How to sharpen an image? Sharpening filter kernel.

Hello, the following is an example of a smoothing filter kernel. How can I make a sharpening filter kernel?

smoothingfilter=[1/9, 1/9, 1/9; 1/9, 1/9, 1/9; 1/9, 1/9, 1/9];

Answer 1

[Sarvesh Kale]

Hi Macy,

You can make the sharpening filter as follows

sharp_image = deatiled_image + original_image,

the mask for detailed image can be [0 -1 0;-1 4 -1;0 -1 0], the mask for original_image is [0 0 0;0 1 0;0 0 0]; when you add the above matrices you will get the sharpened image mask

I=imread('cameraman.tif');
f=[0 -1 0;-1 5 -1;0 -1 0] % f is the image sharpening mask which represents above equation 

f = 3×3

0 -1 0 -1 5 -1 0 -1 0

I_sharp=imfilter(I,f);
imshow([I,I_sharp])

You can also use the inbuilt imsharpen function for image sharpening, I hope this answers your queries, please accept the answer if it does

Thank you

[Macy]

Thanks!