Answered
Circle detection from Irregular arcs.
This looks quite difficult, because the circles are not very circular. You could try the various Hough transforms for circles th...

15 years ago | 0

Answered
Finding tires on a car.
Also see rgb2gray from the Image Processing Toolbox. Note that you should not binarise your image before using Tao's code - i...

15 years ago | 0

Answered
zero crossing
In the context of images, the classic reference is the book "Vision" by David Marr, in which the idea of zero-crossings is heavi...

15 years ago | 1

Answered
Laplacian edge operator
I assume that the mask you applied in C++ was 0 -1 0 -1 4 -1 0 -1 0 and not what you gave in your comment to Oleg's...

15 years ago | 2

| accepted

Answered
Image Stitching/Mosaicing
A common approach to this is to find distinctive features in each of the images, match them up on the basis of their local prope...

15 years ago | 0

Answered
How can i discard half of the fouier transformed (frenquncy domain) components NOT normal image ?
See the last part of my answer to <http://www.mathworks.com/matlabcentral/answers/754-2d-fft-problems-with-fftshift-setting-up-w...

15 years ago | 0

Answered
DTW(Dynamic Time Warping Algorithm)
Perhaps some of <http://www.mathworks.com/matlabcentral/fileexchange/?term=dtw these contributions> to the file exchange would h...

15 years ago | 0

Answered
iFFT for Band-pass Measurement
Solve the problem in two stages: # Read the data from the file into an array, containing complex values. See textread, or the...

15 years ago | 0

Answered
Image processing of confocal images (flattening)
I think this is quite difficult. There seem to be two problems with the images: one is the defocusing; the other is the change i...

15 years ago | 0

| accepted

Submitted

2-D convolution using the FFT
Convolution in 2-D using the Fast Fourier Transform.

15 years ago | 4 downloads |

4.33333 / 5

Answered
how to convert time domain data to frequency domain using fast fourier transform
See doc fft

15 years ago | 1

Answered
Isolate Digits in a number
Well, since Matt's answer has been accepted (!), I guess I might as well offer mine, for non-char input: nary = floor(c*10....

15 years ago | 1

Answered
What is the fastest way to do 2-D convolution in Matlab?
The FFT method may be faster if the two arrays to be convolved are of similar size. You can pad the smaller to be same size as t...

15 years ago | 8

| accepted

Answered
vector not produced missing some '.' ?
If you don't understand the operators, the most straighforward thing is to use g = (0.30 ./ (2 .* (pi .* t .^ 3) .^ 0.5)) ....

15 years ago | 0

Answered
Image Processing ( calculate perimeter)
If you have the Image Processing Toolbox, have a look at using morphology operations to simplify the binary image into one blob....

15 years ago | 0

Answered
assigning probability
if rand < probability A1 = A2; end

15 years ago | 1

| accepted

Answered
Matrix construction
The are a few problems with your code. One is the square brackets in the expression MATRIX([cont1:p*11,cont2:q*11]). This builds...

15 years ago | 1

| accepted

Answered
checking that at least one value in a row of a matrix is greater than zero
if any(T(end, 1:end-(m+1)) < 0) % actions end

15 years ago | 0

Answered
set of points and derivative
It's not clear to me why you'd use the DOT function in this context rather than convolution? (I know convolution is just the dot...

15 years ago | 0

| accepted

Answered
create M file
These are very general questions, and it would be easier to give an answer to a more specific problem. For your first question,...

15 years ago | 0

Answered
Convert Two Arrays into One Matrix Containing Incremented Between Values
bsxfun(@plus, I, 0:i(1)-I(1))

15 years ago | 0

| accepted

Answered
Detecting ROI based on edges(Vertical) Density in image
If you have the Image Processing Toolbox, look at the edge function as a start for finding edges. It may be important to set a g...

15 years ago | 2

| accepted

Answered
Variograms on Images
If I've understood correctly what you need, I'd use a function something like the following (which doesn't use blkproc or any of...

15 years ago | 0

| accepted

Answered
Convert matrix to vector of structs
My answer to your subsequent question, <http://www.mathworks.com/matlabcentral/answers/4581-deleting-the-i-th-entry-from-all-fie...

15 years ago | 1

Answered
Deleting the i-th entry from all fields of a struct
Have a look at the section in the manual on "Organizing Data in Structure Arrays", also available <http://www.mathworks.com/help...

15 years ago | 4

Answered
finding specific value stored in cell
I assume your image dimensions are actually 200 x 200 x 3, and also that the call to mat2cell had the image as the first argumen...

15 years ago | 0

Answered
Finding neighbors of an object from labeled image
One possibility: % assume labelled array is called "labelled" label = 8; % label of object to find neighbours of o...

15 years ago | 0

Answered
random noise matlab.
There are many choices you might make for the distribution of the noise. For independent additive Gaussian noise you could do th...

15 years ago | 1

| accepted

Answered
How can I use attribute GLOBAL efficiently?
If you find a real need to use global variables to share data between functions, consider adopting an object-based approach inst...

15 years ago | 0

Answered
regionprops
Try this for a start: img = zeros(5,5); img(2:4, 2:4) = 1; props = regionprops(img, 'PixelList'); disp(img); disp(pro...

15 years ago | 3

| accepted