How to calculate the entropy of a portion of image as in the following formula?
What about entropy e = entropy(grayImage(row1:row2, col1:col2))

10 dagar ago | 0

can I take pca analysis of columns extracted from pixel values of a converted to gray image?
You can do it. I attach an example where I did it for an RGB image where each column was one of the color channels converted in...

10 dagar ago | 0

mean of elements of a matrix
theAverage = mean(A, 'all') % or theAverage = mean2(A) % In the Image Processing Toolbox.

10 dagar ago | 0

how to solve this
You almost got it. Maybe you just needed to read the manual some more and understand what is x and what is y. p=[101.3 106.6 1...

10 dagar ago | 0

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Plot sinusoid equation of x(t)
This works just fine: t = linspace(0, 5, 500); x = sqrt(2) * (1+1i) * exp(1i*(pi/4)) * exp((-1+((1i)*2*pi)*t)); re = real(x);...

10 dagar ago | 0

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Removing neighbours that are too close from eachother in a vector
Sounds like you want to use the dbscan clustering algorithm. So in the above diagram from Wikipedia the red and yellow poin...

11 dagar ago | 0

X-ray inspection of household typical bags of sugar to find iron in it
I imagine the iron particles would show up as dark spots in your x-ray image. So threshold for dark spots. See my Image Proces...

11 dagar ago | 0

I receive "Could not find version 9.11of the MATLAB Runtime" when running my compiled app, my MATLAB Runtime is 9.13. so this specifically need 9.11 to be run?
You are trying to run a compiled program somebody made with R2021b. It doesn't matter what version you have but if you don't ha...

11 dagar ago | 1

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Speckle Noise Estimation in Ultrassound images
Can you get images from uniform/homgenous soilds/gels with different densities/reflectivities? If so you could get a distributi...

11 dagar ago | 0

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How can I force a figure to refresh?
drawnow should work. Maybe it's some quirk of your video adapter. Have you tried the same program on someone else's computer? ...

11 dagar ago | 0

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Reading uint8 from raw data takes much more RAM then expected
Put the memory command before and after your code. What do you see? Are you sure you're closing the file? memory fid=fopen(f...

11 dagar ago | 0

i need to find the dark spot in this image which is the first minimum of the pattern.(pattern is sinc funtion in y -axis)
Try minR = min(R, 'all') [row, column] = find(R == minR)

11 dagar ago | 0

Index in position 2 exceeds array bounds. Index must not exceed 1024.
I do exactly that in my attached demo.

11 dagar ago | 0

Exclude central pixel from sliding mean calculation of surrounding pixels in a matrix
Try setting the central pixel of the kernel to 0. kernel = ones(3, 3) / 8; kernel(2, 2) = 0; avg = conv2(M, kernel, 'same'); ...

11 dagar ago | 0

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How can I find the length in a binary image?
It looks like it goes from the first white pixel in two different columns down to the bottom of the image, which is just the sum...

12 dagar ago | 0

Can LBP feature extraction computed in MATLAB be realized manually?
The answer is yes. Differences may depend on what pixel you consider to be least and most significant. If you have any more qu...

12 dagar ago | 0

Find total area of all circles
You need to generate an (x,y) point, like in an outer loop. Then in the inner loop you need to loop over all the known circles....

12 dagar ago | 0

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Comparing matrices of different length
Try pdist2 in the stats toolbox. I don't know what your units are but none of your data are closer than 5. So I did it for 210...

12 dagar ago | 0

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Diameter of Almost circular objects and degree of circularity
Just threshold, call imclearborder, and then regionprops, asking for EquivDiameter. Let me know if you can't figure it out.

12 dagar ago | 0

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Hello. I need you to help me with an example of a median filter with a 3x3 pixel to an image that I gave the noise of salt and pepper.
See attached salt and pepper denoising demos, one for color and one for grayscale. Adapt as needed.

13 dagar ago | 0

How can I remove rows containing Nan values in table?
Try this: % Load .mat file. s = load('behrooz Table.mat') % Extract variable from structure into table. t = s.stations_1__3_...

13 dagar ago | 0

problem with plotting two uneven data sets
Try using hold on x = linspace(1, 20, 30); % 30 elements. y = 10 * sin(2 * pi * x / 5) + 5; plot(x, y, 'b.-', 'MarkerSize', ...

13 dagar ago | 0

read all text files in a directory
This is a FAQ, so see robust and general code snippets in the FAQ: https://matlab.fandom.com/wiki/FAQ#How_can_I_process_a_seque...

13 dagar ago | 0

I tried dragging an image into the edit box for an answer on Matlab Central and doing so destroyed my answer.
Yes, but it warns you in advance that that will happen. Granted, it's not the most clear notice. If you need to keep your or...

13 dagar ago | 0

Renaming multiple files in a folder
Try this (untested): % Removes _REF from all filenames in a folder. clc; % Clear the command window. workspace; % Make su...

13 dagar ago | 0

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How can I create randon non-overlapping equal circles under a sine curve?
Click the "circle packing" tag on the right and you'll find lots of questions dealing with circle packing that you can adapt. I...

13 dagar ago | 0

count the number of people eating
There is no people eating function or toolbox, so you'll have to come up with something on your own. Most likely it will involv...

13 dagar ago | 0

How to combine two palettes inside one image?
Yes, there are several ways. You can make up a mask, and then apply the colormap to the whole indexed image and create an RGB i...

13 dagar ago | 0

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