Manual Pages for UNIX Operating System command usage for man wrjpgcom

User Commands                                         wrjpgcom(1)



NAME
     wrjpgcom - insert text comments into a JPEG file

SYNOPSIS
     wrjpgcom [-replace] [-comment text] [-cfile name] [filename]

DESCRIPTION
     wrjpgcom reads the named JPEG or JFIF file, or the  standard
     input  if no file is named, and generates a new JPEG or JFIF
     file on the standard output. A comment block is added to the
     file.

     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.

     wrjpgcom adds a COM block, containing text that you provide,
     to a JPEG file. Ordinarily, the COM block is added after any
     existing COM blocks, but you can delete the old  COM  blocks
     if you wish.

OPTIONS
     The following options are supported:

     -cfile name     Read the text for a new COM block  from  the
                     named file.



     -comment text   Supply the text for a new COM block  on  the
                     command line.



     -replace        Delete any  existing  COM  blocks  from  the
                     file.



OPERANDS
     The following operands are supported:

     filename        The name of the JPEG file to which you  want
                     to add text comments.





SunOS 5.11          Last change: 26 Mar 2004                    1






User Commands                                         wrjpgcom(1)



EXTENDED DESCRIPTION
     To add only one line  of  comment  text,  use  the  -comment
     option  to provide the text on the command line. Specify the
     comment text within quotes, so that the text is treated as a
     single  argument.  Longer  comments  can be read from a text
     file.

     If you specify neither the -comment nor the  -cfile  option,
     wrjpgcom reads the comment text from standard input. In such
     cases, you must supply an  input  image  filename.  You  can
     enter  multiple lines, up to 64KB. Type an end-of-file indi-
     cator, usually Ctrl-D, to terminate the comment text entry.

     wrjpgcom does not add a COM block if  the  provided  comment
     string is empty. Therefore, you can use -replace -comment ""
     to delete all COM blocks from a file.

EXAMPLES
     Example 1: Adding a  Short  Comment  to  in.jpg  to  Produce
     out.jpg

     example% wrjpgcom -c "View of my back yard" in.jpg > out.jpg

     Example 2: Attaching a Long  Comment  Previously  Stored  in
     comment.txt

     example% wrjpgcom in.jpg < comment.txt > out.jpg

     or

     example% wrjpgcom -cfile comment.txt < in.jpg > out.jpg

     In this example, 1000 is a number that is  larger  than  the
     number of rows in the source file.

ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:

     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Availability                | image/library/libjpeg       |
    |_____________________________|_____________________________|
    | Interface stability         | Volatile                    |
    |_____________________________|_____________________________|


SEE ALSO
     cjpeg(1), djpeg(1), jpegtran(1), rdjpgcom(1)





SunOS 5.11          Last change: 26 Mar 2004                    2






User Commands                                         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          Last change: 26 Mar 2004                    3