Add support for reading JPEG-XR images

src/calibre/utils/img.py

@@ -2,17 +2,28 @@
 # vim:fileencoding=utf-8
 # License: GPLv3 Copyright: 2015, Kovid Goyal <kovid at kovidgoyal.net>
 
-from __future__ import (unicode_literals, division, absolute_import,
-                        print_function)
-import os, subprocess, errno, shutil, tempfile, sys
+from __future__ import absolute_import, division, print_function, unicode_literals
+
+import errno
+import os
+import shutil
+import subprocess
+import sys
+import tempfile
 from io import BytesIO
 from threading import Thread
 
-from PyQt5.Qt import QImage, QByteArray, QBuffer, Qt, QImageReader, QColor, QImageWriter, QTransform, QPixmap
+from PyQt5.Qt import (
+    QBuffer, QByteArray, QColor, QImage, QImageReader, QImageWriter, QPixmap, Qt,
+    QTransform
+)
+
 from calibre import fit_image, force_unicode
 from calibre.constants import iswindows, plugins
+from calibre.ptempfile import TemporaryDirectory
 from calibre.utils.config_base import tweaks
 from calibre.utils.filenames import atomic_rename
+from calibre.utils.imghdr import what
 
 # Utilities {{{
 imageops, imageops_err = plugins['imageops']
@@ -39,6 +50,22 @@ def get_exe_path(name):
     if not base:
         return name
     return os.path.join(base, name)
+
+
+def load_jxr_data(data):
+    with TemporaryDirectory() as tdir:
+        if iswindows and isinstance(tdir, type('')):
+            tdir = tdir.encode('mbcs')
+        with lopen(os.path.join(tdir, 'input.jxr'), 'wb') as f:
+            f.write(data)
+        cmd = [get_exe_path('JxrDecApp'), '-i', 'input.jxr', '-o', 'output.tif', '-c', '0']
+        creationflags = 0x08 if iswindows else 0
+        subprocess.Popen(cmd, cwd=tdir, stdout=lopen(os.devnull, 'wb'), stderr=subprocess.STDOUT, creationflags=creationflags).wait()
+        i = QImage()
+        if not i.load(os.path.join(tdir, 'output.tif')):
+            raise NotImage('Failed to convert JPEG-XR image')
+        return i
+
 # }}}
 
 # Loading images {{{
@@ -55,6 +82,8 @@ def image_from_data(data):
         return data
     i = QImage()
     if not i.loadFromData(data):
+        if what(None, data) == 'jxr':
+            return load_jxr_data(data)
         raise NotImage('Not a valid image')
     return i
 
@@ -543,6 +572,9 @@ def test():  # {{{
     despeckle_image(img)
     remove_borders_from_image(img)
     image_to_data(img, fmt='GIF')
+    raw = subprocess.Popen([get_exe_path('JxrDecApp'), '-h'], creationflags=0x08 if iswindows else 0, stdout=subprocess.PIPE).stdout.read()
+    if b'JPEG XR Decoder Utility' not in raw:
+        raise SystemExit('Failed to run JxrDecApp')
 # }}}