This is the first of several blogs about the algorithm behind poly2mask and roipoly. poly2mask takes a set of polygon vertices and produces a binary mask image. The binary mask has 1s for... 続きを読む >>

Last time I showed off custom data cursors with a little utility function that displays object labels as data cursors: My code used label2rgb to display a "colorized" label... 続きを読む >>

A post in comp.soft-sys.matlab this week (see the third post in this thread) asked how to display graphically the numerical labels associated with each labeled object. In this blog I'll show a... 続きを読む >>

Reader JP asked me about my recent blog post on the Hough transform. Specifically, she wanted to know exactly how the rho-theta coordinate system was defined. When I answered her question, ... 続きを読む >>

Image display was added in version 4 of MATLAB, sometime around 1990. Many observant users noticed that the low-level image display object had default pixel values. In other... 続きを読む >>

The morphological operator dilation acts like a local maximum operator. Erosion acts like a local minimum operator. You can use them together to compute something called the... 続きを読む >>

Someone here recently puzzled over the output of the Hough transform functions in the Image Processing Toolbox. The Hough transform is used to detect line segments, typically in binary... 続きを読む >>

Thanks to Kimo Johnson and Perttu Ranta-aho for responding to my custom spatial transformation challenge. Contents Kimo's submission ... 続きを読む >>

Blog reader David A. asked me a while back about how to transform an image based on some mathematical function. For example, the online paper "Visualizing complex analytic functions... 続きを読む >>

The function imtransform has several optional parameters that allow you to fine-tune its behavior. Today's topic is about the parameters that let you control where the input... 続きを読む >>