shorter cache key for images.
shorter cache key for images.

git-svn-id: https://beagle.whoi.edu/svn/ifcb/trunk@71 9f5e5bc8-6430-4f94-ad00-aad15e9f9366

Former-commit-id: 1494413f1e7a6a54cfb1775d003b174aea793c47
hsosik/ifcb-analysis,hsosik/ifcb-analysis,hsosik/ifcb-analysis,hsosik/ifcb-analysis,hsosik/ifcb-analysis