Published

Colormap Test Image
Today I want to tell you how and why I made these images: After the MATLAB R2014b release, I wrote several blog posts (Part...

8 years ago

Published

Customizing REGIONPROPS With Your Own Measurements
I saw a presentation last month that mentioned a user request to have the ability to customize regionprops. That is, a user...

8 years ago

Published

Frequency Samples for the Output of FFT2
A MATLAB user recently contacted tech support with a question about the output of fft2. The user had a function, q(x,y),...

8 years ago

Published

Chessboards, Implicit Expansion, REPELEM, and Unicode Chess Queens
A few weeks ago, I wrote about a solver algorithm for the Eight Queens Problem. The post included diagrams like this one....

8 years ago

Published

The Eight Queens Problem – Generating All Solutions
On April 20, I wrote about an algorithm for solving the Eight Queens Problem. In this problem, the task is to place eight...

8 years ago

Published

The Future of String Arrays in MATLAB
At MathWorks, we almost never talk in detail about product features before they are released. That's why this week's Art of...

8 years ago

Published

The Eight Queens Problem
Today I want to tackle a classic algorithm puzzle known as the Eight Queens Problem. In this problem, your task is to...

8 years ago

Published

Variation on Connected Objects – Using Graphs
Reader Uri Pe'er found an old post from 2011 about shortest paths in binary images, and he asked this follow-up question...

8 years ago

Published

Variations on Connected Objects – Using imfill
Reader Uri Pe'er found an old post from 2011 about shortest paths in binary images, and he asked this follow-up question...

8 years ago

Published

Logical indexing
One of my favorite aspects of MATLAB for image processing is how I can use a binary image to index directly into a grayscale...

9 years ago

Published

Gaussian filtering with imgaussfilt
With the R2015a release a couple of years ago, the Image Processing Toolbox added the function imgaussfilt. This function...

9 years ago

Published

Aliasing and image resizing – part 3
Today I'll try to wrap up my discussion about how aliasing affects image resizing and about how the imresize function tries...

9 years ago

Published

Aliasing and image resizing – part 2
In my 03-Jan-2017 post, I introduced my new topic: aliasing, especially as it relates to resizing images. Today I will get...

9 years ago

Published

Aliasing and image resizing – part 1
Happy New Year!I'm going to kick off 2017 with two or three posts about antialiasing. Specifically, I will discuss what...

9 years ago

Published

MATLAB arithmetic expands in R2016b
Earlier this summer, I was writing some color-space conversion code. At one point in the code, I had a Px3 matrix called...

9 years ago

Published

Filling holes in outline text
Intrepid MathWorks application engineer Brett Shoelson recently got a user question that caught my attention. Consider an...

9 years ago

Published

Getting the math right
Because I work regularly with developers on the MATLAB Math team, I see the questions that come to them from tech support....

9 years ago

Published

Ten years of MATLAB blogging
As I mentioned last time, MATLAB Central is celebrating its 15th anniversary. You should head on over there to try one of...

9 years ago

Published

The MATLAB community and me
As Ned Gulley posted over on the MATLAB Community blog last week, MATLAB Central is 15 years old. Ned commented that...

9 years ago

Published

Friday MATLAB Mystery
Who can tell me the significance of this number: 0.814723686393179 Update: 29-Aug-2016 Sven and Sam are...

9 years ago

Published

Binary image area filtering
In my August 8 post about Pokemon Go (and I still can't quite believe that I did that), one of the processing steps was...

9 years ago

Published

Pokémon Go meets MATLAB
Until about two weeks ago, I had given absolutely no thought to the possibility of a relationship between MATLAB and Pokémon...

9 years ago

Published

Friday MATLAB Mystery
There are some MathWorkers who like to try to stump each other with pictures of "mystery items." For example, last week...

9 years ago

Published

Ineffective preallocation
Today I want to explain a MATLAB coding mistake that I have seen even experienced MATLAB users make.I was looking at some...

9 years ago

Published

Adaptive thresholding for binarization
Despite recent appearances on the blog, I still exist! It's just been a little crazier than usual for the last month or...

9 years ago

Published

Image binarization – Otsu’s method
In my 16-May-2016 post about image binarization, I talked about the new binarization functions in R2016a. Today I want to...

9 years ago

Published

Image binarization – new R2016a functions
In my 09-May-2016 post, I described the Image Processing Toolbox functions im2bw and graythresh, which have been in the...

9 years ago

Published

Image binarization – im2bw and graythresh
As I promised last time, I'm writing a series about functional designs for image binarization in the Image Processing...

9 years ago

Published

Image binarization – new functional designs
With the very first version of the Image Processing Toolbox, released more than 22 years ago, you could convert a gray-scale...

9 years ago

Published

Problem complexity
Twice in the last month, I have read comments about certain problems being intrinsically hard to solve. In a fascinating...

9 years ago