The test hits a corner case that we don't care about much -
many threads writing the same image. In the interests of time I'm
simply using a deepcopy per thread but only in the test for now.
At some point we should actually prevent the threads from calling
Delete simultaneously and do so without a copy.

This writer support writting an image data onto a drive in a threaded manner so the encoding and IO time does not lock the application.
The supported extension/format are: .Z, .png, .jpg, .jpeg, .bmp, .ppm, .tif, .tiff, .vti