Answered

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))

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

Answered

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...

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

Answered

mean of elements of a matrix

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

mean of elements of a matrix

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

10 dagar ago | 0

Answered

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...

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

| accepted

Answered

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);...

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

| accepted

Answered

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...

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

Answered

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...

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

Answered

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...

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

| accepted

Answered

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...

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

| accepted

Answered

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? ...

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

| accepted

Answered

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...

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

Answered

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)

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

Answered

Index in position 2 exceeds array bounds. Index must not exceed 1024.

I do exactly that in my attached demo.

Index in position 2 exceeds array bounds. Index must not exceed 1024.

I do exactly that in my attached demo.

11 dagar ago | 0

Answered

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'); ...

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

| accepted

Answered

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...

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

Answered

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...

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

Answered

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....

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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Answered

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...

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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Answered

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.

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

| accepted

Answered

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.

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

Answered

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_...

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

Answered

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', ...

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

Answered

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...

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

Answered

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...

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

Answered

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...

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

| accepted

Answered

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...

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

Answered

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...

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

Answered

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...

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

| accepted

Answered

How to fit a Gamma Curve to a data?

If you have the formula for the curve, you can use fitnlm to get the coefficients. See attached examples for a variety of diffe...

How to fit a Gamma Curve to a data?

If you have the formula for the curve, you can use fitnlm to get the coefficients. See attached examples for a variety of diffe...

13 dagar ago | 0

| accepted

Answered

how to remove noise from curves and take their derivates

You can use sgolayfilt, which is a sliding polynomial fit within the sliding window, however if I were going to take the derivat...

how to remove noise from curves and take their derivates

You can use sgolayfilt, which is a sliding polynomial fit within the sliding window, however if I were going to take the derivat...

13 dagar ago | 0