Smooth out Image Vector in Matlab

Question

I have an image that I converted to a vector and plotted:

img = imread(image.png');
grayImage = rgb2gray(img);
grayImage(2:2:end,:)=fliplr(grayImage(2:2:end,:));

B = rot90(grayImage);
C = flipud(B);

[x,y]=size(C);
vector = reshape(C ,1,x*y);
plot(vector);

The problem is that although I can visually see a wave pattern, there is a lot of noise that occurs. By noise I mean the signals rapidly go up and down eventually forming a sinusoidal wave but I want to be able to just connect the crest of each spike to one another in order to create a continuous wave pattern. If anyone understands what I am trying to do, help would be appreciated.

Thank you in advance.

score 0 · Accepted Answer · answered Jun 24 '14 at 20:04

Not 100% sure about what you're asking, but the medfilt1 median filter function might be what you're looking for, it's a 1D smoothing filter. Example usage would be:

vector_filt = medfilt1(vector);

Check out the documentation and example at http://www.mathworks.com/help/signal/ref/medfilt1.html.

score 0 · Answer 2 · edited May 23 '17 at 12:10

0

I think performing a gaussian convolution on the vector should solve your problem. Here is a link to a stack overflow question that has a very nice answer on how to do a gaussian convolution in matlab: Gaussian Filter on a vector in Matlab

edited May 23 '17 at 12:10

Community

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answered Jun 25 '14 at 01:10

Haider

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Smooth out Image Vector in Matlab

2 Answers2