DCRAW is a program, written in C, which takes in raw digital image files (not converted to another lossy format) and decodes them for processing.
Using DCRAW on RCC Resources
DCRAW does not require any particular module. In order to run the program, simply call DCRAW from the command line with the options appropriate to your intended application.
dcraw -OPTIONS FILE
For more advanced information either type
dcraw which will give a list of options available or refer to the documentation for more detailed usage information.