Sunday, August 26, 2007

Microsoft HDView and Dynamic Range Adaption

The new beta 2 of HView offers an interesting feature: "Auto Tone Adjust"
It is some sort of dynamic range adaption - a feature highly anticipated by panorama photographers. Instead of pre-computing the best visual appearance for the whole image, you can let the viewer calculate the appearance on the fly.
If you already use HDView on your webpage, this feature is automatically added to your published content - no need to edit or re-publish.

Some interesting uses of this feature:

3 different types of adjustment are available. You can toggle these types by clicking a button in the upper right window of the viewer:

No tone adjust: leaves image as it is

Medium tone adjust: enhanced contrast

High tone adjust: enhanced contrast and colors

You can set the default tone adjust method by adding a parameter to the XML call in your HTML page, e.g.

args =
will change to medium tone adjust setting.

Some caveats:
  • HDView beta 2 still works exclusively with LDR images. Although the new HDPhoto-format can deal with HDR images, HDView can't display them (this may be adressed in one of the next beta versions of HDView).

  • Tone adjustment seems to be calculated on a per-tile base. This can clip small distinct features. Images that consist of one tile (e.g. a single jpeg image viewed with HDView) won't be adjusted at all.

  • Large featureless areas can lead to clipping colors in "high" mode, e.g. a view window with large amount of sky may expose weird colors.

Compare the visual appearance with a standard viewer:

Zoomify version
Microsoft HDView version no tone adjust
Microsoft HDView version medium tone adjust
Microsoft HDView version hight tone adjust