SMPTE RDD 15-2007

This document describes the Color Transformation Language, or CTL, and its reference implementation in the form of a CTL interpreter. CTL is a small software programming language that has been designed to serve as a building block for digital color management systems. CTL allows users to describe color transforms in a concise and unambiguous way by expressing them as software programs. Any digital color management system that supports CTL includes a CTL interpreter. In order to apply a given transform to an image, the color management system instructs the interpreter to load and run the CTL program that describes the transform. The original and the transformed image constitute the CTL program’s input and output.

This document describes the syntax and semantics of CTL, a standard library of functions that can be called from within CTL programs, as well as a C++ programming interface that allows application programs to access and control the CTL interpreter.

The RDD itself is comprised of this document and the reference implementation of the CTL interpreter as described in Annex B. All other referenced documents, sample code and software utilities are provided for informative purposes only.