1. A method for naming an image file, the method comprising: searching for a keyword string in initial scan image data, and identifying an encoded string after the keyword string; generating an initial file corresponding to the initial scan image data, wherein if the keyword string is found, a file name of the initial file is automatically set up according to the encoded string; searching for the keyword string in second scan image data, and identifying a second encoded string after the keyword string; and appending the second scan image data to the initial file if the keyword string is found and the second encoded string is identified as the same as the encoded string.