-line JPEG conversion program, see the IJG source code

described in section 15.  (This code is included as a subdirectory in most

of the X programs described above, although they may not have the latest


Non-X viewers are hard to come by, since they are very hardware dependent.

Linux users with VGA/SVGA displays may like zgv.  Version 3.1 is available


(Several other alternatives are available in the same directory.)

If you use a less popular platform, you're probably out of luck.


Subject: [5] MS-DOS

This covers plain DOS; for Windows or OS/2 programs, see the next sections.

NOTE ABOUT SIMTEL FILES: The best-known Internet collection of PC-related

programs is the Simtel archives (named for the original archive site, now

defunct).  The principal archive site for these files is,

which is the site referenced by the FTP pointers given below.  However,

there are numerous mirror sites that keep copies of the Simtel files.

For quickest response you should use the mirror site closest to you.

Consult the periodic postings in comp.archives.msdos.announce to find your

nearest mirror site.  If you have no FTP capability, the same postings will

tell you how to retrieve Simtel files by e-mail.  You can also access the

Simtel archives via WWW at

QPV (formerly called QPEG) is an extremely fast JPEG viewer. In exchange for

speed, QPV gives up some image quality, particularly on 256-or-less-color

displays.  Its best feature is a really-fast small preview window, which is

great for searching through lots of image files. Also views GIF,TGA,BMP,PNG.

Requires 386-or-better CPU and VGA-or-better display card.  Current version

is 1.7e, from

Shareware, $20.

SEA is a new JPEG/PNG/GIF/etc viewer and file-format converter.  It is

very very fast --- faster than QPV in most cases, according to the authors.

Also, it can read progressive JPEGs; QPV can't.  Current version is 1.3,

available from

Shareware, $30.  Requires 386-or-better CPU and VESA-compatible display.

DVPEG is a free viewer for JPEG, GIF, Targa, and PPM files.  Current version

is 3.0l, available from

(That's lower case l, not digit 1.)  This is a good basic viewer that comes

in both 286 and 386-and-up versions.  The user interface is clunky but

functional.  DVPEG is substantially faster than it used to be; on hi-color

displays it is nearly as fast as QPV.  On 8-bit displays, its two-pass

quantization mode is slow but gives much better image quality than QPV can


Lesser-used DOS viewers include:

* DISPLAY, alias DISP.  The Swiss army knife of DOS viewers.  Does almost

  everything, but a bit intimidating for newcomers.  User interface is much

  improved over early versions, but still awkward in places.  Requires 386

  or better.  Freeware.  Current version is 1.89, available from and

* GDS.  A well-done viewer and image converter for many image formats.

  Installation is simple, and the on-line documentation is very good.

  JPEG loading is a bit slower than the above viewers, though.  Shareware,

  $40.  Current version is 3.1f.  A slightly restricted demo version is

  available from

* NVIEW.  Views JPEG and half a dozen other image formats.  Easy to use,

  very easy to install.  Only moderately fast, but it has lots of options.

  Supports hi-color and true-color modes on some cards, but not mine :-(.

  Requires 386 or better.  Current version is 1.50, available from Shareware, $29.

* CSHOW or CompuShow (recently renamed 2SHOW).  This is a widely used viewer

  for GIF and other formats.  Versions prior to CSHOW 9.00 or 2SHOW 2.00 had

  absolutely abysmal JPEG support; if you have one of those, toss it and get

  a newer version.  The current release is still the slowest DOS JPEG viewer

  listed here, but it's faster than it used to be, and image quality and

  robustness have improved substantially.  The main reason to use CSHOW

  as a JPEG viewer is that it supports a wide range of pre-VGA display

  hardware (most of the above viewers require VGA or better).  Also, CSHOW

  doesn't require a 386.  Current version is 2.04, available from Shareware, $39.

Due to the remarkable variety of PC graphics hardware, any one of these

viewers might not work on your particular machine.  If you can't get *any*

of them to work, you'll need to use one of the following conversion programs

to convert JPEG to GIF, then view with your favorite GIF viewer.  (If you

have hi-color hardware, don't use GIF as the intermediate format; try to

find a hi-color BMP- or TARGA-capable viewer instead.)

