Histogram Assisted Quality Aware Generative Model for Resolution Invariant NIR Image Colorization

TL;DR

HAQAGen is a novel resolution-invariant NIR-to-RGB colorization model that combines histogram matching, perceptual quality measures, and texture-aware supervision to produce high-quality, high-resolution colorized images with improved realism and detail.

Contribution

The paper introduces HAQAGen, a unified generative model that integrates histogram matching, SPADE-based priors, and texture supervision for scalable resolution-invariant NIR-to-RGB colorization.

Findings

Outperforms state-of-the-art methods on multiple datasets.

Produces sharper textures and more natural colors.

Maintains high-quality results at native resolutions.

Abstract

We present HAQAGen, a unified generative model for resolution-invariant NIR-to-RGB colorization that balances chromatic realism with structural fidelity. The proposed model introduces (i) a combined loss term aligning the global color statistics through differentiable histogram matching, perceptual image quality measure, and feature based similarity to preserve texture information, (ii) local hue-saturation priors injected via Spatially Adaptive Denormalization (SPADE) to stabilize chromatic reconstruction, and (iii) texture-aware supervision within a Mamba backbone to preserve fine details. We introduce an adaptive-resolution inference engine that further enables high-resolution translation without sacrificing quality. Our proposed NIR-to-RGB translation model simultaneously enforces global color statistics and local chromatic consistency, while scaling to native resolutions without compromising texture fidelity or generalization. Extensive evaluations on FANVID, OMSIV, VCIP2020, and RGB2NIR using different evaluation metrics demonstrate consistent improvements over state-of-the-art baseline methods. HAQAGen produces images with sharper textures, natural colors, attaining significant gains as per perceptual metrics. These results position HAQAGen as a scalable and effective solution for NIR-to-RGB translation across diverse imaging scenarios. Project Page: https://rajeev-dw9.github.io/HAQAGen/