Function decodeRegion

Decode a bounded ROI from the first uncompressed, single-band strip.

imageio.tiff.TiffDecodeResult decodeRegion(
  transport.source.ByteSource source,
  ulong x,
  ulong y,
  ulong width,
  ulong height
) @safe;

This deliberately narrow decoder gate provides a complete typed transport-to-pixels path. It rejects compression and tiled layouts until their independent format gates pass.