The free IJG JPEG converters are available from (or

if you have a 386-or-better CPU and extended memory).  These programs will

convert JPEG to and from BMP, Targa, and PPM formats; they are DOS

compilations of the free source code described in section 15.

Handmade Software offers free JPEG<=>GIF conversion tools, GIF2JPG/JPG2GIF.

These are quite slow and are limited to conversion to and from GIF format;

thus they can't produce 24-bit color output from a JPEG.  The sole advantage

of these tools is that they will read and write HSI's proprietary JPEG

format as well as the Usenet-standard JFIF format.  Since HSI-format files

are rather widespread on BBSes, this is a useful capability.  Version 2.0

of these tools is free (prior versions were shareware), and is available


NOTE: do not use HSI format for files to be posted on Usenet, since it is

not readable by any non-HSI software.

Handmade Software also has a shareware image conversion and manipulation

package, Image Alchemy.  This will translate JPEG files (both JFIF and HSI

formats) to and from many other image formats.  It can also display images.

A demo version of Image Alchemy version 1.10 is available from

JPGINDEX is a useful tool for making indexes of JPEG image collections.

Available from


Subject: [6] Microsoft Windows

ACDSee is a very fast, easy to use JPEG/GIF/PNG/etc viewer.  Good viewing

and browsing capabilities, including a fast preview display; but no image

editing or conversion functions.  Both Windows 95/NT and Windows 3.1

versions are available from or  Shareware, $30.

IrfanView is a popular viewer/converter for many formats including JPEG,

PNG, and GIF.  Requires Windows 95/NT.  Current version is 2.83, available

from  Free.

LView Pro is a viewer/editor/converter for JPEG, GIF, BMP, and other

formats.  It offers a wide array of image editing functions and can load

JPEGs in either fast/low-quality or slow/high-quality modes.  Requires 386

or better CPU.  The current version, 1.D, runs under Windows 95, Windows NT,

or Windows 3.1 with Win32s 32-bit extension.  It's available from  Shareware, $30.

An older version that can run under vanilla Windows 3.1 is

ThumbsPlus is an image browser and cataloger that handles many file formats.

It can also do some editing and format conversion, but indexing a large

image collection is what it's really aimed at.  Current version is 3.20, at  Shareware, $70.  Requires

Windows 95 or NT, or Windows 3.1 with Win32s.

VuePrint is a widely used viewer and printer for JPEG, GIF, BMP, and

other formats.  Shareware, $40.  Version 7.3 is available from

Another good viewer/browser/indexer is CompuPic, available from (Windows 95, NT, or 3.1+Win32s) or (Windows 3.1).  Shareware, $40.

Many people like Paint Shop Pro.  It's overkill as just a JPEG viewer

(especially since image quality is not very good on 8-bit displays), but

as an image editor and manipulator it is very strong.  Current version is

4.1 for Windows 95 and Windows NT 4.0; an older version is still available

for Windows 3.1.  Available from  Shareware, $69.

WinJPEG displays and converts JPEG, GIF, TIFF, BMP, and other file formats.

It has some other nifty features including screen capture, color-balance

adjustment, and slideshow.  Shareware, $25.  The current version is 2.84,

available from

WinECJ is a fast, no-frills viewer with image quality noticeably worse than

most other JPEG viewers.  (You can purchase a version with better image

quality for AUD$30.)  Version 1.2 is free and available from

QPV and DVPEG (see previous section) work under Windows, but only in

full-screen mode, not in a window.  Also note that you can run the DOS

conversion programs described earlier inside a Windows DOS window.

JPEG Optimizer is a standalone JPEG compression program that lets you

interactively preview the results of different compression settings.  It

also has both automatic and manual selective-compression ability: parts of

the image that have finer detail or are more important can be compressed

less heavily than parts with less detail.  Shareware, $29.  Requires Windows

95 or NT 4.0 or later.  Available from

PIE is a utility program designed for digital camera users: it can extract

auxiliary information (exposure data, etc) that most digicams include in

their JPEG output files.  PIE can also do lossless rotation of JPEGs,

something that you cannot do with traditional image editors (because loading

and resaving in an editor incurs at least roundoff error).  Requires Win32.

Version 2.8 is available from  Shareware, $19.

