Added the rcParams 'pdf.combine_images', 'svg.combine_images', and

'ps.combine_images' to permit users to decide whether they want the
vector graphics backend to combine all images within a set of axes
into a single image.  (If images do not get combined, users can open
vector graphics files in Adobe Illustrator or Inkscape and edit each
image individually.)  Also changed 'renderer.option_nocomposite' to
the clearer name 'renderer.option_combine_images'.

Improved combine image tests to actually count the number of images in the vector graphics files.  Also replaced the rcParams 'pdf.combine_images', 'svg.combine_images', and 'ps.combine_images' with 'vector_backends.combine_images'

Corrected PEP8 coding standard violations

Updated 'combine_images' tests for PS and SVG backends to hopefully make them Python 3 compatible.

Fixed some PEP8 violations to leave the code cleaner than I found it.

Fixed PEP8 violations introduced in my effort to fix PEP8 violations in my last commit.

Changed the rcParam option name from 'vector_graphics.combine_images' to 'image.combine_images', and updated the matplotlibrc.template.

Update the backend tests with the new rcParam name 'image.combine_images'

Added the rcParams 'pdf.combine_images', 'svg.combine_images', and
'ps.combine_images' to permit users to decide whether they want the
vector graphics backend to combine all images within a set of axes
into a single image.  (If images do not get combined, users can open
vector graphics files in Adobe Illustrator or Inkscape and edit each
image individually.)  Also changed 'renderer.option_nocomposite' to
the clearer name 'renderer.option_combine_images'.

Improved combine image tests to actually count the number of images in the vector graphics files.  Also replaced the rcParams 'pdf.combine_images', 'svg.combine_images', and 'ps.combine_images' with 'vector_backends.combine_images'

Corrected PEP8 coding standard violations

Updated 'combine_images' tests for PS and SVG backends to hopefully make them Python 3 compatible.

Fixed some PEP8 violations to leave the code cleaner than I found it.

Fixed PEP8 violations introduced in my effort to fix PEP8 violations in my last commit.

Changed the rcParam option name from 'vector_graphics.combine_images' to 'image.combine_images', and updated the matplotlibrc.template.

Update the backend tests with the new rcParam name 'image.combine_images'

Author: breedlun

CHANGELOG

@@ -2,6 +2,14 @@
            corner masking.  This is controlled by the 'corner_mask' keyword
            in plotting commands 'contour' and 'contourf'. - IMT
 
+2015-01-31 Added the rcParam 'image.combine_images' to permit users 
+		   to decide whether they want the vector graphics backends to combine 
+		   all images within a set of axes into a single image.  (If images do 
+		   not get combined, users can open vector graphics files in Adobe 
+		   Illustrator or Inkscape and edit each image individually.)  Also 
+		   changed 'renderer.option_nocomposite' to the clearer name 
+		   'renderer.option_combine_images'. 
+
 2015-01-23 Text bounding boxes are now computed with advance width rather than
            ink area.  This may result in slightly different placement of text.
 

lib/matplotlib/axes/_base.py

@@ -30,8 +30,6 @@
 import matplotlib.text as mtext
 import matplotlib.image as mimage
 from matplotlib.artist import allow_rasterization
-
-
 from matplotlib.cbook import iterable
 
 rcParams = matplotlib.rcParams
@@ -1241,7 +1239,9 @@ def apply_aspect(self, position=None):
         Xsize = ysize / data_ratio
         Xmarg = Xsize - xr
         Ymarg = Ysize - yr
-        xm = 0  # Setting these targets to, e.g., 0.05*xr does not seem to help
+        # Setting these targets to, e.g., 0.05*xr does not seem to
+        # help.
+        xm = 0
         ym = 0
 
         changex = (self in self._shared_y_axes and
@@ -2028,13 +2028,13 @@ def draw(self, renderer=None, inframe=False):
             dsu = [(a.zorder, a) for a in artists
                    if not a.get_animated()]
 
-        # add images to dsu if the backend support compositing.
-        # otherwise, does the manaul compositing  without adding images to dsu.
-        if len(self.images) <= 1 or renderer.option_image_nocomposite():
+        # add images to dsu if the backend supports combining images.
+        # otherwise, perform manual combining, without adding images to dsu.
+        if len(self.images) <= 1 or not renderer.option_combine_images():
             dsu.extend([(im.zorder, im) for im in self.images])
-            _do_composite = False
+            _combine_images = False
         else:
-            _do_composite = True
+            _combine_images = True
 
         dsu.sort(key=itemgetter(0))
 
@@ -2054,8 +2054,8 @@ def draw(self, renderer=None, inframe=False):
         if self.axison and self._frameon:
             self.patch.draw(renderer)
 
-        if _do_composite:
-            # make a composite image blending alpha
+        if _combine_images:
+            # combine images, blending alpha
             # list of (mimage.Image, ox, oy)
 
             zorder_images = [(im.zorder, im) for im in self.images

lib/matplotlib/backend_bases.py

@@ -527,12 +527,12 @@ def draw_image(self, gc, x, y, im):
         """
         raise NotImplementedError
 
-    def option_image_nocomposite(self):
+    def option_combine_images(self):
         """
         override this method for renderers that do not necessarily
-        want to rescale and composite raster images. (like SVG)
+        want to rescale and composite raster images. (like SVG, PDF, or PS)
         """
-        return False
+        return True
 
     def option_scale_image(self):
         """

lib/matplotlib/backends/backend_agg.py

@@ -322,11 +322,11 @@ def buffer_rgba(self):
     def clear(self):
         self._renderer.clear()
 
