MrSID compressed images on a Mac?

February 27, 2005 1:20 PM

The Library of Congress uses the MrSID image compression format for many maps and other items available online. How can I get the full-resolution files, in whole, onto my mac so that I can edit/print them from photoshop?

Unfortunately, Lizardtech, the folks who make the software, tell me that there is very little support for the Mac platform other than a browser plugin which only allows one to save a small portion of the file at screen resolution. Does anyone know a way to somehow transmute the files - I am able to save the .sid files onto my machine - into another format so that I can save/print the whole file, not just the little pieces that the viewer allows me to see? I just don't understand why the LOC is using this technology which seems deliberately designed to restrict access to these images. They're out of copyright or never were to begin with, and I don't like the fact that they've only made these images available in a format that some people can use.

posted by luriete to computers & internet (7 comments total)

i know the windows version of lizardtech's mrsid viewer has the ability to export to a tiff, but i'm not sure about the mac version. i guess that really doesn't help you though.

maybe you have access to a pc and can export it?
posted by jstew at 1:39 PM on February 27, 2005

A beta version of Graphic Converter has a "much-improved" MrSID import filter.
posted by AlexReynolds at 1:45 PM on February 27, 2005

Ah! This is terrific AlexReynolds. I'll try it now!
posted by luriete at 2:04 PM on February 27, 2005

MrSID is in my list of Top 10 Internet Pet Peeves. Running across this kind of thing on a university site is like being told you may use the library as long as you stay in the kids section.
posted by rolypolyman at 2:59 PM on February 27, 2005

I have never found a MrSID file that I couldn't find a GeoTIFF or flat TIFF of elsewhere. It's not easy, but there's always some USGS ftp server somewhere with the raw tiff files, I've found. I am particularly talking about 1-meter DOQs, so your mileage may vary...
posted by neustile at 4:01 PM on February 27, 2005

There is a Photoshop plugin, and a few other utilities, here (scroll down).
posted by cedar at 6:49 PM on February 27, 2005

Unfortunately, there are thousands upon thousands of historical maps and drawings and newspaper scans on the LOC/American Memory servers that are not availble anywhere else. It's too bad really. The LOC seems completely uninterested in the fact that this severely restricts several minority user-classes from accessing the images completely.

AlexReynolds' suggestion worked - Graphic Converted did it. I was able to open the 700 mb (uncompressed) images and save them to TIF for photoshop, no problem.
posted by luriete at 7:48 PM on February 27, 2005