Photoshop 4.0 supports progressive JPEG.  If you have an older version,

you can get a plugin that enables progressive JPEG loading and saving from

Pegasus,  The plugin is free for loading, shareware

($29) for saving.

Other Windows 95 native releases include:

* PolyView.  Reads JPEG, PNG, GIF, BMP, Photo-CD.  Current version is 3.03,

  available from

  Shareware, $20.

Other popular Windows NT-only viewers include:

* PolyView.  Reads JPEG, GIF, BMP, Photo-CD.  Current version is 1.70,

  available from

  Shareware, $20.

If you're a programmer looking for JPEG support under Windows, consider the

free JPEG source code in item 15, or these pre-canned alternatives:

TwistedPixel, an OCX component that reads and writes JPEG and other formats

(and also does many other kinds of image manipulations), is available at  OCXs are usable by

Visual Basic, Delphi, and other non-C programs.  Shareware, $69.  Requires

Windows 95 or NT.

ImgDLL is a Win32 DLL that reads and writes JPEG, PNG, TIFF, and BMP files

and provides various image processing functions.  Shareware, $15.  Available



Subject: [7] OS/2

The most widely used OS/2 JPEG viewers are:

PMJPEG 1.83: OS/2 2.x port of WinJPEG, a popular viewer/converter for

Windows (see description in previous section).  Shareware, $20.  Available


PMView 1.00: JPEG/GIF/BMP/Targa/etc viewer.  GIF viewing very fast, JPEG

viewing roughly the same speed as the above two programs.  Has image

manipulation & slideshow functions.  Shareware, $35.  Available from

Galleria 2.31:  JPEG/BMP/PCX/Targa/TIFF viewer/editor/converter.

Shareware, $65.  Available from

All of these viewers require Palette Manager for best display quality.

Opinion seems to be about equally split as to which is the best, so try

them all to see which one you like.

JPEGPROC enables all OS/2 multimedia applications to read and write JPEG

files.  Available as part of the "Practice Viewer Upgrade" which also

includes a multimedia browser alleged to be better than IB.EXE.

Shareware.  Available from

OS/2 executables of the free IJG conversion programs are available from

Note: the hobbes OS/2 collection is mirrored at


Subject: [8] Macintosh

Most Mac JPEG programs rely on Apple's JPEG implementation, which is part of

the QuickTime system extension; so you need to have QuickTime installed.

To use QuickTime, you need a 68020 or better CPU and you need to be running

System 6.0.7 or later.  (If you're running System 6, you must also install

the 32-bit QuickDraw extension; in later Systems, that is built in.)  The

latest officially released version of QuickTime is 3.0, available from

QuickTime 3.0 can read progressive JPEGs (but not write them).  Older

versions of QuickTime can't handle them at all, and are also more likely to

crash if fed a corrupted JPEG.  If you're using QuickTime-dependent programs

to handle JPEG then I recommend upgrading to 3.0 pronto.  (Note that many of

the programs recommended in this section contain their own JPEG codecs and

don't depend on QuickTime.)

Mac users should keep in mind that QuickTime's JPEG format, PICT/JPEG, is

not the same as the Usenet-standard JFIF JPEG format.  (See part 1 for

details.)  If you post images on Usenet, make sure they are in JFIF format.

Most of the programs mentioned here can handle either format.

The largest Internet collection of Mac software is the Info-Mac archive,

which is mirrored in many places (the master site is only directly

accessible by the archivists themselves).  The pointers below cite Apple

Computer's mirror site, but you may get better service from a mirror site

closer to you.  See "Introductory Macintosh Frequently Asked Questions" in

the comp.sys.mac.* newsgroups for the current locations of mirrors.

JPEGView is an excellent free program for viewing JFIF,PICT/JPEG,GIF,TIFF,

and other image files.  It can convert between JFIF and PICT/JPEG and can

create preview images for files.  The current version is 3.3.1, available from

Requires System 7; QuickTime is optional.  JPEGView is a fine viewer with an

unusual but well-thought-out design (no scroll bars, for example).

