File Extension CRG File Format Calamus picture image format CRG stands for Calamus picture image format. This was last updated in March 2012 By Margaret Rouse Browse File Extensions Alphabetically: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # Ask a Question. Find an Answer. Ask your peers a question about this file extension. Ask a Question Sexting app could have a use for tech firms Microsoft helps us to see clearly How do I create an OEM-style bootable recovery partition?