Module opcodes 

DNG Opcode List processing.

DNG opcodes are embedded binary records in OpcodeList1/2/3 TIFF tags that describe image corrections: lens shading (GainMap), bad pixel fixing, etc.

Binary layout of an OpcodeList (big-endian throughout):

[4 bytes] count of opcodes
For each opcode:
  [4 bytes] opcode ID
  [4 bytes] minimum DNG SDK version (ignored during parsing)
  [4 bytes] flags  (bit 0 = optional; skip on error if set)
  [4 bytes] parameter data length N
  [N bytes] parameter data

Implemented opcodes (priority order):

1. FixBadPixelsConstant (ID 4) — replace sub-threshold pixels
2. FixBadPixelsList (ID 5) — replace specific known bad pixels
3. GainMap (ID 9) — spatially-varying lens-shading correction (critical for ProRAW)

Structs

GainMap

A parsed DNG GainMap opcode (opcode ID 9).

OpcodeList

A parsed list of DNG opcodes from one of the OpcodeList1/2/3 TIFF tags.

Enums

DngOpcode

A parsed DNG opcode.