Unfortunately, it hasn't been updated in a long time, and is starting to show

its age.  There are reports of bugs under System 7.5.3 and later.  Also, its

built-in JPEG decoder doesn't know about progressive JPEG.  If you like

JPEGView, I suggest installing QuickTime 3.0 and setting JPEGView to use


Jade is a new, very promising freeware viewer for JPEG, GIF, PICT, and

BMP images.  It's fast, simple to use, and has preview and slideshow

capabilities.  And it supports progressive JPEGs.  Since JPEGView is no

longer being updated, Jade will probably supersede it as the most popular

free Mac JPEG viewer before long.  Current version is 1.2, available from

Requires 68020 (or higher) or PowerPC, as well as System 7.5 (or later) or

Thread Manager.

GIFConverter, a shareware ($30) image viewer/editor/converter, supports

JFIF,PICT/JPEG,PNG, and many other image formats.  Current release is 2.4.4,

available from  Requires System 6.0.5 or

later.  GIFConverter is not better than JPEGView as a plain JPEG/GIF viewer,

but it has much more extensive image manipulation and format conversion

capabilities.  Also, GIFConverter is your best bet if your machine is too

old to run System 7 and/or QuickTime.  Hint: if GIFConverter runs out of

memory while loading a large JPEG, try converting the file to GIF with JPEG

Convert, then viewing the GIF version.

GraphicConverter is another popular viewer/editor/converter.  It has even

more functionality than GIFConverter, but is correspondingly larger.  Great

if you like lots of options.  Shareware, $35.  Current version is 3.6,

available from the author's website or various


Sam Bushell has prepared a couple of simple but nicely done drag-and-drop

converter applications, "To JPEG" and "Progressify".  To JPEG converts any

file format understood by QuickTime to regular or progressive JPEG;

Progressify converts losslessly between regular and progressive JPEG

formats.  Both are free and require System 7.0 or later.  Available from and

Cameraid is a useful utility program designed for users of digital cameras,

but having general interest as well.  It does image downloading from many

makes of digicam, lossless rotation and other transformations of JPEGs,

and display of auxiliary information that many digicams include in their

JPEG output files.  It's also a nice viewer.  Version 1.1.1 is available

from  Shareware, $15.

Photoshop 4.0 supports progressive JPEG.  If you have an older version,

you can get two different plugins that enable progressive JPEG support

(they also work in other applications that support Photoshop plugins).

One is ProJPEG, available from

(shareware, $25).  The other is JPEG Transmogrifier's plugin version,

available from (shareware, $22).

ProJPEG is worthwhile even with PS 4.0, because it has a nifty preview

of the results of different compression settings.

HINT: You must set the file type code of a downloaded JPEG file to 'JPEG'

to allow Photoshop to recognize it.  Most of the other programs suggested

here are not so picky about file type codes.

HINT: if you use Fetch to retrieve files by FTP, make sure ".jpg" is in its

list of binary file types under Customize/Suffix Mapping.  Otherwise Fetch's

"automatic" retrieval mode will retrieve JPEGs in text mode, thus corrupting

the data.  Old versions of Fetch do not include ".jpg" in the default list.

Also, Fetch 3.0 is buggy; get 3.0.1 or later for reliable uploads.


Subject: [9] Amiga

Most programs listed in this section are available from "AmiNet" archive

sites.  The master AmiNet site is, but there are many

mirror sites and you should try to use the closest one.

Osma Ahvenlampi posted a good review of Amiga picture viewers in in March 1994.  You can retrieve it from

Opinions here are mostly stolen from his article.

CyberShow is a well-regarded viewer and converter for many image

formats including JPEG.  It can do truecolor/highcolor display with

CyberGraphics software and a suitable graphics board.  Shareware, $25.

Version 7.5 is available as a demo (displays grayscale only) from AmiNet

sites, /pub/aminet/gfx/board/cybershow75.lha.  Requires OS3.0 or better.

FastView is a fast, high-quality JPEG/GIF/ILBM viewer.  Works well on both

ECS and AGA displays.  Shareware, $15; requires OS 2.0.  Version 2.0 is

available from Aminet sites, file /pub/aminet/gfx/show/FView20.lha.