-    def option_image_nocomposite(self):
-        # It is generally faster to composite each image directly to
-        # the Figure, and there's no file size benefit to compositing
+    def option_combine_images(self):
+        # It is generally faster to write each image directly to
+        # the Figure, and there's no file size benefit to combining images
         # with the Agg backend
-        return True
+        return False
 
     def option_scale_image(self):
         """

lib/matplotlib/backends/backend_macosx.py

@@ -170,8 +170,8 @@ def flipy(self):
     def points_to_pixels(self, points):
         return points/72.0 * self.dpi
 
-    def option_image_nocomposite(self):
-        return True
+    def option_combine_images(self):
+        return False
 
 
 class GraphicsContextMac(_macosx.GraphicsContext, GraphicsContextBase):

lib/matplotlib/backends/backend_mixed.py

@@ -43,7 +43,6 @@ def __init__(self, figure, width, height, dpi, vector_renderer,
         self._height = height
         self.dpi = dpi
 
-        assert not vector_renderer.option_image_nocomposite()
         self._vector_renderer = vector_renderer
 
         self._raster_renderer = None
@@ -64,7 +63,7 @@ def __init__(self, figure, width, height, dpi, vector_renderer,
         draw_path_collection draw_quad_mesh draw_tex draw_text
         finalize flipy get_canvas_width_height get_image_magnification
         get_texmanager get_text_width_height_descent new_gc open_group
-        option_image_nocomposite points_to_pixels strip_math
+        option_combine_images points_to_pixels strip_math
         start_filter stop_filter draw_gouraud_triangle
         draw_gouraud_triangles option_scale_image
         _text2path _get_text_path_transform height width

lib/matplotlib/backends/backend_pdf.py

@@ -462,8 +462,8 @@ def __init__(self, filename):
         self.fontNames = {}     # maps filenames to internal font names
         self.nextFont = 1       # next free internal font name
         self.dviFontInfo = {}   # information on dvi fonts
-        self.type1Descriptors = {}  # differently encoded Type-1 fonts may
-                                    # share the same descriptor
+        # differently encoded Type-1 fonts may share the same descriptor
+        self.type1Descriptors = {}
         self.used_characters = {}
 
         self.alphaStates = {}   # maps alpha values to graphics state objects
@@ -1475,6 +1475,7 @@ def is_date(x):
 
         check_trapped = (lambda x: isinstance(x, Name) and
                          x.name in ('True', 'False', 'Unknown'))
+
         keywords = {'Title': is_string_like,
                     'Author': is_string_like,
                     'Subject': is_string_like,
@@ -1576,6 +1577,13 @@ def option_scale_image(self):
         """
         return True
 
+    def option_combine_images(self):
+        """
+        return whether to combine multiple images on a set of axes into one
+        image
+        """
+        return rcParams['image.combine_images']
+
     def draw_image(self, gc, x, y, im, dx=None, dy=None, transform=None):
         self.check_gc(gc)
 

lib/matplotlib/backends/backend_ps.py

@@ -451,6 +451,13 @@ def option_scale_image(self):
         ps backend support arbitrary scaling of image.
         """
         return True
+        
+    def option_combine_images(self):
+        """
+        return whether to combine multiple images on a set of axes into one 
+        image
+        """
+        return rcParams['image.combine_images']
 
     def _get_image_h_w_bits_command(self, im):
         if im.is_grayscale:

lib/matplotlib/backends/backend_svg.py

@@ -527,11 +527,15 @@ def open_group(self, s, gid=None):
     def close_group(self, s):
         self.writer.end('g')
 
-    def option_image_nocomposite(self):
+    def option_combine_images(self):
         """
-        if svg.image_noscale is True, compositing multiple images into one is prohibited
+        if svg.image_noscale is True, combining multiple images into one is 
+        prohibited
         """
-        return rcParams['svg.image_noscale']
+        if rcParams['svg.image_noscale']:
+            return False
+        else:
+            return rcParams['image.combine_images']
 
     def _convert_path(self, path, transform=None, clip=None, simplify=None):
         if clip:

lib/matplotlib/figure.py

@@ -249,7 +249,7 @@ class Figure(Artist):
 
     *suppressComposite*
        For multiple figure images, the figure will make composite
-       images depending on the renderer option_image_nocomposite
+       images depending on the renderer option_combine_images
        function.  If suppressComposite is True|False, this will
        override the renderer.
     """
@@ -1045,16 +1045,16 @@ def draw(self, renderer):
 
         # override the renderer default if self.suppressComposite
         # is not None
-        not_composite = renderer.option_image_nocomposite()
+        combine_images = renderer.option_combine_images()
         if self.suppressComposite is not None:
-            not_composite = self.suppressComposite
+            combine_images = not self.suppressComposite
 
-        if (len(self.images) <= 1 or not_composite or
+        if (len(self.images) <= 1 or not combine_images or
                 not cbook.allequal([im.origin for im in self.images])):
             for a in self.images:
                 dsu.append((a.get_zorder(), a, a.draw, [renderer]))
         else:
-            # make a composite image blending alpha
+            # make a combined image, blending alpha
             # list of (_image.Image, ox, oy)
             mag = renderer.get_image_magnification()
             ims = [(im.make_image(mag), im.ox, im.oy, im.get_alpha())
@@ -1067,15 +1067,15 @@ def draw(self, renderer):
             im.is_grayscale = False
             l, b, w, h = self.bbox.bounds
 
-            def draw_composite():
+            def draw_combined_image():
                 gc = renderer.new_gc()
                 gc.set_clip_rectangle(self.bbox)
                 gc.set_clip_path(self.get_clip_path())
                 renderer.draw_image(gc, l, b, im)
                 gc.restore()
 
             dsu.append((self.images[0].get_zorder(), self.images[0],
-                        draw_composite, []))
+                        draw_combined_image, []))
 
         # render the axes
         for a in self.axes: