Spring 2008
For more details, and talks in past semesters, consult the
full schedule of talks.
Tentative talks:
- Math on a MAC
- How to deal with e-mail spam
- Scripting with Bash
- Power Point presentation using LaTeX
- GNU/Linux text editors
Interested in speaking?
Past topics can (and should) be repeated
occasionally. In addition,
here are some topics people might like to hear about:
- Femlab (PDE modeling environment)
- GAP (computer algebra software)
- Getting started with Maple (or Matlab, or Mathematica, ...)
- How to do math on a Mac
- How to filter e-mail spam
- HTML vs. XHTML (the new HTML standard)
- Octave (free Matlab-like system)
- PDAs (handheld personal digital assistants and much more)
- PHP (server-side webpage scripting)
- R (free statistics system)
- Remote access (SSH, VNC, dial-up, ...)
- Scientific WorkPlace (graphical front end to TeX)
- Setting up a dual boot system (DOS/Linux)
- TeX / LaTeX topics
- Using scanners efficiently
- Using the WINEDT editor (a front end to TeX, HTML)
- XML (extensible markup language)
- [your favorite topic here]
To give a talk, please contact
swig@math.arizona.edu.
Image Conversion Tools
by Mark Hays
Table of Contents
Introduction
This document describes some of the image conversion and
manipulation utilities present on the Departmental Sun system.
Overview of the Utilities
There are a number of locally available tools to convert
between and manipulate a multitude of existing image formats:
-
XV
-
An X-based interactive program for manipulating images. Xv
is more suited to interactive use than batch applications.
Xv enjoys the ability to interactively grab the contents of
windows and save them as images.
-
ImageMagick
-
A small suite of programs with powerful image manipulation
capabilities. The format conversion program is very
flexible, but is larger and slower than Net-PBM.
-
Net-PBM
-
A large suite of programs that can convert just about any
format to just about any other format. It has limited image
manipulation facilities, but does faster image conversion
than ImageMagick.
I have included links to most of the Net-PBM and
ImageMagick
manpages at the end of this
document.
We also have several pieces of software that can do color map
manipulation:
-
XV
-
Xv can do many basic color editing operations on images. To
get to the color editor, select its entry under the
"Windows" menu. Within this window, you can copy, change,
and interpolate colors, as well as do global color
transformations.
-
ImageMagick
-
The ImageMagick programs can perform a number of global
color transformations to a sequence of images; in
particular, ImageMagick usually does a nice job of color
reduction. If you need to perform a bizarre transformation
on a bunch of images, try looking at the mogrify manpage. Chances are, it can do what you
want.
-
IDL
-
IDL can do some really amazing image manipulation in just a
few lines of code. IDL is an array-based programming
language (kind of like matlab) with a syntax similar to C,
FORTRAN, and PASCAL all rolled into one. The XPALETTE
widget in IDL can do all the usual color manipulation
stuff. In addition, it supports color interpolation within
colormaps. To learn more about IDL check out the SWIG IDL documentation.
Xv is most suitable for interactive work on a few images. The
other tools are more suited to batch-style processing of a
large number of images. For example, you might use xv to get
a colormap just right on a single image, and then run mogrify
in a shell script to propagate this colormap to the other
images that will make up your movie.
Finally, if you need to touch up or annotate an image, xpaint
is a fairly nice program. It is similar to MacDraw.
Links:
Manpages:
-
(from the ImageMagick 3.7.7 distribution)
[Note: the latest ImageMagic release (as of January, 2005) is 6.1.8, so this manpage info might be outdated. Check the above link to the ImageMagic Homepage for updates!]
-
Net-PBM manpages:
- From PBM:
- To PBM:
- From PGM:
- To PGM:
- From PPM:
- To PPM:
- From PNM
- To PNM