FastJPEG is a free JPEG viewer; it's fast and has good image quality, but it

doesn't view any formats except JPEG.  Somewhat faster than FastView on ECS

machines, slower on AGA.  Version 1.10 is available from Aminet sites, file


HamLab Plus is an excellent JPEG viewer/converter, as well as being a

general image manipulation tool.  It's cheap (shareware, $20) and can read

several formats besides JPEG.  The current version is 2.0.8.  A demo version

is available from AmiNet sites, file /pub/aminet/gfx/edit/hamlab208d.lha.

The demo version will crop images larger than 512x512, but it is otherwise

fully functional.

PPShow is a good free JPEG/GIF/ILBM/ANIM/Datatype viewer.  Version 4.0 is

available from Aminet sites, file /pub/aminet/gfx/show/PPShow40.lha.  For

viewing JPEGs it is a little slower than FastJPEG, and image quality is not

as good (particularly on ECS machines).

Rend24 (shareware, $30) is an image renderer that can display JPEG, ILBM,

and GIF images.  The program can be used to create animations, even

capturing frames on-the-fly from rendering packages like Lightwave.

The current version is 1.05, available from AmiNet sites, file


Viewtek is a free JPEG/ILBM/GIF/ANIM viewer.  The current version is 2.1,

available from AmiNet sites, file /pub/aminet/gfx/show/ViewTEK21.lha.

Viewtek used to be the best free JPEG viewer for Amiga, but it now faces

stiff competition.  The choice depends on your display hardware and personal

preferences.  Viewtek has poor display quality on OCS/ECS (HAM6) screens;

but it looks very good on AGA (HAM8).

Visage is a free JPEG/ILBM/PNG/Datatypes viewer with lots of features,

including progressive JPEG support (it even does progressive rendering).

Requires OS3.0 or better.  Version 39.14 is available from Aminet sites,

file /pub/aminet/gfx/show/Visage.lha.

There is finally a good JPEG datatype for use with datatype-based viewers

(such as Multiview or ShowDT).  Available from AmiNet sites, file

/pub/aminet/util/dtype/jfif_dtc.lha.  (The version dated 12/12/94

has a bug; you should also get /pub/aminet/util/dtype/jfif_FIX.lha.)

A newer JPEG datatype is now available that supports progressive JPEG.

See AmiNet sites, file /pub/aminet/util/dtype/JFIFdt44.lha.  Shareware.

The free IJG JPEG software is available compiled for Amigas from AmiNet

sites, file /pub/aminet/gfx/conv/jpegV6bin.lha.  (Despite the name, this

is now version 6a.)  These programs convert JPEG to/from PPM, GIF, BMP,

Targa formats.

If you have a DCTV box or a compatible display, try JPEGonDCTV.  Available

from AmiNet sites, file /pub/aminet/gfx/show/JPEGonDCTV100.lha.  Viewtek is

also reported to work well with DCTV.


Subject: [10] Atari ST

GEM-View (shareware, $26) displays JPEG, GIF, and other image formats.

FTP from

This is a well regarded viewer.  The English documentation tends to be a

few versions behind, though.

MGIF is a good free viewer/editor for JPEG and many other image formats.

It's particularly good on monochrome monitors, where it manages to achieve

four-level gray-scale effect by flickering; but it works on all Ataris.

Version 5.00 is at

1stGuide is a small, fast viewer for all ST/TT/Falcon systems; it supports

JPEG, PNG, and other file formats.  Shareware, $35.  Available from

The free IJG JPEG software is available compiled for Atari ST/TT/etc


These programs convert JPEG to/from PPM, BMP, Targa formats.


Subject: [11] Acorn Archimedes

The Acorn archive at contains several JPEG-capable

programs.  Read the file

for retrieval instructions.  Recommended archive entries include:

b008 FYEO 2.02: For Your Eyes Only, fast JPEG/GIF image viewer (shareware)

a110 JPEG 6.a: IJG v6a software (JPEG<=>PPM,GIF,Targa) w/ desktop front end

a121 ChangeFSI 1.15: image format conversion and viewing

e018 SwiftJPEG 0.09: fast JPEG viewer, requires SpriteExtend 0.99

Another widely used image viewer/converter is Translator.  Current release

is 8.02, from  Shareware.

SpriteExtend 0.99 comes with ROS 3.6, and is available for ROS 3.5 from  It provides very

fast JPEG decoding, but sacrifices image quality on 256-color displays.


