Answered
draw a line on an image
Perhaps your problem is that figure coordinates and array indices have different conventions. So, for example imshow(im) ...

15 years ago | 2

Answered
Overriding subsref and subsasgn - effect on private properties
I have, rather belatedly, found an official answer to my question, <http://www.mathworks.co.uk/support/solutions/en/data/1-9N85P...

15 years ago | 6

Answered
determinant of singular matrix is non-zero
I get the same result as you, Marco, in version 2011a. The doc page for the det function says that the calculation is now done ...

15 years ago | 0

Answered
what is step response and step()?
See <http://www.mathworks.co.uk/help/toolbox/control/ref/step.html> How does the step function relate to 2D to 3D image conve...

15 years ago | 0

Answered
[DEPRECATED] What frustrates you about MATLAB?
Overriding subsref and subsasgn in a class is spectacularly awkward. The problem is this. Suppose you override subsref in orde...

15 years ago | 13

Question

Overriding subsref and subsasgn - effect on private properties
I'm overriding subsref and subsasgn for a class. I want to influence the behaviour of obj(...), but I can't find a good way to d...

15 years ago | 5 answers | 6

5

answers

Answered
hexadecimal codes for sine and cosine wave
After making the plot, you can convert the tick labels to the hex representation of the IEEE bit patterns of the numbers with th...

15 years ago | 0

Answered
using gabor filter
I would guess that you need to convolve the image with each of the wavelets in turn. For this you can use conv2 or <http://www.m...

15 years ago | 0

| accepted

Answered
How to calculate a gradient by fft ???
It's still not clear what you mean by 'simple "gradient"' - that could refer to a variety of things. One possibility is that ...

15 years ago | 2

| accepted

Answered
Angle between two vectors in 3d
acos(dot(v1, v2) / (norm(v1) * norm(v2))) *EDIT*: Having seen Jan Simon's reply, and the long thread at CSSM that he refers t...

15 years ago | 0

Answered
Convolution Mask
Something like this? sz = size(matrix); if isequal(sz, [3 3]) % first for loop, function call or whatever elseif...

15 years ago | 0

| accepted

Submitted

Logarithm of complex sine and cosine avoiding overflow
Functions to compute log(sin(Z)) and log(cos(Z)) avoiding overflow for large abs(imag(Z)).

15 years ago | 172 downloads |

0.0 / 5

Answered
Find index in matrix
Assuming it's a numerical matrix, called M: d = 100104; t = 1012; row = find(M(:,1) == d & M(:,2) == t) If it's a ...

15 years ago | 0

| accepted

Answered
Image Processing: Find Edge with Highest Contrast
I think there are two main issues here. The first is how to distinguish between "texture" and "the boundary of an object". There...

15 years ago | 2

Answered
pointing to an element in a returned function
The basic answer is "no" - you need the intermediate variable. There is some discussion of this issue on the newsgroup <http:...

15 years ago | 0

Answered
correlation for multi-dimensional arrays
If you don't have NaNs in the data, and you want the standard Pearson coefficient, then you could try applying the formula for c...

15 years ago | 3

| accepted

Answered
What is the kernel of linear motion blur in fspecial function??
In release 2011a the documentation is precise. Maybe you have an old release that was not so well documented? In case that's the...

15 years ago | 0

Answered
Hough Transform - Detecting angled lines
I'm not sure how are you setting the theta resolution, but hough and houghpeaks use degrees, and if your theta resolution is 0.0...

15 years ago | 0

Answered
How to match and two matrix elements and place it under one matrix...let me explain
nrows = size(B,1); C = zeros(nrows, length(A)); ind = bsxfun(@plus, (1:nrows)', (B-1)*nrows); C(ind(:)) = B(:); C ...

15 years ago | 3

Answered
Object Oriented Programming Performance Comparison: Handle Class vs. Value Class vs. no OOP
There is no way to change an object of a value class on method call, other than to return the updated object as a result, and as...

15 years ago | 1

| accepted

Answered
Controlling detected objects inside an image
Do you mean something like this: % Test array containing a square and a triangel image0 = zeros(10, 10); image0(2:4, ...

15 years ago | 0

| accepted

Answered
how to find the intensity of an image
Please see my reply to <http://www.mathworks.co.uk/matlabcentral/answers/15277-doubt-on-how-to-divide-by-using-the-intensity-of-...

15 years ago | 0

Answered
Problem assigning multiple values simultaneously to a matrix
You can use a loop, like this % data flag=zeros([10 10]); flag(5,5)=1; flag(5,9)=1;%Initialize Flag with 2 1's ...

15 years ago | 0

Answered
doubt on how to divide by using the intensity of an image
You could try using rgb2gray on the initial image. Looking at your code, this would be: I = rgb2gray(maskedRgbImage); th...

15 years ago | 0

Answered
fourier transform
To compute the discrete Fourier transform of a grayscale image, just use fft2. To find the DFT of a colour image, please see ...

15 years ago | 0

| accepted

Answered
smoothing out a matrix
See my answer to <http://www.mathworks.com/matlabcentral/answers/15183-coding-for-implementing-gaussian-filter-in-iris-recogniti...

15 years ago | 0

Answered
coding for implementing gaussian filter in iris recognition system
Provided you have the Image Processing Toolbox, code for Gaussian filtering of an image looks like this: sigma = 2; % set s...

15 years ago | 0

Answered
Detecting a feature in a Medical Image
Try thresholding. binary_image = original_image > threshold; You choose the value of threshold to be less than the value...

15 years ago | 0

Answered
Regarding imwrite()
If you want to read the data back into MATLAB without any loss of accuracy, then use load and save rather than imwrite and imrea...

15 years ago | 0

| accepted

Answered
Additive effects of a 2D Gaussian filter
Suppose you apply a Gaussian filter with width parameter SIGMA1 to an image, and then you apply a second Gaussian filter with pa...

15 years ago | 1