diff --git a/direct/src/showbase/ShowBase.py b/direct/src/showbase/ShowBase.py
index 18fa910ddd..faebae9efa 100644
--- a/direct/src/showbase/ShowBase.py
+++ b/direct/src/showbase/ShowBase.py
@@ -1574,7 +1574,8 @@ class ShowBase(DirectObject.DirectObject):
             self.camFrustumVis.removeNode()
 
     def screenshot(self, namePrefix = 'screenshot',
-                   defaultFilename = 1, source = None):
+                   defaultFilename = 1, source = None,
+                   imageComment=""):
         """ Captures a screenshot from the main window or from the
         specified window or Texture and writes it to a filename in the
         current directory (or to a specified directory).
@@ -1610,7 +1611,7 @@ class ShowBase(DirectObject.DirectObject):
             else:
                 saved = source.write(filename)
         else:
-            saved = source.saveScreenshot(filename)
+            saved = source.saveScreenshot(filename, imageComment)
 
         # Announce to anybody that a screenshot has been taken
         messenger.send('screenshot', [filename])
diff --git a/panda/src/display/displayRegion.cxx b/panda/src/display/displayRegion.cxx
index bd4c2fe69d..08519e005a 100644
--- a/panda/src/display/displayRegion.cxx
+++ b/panda/src/display/displayRegion.cxx
@@ -611,12 +611,13 @@ save_screenshot_default(const string &prefix) {
 //               filename.  Returns true on success, false on failure.
 ////////////////////////////////////////////////////////////////////
 bool DisplayRegion::
-save_screenshot(const Filename &filename) {
+save_screenshot(const Filename &filename, const string &image_comment) {
   PNMImage image;
   if (!get_screenshot(image)) {
     return false;
   }
 
+  image.set_comment(image_comment);
   if (!image.write(filename)) {
     return false;
   }
diff --git a/panda/src/display/displayRegion.h b/panda/src/display/displayRegion.h
index 25a671b5b7..4995cf0e4d 100644
--- a/panda/src/display/displayRegion.h
+++ b/panda/src/display/displayRegion.h
@@ -111,13 +111,16 @@ PUBLISHED:
 
   void output(ostream &out) const;
 
-  static Filename make_screenshot_filename(const string &prefix = "screenshot");
+  static Filename make_screenshot_filename(
+    const string &prefix = "screenshot");
   Filename save_screenshot_default(const string &prefix = "screenshot");
-  bool save_screenshot(const Filename &filename);
+  bool save_screenshot(
+    const Filename &filename, const string &image_comment = "");
   bool get_screenshot(PNMImage &image);
 
 public:
-  INLINE void set_cull_result(CullResult *cull_result, SceneSetup *scene_setup);
+  INLINE void set_cull_result(
+    CullResult *cull_result, SceneSetup *scene_setup);
   INLINE CullResult *get_cull_result() const;
   INLINE SceneSetup *get_scene_setup() const;
 
diff --git a/panda/src/display/graphicsOutput.I b/panda/src/display/graphicsOutput.I
index ea615ca572..f30484e04d 100644
--- a/panda/src/display/graphicsOutput.I
+++ b/panda/src/display/graphicsOutput.I
@@ -423,11 +423,15 @@ save_screenshot_default(const string &prefix) {
 //     Function: GraphicsOutput::save_screenshot
 //       Access: Published
 //  Description: Saves a screenshot of the region to the indicated
-//               filename.  Returns true on success, false on failure.
+//               filename.  The image comment is an optional user
+//               readable string that will be saved with the header
+//               of the image (if the file format supports embedded
+//               data; for example jpg allows comments).  Returns
+//               true on success, false on failure.
 ////////////////////////////////////////////////////////////////////
 INLINE bool GraphicsOutput::
-save_screenshot(const Filename &filename) {
-  return _default_display_region->save_screenshot(filename);
+save_screenshot(const Filename &filename, const string &image_comment) {
+  return _default_display_region->save_screenshot(filename, image_comment);
 }
 
