Cloé picture
From Just Solve the File Format Problem
Cloé picture (also spelled CLOE or cloe) is a raster graphics format associated with the Cloé ray-tracer software by Pierre-e Gougelet (better known as the author of XnView).
It apparently supports truecolor images whose samples are 8-bit integers, 16-bit integers, or floating point numbers.
Identification
Files apparently start with ASCII "CLOEII
".