Here is an animated GIF which includes one of the balloon aerial photos we took over Lake Warner, and two other versions of that scene. One is a false color infrared version, and the other is one of Ned Horning's first attempts at classification (grayscale image) to distinguish water chestnut (Trapa natans). The white circles are areas of water chestnut identified by eye in the RGB photo (let me know if you find any more). The dark areas in the grayscale image are areas that Ned's classification determined to be water chestnut. Only Ned knows how he did this. Update: According to Ned, the grayscale image is derived from an image with four channels: red, green, blue, and near infrared. He did a principal components analysis of the data set (four values for each pixel, so about 10 million sets with four values each). Most of the "information" in the image is quantified by the first couple of principal components, and the grayscale image is the fourth principal component. So the brightness of each pixel is determined by the value of the fourth principal component.
The GIF is used as the main image (above) and also the image below to see if either one supports animated GIFs. Please report if either image is not flashing all three versions (green, gray, pink, gray...) in your particular browser. The GIF is made with full resolution versions of the images, but in case this site downsamples them, I attached it to a post at the grassroots mapping forum. However, Google Groups allows only images with fewer than 2000 pixels in either dimension, so that one is not full resolution either. Click the main image above for a reasonably large view of the GIF. Update: Click the main image, right click and save image as... This will download the full resolution GIF (2500x1875). Drag it into a browser to play it.