Vista users who are also administrators may have noticed that when they select the “Administer Express Server…” option from the “Tools” menu in GeoExpress 7, nothing happens. We intend to fix this in a future release, but in the meantime there are several workarounds that we don’t recommend and one that we do.

You could set GeoExpress to run as an administrator or set it to run in “XP Compatibility Mode”. However, we recommend that you let the Vista operating system fix the problem itself. Here’s how: 

When you attempt to use the “Administer Express Server…” option and it doesn’t work:

1. Close GeoExpress. A dialog appears, shown below, indicating that Vista noticed a “compatibility” issue and will make a change accordingly.



2. Click Close. 

The next time you start GeoExpress and choose Administer Express Server… from the Tools menu, all should be well.

Last time, we talked about despeckling. Another popular workflow with GeoExpress 7 uses two new features: output tiling and decoding.

Lots of customers have massive SID images that they need to chop up into smaller tiles and decode out to TIFF. In prior versions of GeoExpress, you could use a series of command line tools to do this, but of course this was unwieldy.

Here’s how easy it is to do in GeoExpress 7:

1. Add the file(s) you want to work with to the Images tab of the job list.
2. Select Image Crop… from the Tools menu. The Image Crop dialog appears.
3. In the Output Tiling section, choose how many rows and columns you want to divide your image into and click OK.
4. Now, just choose “GeoTIFF” as your output format (use the drop-down menu on the main interface) and click Encode Selected Images.

In no time, you’ll have a series of GeoTIFF tiles created from your original SID image.

Most of you are probably already using GeoExpress 7. We’ve received some rave reviews from some of you about the new features we added, so we thought this might be a good time to introduce and explain how to use some of the great new tools in GeoExpress 7.

If you’ve ever received imagery from the USDA NAIP program, particularly MrSID Generation 2 (MG2) images from previous years, you’ll have noticed that many of the images have black collars around them. If you load these images into your GIS application and drop out these black collars, you’ll see a lot of ugly “speckling.”

These speckling artifacts happen because compressing images to MrSID at high compression ratios requires approximating colors. In other words, “black” becomes “almost black.” While the human eye doesn’t ordinarily notice the difference, this can make it difficult, not to mention ugly, to mosaic images together. Speckling happens with other background colors, too. Below you can see speckling around the edge of a mosaic with a white background.

Not to fear, though. GeoExpress 7 has new “despeckling” tools to clean these images up.

Start GeoExpress, and add your SID files to the “Despeckle” tab of the job list. In most cases, you won’t even need to adjust any options (however, note that despeckling is not available for MG2, so if you want to despeckle your MG2 imagery you’ll need to encode it to MG3 or JP2). Just click the “Despeckle Selected Images” button below the job list and GeoExpress will clean up your images for you. Here’s the result:

Next time, we’ll talk about “tiling out” images as TIFFs.

Images courtesy of MapMart.

GeoExpress 7 was released this past January, and despite the fact that it has met with enthusiastic approval by users and reviewers, it is a product made by humans, and humans on a tight schedule at that. One of the things we were dissatisfied with even as ‘Geo 7′ went out the door was that in one of the new features – publishing images directly to Express Server from GeoExpress – the application appears to hang.

It doesn’t really hang, but the progress meter reaches 100% and then nothing happens for a while.

What’s going on here is that once the images have been uploaded, Express Server then ports them to their specified target. That can take some time. In publishing really large images or lots of small ones, it can be a really long time.

The fix for the misalignment in the meter is not a fully known entity, but it looks like this is a server-side issue, something we’d need to address with a future release of Express Server. In the meantime we decided to add a message in Geo 7 to the effect that ‘Please wait…Express Server is still working’, but in the attempt to do this we found that it involved some incompatibilities with the way we present other messages. We could find no way to do the right thing in the time we had left.

