Thursday, December 29, 2005
PAQ7 compression released
The better compression is achieved by trading memory usage and speed for compression, and the program uses a neural network to combine a number of predictor models that predict what the next bit in the file will be. Of particular interest are the predictor models that are specialized to work with tiff and jpeg files - in my tests the program achieved around about 20% compression of jpegs in the archive. Technically what it does it to partially decode the jpeg stream, back to the image coefficients, and simply apply better lossless compression to that level of data.
PAQ7, as its name suggests, is one in a long line of experimental leading edge compression programs - and this version is roughly 3 times as fast as its predecessor. The program's source code is available under the GPL, and builds for many platforms, including Windows and Liinux.
Also recently released is a beta of the closed source archiver and compressor WinRK version 3. which similarly achieves very high compression ratios whilst taking a long time to compress files. WinRK is a GUI based program, only available for Windows. It also has a special jpeg recompression algorithm.
Currently neither of these jpeg recompression modes achieves quite as high a compression ratio as Stuffit achieves, which I talked about earlier in the year.
Wednesday, December 14, 2005
Yahoo and Google widget APIs go head to head
Friday, December 09, 2005
New Virtual Earth SDK
I also downloaded the help for the new API. This is distributed as a self extracting zip file. Why? In an age where people are understandably wary of exe files, why does Microsoft decide to distribute a help file as something that requires an extra step before it can actually be used? The help file has internal compression anyway, so the zipping up into the exe increases the size of the file, not decreases it. It's also a Windows only format (both as a .exe, and as the .chm it extracts to), yet by nature of being a web service, the mapping control is cross platform.
Saturday, December 03, 2005
London and the UK revealed in very high detail
The BBS announcement lists:
- Scotland (Aberdeen 2001, Craigmore 2003, Dundee 2001, Glasgow 2002,
- Northern Ireland (Northern Belfast 2001, Northern Carrickfergus
2001, North Downs 2001)
- Wales (Blaenau Gwent 2001, Bridgend 2003, Caerphilly 2001, Cardiff
2001, Merthyr Tydfil-2001, Newport 2001, Rhondda Cynon Taff 2001,
Torfaen 2001, Vale of Glamorgan 2001)
This imagery is provided by The GeoInformation Group, who also power the Cities Revealed website, where you can buy printouts of the data.
There are also smaller updates to other international data:
Updated/improved Digital Globe .7m data
- Alexandria, Egypt
- Asuncion, Paraguay
- Bamako, Mali
- Bangalore, India
- Cairo, Egypt
- Hyderbad, India
- Kano, Nigeria
- La Paz, Bolivia
- Mexico City, Mexico
- Montevideo, Uruguay
- Omaha, Nebraska
- Provo, Utah
- Pune, India
- Quito, Ecuador
- Sydney, Australia
NYGIS (updated imagery)
- Albany, NY
- Columbia, NY
- Las Vegas, Nevada
- Springfield, Massachusetts
- Mt. Helena, Montana
- Nashville, TN
- fixed mask for Galapagos Islands
- Digital Globe imagery of Pakistan earthquake area
- Nanaimo, Canada
- NW Arkansas
Friday, December 02, 2005
Google Desktop plugin to search Google Earth files
This was announced via a Keyhole bbs entry. After installing the plugin, any KML or KMZ files created or updated will be indexed - though as the readme states, existing files of these type will not be automatically crawled (though you can force them to be found by adding their location to the directories to be explicitly crawled).
It's author is Davis Eustis who appears to be a new hire - at least he hasn't made any previous posts to the Google Earth BBS.