Category "ENVI"

The ENVI Analytics Symposium is happening again August 23-24 this year in Boulder, CO:

The 2016 ENVI Analytics Symposium (EAS) continues its exploration of remote sensing and Big Data analytics around the theme of geospatial signatures to analytical insights.

Though I don’t use ENVI at all, remote sensing is still interesting to me and I would be interested in how this community is using “Big Data analytics”.

A security update for IDL and ENVI license servers was released today by Harris Geospatial Solutions:

The security vulnerability is limited to computers running a license manager server and should not be an issue when the license server components are only exposed on a trusted network.

If you run an outside facing IDL or ENVI license server, it sounds like you need to update immediately.

The abstracts and presentations for VISualize 2012 are now available from the Exelis VIS website.

Also, James Goodman from HySpeed Computing wrote an article on his experience at VISualize:

A central topic of discussion in the presentation by HySpeed Computing, and a common theme heard around the conference, is the need for increased collaboration, improved access to analysis tools, and greater data accessibility.

I agree. Even though James was talking about the ENVI community and used the IDL community as an example with good code sharing, I think we could do a lot better.

The IDL Data Point has a post showing an example of using the new object-oriented interface for user functions in ENVI 5. Mark discussed batch programs in ENVI 5 last week.

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]

  1. My next question would be is there a way to write an extension that works for both old and new versions of ENVI? I think so. ??

ITT VIS has announced an expanded VISualize 2011 in Washington, DC on April 12 – 14. The new three day format will have Workshops on the first day (morning for IDL, afternoon for ENVI), a day for the IDL User Group Meeting, and a day for the ENVI User Group Meeting.

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

VISualize 2010 will be May 19-20 (the first day is for IDL and the second for ENVI) at the World Wildlife Fund in Washington, DC:

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.

From the CRC Press site for Image Analysis, Classification, and Change Detection in Remote Sensing: With Algorithms for ENVI/IDL, Second Edition:

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.

Mort Canty, 2nd edition

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.

ITT VIS has a YouTube channel. There are quite a few videos describing ENVI features, all of which were uploaded about three weeks ago. They are marketing-oriented, but still provide some useful information about ENVI’s capabilities. A programming language is not as easy to create a video for, but it would be nice to see some for IDL.

ITT VIS on Youtube

A while ago, I wrote a simple ENVI user function to show the location of the current image using Google Maps. Evidently, Google recently changed the Google Maps slightly which was causing the map controls to not appear.

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.

There have been suggestions recently that Google Earth is a “powerful tool” for science. Some disagree. At least one amateur used Google Earth to find an asteroid impact crater.

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).

Screenshot of Google Earth display of bhtmref.img

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.

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