Image Analyst

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32,886 total contributions since 2010

Senior Scientist (male/man) 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. Member of the Mathworks Community Advisory Board. 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 convert two rgb images into grayscale? and then subtract ?
If you don't want negative numbers clipped to zero you can cast to double before subtracting image1 = imread('Image1.jpg'); i...

5 hours ago | 0

Answered
How to get luminance of an image?
Code samples in the FAQ: https://matlab.fandom.com/wiki/FAQ#How_can_I_process_a_sequence_of_files.3F So, try this if you have ...

6 hours ago | 0

Answered
Is there a way to report/flag submissions on the File Exchange?
Not sure if you can report - maybe you can - but for us moderators you can click on the user's name twice to get to their Commun...

7 hours ago | 1

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Answered
i am having problem in Undefined function or variable 'Testftr'. Error in imtest (line 49) TestSet = Testftr;
It's not a built-in function. Therefore you will have to supply that function. Did you write this code or did someone give it ...

9 hours ago | 0

Answered
matlab code for hididn an image into another image using pixel value differencing technique (image steganography)
See attached demo. Adapt as needed.

11 hours ago | 0

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Left ventricular segmentation in Cardiac Magnetic Resonance Imaging
People have been working on that for decades. Look it up in USC Annotated Computer Vision Bibliography I'm sure you'll find d...

11 hours ago | 0

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Answered
I want to learn Matlab coding , I try a lot but very weak .How to improve my Matlab coding and simulink ?
Read over this link: Best way(s) to master MATLAB? - MATLAB Answers - MATLAB Central

12 hours ago | 0

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Eliminate string from vector
You say "For example from c_gls to S1CSAR" so basically up until the last underline. Don't include _V and anything after that. ...

12 hours ago | 0

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Answered
Anyway to do a 3D binary reconstruction without a huge contiguous 3D matrix?
Not sure I understand. Do you have an actual movie file, like in an .mp4 format? Otherwise, maybe check out the memmapfile()...

22 hours ago | 0

Answered
MATLAB crashes every time after launching.
Looks like it's covered by the FAQ: https://matlab.fandom.com/wiki/FAQ#After_installation.2C_MATLAB_crashes_or_gives_an_error_m...

23 hours ago | 0

Answered
What is the best approach to find a smaller matrix within a larger matrix (may not be identical, but need region if highest match)??
You can't use corss correlation reliably to find a math. It's just a myth. See attached demo for proof. However, you can use ...

23 hours ago | 1

Answered
Plot image on different axes
What is the correspondence between the numbers in the plot, and the pixels of the image? There is no -50 pixels. What mapping ...

23 hours ago | 0

Answered
How to see Hyperspectral Image from a .MAT file
What does this say s = load('yourMatFile.mat') % No semicolon. Replace with your actual filename. fieldnames(s) Do you have ...

24 hours ago | 0

Answered
Eliminate string from vector
Did you try the unique() function? It has lots of options so be sure you understand which options to use. If you need more hel...

1 day ago | 0

Answered
How to change the Image colour of ones and zeros to white and black
You don't need a colormap. Just try this: B = randi([0 1],50, 100); imshow(B) impixelinfo();

1 day ago | 0

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Answered
Using the feature points object in matlab(no feature matching)
Just use indexing to get the small sub-image you're interested in and then use histogram subImage = bigImage(row1:row2, column1...

2 days ago | 0

Answered
what is wrong with my code
I'd start by using the Color Thresholder in HSV space to find green, then mask out the grass. Then I'd convert to HSV color spa...

2 days ago | 0

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what is my wrong with my code
Try the color thresholder to segment each color individually. So you'll export 3 createMask() functions from it. Then use bwar...

2 days ago | 0

Answered
How to calculate the coefficients of a line in the standard form
x1=-2; x2=3; y1=4; y2=-5 coefficients = polyfit([x1,x2], [y1, y2], 1) % I need a MATLAB code to calculate A, B, and C in Ax+...

3 days ago | 0

Answered
Error using xlswrite (line 224)
If you're calling xlswrite 1251 times, you're not doing it right -- that will take forever. It's better to use ActiveX. See at...

3 days ago | 0

Answered
Approximation of pi is "too precise" .
For what it's worth, when I tried a pi estimation series, it was so accurate that after 2 terms, MATLAB couldn't tell the differ...

3 days ago | 0

Answered
使用的学生版本matlab,但是之前激活的电脑坏了准备换一台新电脑,这个matlab是否还可以继续使用?还是说需要我先停止原先电脑上的matlab然后在新电脑上重新激活一遍?
You can, but you with a Student license you can have only one activated at a time, so you need to deactivate the computer you're...

4 days ago | 0

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Is there a method to use ‘findpeaks’ to detect bright spots in an otherwise darkimage?
Show/attach/post your original gray scale image. My guess is that you can threshold to find the bright blobs, then find the cen...

5 days ago | 0

Answered
How to split into small pieces of ranges of this graph?
If you simply want to zoom in and look at a narrower viewport window, you can set the left and right ends of the x axis with the...

6 days ago | 0

Answered
How to plot 3D heat map in Matlab
There is not much heat to plot in that small data set. You might just visualize it with plot3() and make the markers somewhat l...

6 days ago | 0

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Answered
From plot to video
See attached demo and adapt as needed.

6 days ago | 0

Answered
Extract email information from webpages/URLs using Matlab
Looks like L is a cell array of web sites, none of which is an email address with @ in it. So why do you think it should find a...

6 days ago | 0

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Answered
How to find an unclear edge?
Try to denoise your image first. You might try imnlmfit() or a mean shift filter or something like that.

6 days ago | 0

Answered
I need help with pixel neighborhood operations
Looks like you've accepted an answer that works (via intensity thresholding) for the image you uploaded. If you want a more rob...

6 days ago | 1

Answered
Subroutine using if statement
Lots of stuff wrong with this. For starters, you're passing in the whole x vector into the (poorly-named) X function yet your f...

7 days ago | 0