Activity10: Preprocessing of Handwritten Text

July 22, 2008 at 4:57 pm (Uncategorized)

The goal of this activity is to pre-process handwritten text for image processing. The original image I used is

with probability distribution

and 2d fft

We used a vertical mask in manipulating our fft to remove the horizontal lines.The processed fft is:

However, the lines were not removed but merely blurred out. This was not the case in activity 7.

The resulting binarized image is shown below.

The opening operation was used but without much success. We did not use the closing operation since we want to retain the holes of the letters, which is a property of the letters.

Code as follows:

chdir(“/home/jeric/Desktop/ap18645activity10”);
clear all;
getf(“imhist.sce”);
im=imread(“ac10.jpg”);
im=im2gray(im);

if max(im)<=255
im=round(im*255);
end

[val,num]=imhist(im);
h=scf(1);
plot(val, num);

ff=fftshift(fft2(im));
h=scf(2);
imshow(abs(ff), []); xset(“colormap”, hotcolormap(64));

[x,y]=size(im);
newff=ff(:,:);

filter=ones(x,y);
for j=y/2–2:y/2+2
for i=1:x/2–2
filter(i,j)=0;
end
for i=x/2+ 2 : x
filter(i,j)=0;
end
end

newff=filter.*ff;
h=scf(3);
imshow(abs(newff), []); xset(“colormap”, hotcolormap(64));

h=scf(4);
im2=abs(fft2(newff));
imshow(abs(fft2(newff)), []);

im=im2bw(im, 160/255);

h=scf(5);
imshow(im, []);

se=ones(2,2); //structuring element

im=erode(im, se); //opening
im=dilate(im, se);

im=erode(im, se); //opening
im=dilate(im, se);

[L,n]=bwlabel(im);

h=scf(6);
imshow(im, []); //preprocessed image

Rating: 6, because of the poor resulting image. The goal was not achieved.