Subject: [12] NeXT

OmniImageFilter is a filter package that converts NeXTStep TIFF to and from

about 30 image formats.  It reads JPEG but does not write it.  It works with

most NeXTStep programs that handle drag-and-drop.  OmniImage is a simple

image viewer that uses the filter package.  Both are free.  Available from and

ImageViewer is a PD utility that displays images and can do some format

conversions.  The current version reads JPEG but does not write it.

ImageViewer is available from the NeXT archives at and  Note that there

is an older version floating around that does not support JPEG.

The "imagetools" archive at includes

NeXTStep compiled binaries for a wide array of free image manipulation tools

including the IJG JPEG tools.

NeXTStep includes built-in support for TIFF/JPEG, but not for the

Usenet-standard JFIF format.  Be warned that the TIFF/JPEG standard is

about to change away from the flavor currently produced by NeXTStep,

so compatibility with other platforms is doubtful.


Subject: [13] Tcl/Tk

Jan Nijtmans' "Img" package is a dynamically loadable Tcl/Tk extension that

adds full support for JPEG, PNG, and TIFF images to the Tk photo widget.

There are a number of incomplete JPEG Tk extensions floating around the net,

but this is the only one I'd recommend.  Version 1.1.4 is free and available

from (source code and some binary

distributions).  Works on Unix and Windows; no Mac port yet.


Subject: [14] Other systems

If you don't see what you want for your machine, check out the free IJG

source code described in the next section.  Assuming you have a C compiler

and at least a little knowledge of compiling C programs, you should be able

to prepare JPEG conversion programs from the source code.  You'll also need

a viewer program.  If your display is 8 bits or less, any GIF viewer will do

fine; if you have a display with more color capability, try to find a viewer

that can read Targa, BMP, or PPM 24-bit image files.


Subject: [15] Freely available source code for JPEG

Free, portable C code for JPEG compression is available from the Independent

JPEG Group.  Source code, documentation, and test files are included.

Version 6b is available from

If you are on a PC you may prefer ZIP archive format, which you can find at (or at any

Simtel mirror site).  On CompuServe, see the Graphics Learning forum

(GO CIS:LEARN), library 12 "JPEG Tools", file

The IJG code includes a reusable JPEG compression/decompression library,

plus sample applications "cjpeg" and "djpeg", which perform conversion

between JPEG JFIF format and image files in PPM/PGM (PBMPLUS), BMP,

Utah RLE, and Targa formats.  A third application "jpegtran" provides

lossless transcoding between different JPEG formats --- for example, it can

convert a baseline JPEG file to an equivalent progressive JPEG file.

jpegtran can also do lossless rotation and flipping of JPEG files.  Two

small applications "wrjpgcom" and "rdjpgcom" insert and extract textual

comments in JFIF files.  The package is highly portable; it has been used

successfully on many machines ranging from Apple IIs to Crays.

The IJG code is free for both noncommercial and commercial use; only an

acknowledgement in your documentation is required to use it in a product.

(See the README file in the distribution for details.)

The IJG code has recently been translated into Pascal --- see  This version

has been tested under Turbo Pascal and Delphi, and it should be portable

to compatible Pascal compilers.

A different free JPEG implementation, written by the PVRG group at Stanford,

is available from  The PVRG

code is designed for research and experimentation rather than production

use; it is slower, harder to use, and less portable than the IJG code, but

the PVRG code is easier to understand.  Also, the PVRG code supports (the

original form of) lossless JPEG, while the IJG code does not.  But PVRG does

not support progressive JPEG.

There's also a lossless-JPEG-only implementation available from Cornell,  Caution: the Cornell coder

is known to have bugs for 16-bit data.

Neither the PVRG nor Cornell codecs are being actively maintained, but the

IJG code is.


Subject: [16] Which programs support progressive JPEG?

With luck, this will only be a Frequently Asked Question for a short time,

after which most JPEG-supporting programs will have been upgraded to include

p-JPEG capability.  But right now it's a hot topic.  Here's the latest

I've heard (if you have newer info, please send mail):

WWW Browsers:

Netscape 2.0b1 (Unix/X, Windows, Mac, OS/2): full implementation

Spyglass Enhanced Mosaic 2.1 (Unix/X, Windows, Mac): full implementation

(Note: lots of other people license Spyglass' code, but I don't know

which licensees are shipping the latest version.)

