Linear VOI LUT doesn't match standard

[kosar2]

The window_level_linear function (defined here) uses wc - (ww - 1.) / 2. for the minimum. The dicom standard (see here) uses wc - 0.5 - (ww - 1.) / 2..

[Enet4]

Thank you for reporting. The discrepancy is by half a value, but it is worth being accurate. Would you be able to send in a pull request with the change and updated test cases?