Readme PTViewer 0.4

Changes to Version 0.3
- Windows version added
- works now on any screen bitdepth
- Mac version can save self-displaying panos
- Mac version reads embedded panoramic images
- Viewer window is correctly updated when offscreen
  or in the background.


Changes to Version 0.2
- Faster and smoother zooming.
- Zooming while panning is now possible
- Changed Zoom keys to Shift and Control (same as LivePicture)
- Much smaller memory requirements


Changes to Version 0.1

- Fixed a bug causing steps at -90 degree yaw
- Fixed a bug causing steps at -180 degrees yaw ("LivePicture bug")
- Significantly faster panning. 

About PTViewer

This is the 0.4 release of PTViewer, a free and open
spherical Panorama Viewer. Open any spherical 360 x 180 
degree Panorama (equirectangular projection) or simply drop
the imagefile onto the viewer icon. Navigate by pressing and moving
the mouse. Zoom in and out by using shift and control keys.
Resize viewer window to any size.

PTViewer runs on Macintosh PowerPCs with System > 7.6
and Windows PCs (Win95/98/NT). It works with optimum
speed and image quality if you set your monitor to
Millions of color (32bit), although it will run on any
display.

The Macintosh version reads images through the Quicktime
importer. Therefor, it can read almost any format, but
size of the panoramic image is limited to 8000 pixels width.
The Windows version only reads JPEG-compressed images,
and is independent of the presence of Quicktime. Consequently,
file size is somewhat larger, since the jpeg-6 library is
linked to the program. The Windows version can read 
panoramic images up to the JPEG limit (60000pixels wide/high).

PTViewer employs high quality bilinear rendering, and switches
to faster nearest neighbor interpolation during panning and zooming.

There are a few additional features in the Macintosh
version: This version can read formats with embedded
JPEG-images, which can not be read by usual image 
readers. Eg, SmoothMove Panoramic images can be
viewed using PTViewer. Any Hotspot information
or additional media types are ignored.

The Macintosh version can attach itself to a
panorama image which then becomes a self displaying
pano. This image can be viewed on any Macintosh
without the need for viewer or plug-in installation.
This option is available using the standard
'Save as' dialog option. Please note that this option only works
if the image has JPEG-format.

Images for PTViewer can be generated using commercial
packages (LivePicture, SmoothMove) or using the free
Panorama Tools from <http://www.fh-furtwangen.de/~dersch>.



Enjoy.

Helmut Dersch
der@fh-furtwangen.de

Copyright © 2000 H. Dersch