Solarization
From The Glossary of Digital Photography
More properly known as the Sabbatier effect. A partial reversal of the image such that it contains both positive and negative parts relative to the original subject matter. See Sabbatier effect

ONLINE GLOSSARY OF DIGITAL PHOTOGRAPY
More properly known as the Sabbatier effect. A partial reversal of the image such that it contains both positive and negative parts relative to the original subject matter. See Sabbatier effect