A post in MATLAB Answers earlier this year reminded me that working on a discrete grid can really mess up apparently obvious notions about geometry.User Hg offered an image containing two... read more >>

Last week I talked about displaying gray-scale and binary images. In that post, I showed how to control the grayscale range. For example, the call imshow(I,[0.4 0.6]) displays the matrix I as a... read more >>

In my previous posts (February 9, February 22, and February 29), I discussed the truecolor and indexed image display models in MATLAB, as well as the direct and scaled variations of indexed display. The Image Processing Toolbox has conventions for two additional image display models: grayscale and binary. These conventions are used by the MATLAB image display function imshow, which originated in the Image Processing Toolbox.... read more >>

ContentsMATLAB image display - truecolor and indexed imagesTruecolor imagesIndexed imagesMATLAB image display - truecolor and indexed imagesLast time I posed this question: How does MATLAB associate... read more >>

Updated 04-Jan-2016 to fix a problem with the maze image that was causing an incorrect result for the cheating maze solver.... read more >>

Last time I showed you the basics of using the new graph theory functionality in MATLAB R2015b. Today I want to talk about some functions I put on the File Exchange for making graphs from images. Those of you working with graph-based image analysis algorithms might find them useful. I would be very interested in receiving feedback on these functions.... read more >>

This question landed in my inbox recently:I have a 721x1441 matrix, T, of temperature values. The x-axis goes from 0 to 360 degrees in steps of 0.25 degrees. The y-axis goes from -90 to 90 degrees,... read more >>

A blog reader asked me recently how to visualize the ellipse-based measurements computed by regionprops. The reader wanted to superimpose the estimated ellipses on the image.To refresh your memory:... read more >>

Today I want to show you how to use a linear system of 90,300 equations and 90,300 unknowns to get rid of a leaf.Earlier this month I told you how the function roifill was recently renamed to... read more >>

About a year ago, I wrote a blog post criticizing one of my functional designs from the 1990s, roifill. Now I have an update based on the R2015a release of Image Processing Toolbox.Let me show you an... read more >>