DOCX Input: Automatically resize large images used as bullets in lists, to compensate for the fact that HTML renderers do not do this.

src/calibre/ebooks/docx/images.py

@@ -10,10 +10,12 @@ import os
 
 from lxml.html.builder import IMG, HR
 
+from calibre import fit_image
 from calibre.constants import iswindows
 from calibre.ebooks.docx.names import barename
 from calibre.utils.filenames import ascii_filename
 from calibre.utils.imghdr import what
+from calibre.utils.magick import Image
 
 class LinkedImageNotFound(ValueError):
 
@@ -105,6 +107,7 @@ class Images(object):
         self.namespace = namespace
         self.rid_map = {}
         self.used = {}
+        self.resized = {}
         self.names = set()
         self.all_images = set()
         self.links = []
@@ -113,11 +116,7 @@ class Images(object):
     def __call__(self, relationships_by_id):
         self.rid_map = relationships_by_id
 
-    def generate_filename(self, rid, base=None, rid_map=None):
+    def read_image_data(self, fname, base=None):
-        rid_map = self.rid_map if rid_map is None else rid_map
-        fname = rid_map[rid]
-        if fname in self.used:
-            return self.used[fname]
         if fname.startswith('file://'):
             src = fname[len('file://'):]
             if iswindows and src and src[0] == '/':
@@ -128,23 +127,25 @@ class Images(object):
                 raw = rawsrc.read()
         else:
             raw = self.docx.read(fname)
-        base = base or ascii_filename(rid_map[rid].rpartition('/')[-1]).replace(' ', '_') or 'image'
+        base = base or ascii_filename(fname.rpartition('/')[-1]).replace(' ', '_') or 'image'
         ext = what(None, raw) or base.rpartition('.')[-1] or 'jpeg'
         if ext == 'emf':
             # For an example, see: https://bugs.launchpad.net/bugs/1224849
-            self.log('Found an EMF image: %s, trying to extract embedded raster image' % base)
+            self.log('Found an EMF image: %s, trying to extract embedded raster image' % fname)
             from calibre.utils.wmf.emf import emf_unwrap
             try:
                 raw = emf_unwrap(raw)
-            except Exception as e:
+            except Exception:
                 self.log.exception('Failed to extract embedded raster image from EMF')
             else:
                 ext = 'png'
-
         base = base.rpartition('.')[0]
         if not base:
             base = 'image'
         base += '.' + ext
+        return raw, base
+
+    def unique_name(self, base):
         exists = frozenset(self.used.itervalues())
         c = 1
         name = base
@@ -152,7 +153,37 @@ class Images(object):
             n, e = base.rpartition('.')[0::2]
             name = '%s-%d.%s' % (n, c, e)
             c += 1
-        self.used[fname] = name
+        return name
+
+    def resize_image(self, raw, base, max_width, max_height):
+        img = Image()
+        img.load(raw)
+        resized, nwidth, nheight = fit_image(img.size[0], img.size[1], max_width, max_height)
+        if resized:
+            img.size = (nwidth, nheight)
+            base, ext = os.path.splitext(base)
+            base = base + '-%dx%d%s' % (max_width, max_height, ext)
+            raw = img.export(ext[1:])
+        return raw, base, resized
+
+    def generate_filename(self, rid, base=None, rid_map=None, max_width=None, max_height=None):
+        rid_map = self.rid_map if rid_map is None else rid_map
+        fname = rid_map[rid]
+        key = (fname, max_width, max_height)
+        ans = self.used.get(key)
+        if ans is not None:
+            return ans
+        raw, base = self.read_image_data(fname, base=base)
+        resized = False
+        if max_width is not None and max_height is not None:
+            raw, base, resized = self.resize_image(raw, base, max_width, max_height)
+        name = self.unique_name(base)
+        self.used[key] = name
+        if max_width is not None and max_height is not None and not resized:
+            okey = (fname, None, None)
+            if okey in self.used:
+                return self.used[okey]
+            self.used[okey] = name
         with open(os.path.join(self.dest_dir, name), 'wb') as f:
             f.write(raw)
         self.all_images.add('images/' + name)

src/calibre/ebooks/docx/numbering.py

@@ -119,7 +119,7 @@ class Level(object):
             rid = pic_map.get(self.pic_id, None)
             if rid:
                 try:
-                    fname = images.generate_filename(rid, rid_map=rid_map)
+                    fname = images.generate_filename(rid, rid_map=rid_map, max_width=20, max_height=20)
                 except Exception:
                     fname = None
                 else: