This FAQ last updated on Wed Dec 6 15:42:48 CST 2000.

Viewing Map Images
How do I find a map?
How do I find maps by a particular author or cartographer?
Which viewer should I use? Default, plug-in, or java?
Can I rotate an image?

Saving Map Images
How do I save the images displayed in my browser?

Downloading Map Images
There is sometimes a link that says I can "download the source image." What does this mean?
How do I use the .sid file I downloaded?
Why would I want to view the file locally?
Will an exported image be a perfect reproduction of the original document?

About the Map Images
There is a splotch on the map. Why?
Why are some of the thumbnails blurry?

Downloads
Where can I download the plug-in or stand-alone viewers?

Lizardtech software
Where can I get support for the Lizardtech Online Viewer (plugin)?
Where can I get support for the Lizardtech Stand-alone Viewer?
Where can I get support for the Lizardtech Java Viewer?

Viewing Map Images

How do I find a map?
Start at the Virtual Map Library. From there you can:

• Search by Keyword - search for "Texas", "Arrowsmith", "Geographical", etc. The search is case insensitive.
• Search by Date Range to find maps published between particular years.
• View a much larger page that shows "all maps" or some other large category. As these pages are slow, the previous searches are preferable.

How do I find maps by a particular author or cartographer?
Do a keyword search on the author's name; the last name will usually work best.
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Which viewer should I use? Default, plug-in, or java?
It depends on what you want to do. Most people will have a satisfactory experience with the default viewer (the one that pops up when you click to see a zoomable image). If you are an experienced web user, you may like the smoother panning available with the java and plug-in clients. If you want to rotate the images you will need to use the plug-in.
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Can I rotate an image?
If you use the plug-in you can right-click on the image and select Transpose Image, which will allow you to rotate the image. This might be useful on maps that have text written in a variety of orientations.
Or for more control (and complexity) you could download the image in .sid format, install the stand-alone viewer, export the image as a .tiff, and import that into your favorite imaging soft (like Photoshop, Paint Shop Pro, etc.) and adjust at will.
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Saving Map Images

How do I save the images displayed in my browser?
Your browser will have a way to save images it displays. In Netscape, right-click on the image and select "Save image as". In MS Internet Explorer, right-click and select "Save picture as".

In either case be certain that you name the file something with a .jpg extension like TexasBurrMapZoom.jpg, because the default name presented to you in the dialog box might be something like makeJpg.cgi. This odd name is a result of the graphic being generated on-the-fly from the (huge) master image rather than existing on the server somewhere.
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Downloading Map Images

There is sometimes a link that says I can "download the source image." What does this mean?
The source image is a Lizardtech .sid file the server uses to send you a particular view. If you want, you can download the file to your machine and view it locally with the Lizardtech viewer.
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How do I use the .sid file I downloaded?
You will need to install the free MrSid Stand-alone Viewer. Then you can zoom, pan, and export files at your leisure.
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Why would I want to view the file locally?
Local viewing tends to be much faster when using a slow connection, and (for technical reasons involving how browsers render images) visually clearer.

You can also use the local viewer to save (export) particular map views or subsections as a .tif file on your drive. You could pull that into image software (like Photoshop or Paint Shop Pro) and manipulate it.
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Will an exported image be a perfect reproduction of the original document?
It will be quite close, and you probably would not be able to tell the difference by looking at it. The slight degradation is due to the MrSID format being slightly lossy.
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About the Map Images

There is a splotch on the map. Why?
There are several possibilities:

1. The original map has a splotch on it!
2. The maps were usually too big for one scan. Sometimes there are slight color shifts between pieces when they are stitched together; this is rare.

Why are some of the thumbnails blurry?
Depending on the size of the original document, some of the thumbnails are less than 1% of the size of the original. This extreme condensation of information is difficult to do with perfect clarity. The role of the thumbnail is to help you figure out if a particular map is the one you are looking for.
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Downloads

Where can I download the plug-in or stand-alone viewers?
Both the Lizardtech Online Viewer plug-in and MrSID Stand Alone viewers are free downloads from Lizardtech.
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Lizardtech software

Where can I get support for the Lizardtech Online Viewer (plugin)?
See our pointers to Lizardtech help pages.
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Where can I get support for the Lizardtech Stand-alone Viewer?
See our pointers to Lizardtech help pages.
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Where can I get support for the Lizardtech Java Viewer?
See our pointers to Lizardtech help pages.
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