The CTG file extension is created on Canon digital camera memory cards. This file is a catalog index file for the images and stored on the memory card. The CTG files includes information about the number of images stored in each folder on the memory card. This files cannot be opened or edited by the users and will be removed completely when the folder containing the pictures are removed or erased. CTG files do not contain any image data and cannot be converted to other image fomarts.
The CTG file extension is associated with the ChessBase, a multi-featured chess database program. This file allows users to read information of Chess matches. The CTG file stores various data of ChessBase.