Image-Compression Plug-ins

JPEG may be the tried-and-true photo format for the Web, but with its tendency to add blocky artifacts to compressed images, it still doesn't get any respect. Several companies have released Adobe Photoshop plug-ins that compress images without introducing those unsightly distortions. Joining Altamira Group's Genuine Fractals (

4.5 mice
; Reviews , March 1999) and LizardTech's MrSID (
3.5 mice
; Reviews , December 1999) are LuraTech's LuraWave and BitJazz's PhotoJazz 2.

PhotoJazz, intended largely for use with prepress applications, is based on a lossless compression scheme but offers relatively limited compression ratios–an average of 2.5:1, compared with 10:1 or more for lossy compression schemes, such as JPEG. However, PhotoJazz gives you smaller files than Photoshop's TIFF LZW option.

The $29 entry-level version produces RGB output only, the $79 version provides CMYK output as well, and the $99 version supports output of 16-bit multichannel files. All three include PhotoJazz XT for importing PhotoJazz images into QuarkXPress, and PhotoJazz QT, which lets you open and save PhotoJazz images using QuickTime programs. BitJazz offers a free version that lets you open PhotoJazz images in Photoshop and most QuickTime-savvy programs.

LuraWave competes not so much with PhotoJazz as with MrSID. Both are based on wavelet technology , a lossy compression scheme that yields fewer distortions at any given compression ratio than JPEG. LuraWave's compression scheme appears to be just as effective as MrSID's. Images compressed at 10:1 had no perceptible artifacts; images compressed at 20:1 had only minor artifacts. LuraWave also includes a lossless option, but its compression ratios appear to be no better than LZW's.

LuraWave's best feature is its price: just $79, compared with MrSID's $495. Unfortunately, LuraTech does not offer a free Photoshop plug-in for opening the files.


LuraWave offers compression features similar to MrSID's and costs much less. PhotoJazz is a tougher sell, offering marginally better lossless compression than Photoshop's TIFF LZW option but little else.


RATING:  

4.0 mice
  PROS: Affordable. CONS: No free decompression plug-in. COMPANY: LuraTech (650/326-8829, http://www.luratech.com ). COMPANY'S ESTIMATED PRICE: $79.


RATING:  

3.0 mice
  PROS: Better lossless compression than Photoshop's TIFF LZW. CONS: One-trick pony. COMPANY: BitJazz (415/488-9626, http://www.bitjazz.com ). COMPANY'S ESTIMATED PRICE: RGB version, $29; CMYK version, $79; multichannel version, $99.

March 2000 page: 58

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