 ////////////////////////////////////////////////////////////////////
diff --git a/panda/src/display/graphicsOutput.h b/panda/src/display/graphicsOutput.h
index 791762fb32..c55dbb459a 100644
--- a/panda/src/display/graphicsOutput.h
+++ b/panda/src/display/graphicsOutput.h
@@ -145,16 +145,20 @@ PUBLISHED:
   int get_num_active_display_regions() const;
   PT(DisplayRegion) get_active_display_region(int n) const;
 
-  GraphicsOutput *make_texture_buffer(const string &name, int x_size, int y_size,
-                                      Texture *tex = NULL, bool to_ram = false);
+  GraphicsOutput *make_texture_buffer(
+      const string &name, int x_size, int y_size,
+      Texture *tex = NULL, bool to_ram = false);
   GraphicsOutput *make_cube_map(const string &name, int size,
                                 NodePath &camera_rig,
                                 DrawMask camera_mask = DrawMask::all_on(),
                                 bool to_ram = false);
 
-  INLINE static Filename make_screenshot_filename(const string &prefix = "screenshot");
-  INLINE Filename save_screenshot_default(const string &prefix = "screenshot");
-  INLINE bool save_screenshot(const Filename &filename);
+  INLINE static Filename make_screenshot_filename(
+      const string &prefix = "screenshot");
+  INLINE Filename save_screenshot_default(
+      const string &prefix = "screenshot");
+  INLINE bool save_screenshot(
+      const Filename &filename, const string &image_comment);
   INLINE bool get_screenshot(PNMImage &image);
 
   NodePath get_texture_card();
diff --git a/panda/src/pnmimage/pnmImage.cxx b/panda/src/pnmimage/pnmImage.cxx
index 19570a1eca..64a0ddd31d 100644
--- a/panda/src/pnmimage/pnmImage.cxx
+++ b/panda/src/pnmimage/pnmImage.cxx
@@ -41,6 +41,7 @@ clear() {
   _y_size = 0;
   _num_channels = 0;
   _maxval = 255;
+  _comment.clear();
   _type = (PNMFileType *)NULL;
 }
 
@@ -60,6 +61,7 @@ clear(int x_size, int y_size, int num_channels,
   _y_size = y_size;
   _num_channels = num_channels;
   _maxval = maxval;
+  _comment.clear();
   _type = type;
 
   if (has_alpha()) {
diff --git a/panda/src/pnmimage/pnmImageHeader.I b/panda/src/pnmimage/pnmImageHeader.I
index 90daee6830..7b7fd5ddad 100644
--- a/panda/src/pnmimage/pnmImageHeader.I
+++ b/panda/src/pnmimage/pnmImageHeader.I
@@ -56,6 +56,7 @@ operator = (const PNMImageHeader &copy) {
   _y_size = copy._y_size;
   _num_channels = copy._num_channels;
   _maxval = copy._maxval;
+  _comment = copy._comment;
   _type = copy._type;
 }
 
@@ -180,6 +181,26 @@ get_y_size() const {
   return _y_size;
 }
 
+////////////////////////////////////////////////////////////////////
+//     Function: PNMImageHeader::get_comment
+//       Access: Published
+//  Description: Gets the user comment from the file.
+////////////////////////////////////////////////////////////////////
+INLINE string PNMImageHeader::
+get_comment() const {
+  return _comment;
+}
+
+////////////////////////////////////////////////////////////////////
+//     Function: PNMImageHeader::set_comment
+//       Access: Published
+//  Description: Writes a user comment string to the image (header).
+////////////////////////////////////////////////////////////////////
+INLINE void PNMImageHeader::
+set_comment(const string& comment) {
+  _comment = comment;
+}
+
 ////////////////////////////////////////////////////////////////////
 //     Function: PNMImageHeader::has_type
 //       Access: Published
diff --git a/panda/src/pnmimage/pnmImageHeader.h b/panda/src/pnmimage/pnmImageHeader.h
index 5bd3eebc33..addb65c472 100644
--- a/panda/src/pnmimage/pnmImageHeader.h
+++ b/panda/src/pnmimage/pnmImageHeader.h
@@ -72,6 +72,9 @@ PUBLISHED:
   INLINE int get_x_size() const;
   INLINE int get_y_size() const;
 
