Improve high noise histogram equalization

[JohnDMcMaster]

When a sample is really thick, it signal becomes small and the workflow relies on the relatively high bit depth (native 14, averaged to 16) + histogram equalization to get decent images. However, its currently limited by, after averaging, the data is truncated to 16 bit during histogram equalization. To get the full sensor range, need to calibrate the sensor to higher precision. This may require hacks to get additional bits on image data, such as shifting up and/or creating a second image file with LSB

[JohnDMcMaster]

A recent fix improved low noise performance by fixing an internal error in numpy or something of that sort. This should be revisited