More JPEG documentation, fixes #890

docs/handbook/image-file-formats.rst

@@ -117,20 +117,48 @@ converting ``RGB`` images to ``L``, and resize images to 1/2, 1/4 or 1/8 of
 their original size while loading them. The :py:meth:`~PIL.Image.Image.draft`
 method also configures the JPEG decoder to trade some quality for speed.
 
-The :py:meth:`~PIL.Image.Image.open` method sets the following
-:py:attr:`~PIL.Image.Image.info` properties:
+The :py:meth:`~PIL.Image.Image.open` method may set the following
+:py:attr:`~PIL.Image.Image.info` properties if available:
 
 **jfif**
     JFIF application marker found. If the file is not a JFIF file, this key is
     not present.
 
+**jfif_version**
+    A tuple representing the jfif version, (major version, minor version). 
+
+**jfif_density**
+    A tuple representing the pixel density of the image, in units specified
+    by jfif_unit.
+
+**jfif_unit**
+    Units for the jfif_density:
+
+    * 0 - No Units
+    * 1 - Pixels per Inch
+    * 2 - Pixels per Centimeter
+
+**dpi**
+    A tuple representing the reported pixel density in pixels per inch, if 
+    the file is a jfif file and the units are in inches. 
+
 **adobe**
     Adobe application marker found. If the file is not an Adobe JPEG file, this
     key is not present.
 
+**adobe_transform**
+    Vendor Specific Tag.
+
 **progression**
     Indicates that this is a progressive JPEG file.
 
+**icc-profile**
+    The ICC color profile for the image.  
+
+**exif**
+    Raw EXIF data from the image. 
+
+
 The :py:meth:`~PIL.Image.Image.save` method supports the following options:
 
 **quality**
@@ -147,6 +175,19 @@ The :py:meth:`~PIL.Image.Image.save` method supports the following options:
     If present, indicates that this image should be stored as a progressive
     JPEG file.
 
+**dpi**
+    A tuple of integers representing the pixel density, ``(x,y)``.
+
+**icc-profile** 
+    If present, the image is stored with the provided ICC profile. If
+    this parameter is not provided, the image will be saved with no
+    profile attached. To preserve the existing profile::
+
+        im.save(filename, 'jpeg', icc_profile=im.info.get('icc_profile'))
+
+**exif**
+    If present, the image will be stored with the provided raw EXIF data. 
+
 **subsampling**
     If present, sets the subsampling for the encoder. 
     
@@ -670,7 +711,7 @@ files, using either JPEG or HEX encoding depending on the image mode (and
 whether JPEG support is available or not).
 
 PIXAR (read only)
-^^^^
+^^^^^^^^^^^^^^^^^
 
 PIL provides limited support for PIXAR raster files. The library can identify
 and read “dumped” RGB files.