Netshark 1.1 (Windows, Mac): full implementation

Microsoft Internet Explorer 2.0 (Windows): no incremental display

(there are rumors that MSIE 5 will finally do progressive display properly)

Microsoft Internet Explorer 2.0 (Mac): full implementation

AOL 3.0 (Windows, Mac): full implementation

Java 1.0 (Windows 95/NT, Solaris, more coming): full implementation

OmniWeb 2.0 (NeXTStep): full implementation

Wollongong's Emissary 1.1 (Windows): full implementation (? not sure)

I-Comm 1.09beta (Windows): full implementation (?)

UdiWWW 1.0.010 (Windows): full implementation

NCSA Mac Mosaic 3.0a2 (Mac): full implementation

NCSA Windows Mosaic 2.1.1 (Windows): reads p-JPEG, no incremental display

NCSA X Mosaic 2.7b2 (Unix/X): reads p-JPEG, no incremental display

Arena beta-1e (Unix/X): reads p-JPEG, no incremental display

Fresco 0.72 (Acorn): reads p-JPEG; full incremental display in Release II

(A browser that doesn't do incremental display of images won't be able to

give you the progressive effect, but it's still useful to have p-JPEG

compatibility so that you can at least see the image.)

See "BrowserWatch" at for contact information

for these browsers.  Versions mentioned are the first to support p-JPEG,

not necessarily the current release.

Image Viewers & Converters:

See the appropriate prior sections for exact pointers to these programs.

Note that image viewers generally won't bother with doing incremental

display of p-JPEG files; they'll just read them in one pass for speed.

IJG command-line programs (almost any platform): see section 15 for source

code.  Precompiled executables are also available for some platforms;

see subject heading for your system.  You need v6 or later.

XV (Unix/X): recompile v3.10 with IJG v6 to read p-JPEG

ImageMagick (Unix/X): 3.6.6 or later

ACDSee16 (Windows 3.1): 2.0 or later

ACDSee32 (Windows 95/NT): 1.0 or later

LView Pro (Windows 95/NT, or Win 3.1 + Win32s): 1.C or later

Paint Shop Pro (Windows 95/NT): 4.0 or later

PolyView (Windows 95): 2.18 or later

ThumbsPlus (Windows 95/NT, or Win 3.1 + Win32s): 3.0c or later

VuePrint (Windows): 5.0 or later

DISPLAY (DOS): 1.89 or later

SEA (DOS): 1.2b or later

JPEGPROC (OS/2): 1.1.0 or later

PMView (OS/2): 0.92 or later

Adobe Photoshop (Mac, Windows): 4.0 or later

Jade (Mac): all versions

GIFConverter (Mac): 2.4 or later

GraphicConverter (Mac): 2.3.1 or later

ProJPEG (Mac Photoshop plugin): all versions

JPEG Transmogrifier (Mac Photoshop plugin): all versions

DeBabelizer (Mac): 1.6.5 or later

akJFIF datatype (Amiga): 40.1 or later

CyberShow (Amiga): 7.1 or later

Visage (Amiga): 39.12 or later

1stGuide (Atari): 10.Jan.96 or later


Subject: [17] Where are FAQ lists archived?

Many FAQs are crossposted to news.answers.  Well-run netnews sites will have

the latest versions available in that newsgroup.  However, there are a *lot*

of postings in news.answers, and they can be hard to sort through.

The latest versions of news.answers postings are archived at

You can retrieve this FAQ by FTP as

and  If you have no FTP access,

send e-mail to containing the lines

        send faqs/jpeg-faq/part1

        send faqs/jpeg-faq/part2

(If you don't get a reply, the server may be misreading your return address;

add a line such as "path myname@mysite" to specify your correct e-mail

address to reply to.)  For more info about the FAQ archive, retrieve the


The same FAQs are also available from several places on the World Wide Web,

of which my favorite is

This FAQ is

Other popular WWW FAQ archives include



                        tom lane

                        organizer, Independent JPEG Group


Part1 - Part2

Send corrections/additions to the FAQ Maintainer:

Last Update April 18 1999 @ 03:40 AM