you cant make audio books, illustrations, or translations of a book without the authors permission
note that text to speech isnt considered derivative work. its considered a tool rather than creating content. so its legal for a kindle to read it to you
so yes even at home, making art for a book you dont have permission for, and isnt seen by anyone but you, is still copyright infringement
That's the important bit - the things you called illegal a few comments back were obvious examples of (presumptive) fair use.
More generally, whether something is copyright infringement can be vague and subjective - so the bar for going around saying "yes, that is infringement" is not "does it meet a description I read online?". The bar is: "have courts previously ruled that a very similar case was infringement?".
It's somewhat of a case by case basis matter and it's rarely brought to the court, but just because you own a piece doesn't always make it all to your discretion to modify it.
It seems to me that computers programs have more rights than humans.