home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Media Share 9
/
MEDIASHARE_09.ISO
/
os2
/
vf02r1.zip
/
VIEWFITS.DOC
< prev
next >
Wrap
Text File
|
1993-06-11
|
3KB
|
102 lines
ViewFITS : FITS viewer for OS/2 PM.
-----------------------------------
Current status: Version 0.2, release 1, June 11, 1993
Introduction:
------------
ViewFITS is a FITS viewer for the OS/2 PM. "FITS" stands for "Flexible
Image Transport System", a standard in use for many years by professonials.
ViewFITS, in the current version, can display images of any format, 8 to 32
bits per pixel, integers or floating points. The color palette (LookUp Table)
can be easily modified to help the user to get the maximum of the image. Let's
see the principal characteristics.
Handling datas:
--------------
In the present version, new image can only be gotten via menu (FILE/NEW).
In a future release, we project to make the application be able to
read arguments on command line and use pipes to communicate with other
programs. It will then be used as a "client" program.
The color palette:
-----------------
The color palette, or lookup table, contains 64 colors. They are scaled
via a linear equation. So, the user can modify the slope and the intercept
of the palette to customize the display as s/he wants. Negativation can be
do as well. In all cases, datas are processed to be spread over all the dynamic
range of the palette:
e.g.:
Your image has pixels with values from 100 to 300, so the dynamic range is
200. The intercept of the image is then Ii=100 and the slope is given by
Si= (number of color) / (dynamic range) = 64/200 = 0.32.
This way, each a pixel is drawn, its color is Cp=(Vp - Ii) * Si. Let's
imagine we have Vp=150, Cp = (150 -100) * 0.32 = 16. Pixels with Vp=100
will get Cp=0 and Vp=300, Cp=63 (not 64!) where Cp is the color index, i.e.
the position in the lookup table.
The menu PALETTE allows the user to modify the slope and the intercept of
the lookup table. This way, a given pixel will always have the same color
index but the corresponding color value will change.
The PALETTE menu allows the user to do negativation too.
Known bugs:
----------
Here is a short list of know bugs:
1- There is an error in the palette manager (I have nothing to do with this).
If you have a window that modify the palette over the image, the palette
won't be restored once the window has moved. To correct that, use REFRESH.
2- Because it use palette manager, this application cannot be used under OS/2
2.0. It only works under version 2.1 beta.
3- Drawing is very slow! Bitmapping will be implemented soon.
Improvments since last release:
------------------------------
1- The sliders in the palette controler are calibrated. It is easier to use
them.
2- Now, the LUT modifications are done instantly, you don't have to click on
"APPLY" or "OK".
3- These sliders set themselves automaticaly when the controler is called.
4- The menu to open a file is now the standard PM open menu. A much easier
way to find a file!
5- You can now do negativation...
6- I use now dynamic link libraries. The program is now 17k long instead of
75k...
Unknown bugs:
------------
I'm waiting for your reports! You can join me via e-mail at
beaucham@phy.ulaval.ca
or on the FIDONet forum "astronomy echo".
VERSION 0.2, is FREEWARE.
Dominique Beauchamp
Quebec City
June 11, 1993