Image Analyst

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31,410 total contributions since 2010

Senior Scientist and Inventor in one of the world's 10 largest industrial corporations doing image analysis full time. Ph.D. in Optical Sciences specializing in imaging, image processing, and image analysis. 40+ years of military, academic, and (mostly) industrial experience with image analysis programming and algorithm development. Experience designing custom light booths and other imaging systems. Experience with color and monochrome imaging, video analysis, thermal, ultraviolet, hyperspectral, CT, MRI, radiography, profilometry, microscopy, NIR and Raman spectroscopy, etc. on a huge variety of subjects. Be sure to click "View All" in my File Exchange to see ALL of my demos and tutorials: http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862

Professional Interests: Image analysis and processing

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Answered
How to find multiple means of an array
Yes, A(b:c) is A(2 : 1) which is null since your starting index, 2, is after your ending index, 1. So that's why it didn't work...

29 minutes ago | 0

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Answered
Trying to take the median values of all of the columns within a 16000x171 table
Try this: % Create sample data. col1 = rand(160, 1); col2 = rand(160, 1); t = table(col1, col2) % Convert table to matrix. ...

1 day ago | 0

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Answered
start up error R2020b
See the FAQ: During_installation.2C_the_installer_crashes.2C_hangs.2C_gives_an_error_message.2C_does_not_authenticate_your_licen...

1 day ago | 0

Answered
HSV and thresholding for marine growth project
It looks like it's 100% covered after day 7. I would not recommend imaging. Once the blue background is covered, imaging can't...

1 day ago | 0

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MATLAB App GUI :: System Stability
Sure. Try these links: Best way(s) to master MATLAB? - MATLAB Answers - MATLAB Central MATLAB Academy - Free 2 hour training ...

2 days ago | 0

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How to find a point within a curve?
Try this: % Extract the curve for X (Volume) x = Array_demand{w}.Volume; % Extract the curve for Y (Price) y = Array_demand{...

2 days ago | 0

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Answered
Can you solve this??
% "how to whrite this in code 0,01x^5-1.4x^3+80x+16.7" % Commas do both statements in sequence - one after the other. % The fi...

2 days ago | 0

Answered
Pair of dice always rolled until all results happened between (2-12) ..Expected value of throws to find
I'd do something like... numExperiments = 2000 numRollsPerExperiment = 800; % Instantiate array for the number of rolls it to...

3 days ago | 0

Answered
Detect Edges having length greater than 50km
You forgot to attach preprocessed2010.mat. After you get the binary image, A, you can call bwareaopen() to extract only those b...

3 days ago | 0

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Answered
how to avoid for loops or faster way for compute 3x3 avarage value of an image
If you're only doing it at 3 locations, don't worry about using for loops. It will be fast. If you insist on using built-in fu...

3 days ago | 0

Answered
How to detect people from top view
I'd try snapping a photo with no people in there first, and then subtract your people photo from it. Then threshold it. backgr...

3 days ago | 0

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How to combine the multiple .mat files of ecg to get a single file.
Try this: folder = pwd; %'path to the folder where the files are saved'; fileList = dir(fullfile(folder, '*.mat')); numFiles ...

3 days ago | 0

Answered
image processing using entropy
There is an entropyfilt() function in the Image Processing Toolbox.

4 days ago | 0

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Answered
Display Image in separate figure in app designer
You can still call figure() in your code to bring up a separate figure, separate from your main GUI that you built with App Desi...

4 days ago | 1

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Gaussian filtering in spatial domain
Did you know about imgaussfilt()?

4 days ago | 0

Answered
How to apply spatially-varying blur to an image?
See my manual convolution demo. You'll need to change it to make the inner loops change their starting and ending values depend...

4 days ago | 0

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How do you average each pixel in an image with a 9x9 square?
Try conv2() or imfilter(): kernel = ones(9)/81; % Define filter window to take the mean in a 9x9 square. blurredImage = imfilt...

4 days ago | 0

Answered
Determine periodicity of a signal x(t)=4sin (2 pi t /7 )+ 5 sin (2 pi t/9)
This is not a MATLAB question. It doesn't even need fft or correlation. If you do FFt, you'll simply see two spikes, one for o...

4 days ago | 1

Answered
Plotting sinewave looks weird.
This is what I get % Plot a sinewave with a length of 1000 samples, with a sample rate of 40kHz and center frequency at 19kHz. ...

5 days ago | 0

Answered
Code for Counting and Lookup
If you have the Image Processing Toolbox, you can also use bwareaopen() and regionprops(): A = [1 0 0 1 1 1 1 1 1 0 0 1 1 1 0 1...

5 days ago | 0

Answered
Why is my plot not showing?
Look at the first few lines: clear all; close all; clc; test_points=3; start_point=1000; x_rec(1)=x(start_point); Now...

5 days ago | 0

Answered
Line selection if the temperature difference does not change?
To find out if you have stretches of 1's in Adif that are 15 or longer, you can use regionprops Adif = [1, 0, 1,1,1,1,1,1,1,1,1...

5 days ago | 0

Answered
Dot indexing is not supported for variables of this type when trying to write value into static text box
Do not put anything into the CreateFcn() functions of controls. If you want something to be initialized with a value, then put ...

5 days ago | 0

Answered
Generating URLs from MATLAB
I imagine you'd strip off the "GET " and call webread() with the URL. v = {'a','b','c','d','e','f','g','h','i','j','k','l','m',...

5 days ago | 0

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Answered
Signal go down in low pass filter
Unfortunately you delayed a solution because you bloew by the posting guidelines and forgot to attach '118e12m.mat'. However, y...

6 days ago | 0

Answered
How do I multiply two elements?
You need to be using .* instead of * to do an elemenet by element multiplication instead of a matrix multiplication. Try this: ...

6 days ago | 0

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Answered
How can i separate the content of the structure array and make two new arrays?
This will do it: Event = ["boys day out"; "girls day out" ; "girls day out" ; "boys day out"; "boys day out"; "girl...

6 days ago | 0

Answered
how to filter imported data which is imported from excel?
Not sure what T1 is, but how does this work for you? clc; % Clear the command window. close all; % Close all figures (exce...

6 days ago | 1

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Answered
Localization defect real coordinate
What do you mean by "actual location"? Do you want a list of all the (row, column) coordinates of all the pixels in your blob? ...

6 days ago | 1

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Answered
why this error ??
x has only one row, not two. So what value are you thinking of when you try to get the value in row 2, column n? Why do you th...

6 days ago | 0