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Gaussian Bandpass Filter for Image Processing

version 1.1 (2.33 KB) by

This function performs Gaussian bandpass filtering in the frequency domain

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Butterworth Bandpass Filter
This simple function was written for my Digital Image Processing course
at Eastern Mediterranean University taught by
Assoc. Prof. Dr. Hasan Demirel
for the 2010-2011 Spring Semester
for the complete report:
http://www.scribd.com/doc/51981950/HW4-Frequency-Domain-Bandpass-Filtering

Written By:
Leonardo O. Iheme (leonardo.iheme@cc.emu.edu.tr)
24th of March 2011

I = The input grey scale image
d0 = Lower cut off frequency
d1 = Higher cut off frequency

The function makes use of the simple principle that a bandpass filter
can be obtained by multiplying a lowpass filter with a highpass filter
where the lowpass filter has a higher cut off frquency than the high pass filter.

Usage GAUSSIANBPF(I,DO,D1)
Example
ima = imread('grass.jpg');
ima = rgb2gray(ima);
filtered_image = gaussianbpf(ima,30,120);
Gaussian Bandpass Filter

Comments and Ratings (6)

Sajjad Ali

When I am executing this code getting error
'Undefined function 'gaussianbpf' for input arguments of type 'uint8'.'

while my code is
c=imread('C:\Users\Sajjad\Desktop\16144683_1510254389004641_646218756_n.jpg');
>> c = rgb2gray(c);
>> filtered_image = gaussianbpf(c,30,120);

John D

John D (view profile)

Hi Leonardo, Why is the fft of the original image being added to the filtered version of the fft?

filtered_image = fftI + filter3.*fftI;

Hello Sudarshan,
Thanks for the 5* rating.
Have you tried initializing with zeros instead? I think you should and then tell us all what happens.

Sudarshan

Why do you initialise the filters that way? lines 45-47. Would be of great help.. Thanks in advance

Anfisa

Anfisa (view profile)

Robin Martin

Updates

1.1

Updated the title

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MATLAB 7.10 (R2010a)

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