Well, presumably, if it is your computer, running your program, using your equipment, you've got the copyright until your computer gains consciousness and a lawyer capable of filing a lawsuit.

Not even, no. There was a famous case recently about this: https://www.smithsonianmag.com/smart-news/us-copyright-offic....

The problem isn't really about using it yourself, it's that people don't need to ask your permission to use it, therefore you can't (easily) profit from it. Possibly quite annoying if you're in the AI business.

I admit I was being somewhat facesciuos. But clearly If you took credit for the work your computer did running your program, you would probably not get an argument from your computer until the conditions I mentioned were met

-randomly

You don’t own the copyright for any picture generated by a computer, whether random or intentional

Good point, if I believe the other commenter, the image only needs to be varied, randomization is only one way to achieve this.

That said, chicken can't own copyright, and they are the author, therefore no one owns the copyright.

Out of curiosity, is this true even if you wrote the program that generates the image?

Generally, yes, if the output is perceptually varied each run. Generally, no, if the output is perceptually static each run.

The law generally won’t help you narrow down where the exact line is between those two, as that’s up to the courts to decide on a case-by-case basis.

How does that apply to 'upscaled' video?

That would be a derivative work. Original copyright applies.

but artists use computer for their artwork in a long time?

When it’s used like a tool, it’s considered the same as a chisel or a paint brush: the tool does not create the art, the artist makes the art by using the tool.

It’s when then computer creates the art itself that it becomes the artist