Image Analyst

28 856 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 do I deactivate MATLAB?
If you're using Windows, you can use the "Deactivate MATLAB R2019a" link under the "MATLAB 2019a: group under the Start Menu.

environ 11 heures ago | 0

Answered
Help! How to convert grey scale image to colour contrast image?
Try a bottom hat filter on the dark hole image filteredImage = imbothat(grayImage, .......................

1 jour ago | 0

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Can anyone please help me to calculate average(mean) RGB value from the image in matlab? and also show the image using that average values.....
What does "enhance" mean to you? Increase the saturation? If so, convert to HSV space with rgb2hsv() and multiply the second c...

3 jours ago | 0

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Answered
How to calculate rgb chromaticity value for set of images?
To convert ot grayscale, use rgb2gray(). To change the colors or enhance the colors, try the attached demos.

3 jours ago | 0

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how to draw a rectangle on the matlab.ui.control.image object?
If you want to draw a rectangle into the overlay above an image, use rectangle(): hold on; rectangle('Position', [xleft, yTop,...

4 jours ago | 0

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how to connect the adjacent lower edges of each bounding box
Use kmeans on the y values to identify boxes in one of the 5 lines that your image has. [classIndexes, classCentroid] = kmeans(...

4 jours ago | 0

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Is the gplotmatrix function capable of plotting with more than the 7 built in colors?
Not sure but you might try a strategy similar to the attached emo where I plot more than the standard 7 or 8 colors with line pl...

5 jours ago | 0

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i need help with bwboundaries function
I presume your foreground is white and background black. So just call imclearborder(). bwboundaries() and regionprops(BW, 'Bou...

5 jours ago | 0

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How to close the boundary of a surface already generated by filling the holes
Is the data (circle) expected to be convex? If so the ultra-easy way is to just use bwconvhull() followed by bwboundaries(), po...

5 jours ago | 1

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Answered
Best Way to find density of [x,y] coordinates within set window
James: Attached is how you do it using a rectangular window. Choose the window width to be square if you want. It counts the ...

5 jours ago | 2

Answered
how are number of edges differ from one edge detecting method to another?
They use different algorithm so of course they're not going to agree on every single pixel. You can look up the precise algorit...

5 jours ago | 0

Answered
I want to add a line of best fit to my plot using the polyfit function.
See attached demo of polyfit where I fit a line and a dubic to some data. Attach your data and show a screenshot of it plotted ...

6 jours ago | 0

Answered
Best Way to find density of [x,y] coordinates within set window
Can you supply your x and y in a .mat file save('answers.mat', 'x', 'y'); Use the paper clip icon. I'll probably just scan al...

6 jours ago | 1

Answered
Apply a Local Averaging Mask
You can use imfilter() instead of convolution, but it's doing pretty much a similar thing (multiplying a sliding window by the i...

7 jours ago | 0

Submitted

Plot audio file waveforms
Plots all the audio waveforms of all the sound files in a folder that you specify.

7 jours ago | 11 downloads |

Answered
How to find mean line of the this edge?
Call bwareafilt() to get the largest blob: mask = bwareafilt(mask, 1); Then scan across column by column to get the midline [...

7 jours ago | 0

Answered
How to select a roi in greyscale image and put values to zero
Use = to assign, not == which is a comparison. Raw(p(2):(p(2)+p(4)), p(1):(p(1)+p(3))) = 0; or mask = h.createmask(); Raw(ma...

8 jours ago | 0

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Answered
Exponential decay extrap to y=0
I don't have the curve fitting toolbox so I did it with fitnlm() from the Statistics and Maching Learning Toolbox. Do I get t...

9 jours ago | 0

Answered
Matlab image processing using hex2dec to generate two block of colour
Here's a start on your homework: hexColor = '05A7AB' redChannel = hex2dec(hexColor(1:2)) * ones(100, 100, 'uint8'); greenChan...

10 jours ago | 0

Answered
Data Filtering Help Needed?
Try something like this: col = 2; % Whatever it is... theColumn = x{:, col}; % Extract column 2 as a cell array from the table...

10 jours ago | 0

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Answered
Subtracting in matrix, column to column (Basic MatLab)?
You need to put the matrix name in there, and a result variables, like result = m(:,44) - ..................... etc.

10 jours ago | 0

Answered
Fitting Gamma to a curve with two peaks
Attached is a demo where I fit two Gaussians. Adapt to your gamma functions.

10 jours ago | 0

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Answered
Iterating over an array to produce an array of calculated variances based on the next 9 entries and previous 9 entries
Replace for i=1:length(x_coordinates); with for i = 1 : length(x_coordinates) - 9

10 jours ago | 1

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Answered
Determining values in array (of 1s and 0s) that neighbour similar values
Your largest central blob is actually connected to several other blobs as you can see in the lower left image. So you can't sim...

10 jours ago | 0

Answered
How to perform piece-wise linear regression to determine break point?
I didn't know there was any existing functions to do it, so (a while ago) I just came up with my own intuitive approach. I just...

13 jours ago | 0

Answered
Cant change the background using image segmentaton
Why do you think that code will identify background, whatever that is, in an image of a bunch of leaves? What is the background...

13 jours ago | 0

Answered
How to join an image to multiple images with a loop?
If the number of columns are the same: tallImage = [topImage; bottomImage]; If the number of rows are the same wideImage = [l...

13 jours ago | 0

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Answered
How to replace image pixels
Try this if your data is stored row, column, new gray level: data = csvread(filename); % Assumes columns of row, column, new g...

16 jours ago | 0

Answered
Point Spread Function with Gaussian (radial direction) and exponential (axial direction)
I don't know. You can use fspecial() to get a Gaussian image/pattern/matrix. Of course the values of that Gaussian are determi...

16 jours ago | 1

Answered
problem with using Gabor filter to segment floor
It looks like a frame from a video. Assuming the humans are moving, it's probably best to either get a snapshot when no one is ...

17 jours ago | 2