Boundary-Continuous Cross-Camera RGB Mapping via Hue-Split Model Trees
This work addresses the problem of RGB color inconsistency across cameras caused by differences in sensor spectral responses and image signal processing pipelines. To tackle this, the authors propose a model tree structure based on recursive hue partitioning, where an affine color correction matrix (CCM) is learned in the logarithmic domain for each node. To mitigate chromatic discontinuities at hue boundaries induced by hard partitioning, they introduce a path-weighted fusion strategy combined with an explicit continuity regularizer defined over boundary prototype pairs and simplex-constrained optimization. Evaluated on the mapping task from Canon EOS-1Ds Mark II to EOS 20D, the method significantly reduces log-RMSE and effectively suppresses false contours near hue thresholds under diverse illumination and exposure conditions, achieving both high colorimetric accuracy and perceptual smoothness.