I accidentally discovered 'convert'. It is a command line utility. Changing a file from png to gif works like this
convert aaa.png aaa.gif
Amazingly simple, powerful and effective.
I've since discovered it has an amazing list of options
convert --help
a manual
file:///usr/share/doc/ImageMagick-6.2.8/www/convert.html
and a web site
Does anyone have suggestions for a GUI which works for Centos 5.6 ? In production I run the command line program from PHP with 'exec'.
Thank you,
Paul.
Currently automatically, rotating when necessary, downsizing photographs to 900 pixels wide (the software calculates the height) and labelling them with the file reference and photograph date - all in one quick operation. Mind boggling options, more than I've ever seen in similar software.
Really amazed :-)