Photometry on Structured Backgrounds: Local Pixelwise Infilling by Regression

A.S. gratefully acknowledges support by a National Science Foundation Graduate Research Fellowship (DGE-1745303). D.F. acknowledges support by NSF grant AST-1614941, "Exploring the Galaxy: 3-Dimensional Structure and Stellar Streams." This work was supported by the National Science Foundation under Cooperative Agreement PHY-2019786 (The NSF AI Institute for Artificial Intelligence and Fundamental Interactions). We would like to thank Edward Schlafly and Lucas Janson for feedback during the development of this project and writing of this manuscript. We acknowledge Eugene Magnier, Josh Speagle, Catherine Zucker, Justina R. Yang, Nayantara Mudur, and Christopher Stubbs for helpful discussions. A.S. acknowledges Sophia S\'{a}nchez-Maes for helpful discussions and much support. Computations in this paper were run on the FASRC Cannon cluster supported by the FAS Division of Science Research Computing Group at Harvard University. We acknowledge the developers and maintainers of the Julia ecosystem, from whom we have learned and benefited greatly.