git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@6000 dfc29bdd-3216-0410-991c-e03cc46cb475
		
			
				
	
	
		
			104 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			Groff
		
	
	
	
	
	
			
		
		
	
	
			104 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			Groff
		
	
	
	
	
	
| .TH WRJPGCOM 1 "15 June 1995"
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| .SH NAME
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| wrjpgcom \- insert text comments into a JPEG file
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| .SH SYNOPSIS
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| .B wrjpgcom
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| [
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| .B \-replace
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| ]
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| [
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| .BI \-comment " text"
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| ]
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| [
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| .BI \-cfile " name"
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| ]
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| [
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| .I filename
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| ]
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| .LP
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| .SH DESCRIPTION
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| .LP
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| .B wrjpgcom
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| reads the named JPEG/JFIF file, or the standard input if no file is named,
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| and generates a new JPEG/JFIF file on standard output.  A comment block is
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| added to the file.
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| .PP
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| The JPEG standard allows "comment" (COM) blocks to occur within a JPEG file.
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| Although the standard doesn't actually define what COM blocks are for, they
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| are widely used to hold user-supplied text strings.  This lets you add
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| annotations, titles, index terms, etc to your JPEG files, and later retrieve
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| them as text.  COM blocks do not interfere with the image stored in the JPEG
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| file.  The maximum size of a COM block is 64K, but you can have as many of
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| them as you like in one JPEG file.
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| .PP
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| .B wrjpgcom
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| adds a COM block, containing text you provide, to a JPEG file.
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| Ordinarily, the COM block is added after any existing COM blocks; but you
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| can delete the old COM blocks if you wish.
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| .SH OPTIONS
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| Switch names may be abbreviated, and are not case sensitive.
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| .TP
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| .B \-replace
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| Delete any existing COM blocks from the file.
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| .TP
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| .BI \-comment " text"
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| Supply text for new COM block on command line.
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| .TP
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| .BI \-cfile " name"
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| Read text for new COM block from named file.
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| .PP
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| If you have only one line of comment text to add, you can provide it on the
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| command line with
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| .BR \-comment .
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| The comment text must be surrounded with quotes so that it is treated as a
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| single argument.  Longer comments can be read from a text file.
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| .PP
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| If you give neither
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| .B \-comment
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| nor
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| .BR \-cfile ,
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| then
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| .B wrjpgcom
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| will read the comment text from standard input.  (In this case an input image
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| file name MUST be supplied, so that the source JPEG file comes from somewhere
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| else.)  You can enter multiple lines, up to 64KB worth.  Type an end-of-file
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| indicator (usually control-D) to terminate the comment text entry.
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| .PP
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| .B wrjpgcom
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| will not add a COM block if the provided comment string is empty.  Therefore
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| \fB\-replace \-comment ""\fR can be used to delete all COM blocks from a file.
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| .SH EXAMPLES
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| .LP
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| Add a short comment to in.jpg, producing out.jpg:
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| .IP
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| .B wrjpgcom \-c
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| \fI"View of my back yard" in.jpg
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| .B >
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| .I out.jpg
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| .PP
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| Attach a long comment previously stored in comment.txt:
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| .IP
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| .B wrjpgcom
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| .I in.jpg
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| .B <
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| .I comment.txt
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| .B >
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| .I out.jpg
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| .PP
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| or equivalently
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| .IP
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| .B wrjpgcom
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| .B -cfile
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| .I comment.txt
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| .B <
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| .I in.jpg
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| .B >
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| .I out.jpg
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| .SH SEE ALSO
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| .BR cjpeg (1),
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| .BR djpeg (1),
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| .BR jpegtran (1),
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| .BR rdjpgcom (1)
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| .SH AUTHOR
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| Independent JPEG Group
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