| """The editing metric: region-free whole-image change, zero tolerance. |
| |
| An edit's score is the fraction of pixels that changed AT ALL between the |
| shared starting design and the model's result -- max per-channel delta > 0 |
| counts the pixel as changed. No region masks and no tolerance band: a |
| non-destructive editor leaves untouched pixels byte-identical, and anything |
| else is change the user did not ask for. |
| |
| Whether the edit was actually performed is judged separately (an independent |
| LLM reviewer; see ``prompts/judge.txt``) and reported alongside -- a model |
| that returns its input unchanged scores 0 here but fails the judge. |
| """ |
|
|
| from __future__ import annotations |
|
|
| import numpy as np |
| from PIL import Image |
|
|
|
|
| def whole_change(start: Image.Image, result: Image.Image) -> float: |
| """Fraction of pixels changed between ``start`` and ``result``. An arm |
| that returns another canvas size is resized onto the start's grid first.""" |
| a = np.asarray(start.convert("RGB")) |
| b = np.asarray(result.convert("RGB")) |
| if b.shape != a.shape: |
| resized = Image.fromarray(b).resize((a.shape[1], a.shape[0]), Image.LANCZOS) |
| b = np.asarray(resized) |
| delta = np.abs(a.astype(np.int16) - b.astype(np.int16)).max(axis=-1) |
| return float((delta > 0).mean()) |
|
|
