Reading File

Possible options for this include:

1. Reading the file entirely into memory at the beginning before any operations are attempted.
2. Reading the file into memory as required for each read, i.e. memory mapped IO.

The option that will be used however depends on how the higher level image classes work, they may require the image to be loaded into memory entirely befire processing can occur, if this is the case the amount of memory used could become an issue.