[multimedia] Add apply-exif-orientation.sh

bin/apply-exif-orientation

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+../multimedia/apply-exif-orientation.sh

multimedia/README

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+# apply-exif-orientation.sh #
+
+apply-exif-orientation.sh retrieves the Orientation EXIF tag from an
+image file and rotates the actual image data according to the said
+orientation. The EXIF Orientation tag is deleted in the process. The
+goal is to allow the image to be displayed correctly by tools that don't
+handle EXIF metadata (such as ImageMagick's display).
+
+EXIF information is manipulated using exiftool, shipped with the
+Image::ExifTool Perl module (Debian package: libimage-exiftool-perl).
+Image is rotated using ImageMagick's convert.
+
+Warning: no backup of the original file is made!
+
+
 # just-play-something.sh #
 
 As its name indicates, the main goal of just-play-something.sh is to put

multimedia/apply-exif-orientation.sh

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+#!/bin/sh
+#
+# apply-exif-orientation.sh, Copyright © 2016 Matteo Cypriani
+#
+# This program is free software. It comes without any warranty, to
+# the extent permitted by applicable law. You can redistribute it
+# and/or modify it under the terms of the Do What The Fuck You Want
+# To Public License, Version 2, as published by Sam Hocevar. See
+# http://sam.zoy.org/wtfpl/COPYING for more details.
+#
+# This script gets the Orientation EXIF tag from an image file (with
+# exiftool) and rotates the image (with convert) to apply the
+# orientation to the image data; the EXIF Orientation tag is deleted.
+#
+# About EXIF orientations, see:
+#   http://jpegclub.org/exif_orientation.html
+
+if [ $# -ne 1 ] ; then
+	echo "Usage: $0 <image_file>" >&2
+	exit 1
+fi
+
+SOURCE="$1"
+
+ORIENTATION=$(exiftool -n -veryShort -Orientation "$SOURCE" | sed -n 's/^.*: //p')
+
+if [ "$ORIENTATION" = "" ] ; then
+	echo "No EXIF Orientation tag. Nothing to do."
+	exit 0
+fi
+
+case $ORIENTATION in
+	1) echo "Horizontal orientation. Nothing to do." ; exit 0 ;;
+	3) ORIENTATION=180 ;;
+	6) ORIENTATION=90 ;;
+	8) ORIENTATION=-90 ;;
+	*) echo "Orientation code $ORIENTATION unknown" >&2 ; exit 2 ;;
+esac
+
+echo "Rotating image by $ORIENTATION°"
+TMP=$(mktemp)
+convert -rotate $ORIENTATION "$SOURCE" "$TMP"
+exiftool -quiet -overwrite_original_in_place -Orientation= "$TMP"
+chmod a+r "$TMP"
+mv "$TMP" "$SOURCE"