IMAGE CONVERSION ASSISTANCE

I've been reverse engineering some old dos and pc-98 games for modern use. However, I can not seem to figure out a way of extracting the graphics. I believe they are stored in a .GRA format, a format I have never seen before. Can anyone help?

Okay, but watch out, as I am not sure excatly which one is which, as the code is near assembler level.
Oh, I think most of them should be fine, but it might be NSFW, so be careful.