# 📐 L2 Spec — HDR Multi-Exposure Fusion Mismatch-Only Spec
**ID:** `L2-079-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-079`](/artifact/l1/L1-079)
> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.42 · **Delta tier:** 5
> **⛓ On-chain block:** 41554174
---
## 1. Domain Ω
**Type:** `range`
| Parameter | Unit | Range |
|---|---|---|
| H | px | 256 – 4096 |
| W | px | 256 – 4096 |
| Bit depth | — | 8 – 14 |
| K exposures | — | 2 – 9 |
| Exposure stops | — | 1.0 – 4.0 |
| Under coverage | — | 0.0 – 0.3 |
| Motion ghosting | — | 0.0 – 0.5 |
| Vignetting residual | — | 0.0 – 0.1 |
| White balance drift | — | 0.0 – 0.1 |
| Crf calibration error | — | 0.0 – 0.05 |
## 2. Tolerance (ε)
**Type:** `fn`
```
32.0 + 3.0 * log2(K_exposures / 2) + 2.0 * (bit_depth - 8) - 20.0 * motion_ghosting - 15.0 * under_coverage / 0.30
```
## 3. Difficulty
| Property | Value |
|---|---|
| Difficulty score | 0.42 |
| Delta tier | 5 |
## 4. Fingerprint
`b35e53a9e43cbb36091a7fe8bf05df05cfff3f38fc8096d1e1af46bfcd376492`
## 5. On-chain Registration
- **Chain hash:** `0xdab83aae5d166a6ed62cc50e132b37789770de16887c831a2e35c08414255fc9`
- **Chain tx hash:** `0x7977e9a8ee224c336993183afb1e86ecaac460b3dddfbde83f4b3439cd26ea32`
- **Chain block:** `41554174`
---
## File Mapping
This bundle consists of: `L2-079-001.md`, `L2-079-001.json`.
| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-079-001.md` | Source of truth — edit this | Human or LLM |
| `L2-079-001.json` | Structured metadata for the registry | LLM regenerates from the sections above |
**Prompt for your LLM after editing this Markdown:**
> Read the attached Markdown. Regenerate the sibling `.json` so every field matches.
> Preserve the schema documented in the rows above.
> Output each file in its own fenced code block tagged with the filename.
> Output only the JSON object.
_This Markdown was auto-synthesized from the catalog row for `L2-079-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._