Use NPY for primitive numeric arrays
NPY stores a numeric dtype, shape, storage order and binary values. This workbench writes primitive integer and float datasets in little-endian order after reading their values through the HDF5 engine. The original byte order is recorded in the report, so a big-endian source does not become an undocumented interpretation change.
The output retains selected axes, including length-one axes. Integer widths and signedness remain explicit. A 64-bit identifier is not converted through a JavaScript floating-point number before being written. The independent fixture checks include integers beyond the safe JavaScript integer range and a big-endian compressed numeric cube.
Treat CSV as an import decision
CSV is useful for inspecting coordinates and values but carries no universal numeric type system. Exact 64-bit integer values are written as decimal strings. A spreadsheet may still infer a floating-point number and round it when opening the file. Import such columns as text or use NPY/JSON when exact type retention matters.
Strings that resemble formulas are neutralized in CSV by the shared safe-export rule. The unmodified values remain in JSON. Flat compound datasets have one output field per supported member, while nested or variable-length compound structures are metadata-only. The report explains which source features were not represented in the destination.
Do not measure from a normalized PNG
The optional PNG maps the finite minimum and maximum of a small slice to grayscale. It is meant for visual inspection and can help reveal an orientation or gross pattern. Nonfinite values are transparent, and a constant finite slice uses middle gray. The output report states the normalization range and dimensions.
A normalized image is not quantitative scientific data, and two independently normalized images cannot be compared by brightness alone. Keep NPY or JSON for calculations. The workbench excludes 64-bit integer PNG previews to avoid suggesting exact visual resolution for values that cannot all be distinguished in an 8-bit grayscale image.