Professional Interests: Image Processing

Question

Inverse Fourier Transform ignores oscillations

Hi. I am doing some time and freq analysis. So lets say I have some x-t data, I use fft to take them in freq domain, do some cal...

3 días ago | 0 answers | 0

Question

How to skip a file in reading a series of csv files using csvread?

Hi. I am reading a large number of data from say, 100 csv files using csvread. But some of these files (say 10) have nonnumeri...

alrededor de 1 mes ago | 1 answer | 0

Question

How to find volume under fitted data?

I have a set of data, fitted by polynomial of 8th order. I want to find the volume under this surface (due to rotation around y ...

alrededor de 2 años ago | 1 answer | 0

Question

How to get Greek letters in text in an IMAGE using Inserttext?

Hi I want to use text with Greek letter in an image (use text as part of the image) using "Inserttext" as suggested by Mathwor...

más de 3 años ago | 2 answers | 0

Question

How to rotate back a streched image?

I have an image which is stretched in one direction. How can I turn it back to normal plane, so it becomes again a circle? I kno...

más de 3 años ago | 1 answer | 0

Question

How to identify the disk edge?

How can MATLAB determine the radius of the disk? (imagine the center is known) I know that if the whole circle is visible, I ...

más de 3 años ago | 1 answer | 0

Question

How to get dominent frequency from intensity along a curve in an image?

I want to find the dominant frequency. I used fft in this way yf3 = fftshift(fft2(intensity_profile)); and I got, again fo...

más de 3 años ago | 1 answer | 0

Question

How to fill BLACK a region in an image?

I have an image (no matter gray or binary). I want to fill several regions (that are selected by the user through interface) in ...

más de 3 años ago | 3 answers | 0

Question

How to make the edge darker (increase contrast?)

I want to somehow increase the contrast if it is the thing to do. What I want is make the edge darker and clearer, so that I can...

más de 3 años ago | 2 answers | 0

Question

FFT range for a signal

Hi I have a signal from which I want to find the dominant frequency. Does fft ignore the part which is constant (like DC)...

casi 4 años ago | 1 answer | 0

Question

Matlab opens a figure on its own with this funny feature!

Hi I am sure I have only one figure,plot(...) command in my code, but when I run it, it first creates this funny figure (with...

alrededor de 4 años ago | 2 answers | 1

Question

Adjust the intensity of images with nonuniform light

My laser light is blinking (I don't know why?!), so the images I have is something like the followings. The intensity is differe...

alrededor de 4 años ago | 1 answer | 0

Question

How to smooth signal and find dominant freqeuncy using FFT?

Hi. I am not so familiar with signal processing. I have this oscillation which I like to find its dominant frequency. I used ...

alrededor de 4 años ago | 1 answer | 0

Question

Relation between "Image" intensity and "Light" Intensity?

What is the relation between "Light" intensity and "Image" intensity? Is there any reference that I can rad about it? I sear...

más de 4 años ago | 2 answers | 0

Question

Light intensity or Grayvalue?

Hi. I have a trivial question! I looked about it, but I am still not sure! Something simple confuses me! I would be grateful...

más de 4 años ago | 1 answer | 0

Question

How to plot 3D? Surf or Plot3?

Hello, Imagine I have a function A(x,y,t). But the dimensions of y and t are different with that of x (and so A). What I...

más de 4 años ago | 1 answer | 0

Question

Increase edge thickness in binary?

Hi I have detected the edges of an image using "bwperim". I want to increase the thickness the edges (such as the sides of a ...

casi 5 años ago | 1 answer | 2

Question

Why does bwperim give wrong perimeter?

I wanted to get the perimeter of the following circle. I used two methods, but got completely different results! <</matla...

más de 5 años ago | 2 answers | 0

Question

How to remove small CLUTTER from images?

Hi. How can I remove small clutters in an image? For example in the following image (this is a binary one obtained from the ...

más de 5 años ago | 2 answers | 0

Question

Too many digit numbers in MATLAB strings?

Hi I am using strings in a format like: sprintf('image-%f-%d.jpeg'),i,j) but it writes the files for me in long digits,...

más de 5 años ago | 1 answer | 0

Question

How to get correct Fourier Transform from Spatial Coordiantes?

Hi. Imagine I have the following profile for gray intensity along a known curve: <</matlabcentral/answers/uploaded_file...

más de 5 años ago | 2 answers | 0

Question

How to smooth plot of data?

Hi How can I smooth the following data? This is the gray intensity of an image. I could not use "smooth" function for that. ...

casi 6 años ago | 2 answers | 0

Question

How to draw circle with imellipse?

Hi I want to draw a circle with imellipse. I used something like: AA = imellipse(gca,[xmin ymin radius radius]); but I ...

casi 6 años ago | 2 answers | 0

Question

How to get INTENSITY along a spcific curve?

Hi. How can I get the intensity along a specific curve? I mean for the following image, I want the intensity along the re...

casi 6 años ago | 2 answers | 0

Question

How to calculate diameter from side view?

Hi! Imagine we have a side view of a circular object such as a coin. How can I accurately calculate the diameter of an obje...

casi 6 años ago | 1 answer | 0

Question

Add extra marker to the plot?

Happy New Year! How can I add extra marker to a plot with several curves? I mean suppose that the plot with several curv...

casi 6 años ago | 1 answer | 0

Question

why does bwperim make the border WHITE?!!

I want to use bwperim to calculate the perimeter of an object, but I got a strange thing! I use bwperim in two different stat...

casi 6 años ago | 1 answer | 0

Question

how to plot os many curves in one figure with distinct marker?

I want to draw many plots (say 30) in one figure with distinct color and maker. How can I ask MATLAB to do it automatically? ...

casi 6 años ago | 1 answer | 0

Question

How to read several times similarly from EXCEL?

How can we read data from Excel for similar sheet names and even file names, I mean in a loop? for example, we want to read ...

casi 6 años ago | 1 answer | 0

Question

How to change CELL components value?

How can we change the values of a cell component? I mean for example, A{i}. For example when I want to divide all the values ...

casi 6 años ago | 1 answer | 0