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JPEG 2000 Viewer

Plugin for Directory Opus

Allows you to view JPEG 2000 images & thumbnails in Directory Opus.

Directory Opus is a file manager for Windows. Read my guide, Getting to know Directory Opus, for an introduction.

This plugin allows you to view JPEG 2000 images and thumbnails in Directory Opus.

The plugin is based on the J2K-Codec by Alex Saveliev. I would like to thank Alex for creating such a fast, inexpensive and easy-to-use library, and for his excellent support.

JPEG 2000 viewer plugin screenshot
Various JPEG 2000 files displayed via the plugin.

This is actually the second JPEG 2000 plugin for Directory Opus, replacing part of my older JP2Raw plugin This newer JPEG 2000 plugin improves on the old JasPer-based plugin in several ways, mainly thanks to J2K-Codec:

  • Much faster at viewing files.
  • Much, much faster at generating thumbnails.
  • Support for x64 (64-bit Windows).
  • Support for alpha channels (transparency).
  • Support for less common .J2C & .J2K code-stream data files.
  • Support for Unicode filepaths.
  • Support for Opus's USB-Mode.
  • Doesn't call abort() on decode errors. (An aspect of JasPer which I dislike even more than its speed.)

The new plugin continues support for:

  • 8bpp images.
  • 16bpp images.
  • Color (RGB) images.
  • Greyscale images.
  • .JP2 format files.

J2K-Codec speed comparison
J2K-Codec speed comparison. Bigger means faster. (Source: J2K-Codec site)

While the new plugin is much faster and generally better than the old JP2Raw plugin, there is one downside: J2K-Codec supports a slightly smaller subset of the JPEG 2000 standard than JasPer. For example, JPEG 2000 images with indexed colour palettes work in the old plugin but may display incorrectly in the new one. Such images are very rare (yes, even rarer than normal JPEG 2000 images!) so this is unlikely to cause you problems. J2K-Codec is so much faster than JasPer, and these images so rare, that this trade-off was an easy choice to make.

(By the way, I am not sure if anything, even the libraries costing thousands of dollars, actually supports the full JPEG 2000 standard. The standard is huge and tries to do absolutely everything with the result that much of it is rather esoteric. It seems unlikely that any one person or library would need or implement the entire standard, although there are definitely some which implement all or most of Parts 1 & 2.)

If you do encounter images which do not decode properly then please contact me and I will consider making a version of the plugin which falls back on the slow JasPer or OpenJPEG libraries for images that require it.

The JPEG 2000 plugin is packaged as part of Directory Opus itself but you may sometimes find a newer version here.

  • Directory Opus 9:

    You should already have the latest version of the JPEG 2000 plugin if you have Opus (22nd May 2009) or above installed.

    (Newer versions of the plugin may be posted here between Opus releases.)

  • Directory Opus 8:

    You should use the older JP2Raw plugin instead as it works with Opus 8.

    The newer JPEG 2000 plugin requires features of Opus 9 and will not work with Opus 8.

  • Directory Opus 6:

    There is no JPEG 2000 plugin which works with Opus 6.

Version (15th May 2008):

  • Included in Directory Opus and above.
  • Requires Directory Opus or above.
  • Initial public release.