Although most cameras produce JPEG-encoded images ready for viewing, many also offer the ability to save the digitized, but otherwise unprocessed, sensor data in a file so that more sophisticated processing can be applied later. For recent Sony cameras, the raw data is encoded in
a format known as ARW (Alpha RaW). Controversially, ARW version 2.0 and later employ lossy compression for 32x1-pixel blocks, combining a non-linear reduction of value range and a form of delta encoding. This compression has been associated with occasionally severe visual artifacts. In this
paper, the artifacts observed with real cameras using this compression scheme are characterized and several algorithms for credible repair of those artifacts, including computational texture synthesis, are presented and experimentally evaluated.