kunstloser Natur oder Ursprung von vexierbildhafter Kunst ? », Gerhart von Graevenitz, Stefan Rieger, Felix Thürlemann (eds.), Die Unvermeidlichkeit der Bilder, Tübingen, 2001, pp. 147-172. Omar Calabrese (2006): Artists' Self-Portraits, (The book has a chapter on artists who hide self-portraits in their pictures: e.g. Leonardo da Vinci, Michelangelo, Rembrandt, van Gogh, Munch, Dalí, Albrecht Dürer, Velàzquez, Elisabeth Vigée-Lebrun, Ingres, Degas, Toulouse-Lautrec, Gainsborough, Matisse, James Ensor, Egon Schiele, Frida Kahlo, Man Ray, Henry Moore, Robert Rauschenberg, Norman Rockwell, and Roy Lichtenstein.) On crypto-images more broadly Walter Melion, Bret Rothstein, Michel Weemans (eds.), The Anthropomorphic Lens: Anthropomorphism, Microcosmism and Analogy in Early Modern Thought and Visual Arts, Leiden: Brill, 2015. Jean-Hubert Martin (ed.), Une image peut en cacher une autre - Arcimboldo, Dalí, Raetz (exhibition catalogue), Paris: Galeries nationales du Grand Palais, 2009. Jean-Hubert Martin, Stephan Andreae (eds.), Das endlose Rätsel. Dalí und die Magier der Mehrdeutigkeit (exhibition catalogue, Düsseldorf, Museum Kunst Palast), Ostfildern-Ruit, 2003. Dario Gamboni, Potential images: ambiguity and indeterminacy in modern art, London: Reaktion, 2002. Jean-Claude Lebensztejn, L'art de la tache: Introduction à la Nouvelle methode d'Alexander Cozens, Paris: Éditions du Limon, 1990. Jean-Didier Urbain, "La crypto-image ou le palimpseste iconique", Eidos, 5, 1991, p. 1-16, et On chance images Horst W. Janson, "The ‘Image made by Chance’ in Renaissance Thought", Millard Meiss (ed.), De Artibus opuscula XL. Essays in Honor of Erwin Panofsky, New York, 1961, I, pp. 254– 266, II, pp. 87–88. Horst Woldemar: "Chance Images", in: Dictionary of the History of Ideas. Studies of Selected Pivotal Ideas, ed. Philip P. Wiener, vol. 1, New York 1973, pp. 340-353. Notes Optical illusions Optical phenomena Artistic techniques