diff --git a/README.txt b/README.txt
--- a/README.txt
+++ b/README.txt
0. FEATURES
-----------
-fits2jpeg is a tiny program to read FITS Images and convert them
-to jpeg, which is more popular. This software supports various
-type of intensity scaling and image enhancements. fits2jpeg do not
-support coordinate axes overlay. fits2jpeg supports batch mode
-operations - for instance, converting several fits files to jpeg
-at once.
+fits2jpeg is a tiny program to read FITS Images and convert them to jpeg, which
+is more popular. This software supports various type of intensity scaling and
+image enhancements. fits2jpeg do not support coordinate axes overlay. fits2jpeg
+supports batch mode operations - for instance, converting several fits files to
+jpeg at once.
1. BUILD/INSTALL
http://heasarc.gsfc.nasa.gov/docs/software/fitsio/fitsio.html
b) JPEGLIB
- jpeg library and headers. libjpeg is installed by default on most
- platforms, but we need the header files too. Once you have cfitsio
- and jpeglib installed, you may proceed with compiling jpeg2fits.
+ jpeg library and headers. libjpeg is installed by default on most platforms,
+ but we need the header files too. Once you have cfitsio and jpeglib
+ installed, you may proceed with compiling jpeg2fits.
+
Follow these 4 steps:
2. Type `make' to compile the package.
3. Type `make install' to install the programs and any data files and
- documentation. By default, the binary is copied to /usr/local/bin.
- You may change this destination by passing on the following
- argument to configure:
+ documentation. By default, the binary is copied to /usr/local/bin. You may
+ change this destination by passing on the following argument to configure:
--prefix=/your/chosen/destination
Which would result in the binary in /your/chosen/destination/bin
You may need to ensure that in $PATH to run the program.
- 4. You can remove the program binaries and object files from the
- source code directory by typing `make clean'.
+ 4. You can remove the program binaries and object files from the source code
+ directory by typing `make clean'.
-You may read more about configure script and others in the accompanying
-file named `INSTALL.txt'.
+You may read more about configure script and others in the accompanying file
+named `INSTALL.txt'.
2.USAGE
0.5 Shrink output to half of input
2.0 Magnify output to double the size
+ fits2jpeg uses a bilinear interpolation based algorithm
+ to scale the image. Allowed range: 0.01 to 4.0
+ NOTE: Anything outside the allowed range will be clipped
Output will be written to <fits_file_root>.jpg. For eg.,
writes output to jpeg file 30dor.jpg
- Wild card entries allowed in <fits_file>. For eg: *.fits,
- m31*.fits ngc???.fits etc.
+ Wild card entries allowed in <fits_file>. For eg: *.fits, m31*.fits
+ ngc???.fits etc.
More examples:
units.
+3.1. Sequence of operations
+---------------------------
+Here is the sequence of operations, after reading the fits file:
+
+ i. clip the image to user specified pixel limits, if it was requested
+ ii. Squeeze image pixel values to jpeg limits (0 - 255)
+ iii. image scaling function, default being linear pixel scale
+ iv. Negate the image, if requested
+ v. Image zoom - magnify or shrink the image
+ vi. Write out jpeg file
+
3. DOCUMENTATION
----------------
-An extensive coverage of how this program works along with line
-by line account of the happenings within the code, are dealt with
-in the user manual, which is yet to be written :(
+An extensive coverage of how this program works along with line by line account
+of the happenings within the code, are dealt with in the user manual, which is
+yet to be written :(
4. LICENSE: GPL [See the file COPYING.txt for details]
5. DISCLAIMER
-------------
-You may encounter bugs in this software. If you do, please
-report them. Your bug reports are valuable contributions,
-since they allow us to notice and fix problems on
-machines/platforms we don't have, and/or remained un-noticed.
+You may encounter bugs in this software. If you do, please report them. Your bug
+reports are valuable contributions, since they allow us to notice and fix
+problems on machines/platforms we don't have, and/or remained un-noticed.
6. REPORTING BUGS
Either way, please include as many details as possible.
+
-----------------------------------------------------------
Reks, 28 June 2012 <reks_at_iiap.res.in>
Last modified: 10 July 2012