Note added July 30, 2008: See this post for an update. In September I wrote about customer-reported speed issues related to TIFF files containing a very large number (thousands or tens of... 続きを読む >>

Didja know about the Image Processing Toolbox function bwselect? For a blog post I wrote earlier this month, I wanted a binary image containing only the central blob indicated in red... 続きを読む >>

Back in March I started writing about an algorithm implementation experiment for computing upslope area. Given an "image" whose pixel values are terrain elevations, the upslope area of a pixel is... 続きを読む >>

In a blog comment earlier this summer, someone asked how to find "which labeled regions have a bright spot greater than some threshold?" That's a good question. It can be done efficiently... 続きを読む >>

Since I originally posted my upslope toolbox to MATLAB Central back in August, I have heard from some experts about an issue related to NaNs in the DEM data. Specifically, some data sets... 続きを読む >>

We recently changed the view when you click on a category in the sidebar on the right. I haven't used categories much, but the other bloggers (Loren on the Art of MATLAB, Doug's Pick of the Week,... 続きを読む >>

At the beginning of the upslope area series, I posted code showing how to compute the direction of maximum slope for a triangular facet, and how to compute the flow direction for a pixel. This... 続きを読む >>

In photography and color science, MathWorks developer Jeff Mather's personal interests intersect with his work. He guest-blogged here last year with a post about the CIE Standard Observer. Earlier... 続きを読む >>

In my August 7th post on upslope area, I showed how to construct and solve the flow matrix to determine the upslope area for every pixel in a digital elevation model (DEM). In addition,... 続きを読む >>