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VisCurate: Evaluating Behavioral Equivalence of Visual Skills

1Islamic University of Technology, 2University of Utah
WACV 2027

Abstract

Modern vision-based agents have shifted toward skill-based problem-solving, where a skill is an executable image-to-image operation, e.g., cropping, thresholding, or edge detection. As these skill libraries grow, they accumulate duplicated, mislabeled, and defective skills. The signals normally used to curate them (a skill's name, description, or source code) say little about how the skill visually changes the image. We present VisCurate, a framework and benchmark that curates visual skill libraries from observed execution rather than from text. VisCurate runs each candidate skill pair on a shared probe battery and assigns one of six behavioral relations, each tied to a library edit that is safe to make. The benchmark injects seven defect types into a clean library at controlled rates, producing 300 reproducible instances with ground-truth relations and repairs. While text baselines accept up to five of six false merges on hard negatives, our verifier accepts none and recovers 51.2% of the pairs that are truly mergeable. On two real, uncurated libraries, VisCurate finds that 92% of the skills a package shares with its downstream copy are redundant, while execution confirms only 10 of 17 published equivalence claims. The curation problem also remains open, as the strongest of the nine automated curators recovers only about half of the repairs. We emphasize that visual skill libraries should be curated by behavior, not by description.

Overview

Overview of the VisCurate pipeline: (a) pairwise verification on shared probes assigns a behavioral relation; (b) an LLM curator proposes edits that are verified before the library is updated.

Method

A visual skill is a deterministic function that transforms an input image into an output image. Similar descriptions can hide different outputs, causing a silent merge, while different implementations can behave identically, causing a missed consolidation. VisCurate therefore compares the executed outputs instead of the descriptors. Because most skills are parameterized, it never compares at a single operating point: it evaluates both skills over a matched parameter grid on a probe battery \(x_1, \dots, x_m\) and aggregates by the worst case,

\[ D(s_a,s_b)=\max_{\theta\in\Theta^{\mathrm{grid}}}\;\frac{1}{m}\sum_{i=1}^{m} d\Big(\phi\big(f_{s_a}(x_i,\theta)\big),\,\phi\big(f_{s_b}(x_i,\theta)\big)\Big), \]

where \(\phi\) canonicalizes the outputs. The worst case is what blocks spurious merges between skills that coincide on part of their domain: a Gaussian blur and a box blur agree at small kernels but diverge at large ones, and the max over the grid surfaces that divergence rather than averaging it away.

The equivalence taxonomy

Each ordered pair receives exactly one relation. The classifier is hierarchical and stop-at-first: it evaluates relations cheapest-and-strictest first and returns the first that holds, so a stronger, more actionable relation is never masked by a weaker one.

Relations in the order the classifier checks them, from cheapest and strictest to most expensive. It stops at the first relation that holds.
CheckRelationPermits
1=ExactMerge
2≈PerceptualMerge
3⊆SubsumptionParameterize
4≡Semantic-preservingParameterize, never merge
5≠DistinctKeep separate
Abstain?UncertainHuman review
Advisory⊕ComplementaryAdvisory only

Experimental Results

Mean F1 by corruption rate1 / 6
Mean F1 by corruption rate for GPT-5.5, Qwen 3.5 27B, Gemma 4 12B and Qwen 3.5 4B.
Mean F1 by corruption rate ρ for the four strongest curators (n = 30 episodes per cell). Difficulty is not monotone in ρ as GPT-5.5 improves as defects multiply, Qwen 3.5 27B stays flat, and the smaller models collapse.
Bar chart of the share of runs each model ended with the END action.
Percentage of runs that the models have ended using the End action.
Per-relation precision, recall and F1 of the verifier for subsumption, semantic-preserving, complementary and distinct.
Per-relation precision, recall, and F1 of the output-grounded verifier on G0 (one-vs-rest). Exact and Perceptual have no support in a clean reference graph and are omitted.
Merge recall and share of pairs discarded as the screening neighbour count k grows.
Screening trade-off across neighbor count k at radius 0.05, over ten corrupted instances (80 mergeable positives, 76,031 pairs). Merge recall saturates at k = 10 while 95.1% of pairs are still discarded, and the curves are insensitive to radius from 0.05 to 2.0.
Candidate-set size and share of all pairs proposed by screening as the library subsample grows.
Candidate-set growth over nested random subsamples of L0. The log-log fit |C| = 2.38 n1.13 (R2 = 0.998) is close to linear, and the share of all pairs that screening proposes falls from 66.7% at n = 10 to 8.2% at n = 100.
Cache footprint by library size for raw output caches and features-only caches, on a log scale.
Cache footprint by library size for (a) raw output sets and (b) backend features only. The measured unit is 214.8 MB per skill for raw outputs over the 177-probe battery (median of 8 builtin skills), against an analytic features-only cache, a 395× saving at 104 skills.

Findings

Text and code are not safe proxies for behavior. Name matching and sentence embeddings each accept five of the six possible false merges on the hard negatives; the output-grounded verifier accepts none.
Safety holds at every corruption rate. The verifier finds 51.2% of truly mergeable pairs and makes no false merges at any ρ, so safety does not decay as the library gets dirtier.
The misses sit one threshold away. Almost all missed merges are Perceptual pairs labeled Semantic-Preserving, one conservative notch below a merge.
Real libraries carry hidden redundancy. 92% of the filters a package shares with its downstream copy are exactly redundant, while only 10 of 17 published equivalence claims survive execution.
Curation remains an open problem. The strongest of nine curators, GPT-5.5, recovers only about half of the required repairs, and Llama 3.2 1B never produces a correct action.
Difficulty does not simply rise with corruption. GPT-5.5 rises from 0.420 at ρ = 0.1 to 0.641 at ρ = 0.6, while Gemma 4 12B and Qwen 3.5 4B fall by roughly 0.18.
Output screening scales near-linearly. The candidate count fits |C| = 2.38 n1.13 (R2 = 0.998) against quadratic exhaustive pairing, and 54.9% of pairs are settled before any learned backend runs.

Citation

@inproceedings{ishraq2027viscurate,
  title     = {{VisCurate}: Evaluating Behavioral Equivalence of Visual Skills},
  author    = {Ishraq, Md Farhan and Ishmam, Md Farhan and Joarder, Reaz Hassan and Kabir, Md Hasanul},
  booktitle = {Proceedings of the IEEE/CVF Winter Conference on Applications of Computer Vision (WACV)},
  year      = {2027}
}

Acknowledgements

We thank Didhiti Nahid for her helpful feedback on an earlier draft of this paper. Md. Farhan Ishraq, in particular wants to thank his parents, Md. Shah Alam and Afia Khatun Mily, for everything.