new vips dzsave

[jcupitt at gmail.com]

Hi all,

There's a new version of vips out with an interesting new feature: it
can directly write zip files of image pyramids.

Previously you needed to run "vips dzsave" to create the huge
directory tree of image tiles, then zip up the tree so it could be
easily copied to a server, then delete the directory tree again. In
this new version you can just do:

vips dzsave somefile.svs mytree.zip

and it'll create the zip file directly.

This can have a big effect on throughput on some platforms. On Windows
servers, this change make dzsave two to three times faster, depending
on how you have configured your system.

Sources and Window binaries here:

http://www.vips.ecs.soton.ac.uk/supported/7.40

Many thanks to Martin for supporting the development of this.

John