.GIF and .JPG are bitmap formats. This means the size of an image file will be proportional to the displayed size of the image. Pixie is a vector format, which is scalable, so that images which are drawn large can be physically small. This means they can download faster.
Two reasons. Firstly, XFIG is an ASCII format, which means it is rather verbose. For web use you want images to be as small as possible. Pixie is very terse and has built-in compression. Pixie files are typically much smaller even than other binary formats such as Windows Metafiles.
Secondly, to keep the Java viewer program small. The current Pixie viewer is about 6k long, which will only take a few seconds to download. A viewer for a more complex format like XFIG could mean a hit of several minutes when people first visit your web site. Many of your visitors won't bother to wait.
Because not everyone uses Netscape. A lot of people don't even use Windows. Those who do probably won't bother to download a special add-in just to look at your site.
Ah, erm, true. I was hoping you wouldn't mention that.
If you are really anxious that everyone can see your images, you shouldn't rely on Pixie alone. Fortunately the Java support in HTML is designed to degrade gracefully. If you want you can provide a .GIF or JPEG to fall back on for the Java-impaired.
The viewer applet avoids using Java features which are not supported by older browsers. Specifically, it uses Java 1.0.2 rather than 1.1. Everyone who can use Java applets, should be able to see Pixie images.
Yes, there are a few of these. I keep a list in Problems.htm.
Pixie is a relatively undemanding applet, so if any Java works at all Pixie should. Where possible I work around known browser bugs. Browser vendors themselves strive to release bug-free products, and if they discover problems they usually release fixed versions within a few weeks.
Still, some visitors to your site may be using bang up to date, state of the art browsers. With any power feature - JavaScript, frames, style sheets, forms, whatever - there's always a chance that some new browser won't support it properly. You and your visitors should be aware that the leading edge carries a certain risk. Ultimately, if you can't tolerate that risk, stick with proven browsers or don't use Java applets such as Pixie on your site.
Because the world doesn't need another drawing program. You are much better off using a well-established product and converting the result into something Pixie can understand.
If you don't have a drawing program already, take a look at Serif's DrawPlus. There is a free intro version for Windows on their web site. (Be aware that I was Software Architect for that product while I was working at Serif, so I might be a little biased.)
Currently, the Pixie Converter program only understands Windows Metafiles (the .WMF extension) and its own ascii scripts (.PXS). Most Windows programs can export Metafiles. I plan to support other formats later. Let me know which ones you think I should do first.
You need to use PixieSlide. The simple Pixie viewer applet cannot support those things, but PixieSlide does all that and more.
The key question. It depends on the image. Large, complex images are the ones that tend to do better with Pixie.
When comparing file sizes, you should bare in mind that most users have hardware compression in their modems, and Pixie files compress by about 30% more than .GIF and .JPG. You should include the size of the Pixie viewer applet for the first image on your site, but remember it will compress well (by over 40%) too.
Here are some sample figures (in bytes) for a complex Excel chart I tested recently.
Normal | Compressed | |
.GIF (816x1056x16) | 12736 | 12736 |
.WMF | 67534 | 34943 |
.PXI | 3857 | 2855 |
.PXI + Pixie.class | 10108 | 6741 |
The chart used 10 different colors, so I used a 16-color GIF. I've included the metafile size out of interest. (JPEG was unsuitable because it blurred the chart.) The first and last figures in the final column probably give the best comparison of download times.
Obviously, your milage may vary. A lot depends on the type of image.
Download the converter and try it out!