Dont use IM for auto-trim of images

src/calibre/ebooks/metadata/sources/covers.py

@@ -15,7 +15,7 @@ from io import BytesIO
 from calibre.customize.ui import metadata_plugins
 from calibre.ebooks.metadata.sources.base import create_log
 from calibre.ebooks.metadata.sources.prefs import msprefs
-from calibre.utils.img import save_cover_data_to
+from calibre.utils.img import save_cover_data_to, remove_borders, image_to_data, image_from_data
 from calibre.utils.imghdr import identify
 
 class Worker(Thread):
@@ -61,11 +61,10 @@ def process_result(log, result):
     plugin, data = result
     try:
         if getattr(plugin, 'auto_trim_covers', False):
-            from calibre.utils.magick import Image
-            im = Image()
-            im.load(data)
-            im.trim(10)
-            data = im.export('JPEG')
+            img = image_from_data(data)
+            nimg = remove_borders(img)
+            if nimg is not img:
+                data = image_to_data(nimg)
         fmt, width, height = identify(data)
         if width < 0 or height < 0:
             raise ValueError('Could not read cover image dimensions')

src/calibre/gui2/dialogs/metadata_bulk.py

@@ -200,15 +200,15 @@ class MyBlockingBusy(QDialog):  # {{{
                     if covers:
                         cache.set_cover({book_id:covers[-1][0]})
         elif args.cover_action == 'trim':
-            from calibre.utils.magick import Image
+            from calibre.utils.img import remove_borders, image_to_data, image_from_data
             for book_id in self.ids:
                 cdata = cache.cover(book_id)
                 if cdata:
-                    im = Image()
-                    im.load(cdata)
-                    im.trim(tweaks['cover_trim_fuzz_value'])
-                    cdata = im.export('jpg')
-                    cache.set_cover({book_id:cdata})
+                    img = image_from_data(cdata)
+                    nimg = remove_borders(img)
+                    if nimg is not img:
+                        cdata = image_to_data(nimg)
+                        cache.set_cover({book_id:cdata})
         elif args.cover_action == 'clone':
             cdata = None
             for book_id in self.ids:

src/calibre/gui2/metadata/basic_widgets.py

@@ -1105,15 +1105,15 @@ class Cover(ImageView):  # {{{
         self.current_val = None
 
     def trim_cover(self, *args):
-        from calibre.utils.magick import Image
         cdata = self.current_val
         if not cdata:
             return
-        im = Image()
-        im.load(cdata)
-        im.trim(tweaks['cover_trim_fuzz_value'])
-        self.current_val = im.export('png')
-        self.cdata_before_trim = cdata
+        from calibre.utils.img import remove_borders, image_to_data, image_from_data
+        img = image_from_data(cdata)
+        nimg = remove_borders(img)
+        if nimg is not img:
+            self.cdata_before_trim = cdata
+            self.current_val = image_to_data(nimg, fmt='png')
 
     def manual_trim_cover(self):
         cdata = self.current_val

src/calibre/gui2/tweak_book/editor/canvas.py

@@ -19,8 +19,8 @@ from calibre.gui2 import error_dialog, pixmap_to_data
 from calibre.gui2.dnd import (
     IMAGE_EXTENSIONS, dnd_has_extension, dnd_has_image, dnd_get_image, DownloadDialog)
 from calibre.gui2.tweak_book import capitalize
-from calibre.utils.config_base import tweaks
 from calibre.utils.imghdr import identify
+from calibre.utils.img import remove_borders
 from calibre.utils.magick import qimage_to_magick
 
 def painter(func):
@@ -98,10 +98,7 @@ class AutoTrim(Trim):
     TEXT = _('Auto-trim image')
 
     def __call__(self, canvas):
-        img = canvas.current_image
-        i = qimage_to_magick(img)
-        i.trim(tweaks['cover_trim_fuzz_value'])
-        return i.to_qimage()
+        return remove_borders(canvas.current_image)
 
 class Rotate(Command):
 

src/calibre/utils/img.py

@@ -200,10 +200,15 @@ def flip_image(img, horizontal=False, vertical=False):
     return image_from_data(img).mirrored(horizontal, vertical)
 
 def remove_borders(img, fuzz=None):
+    ''' Try to auto-detect and remove any borders from the image. Returns
+    the image itself if no borders could be removed. `fuzz` is a measure of
+    what colors are considered identical (must be a number between 0 and 255 in
+    absolute intensity units). Default is from a tweak whose default value is 10. '''
     if imageops is None:
         raise RuntimeError(imageops_err)
     fuzz = tweaks['cover_trim_fuzz_value'] if fuzz is None else fuzz
-    return imageops.remove_borders(image_from_data(img), max(0, fuzz))
+    ans = imageops.remove_borders(image_from_data(img), max(0, fuzz))
+    return ans if ans.size() != img.size() else img
 
 def run_optimizer(file_path, cmd, as_filter=False, input_data=None):
     file_path = os.path.abspath(file_path)