todo
script hovmoller creation
fix y dimension error
lazy props for generated properties
todo
remove excess test images
update tests for change in config
move stitched images inside ProcessedImage
contain methods
make real / pixel coords lazy
todo
move read_parameters, run_data into class
Use json file to store config used to process run

This is so that processed runs are immune to changes in config, getting
all that they need from a .json file stored with the output from initial
processing.

There was an issue with serializing numpy.int64 types, which is solved
with using .tolist() where needed.

Still need to put real <-> pixel conversion into a Processed class, so
it is dependent on the crop box from the json and not the config.
add a parallel keyword
move stitcher inside processedrun
move real to pixel inside class. fiddle masking
add total depth to parameters
command line interface for simple operations