Scrambled pixel data

[jas88]

Describe the bug
The pixel data in generated DICOM files is rather garbled.

To Reproduce
Generate some DICOM files, open in e.g. MicroDICOM.

Expected behavior
A clear black image with numbers displayed.

Screenshots

Desktop (please complete the following information):

• Windows Server 2019 build 17763.2928
• Run under .Net 6.0.300 CLI

Additional context

• Replacing the pixel handling per Use of System.Drawing.Common makes library Windows-only #81 will help here but some further adjustment may be needed.