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Netware: JPEGView

by Radical Liberation <>

It has been my great pleasure to discover that some netware has achieved commercial quality. In particular, JPEGView, by Aaron Giles <>, is a useful and stable program with a good interface. JPEGView serves primarily as an image viewer for JPEG-compressed images. The most recent version, 3.3, comes as a "fat-binary" and works on regular Macintoshes equipped with System 7 and on Power Macintoshes.

JPEG compression is a "lossy" algorithm which achieves phenomenal compression by throwing away image information that we probably won't miss much anyway. JPEG compressed images can contain millions of colors, (most JPEG images available on the nets do). To facilitate viewing images, JPEGView provides fast JPEG decompression, the best color reduction available, and a new kind of window optimized for image viewing.

JPEGView windows automatically scale images to fit inside the window, eliminating the need for scroll bars. The windows can be resized or a portion of the window can be selected to make a new window (this is nice for zooming in on details of a large image). My one quibble with JPEGView's otherwise excellent interface is the resize box. If you move your pointer to where the resize box normally lives, your pointer turns into a resize box, telling you that the image will be resized if you click and drag. Since discovering this feature requires noting the pointer change when you pass over that small area of the image (or reading the online help), I used JPEGView for a good six months before I discovered it.

Color Reduction is an extremely important feature, since most JPEGs come in millions of colors but most Macintosh monitors are limited to 256 colors. To give you some idea of how well JPEGView's color reduction works, I visually compared the same image with three different setups, using TeachText with QuickTime.

  Image viewer         Monitor colors setting
  1) TeachText         256
  2) JPEGView          256
  3) TeachText         Thousands

I found a great image quality difference between 1 and 2, but a barely noticeable image quality difference between 2 and 3. How does JPEGView do it? I don't know, but I like it. Since JPEGView is scriptable via Apple events, you can use AppleScript or Frontier to take advantage of this excellent color reduction algorithm.

Additional features that are peripheral to JPEGView's major purpose in life, but useful nonetheless, include viewing of GIF-compressed images, slide shows, and creating previews and/or custom icons for all supported image types. All of these services are performed with distinction. In particular, JPEGView's custom icons look better than the ones that System 7 creates when a PICT is pasted into the icon area of the Get Info dialog.

In addition, JPEGView, in part because it's postcardware, is the graphics viewer of choice for many Internet applications like NCSA Mosaic and TurboGopher. When you download a JPEG or GIF image, Mosaic simply asks the Finder to open the image with JPEGView, making for an almost seamless display of images from the Internet.

Online support from Aaron Giles is excellent, something many commercial companies could watch more closely. JPEGView has its own forum on America Online (keyword: JPEGView), Aaron <> responds fairly promptly to email, and he has fixed all bugs that I have pointed out to him by the next release. Aaron always seems to be first with whatever neat new thing Apple wants programs to do. JPEGView fully supports Apple events, has extensive on-line help, balloon help, and was the first Power Macintosh native application that I could get. To show off JPEGView's native PowerPC performance, and for fun, I timed a slide show of about a dozen images of different types on several different systems. Here are the results (using JPEGView 3.2.1), all done with 14" monitors set to 256 colors; images on RAM disk; using QuickTime.

  System                  Seconds
  LC III                  145
  Quadra 950               50
  Power Mac 7100           34
  Quadra 950 with
   Power Mac upgrade card  29

Wrap-Up -- JPEGView costs a postcard, preferably color. I put my money where my mouth is by not only sending in a postcard but also paying the (optional) U.S. $20 to receive a printed manual and some images hand-picked by Aaron. JPEGView does it better than any other program, commercial or netware.

Also, be sure to check out the large and still growing collection of JPEG images at: