shreshthsaini/brightrate-study-gemma4-e4b-sdr

Gemma-4-E4B BrightVQ SDR study adapter

This PEFT adapter is one result from the BrightRate-LM controlled input and scaling study.

Base model

google/gemma-4-E4B-it

Input interface

Eight uniformly sampled HDR frames are tone-mapped to an SDR proxy and passed as images in temporal order.

Training data and recipe

This adapter was trained on the content-separated split 0 of BrightVQ. Training uses two epochs, a three-epoch cosine schedule horizon, learning rate 1e-4, micro-batch 1, gradient accumulation 8, and rank-16 LoRA with alpha 32 and dropout 0.05. MOS targets are interpolated across five quality words.

Training data: BrightVQ.

Metrics

On the 420-video split-0 test set: SROCC 0.8624, PLCC 0.8805, KRCC 0.6811, RMSE 6.4313.

Intended use

This adapter is intended for research on no-reference perceptual quality assessment of user-generated HDR video. Scores are not calibrated for other datasets, display pipelines, or video domains.

Code and input construction are available in BrightRate-LM.

Citation

@article{saini2026brightratelm,
  title   = {BrightRate-LM: Representation-Aware Quality Assessment for User-Generated HDR Video},
  author  = {Saini, Shreshth and Wang, Yilin and Birkbeck, Neil and Adsumilli, Balu and Bovik, Alan C.},
  journal = {Machine Vision and Applications},
  year    = {2026},
  note    = {Submitted}
}