Mercurial > hgrepos > Python2 > PyMuPDF
diff mupdf-source/thirdparty/libjpeg/rdjpgcom.1 @ 2:b50eed0cc0ef upstream
ADD: MuPDF v1.26.7: the MuPDF source as downloaded by a default build of PyMuPDF 1.26.4.
The directory name has changed: no version number in the expanded directory now.
| author | Franz Glasner <fzglas.hg@dom66.de> |
|---|---|
| date | Mon, 15 Sep 2025 11:43:07 +0200 |
| parents | |
| children |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mupdf-source/thirdparty/libjpeg/rdjpgcom.1 Mon Sep 15 11:43:07 2025 +0200 @@ -0,0 +1,63 @@ +.TH RDJPGCOM 1 "13 September 2013" +.SH NAME +rdjpgcom \- display text comments from a JPEG file +.SH SYNOPSIS +.B rdjpgcom +[ +.B \-raw +] +[ +.B \-verbose +] +[ +.I filename +] +.LP +.SH DESCRIPTION +.LP +.B rdjpgcom +reads the named JPEG/JFIF file, or the standard input if no file is named, +and prints any text comments found in the file on the standard output. +.PP +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. +.SH OPTIONS +.TP +.B \-raw +Normally +.B rdjpgcom +escapes non-printable characters in comments, for security reasons. +This option avoids that. +.PP +.B \-verbose +Causes +.B rdjpgcom +to also display the JPEG image dimensions. +.PP +Switch names may be abbreviated, and are not case sensitive. +.SH HINTS +.B rdjpgcom +does not depend on the IJG JPEG library. Its source code is intended as an +illustration of the minimum amount of code required to parse a JPEG file +header correctly. +.PP +In +.B \-verbose +mode, +.B rdjpgcom +will also attempt to print the contents of any "APP12" markers as text. +Some digital cameras produce APP12 markers containing useful textual +information. If you like, you can modify the source code to print +other APPn marker types as well. +.SH SEE ALSO +.BR cjpeg (1), +.BR djpeg (1), +.BR jpegtran (1), +.BR wrjpgcom (1) +.SH AUTHOR +Independent JPEG Group
