I don’t look forward to rewriting old ENVI user functions, but the new interface does look much better than the clunky old ENVI programming interface. My biggest question is how well is it documented?¹

Abstracts for talks can be submitted until March 11:

Suggestions for topic areas include, but are certainly not limited to:

1. Remote Sensing, GIS and Geospatial Applications
2. Atmospheric & Climate Applications
3. Data Analysis & Visualization
4. Astronomy, Astrophysics & Planetary Physics
5. Medical/Biological Applications

This event is designed to bring together IDL and ENVI users to provide opportunities for networking, sharing ideas, and working on strategies that advance our scientific data analysis and visualization community. We hope you will join us for one or two full days of presentations from professionals in a variety of industries who use visualization technologies for a wide range of applications.

ITT VIS is now accepting abstracts for talks. Pre-registration is required to attend and there is a $40 per day fee.

This popular introduction to the processing of remote sensing imagery has been updated to include coverage of the latest versions of the ENVI software environment. This new edition covers support vector machines and other kernel-based methods. Illustrating many programming examples in the array-oriented language ID, the text includes coverage of basic Fourier, wavelet, principal components and minimum noise fraction transformations; convolution filters, topographic modeling, image-to-image registration and ortho-rectification; image fusion; supervised and unsupervised land cover classification with neural networks; hyperspectral analysis; multivariate change detection.

I was excited to hear that GPULib was used in this version of the book. Mort says:

In the text I discuss routines for nonlinear principal component analysis, supervised classification and nonlinear clustering, and explain that they can take advantage of GPULib/CUDA, if installed. (I use your routine GPU_DETECT() to check for GPULib).

Full disclosure: I work for Tech-X Corporation and worked on the IDL bindings and examples for GPULib.

This update requires no change to the ENVI user function MG_GOOGLE_LOOKUP, only to the server-side code. So, if you already downloaded the code, things should just work for you now. If you would like to try it out, check the installation instructions in the original article.

I just wanted to give context to imagery viewed in ENVI (similar to my Google Maps user function). MG_WRITE_KML produces a KML file and an image suitable for viewing in Google Earth. The KML file includes lat/lon information to locate the image. The user function is only one file: MG_WRITE_KML (docs).

Let me know if you use Google Earth for science and if this user function is useful for you.

Usage of MG_WRITE_KML is bit more complicated than MG_GOOGLE_LOOKUP, but still straightforward:

1. Download MG_WRITE_KML and put it in ENVI’s save_add directory.
2. Open an image with map info in ENVI.
3. Display the image.
4. In the menu for the display window, select Tools > Write KML file for Google Earth.
5. After you select an output filename, MG_WRITE_KML will write the KML and TIFF files.
6. Open the KML file in Google Earth.

1. The Overview map control displays a collapsible overview map in the lower-right corner of the browser window.
2. The Javascript is half the size, so it should be a faster download.
3. Increased imagery resolution and coverage.
4. Other customization features make future enhancements to MG_GOOGLE_LOOKUP possible.

The best part is that all the changes are on the server side, so this will just happen automatically for those who are using MG_GOOGLE_LOOKUP already. If you for some reason want to keep using Version 1 of the Google Maps API, change the URL inside MG_GOOGLE_LOOKUP from envi_lookup.html to envi_lookup1.html.

See previous post Google Maps lookup for ENVI.

Also included is a helper routine called MG_OPEN_URL which is useful in general to open an URL in the default browser from IDL. It will work on any IDL platform. On Unix platforms, the first time it is used it requires the user to locate the web browser. It stores this location and uses it for future calls. This is not necessary on Windows and Mac since they have a nice way to start the default application for URLs.

ENVI and an internet connection are required to use this ENVI user function.

Installation instructions

1. Download mg_google_lookup.sav or the source code.
2. Move the .sav file or .pro files into the save_add directory of your ENVI distribution.
3. On UNIX (but not Mac or Windows) platforms, the first time MG_GOOGLE_LOOKUP is used it will ask for the location of the web browser you want to use to display the Google Maps.