Extended Data Fig. 4: Mask construction pipeline.
From: Physical restoration of a painting with a digitally constructed mask

a, Base images are prepared for further processing through brightening, blurring, and coordinate conversion. b, The base mask is constructed through analysis of human-perceived visual differences and identification of features based on contrast with local context. Further processing accounts for tolerance analysis. c, Manual adjustments and final corrections are made to the base mask, which is split for fabrication.