how can I do sharpening attack?

Hi, I want to do sharpening attack on image but I do not know how can I do it in matlab. is it any function or code for this?

[Guillaume]

You may want to explain what a sharpening attack is for those of us who've never heard the term. Neither google nor sciencedirect are particularly enlightening on the subject.

I suspect it's something you're going to have to code yourself in any case.

[nadia]

sharpening attack is kind of attack that is used in watermarking test like jpeg. I know imsharpen function in matlab do this and enhances edges and changes high and low frequencies in image. but I want to know other functions or code like this that change low frequency band in image?

Answer 1

[Walter Roberson]

Use imsharpen in combination with fspecial unsharp

See some of discussion at https://www.mathworks.com/help/vision/ug/sharpen-an-image.html