rdjpgcom(1)							   User Commands						       rdjpgcom(1)

NAME

       rdjpgcom - display text comments from a JPEG file

SYNOPSIS

       rdjpgcom [-verbose] [filename]

DESCRIPTION

       rdjpgcom  reads the named JPEG or JFIF file, or the standard input if no file is named, and displays any text comments found in the file on
       the standard output.

       The JPEG standard allows "comment" (COM) blocks to occur within a JPEG file. Although the standard does not actually  define  the  intended
       function  of COM blocks, they are widely used to hold user-supplied text strings. This enables you to add annotations, titles, index terms,
       and so on to your JPEG files, and later retrieve the COM blocks as text. COM blocks do not interfere with the  image  stored  in  the  JPEG
       file. The maximum size of a COM block is 64K, but you can have many COM blocks in one JPEG file.

OPTIONS

       The following options are supported:

       -verbose        Causes rdjpgcom to also display the JPEG image dimensions.

OPERANDS

       The following operands are supported:

       filename        The name of the JPEG file that contains text comments.

EXTENDED DESCRIPTION

       rdjpgcom does not depend on the IJG JPEG library. The rdjpgcom source code is intended to illustrate the minimum amount of code required to
       parse a JPEG file header correctly.

       In -verbose mode, rdjpgcom also attempts to display the contents of any "APP12" markers as text. Some digital cameras produce APP12 markers
       that contain useful textual information. You can also modify the source code to display other APPn marker types.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWjpg			   |
       +-----------------------------+-----------------------------+
       |Interface stability	     |Volatile			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       cjpeg(1), djpeg(1), jpegtran(1), wrjpgcom(1)

NOTES

       This man page was originally written by the Independent JPEG Group.  Updated by Breda McColgan, Sun Microsystems Inc., 2004.

SunOS 5.11							    26 Mar 2004 						       rdjpgcom(1)