Since PHP doesn't know the dimensions of the image until after it has been uploaded and stored in the filesystem, the only thing I can think of at this point is to throw a cleaner error after upload, saying the image could not be processed. It's better than a fatal error. It really comes down to controlling your user input. It's not unreasonable to say that a 6000 pixel image is not acceptable.
My hosting company tells me "sorry, the php allowed memory size parameter may not be changed"...
What can I do apart from switching to a different hosting service please?
Thanks in advance!
Uncle Cheese - please answer this post - is there anything I can do besides finding a different hosting company (by the way - the major ones in my country tell me that the 64M limit is a standard, and it's not possible to change it.