Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help
WRJPGCOM(1)		    General Commands Manual		   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/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	text
	      Supply text for new COM block on command line.

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

       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.  Longer com-
       ments can be read from a	text file.

       If you give neither -comment nor	-cfile,	then wrjpgcom  will  read  the
       comment	text  from  standard input.  (In this case an input image file
       name MUST be supplied, so that the source JPEG file  comes  from	 some-
       where  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.

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

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

       Attach a	long comment previously	stored in comment.txt:

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

       or equivalently

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

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

AUTHOR
       Independent JPEG	Group

				 15 June 1995			   WRJPGCOM(1)

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXAMPLES | SEE ALSO | AUTHOR

Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=wrjpgcom&sektion=1&manpath=FreeBSD+12.0-RELEASE+and+Ports>

home | help