Module htj2k97_codeblock_oracle 

Shared scalar oracle: float 9/7 bands into prequantized HTJ2K code-blocks.

This module uses the native encoder’s public irreversible 9/7 quantization step helper plus the native code-block layout rules, so both GPU backends can compare their fused code-block kernels against one authoritative CPU reference instead of each re-deriving the math.

The re-derivation is anchored to native truth by a codestream pin test (see the module tests): encoding the oracle’s prequantized output reproduces the native precomputed-DWT codestream byte-for-byte.

Functions

htj2k97_subband_delta

Deadzone quantization step size Δ for a subband.

htj2k97_subband_total_bitplanes

Total declared bitplanes for every code-block in a subband.

prequantized_component_from_dwt97

Quantize one level of float 9/7 bands into a prequantized HTJ2K component.

quantize_codeblock_subband

Quantize a single float subband and slice it into code-block-major layout.

validate_htj2k97_codeblock_options

Validate 9/7 code-block options against the numeric limits both GPU backends must agree on, returning the decoded (cb_width, cb_height).