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
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
