Read images

[dancergraham]

Allow image file reading including metadata

[dancergraham]

This could be based on the unpack images section of this tool

https://github.com/cry-inc/e57/blob/master/tools/e57-unpack/src/main.rs

Outputting to a numpy array would be a nice option without additional dependencies. It would be good if the output format was fairly easy to use with open cv or similar python image processing libraries as people might want to do image processing on the photos with the pointcloud

[dancergraham]

My experience of images in e57 files is the panoramic photos from individual scan stations - A single e57 file contains multiple scans each taken from a single position, a scan station. Each scan may also be associated with 6 images forming a cube around the scanner position. It would therefore be useful to be able to get the 6 images (is it always 6?) for each scan station and to associate them with the points from the same station.