WRJPGCOM(1)              USER COMMANDS                WRJPGCOM(1)



NAME
     wrjpgcom - insert text comments into a JPEG file

SYNOPSIS
     wrjpgcom [ -replace ] [ -comment _t_e_x_t ] [ _f_i_l_e_n_a_m_e ]

DESCRIPTION
     wrjpgcom reads the named JPEG/JFIF  file,  or  the  standard
     input  if  no  file  is named, and generates a new JPEG/JFIF
     file on 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 doesn't actually
     define what COM blocks are for, they are widely used to hold
     user-supplied  text strings.  This lets you add annotations,
     titles, index terms, etc  to  your  JPEG  files,  and  later
     retrieve them 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 as many of them as you like
     in one JPEG file.

     wrjpgcom adds a COM block, containing text 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
     Switch names may be abbreviated, and are not case sensitive.

     -replace
          Delete any existing COM blocks from the file.

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

     If you have only one line of comment text to  add,  you  can
     provide  it  on the command line with -comment.  The comment
     text must be surrounded with quotes so that it is treated as
     a single argument.

     If your comment text is longer than one line, omit the -com-
     ment  switch  from  the command line.  In this case wrjpgcom
     will read the comment text from  standard  input  (an  input
     file  name  MUST  be  supplied  so that the source JPEG file
     comes from somewhere else).  You can enter  multiple  lines,
     up  to  64KB  worth.  Type an end-of-file indicator (usually
     control-D) to terminate the comment text entry.

     wrjpgcom will not add a COM block if  the  provided  comment
     string is empty.  Therefore -replace -comment "" can be used
     to delete all COM blocks from a file.



Sun Release 4.1     Last change: 17 July 1994                   1






WRJPGCOM(1)              USER COMMANDS                WRJPGCOM(1)



EXAMPLES
     Add a short comment to in.jpg, producing out.jpg:

          wrjpgcom -c "_V_i_e_w _o_f _m_y _b_a_c_k _y_a_r_d" _i_n._j_p_g > _o_u_t._j_p_g

     Attach a long comment previously stored in comment.txt:

          wrjpgcom _i_n._j_p_g < _c_o_m_m_e_n_t._t_x_t > _o_u_t._j_p_g

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

AUTHOR
     Independent JPEG Group









































Sun Release 4.1     Last change: 17 July 1994                   2