I started writing a post today about the ConvexImage property returned by regionprops. But I got sidetracked along the way, and this post turned into a description of how to overlay a pixel grid... 続きを読む >>

"Why do you have M&Ms on your desk?" my friend Nausheen wanted to know. Well, the truth is, for playing around with color images, M&Ms are simply irresistable. url =... 続きを読む >>

A reader asked in a blog comment recently why a vertical line (or edge) shows up in the Fourier transform of an image as a horizontal line. I thought I would try to explain this using the... 続きを読む >>

The Image Processing Toolbox function regionprops gives you measurements of shape-based measurements of image regions. It's pretty useful, and I have shown many examples of it on this... 続きを読む >>

One of the discrete-time Fourier transform properties that many people learn is that if a sequence is conjugate symmetric, , then the Fourier transform is real. Therefore it... 続きを読む >>

In my Fourier transform series I've been trying to address some of the common points of confusion surrounding this topic. For today's espisode I want to look at how to use the fft... 続きを読む >>

OysterEngineer (I love that name!) asked some interesting questions in response to my last Fourier transform post, which concerned the relationship between the discrete-time Fourier transform... 続きを読む >>

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One challenge of teaching Fourier transform concepts is that each concept can be (and is) interpreted and explained in many different ways. It isn't always obvious how the different... 続きを読む >>

Many of you were onto me immediately last week. I asked you to estimate the frequency of the sampled cosine signal below, and readers quickly chimed in to guess that this question was... 続きを読む >>