We momentarily considered some inelegant hacks, but because this didn’t appear to be a dealbreaker, better sense prevailed. We’re tracking the issue and we wrote a knowledge base article about it, which basically says what I’ve told you here. That KB article will be updated when there’s more to tell.

For now, be aware that the extra time after the progress meter shows completion may be as much as 30% of the original upload time.

Optimizing is a trick we wish all users of GeoExpress knew about. If you have files in MrSID Generation 3 (MG3) format, and they were originally encoded as “optimizable” (it’s the default, so chances are good that they were), you can perform additional compression and a number of other operations on them without having to decode and reencode them.

Why is that useful? Not having to decode (i.e. bring the image out of wavelet space) has two advantages:

• Optimizing is much faster than encoding
• Optimize operations are free (if you’re using a data cartridge, they don’t charge against it)

Loading Images and Accessing Options
Among the six tabs on the Job list is one called Optimize (shown at right). You may have noticed this tab before and never felt like venturing into it. We urge you to gird up thy loins and use it. Images you want to optimize are staged on this tab.

After you load an image into the Optimize tab (and make sure it’s selected), you can access options in one of three ways:

• Right-click on the filename in the job list and choose Optimize Options… from the context menu.
• Choose Encode Options… from the Options menu.
• Click the More Optimize Options… button on the Properties tab.

In each case, a dialog box appears that has tabs for Input, Output, Optimize Settings, and Advanced Settings.

Basic optimization settings
On the Optimize Settings tab (shown below) you can specify additional compression by ratio or by target file size, and you can resample (reduce the dimensions) by factors of 2.

The options for compression based on encoding ratio and target file size are pretty self-explanatory. If you need to fit particular images on a CD, compress by target file size to make sure you stay under the limit. If you want your images to be uniformly compressed to a fifth of their current size, set a ratio of 20:1.

Resampling in GeoExpress means changing the resolution of an image. For example, if your image measures 1000 x 1000 and you resample by a factor of 2, the result will be a 500 x 500 image. Resampling is achieved by discarding zoom levels; thus, the number of zoom levels in the image (remember, MrSID is inherently multiresolutional) determines the factors available in the drop-down.

Advanced optimization settings
The Advanced Settings tab (shown below) gives you the following additional options, which are described further on:

• Frequency balance
• Sharpness
• One-pass or two-pass optimizer
• Optimizable
• Use temp file

Frequency Balance – This determines the emphasis given to edges and flat areas in color and grayscale images. Set frequency balance lower for images requiring precise edge definition. If precise edges are not as important as consistency in flat color areas, use a higher setting. Range of acceptable values is 0.0 – 10.0. Default is 2.

Sharpness – This determines the sharpness of boundaries between different areas of an image. Use a lower setting for images with large amounts of textured area (where color or intensity changes are occurring throughout a region, rather than just at a boundary). Use a higher setting for images with little textured area. Range of acceptable values is 0.0 – 1.0. Default is 0.0.

1-Pass or 2-Pass Optimizer – This option is only available for MrSID Generation 3 (MG3) images. The 1-pass and 2-pass optimizer parameters affect encode performance and memory usage. Although not as fast as the 1-pass optimizer, the 2-pass optimizer (used by default) requires much less memory because it splits the encode operation into two passes. This is required on very large files. Encoding with the 1-Pass Optimizer is faster but requires that the entire image be loaded into memory. If sufficient RAM is not available for the image selected, the encode job will fail.

The 2-Pass Optimizer is automatically used for Area of Interest encoding even if this checkbox has not been selected.

Note that the “Estimated Memory Usage” is only displayed when the 2-pass optimizer is used (look on the Properties tab or on the Advanced Settings tab of the Encode Options dialog box).

Optimizable – Select the Optimizable checkbox if you want the output MG3 file to be optimizable later on. By default this checkbox is selected.

Use Temp File – A temp file can be used to store necessary statistical data about the image data during processing. If your image is very large this can help alleviate the memory burden on a given job.

Let us know whether or not you find the optimization functionality useful and how you think it could be better.