Automatic Detection and Correction of Random Telegraph Signal Artifacts in Earth Observation Images

Abstract

Satellite optical and infrared images can be degraded by a piecewise-constant random artifact called random telegraph signal (RTS), which is caused by unstable semiconductor defects in the photodetector. In this letter, we aim at proposing new techniques to detect and correct such artifacts in the specific context of push-broom detectors, where some columns exhibit RTS that superimposes with the landscape. Our detector is based on a nonparametric statistical test that compares the distribution of each column to its neighbors. Concerning the RTS correction, we first propose a signal processing method that estimates the levels and jumps of the RTS. Then, we propose another method inspired by variational image destriping, which directly estimates the RTS through the use of total variation (TV). Experiments—on Pléiades images with synthetic RTS and on a real SPOT-5 image—show the effectiveness of the proposed techniques.