30. November 2001
Jpeg2000 - a new picture format

Digital imaging is undergoing a revolution these days. We get better digital cameras almost every month or so and we get better scanners and faster computers etc.
Sometimes it can become a bit frustrating, but a good news for photographers is, that image quality on the Internet now is getting better also.
Jpeg2000 is a new coding system for images, that provides very high quality at a very high compression. It is very superior in quality to the normal Jpeg that we know from our browsers and digital cameras etc.

The format is based on a technology called wavelets and is defined by the Joint Photographic Expert Group (JPEG).
The normal Jpeg compresses images in 8x8 blocks that gives the infamous "blocking artifacts". Highly compressed wavelet images on the other hand, produces a more "soft" image because high-contrast areas are blurred.
It seems that Jpeg2000 is supporting (or will be supporting) CMYK and LAB encoded images (normal Jpeg only supports RGB) and can include color profiles (ICC profiles). Jpeg2000 also supports progressive download.

The Jpeg2000 format is an international standard by now, but the browsers does not (yet) support it and therefore a plug-in is necessary in order to see the pictures compressed with wavelet technology.

The Quality
LuraTech^® is a German company with many years of experience with image compression and the wavelet technology.
They have a plug-in for Photoshop^® for producing Jpeg2000 files.
I have tested this plug in and here are some of the results.

After installation of the Photoshop^® plug-in, you can save your images as LuraWave^® Jpeg2000 files (*.jp2).
When you do so, you are presented with this dialog, in which you can select the image quality. You can even preview the image before saving:



Here are some of the results:


Original image at jpg quality 10. Uncompressed TIF size is 116KB.


Left: Jpeg2000 image at 14KB (approx. 8:1). Right: Jpg image also at 14KB (8:1), quality 2. (The jp2 and the tif image above is re-saved as a jpg with quality 10 in Photoshop)

As it can be seen, the normal jpg image is clearly more "destroyed" than the Jpeg2000 image.
Here's another test:


Original image at jpg quality 10. Uncompressed TIF size is 114KB.


Left: Jpeg2000 image at 8KB (approx. 14:1). Right: Jpg image also at 8KB (14:1), quality 2. (The jp2 and the tif image above is re-saved as a jpg with quality 10 in Photoshop)

Again is it very clearly seen, that the Jpeg2000 format is far superior to the normal Jpeg. There are actually only very few differences between the original image and the Jpeg2000 image.
Now of course, all we need is to have the browsers support the Jpeg2000 format!

Links
The 13x13x300 gallery contains more pictures compressed using Jpeg2000.
They can be downloaded for free and printed out on your own photo or color printer.
• The 13x13x300 Gallery

If you are more interested in Jpeg2000, try one of these:
• www.jpeg.org
• www.jpeg2000info.com
and of course visit LuraTech^®:
• www.luratech.com
or perhaps at:
• www.google.com