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| author | priyanka | 2015-06-24 15:03:17 +0530 |
|---|---|---|
| committer | priyanka | 2015-06-24 15:03:17 +0530 |
| commit | b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b (patch) | |
| tree | ab291cffc65280e58ac82470ba63fbcca7805165 /3176/CH4/EX4.15/Ex4_15.sce | |
| download | Scilab-TBC-Uploads-b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b.tar.gz Scilab-TBC-Uploads-b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b.tar.bz2 Scilab-TBC-Uploads-b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b.zip | |
initial commit / add all books
Diffstat (limited to '3176/CH4/EX4.15/Ex4_15.sce')
| -rw-r--r-- | 3176/CH4/EX4.15/Ex4_15.sce | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/3176/CH4/EX4.15/Ex4_15.sce b/3176/CH4/EX4.15/Ex4_15.sce new file mode 100644 index 000000000..32709a8a3 --- /dev/null +++ b/3176/CH4/EX4.15/Ex4_15.sce @@ -0,0 +1,68 @@ +//Ex4_15
+// Obtaining a Frequency domain Filter from a Small Spatial Mask
+// Version : Scilab 5.4.1
+// Operating System : Window-xp, Window-7
+//Toolbox: Image Processing Design 8.3.1-1
+//Toolbox: SIVP 0.5.3.1-2
+//Reference book name : Digital Image Processing
+//book author: Rafael C. Gonzalez and Richard E. Woods
+
+clc;
+close;
+clear;
+xdel(winsid())//to close all currently open figure(s).
+
+function[H]=sobelfilter(mask_pad)//lowpassfilter is used to filter an image.
+ x=fft2(mask_pad);
+ [nr nc]=size(mask_pad);
+ x_real=real(x);
+ x_imag=imag(x);
+ z=zeros(nr,nc)+%i*x_imag
+ H=fftshift(z);
+ y=log(1+abs(H));
+ y=mat2gray(y)
+ figure,ShowImage(y,'Frequency Spectrum');
+ title('Frequency Spectrum','color','blue','fontsize',4);
+endfunction
+
+
+
+
+a=imread("Ex4_15.tif");
+gray=im2double(a);
+mask=[-1 0 1;-2 0 2;-1 0 1];
+figure,ShowImage(gray,'Gray Image');
+title('Original Image','color','blue','fontsize',4);
+[M,N]=size(gray);
+gray_pad=zeros(M+2,N+2); // Zero Padding
+mask_pad=zeros(M+2,N+2); // Zero Padding
+gray_pad(1:M,1:N)=gray(1:$,1:$);
+mask_pad(1:3,1:3)=mask(1:$,1:$);
+
+h=fft2(gray_pad);//fft2() is used to find 2-Dimensional Fast Fourier Transform of an matrix
+
+in=fftshift(h);//fftshift() is used to rearrange the fft output, moving the zero frequency to the center of the spectrum.
+i=log(1+abs(in));
+inm=mat2gray(i)
+figure,ShowImage(inm,'Frequency Spectrum');
+title('Frequency Spectrum','color','blue','fontsize',4);
+
+///////////////////////////// Filtering Domain Filtering ///////////////////////
+filt=sobelfilter(mask_pad); // Function which generate Filter Mask
+n=filt.*in;//Multiply the Original Spectrum with the Filter Mask.
+n=fftshift(n);
+Image_filter=real(ifft(n));
+Image_filter=mat2gray(Image_filter)
+figure,ShowImage(Image_filter,'Filtered Image');
+title('Filtered Image in Frequency Domain','color','blue','fontsize',4);
+
+///////////////////////////// Spatial Domain Filtering ///////////////////////
+
+imf = imfilter(a,mask);
+//imf=1*(imf.^1.2);
+[r c]=find(imf==0 | imf<=110);
+ for i=1:length(r)
+ imf(r(i),c(i)) = 125;
+ end
+figure,ShowImage(imf,'Filtered Image');
+title('Filtered Image in Spatial Domain','color','blue','fontsize',4);
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