David Young
University of Sussex and University of Southampton
859 total contributions since 2009Professional Interests: Image Processing
David Young's Badges
Contribute at least one answer each month for 12 consecutive months
Awarded to David Young on 20 Jul 2017
Accept 1 answer given by other contributors
Awarded to David Young on 20 Jul 2017
Answer 3 questions that were unanswered for more than 30 days
Awarded to David Young on 20 Jul 2017
100 of your answers have been accepted
Awarded to David Young on 20 Jul 2017
Provide your first answer ever to someone else's question
Awarded to David Young on 20 Jul 2017
Solve a problem with a best solution
Awarded to David Young on 24 Feb 2012
Create a problem
Awarded to David Young on 09 Feb 2012
Be the first to solve a problem
Awarded to David Young on 09 Feb 2012
Like a problem or solution
Awarded to David Young on 01 Feb 2012
Comment on a problem or solution
Awarded to David Young on 31 Jan 2012
Solve a problem for the first time
Awarded to David Young on 30 Jan 2012
How can I overlap two images/pictures in Matlab?
You can use |hold| to superimpose contour lines on an image. Here's an example: % Get an image from a jpg file img = imr...
2 years ago | 0
Image to Image correlation (moving window) function colfilt
You are likely to find <http://uk.mathworks.com/help/images/ref/normxcorr2.html normxcorr2> more suitable that |colfilt| for thi...
2 years ago | 0
create a sliding window to determine when a % of numbers in a sequence equal a certain value.
The answer to problems involving a sliding window is very often to use the convolution operation, as here. % some random t...
2 years ago | 0
Submitted
Affine optic flow
Estimates the parameters of an affine (first-order) optic flow model from two images.
2 years ago | 15 downloads |
Submitted
Hough transform for circles
A Hough transform function for detecting circles, optimised to allow search over radii.
2 years ago | 108 downloads |
How do I connect plot points with lines using ginput?
The attached function should show you how to do what you need, though you will have to modify it for your purpose.
2 years ago | 0
| accepted
Finding columns that contain both integers and NaN
Yes, |isnan(x)| does what |x == NaN| would do if NaNs were equal to each other.
2 years ago | 0
How do I use the ismember function (if possible) to locate the min/max GMT time elements within a cell array?
The problem is that you are passing |ismember| a cell array containing numbers, but it can handle cell arrays only if all they c...
2 years ago | 1
| accepted
Creating Gibbs Ringing by changing tissue intensity
I guess you haven't had an answer yet because "Gibbs Ringing" is quite a technical and specialised area. However, the substance ...
2 years ago | 0
Save ginput values under a for loop
Just replace [B,A]=ginput; with [B(index), A(index)] = ginput; to store each pair of inputs in array elements. I...
2 years ago | 0
How can I use plus operation with more than 2 array
Either use A + B + C + D + Z or plus(A, plus(B, plus(C, plus(D, Z))))
2 years ago | 0
ICA image analysis steps
There's an ICA package on the <http://uk.mathworks.com/matlabcentral/fileexchange/38300-pca-and-ica-package file exchange> and a...
2 years ago | 0
What does step instruction in matlab do?
It is documented: see <http://uk.mathworks.com/help/vision/ref/vision.videofilereader.step.html this>. Note that you have to loo...
2 years ago | 0
| accepted
Is fftn() and ifftn() equivalent to a 3D Fourier Transform in this case?
|fftn(X)| and |ifftn(X)| carry out a 3-D FFT or a 3-D inverse FFT if |length(size(X))| is equal to 3.
2 years ago | 0
| accepted
How to smoothen cropped image?
If you have the Image Processing Toolbox, you could use <http://uk.mathworks.com/help/images/ref/imgaussfilt.html imgaussfilt>.
2 years ago | 0
ellispse detection for cornea edges
General purpose ellipse detection may not be the best solution to this problem - if you haven't already seen it, <http://users.s...
2 years ago | 0
What is the difference in these two methods of finding coordinates of image?
The results of |find| are |[row, column]|. The results of |ginput| are |[column, row]|. That is, |find| uses the matrix conve...
2 years ago | 0
| accepted
please give me a detailed description of sift transform in matlab coding and how they works
The <https://en.wikipedia.org/wiki/Scale-invariant_feature_transform Wikipedia article> is a good starting point. It has referen...
2 years ago | 0
NEED A GAUSS FILTER CODING USING IMAGE PROCESSING with some Examples
If you have the Image Processing Toolbox, use <http://uk.mathworks.com/help/images/ref/imgaussfilt.html imgaussfilt>.
2 years ago | 0
| accepted
How to deform an image
Yes, it's <http://uk.mathworks.com/help/images/ref/imwarp.html imwarp>. You'll probably also want <http://uk.mathworks.com/help/...
2 years ago | 1
| accepted
how to colored the edge detection result(binary image)?
You can set the colour map when you display the binary image. For example img = imread('pout.tif'); imedge = edge(img, '...
2 years ago | 0
command or code for detecting zero crossing points in a signal
You can use logical tests to find the indices between which the signal changes sign. Then you need to interpolate if you want to...
2 years ago | 0
How can I repeat the following text 5000 times and save the solutions for the 5000 different betas in a 1x 5000 matrix ?
betas = zeros(1, 5000); % make array to store results for k = 1:5000 % ... your code ... betas(k) = beta; ...
2 years ago | 0
how to make global variable in matlab so that we can use in any .m file or any other method to use a variable in many .m files
If the m-files are scripts, they share the same top-level workspace and you can access the same variables from both of them. ...
2 years ago | 0
How to calculate phase angle between two sine wave from vectors
If you know the frequency, it is probably more accurate to fit a sine wave to each of the two vectors than to use the FFT. The p...
2 years ago | 0
How do reshape cell array row to new vectors?
First, there's an error to correct. |Big_RIR_AVG(1)| is not a 59x1 double. It's a scalar cell containing a 59x1 double. This mig...
2 years ago | 1
| accepted
Enable/Disable uitabs in uitabgroup, with v2015b
A quick thought - how about using the SelectionChangedFcn callback of the uitabgroup object, to select another tab when one of t...
2 years ago | 0
Shortest path that passes through certain nodes
If you search online for "travelling salesman problem matlab" you will find discussion and code that will help with this problem...
2 years ago | 0
| accepted
How can I add a digit to a pre-existing number randomly ?
To take a random sample from a vector, just use *randi* - no need for *randsample*. Example: numbers = [2, 3, 9, 7]; ran...
2 years ago | 1
Help using accumarray on a 3d-matrix
I think it's simpler to use *mean* directly and avoid *accumarray*. So to get all the rainfall for 1999, for example, you could ...
2 years ago | 0
| accepted