If manipulating an image is crime, then is not abusing in public equally illegal?a lady teacher tries to be very cool and uses foul language while addressing the class.

if you are victim then give complaint to administration as well as police. if you are for teacher better consult a lawyer (in case boy has initiated against you)

As per your query, I would suggest you that if you're a victim of such a thing you may proceed to report the matter to your college/institution adminstration department about the unprofessional attitude of the teacher, such that they take care of the matter.

However, if the administration fails to take an appropriate action or if the issue still persist, then you may lodge an FIR against the person under section 499 & 500 of the Indian Penal Code, such that the police handled the matter.

Now, let me tell you what sections 499 & 500 of the Indian Penal Code deals with.

Basically, Section 499 of IPC deals with the offence of "DEFAMATION".
The section states that — "Whoever, by words either spoken or intended to be read, or by signs or by visible representations, makes or publishes any imputation concerning any person intending to harm, or knowing or having reason to believe that such imputation will harm, the reputation of such person, is said, except in the cases hereinafter expected, to defame that person".

While on the other hand, section 500 of IPC (1860) deals with "PUNISHMENT FOR DEFAMATION".
The section states that — "Whoever defames another shall be punished with simple imprisonment for a term which may extend to two years, or with fine, or with both".

Hope It Helps!

Regards
Kevin M. Paul