+  INLINE string get_comment() const;
+  INLINE void set_comment(const string &comment);
+
   INLINE bool has_type() const;
   INLINE PNMFileType *get_type() const;
   INLINE void set_type(PNMFileType *type);
@@ -128,6 +131,7 @@ protected:
   int _x_size, _y_size;
   int _num_channels;
   xelval _maxval;
+  string _comment;
   PNMFileType *_type;
 };
 
diff --git a/panda/src/pnmimagetypes/pnmFileTypeJPGReader.cxx b/panda/src/pnmimagetypes/pnmFileTypeJPGReader.cxx
index 76306bed18..72b6bba477 100644
--- a/panda/src/pnmimagetypes/pnmFileTypeJPGReader.cxx
+++ b/panda/src/pnmimagetypes/pnmFileTypeJPGReader.cxx
@@ -262,7 +262,7 @@ Reader(PNMFileType *type, istream *file, bool owns_file, string magic_number) :
   // Hope we can putback() more than one character.
   for (string::reverse_iterator mi = magic_number.rbegin();
        mi != magic_number.rend();
-       mi++) {
+       ++mi) {
     _file->putback(*mi);
   }
   if (_file->fail()) {
@@ -284,8 +284,10 @@ Reader(PNMFileType *type, istream *file, bool owns_file, string magic_number) :
   /* Step 2: specify data source (eg, a file) */
   jpeg_istream_src(&_cinfo, file);
 
-  /* Step 3: read file parameters with jpeg_read_header() */
+  /* Step 3: let lib jpeg know that we want to read the comment field */
+  jpeg_save_markers(&_cinfo, JPEG_COM, 0xffff);
 
+  /* Step 4: read file parameters with jpeg_read_header() */
   jpeg_read_header(&_cinfo, TRUE);
   /* We can ignore the return value from jpeg_read_header since
    *   (a) suspension is not possible with the stdio data source, and
@@ -293,11 +295,11 @@ Reader(PNMFileType *type, istream *file, bool owns_file, string magic_number) :
    * See libjpeg.doc for more info.
    */
 
-  /* Step 4: set parameters for decompression */
+  /* Step 6: set parameters for decompression */
   _cinfo.scale_num = jpeg_scale_num;
   _cinfo.scale_denom = jpeg_scale_denom;
 
-  /* Step 5: Start decompressor */
+  /* Step 7: Start decompressor */
 
   jpeg_start_decompress(&_cinfo);
   /* We can ignore the return value since suspension is not possible
diff --git a/panda/src/pnmimagetypes/pnmFileTypeJPGWriter.cxx b/panda/src/pnmimagetypes/pnmFileTypeJPGWriter.cxx
index 9286be067d..e2a9b76922 100644
--- a/panda/src/pnmimagetypes/pnmFileTypeJPGWriter.cxx
+++ b/panda/src/pnmimagetypes/pnmFileTypeJPGWriter.cxx
@@ -201,7 +201,6 @@ Writer(PNMFileType *type, ostream *file, bool owns_file) :
 {
 }
 
-
 ////////////////////////////////////////////////////////////////////
 //     Function: PNMFileTypeJPG::Writer::write_data
 //       Access: Public, Virtual
@@ -297,6 +296,12 @@ write_data(xel *array, xelval *) {
    */
   jpeg_start_compress(&cinfo, TRUE);
 
+  /* Write the user comment, if any */
+  if (_comment.size()) {
+    jpeg_write_marker(
+      &cinfo, JPEG_COM, (JOCTET *)_comment.c_str(), strlen(_comment.c_str()));
+  }
+
   /* Step 5: while (scan lines remain to be written) */
   /*           jpeg_write_scanlines(...); */
 
diff --git a/panda/src/testbed/pview.cxx b/panda/src/testbed/pview.cxx
index 57cdb34ee2..df5062d2bb 100644
--- a/panda/src/testbed/pview.cxx
+++ b/panda/src/testbed/pview.cxx
@@ -55,7 +55,7 @@ output_screenshot(Filename &fn)
   framework.do_frame();
 
   WindowFramework *wf = framework.get_window(0);
-  bool ok = wf->get_graphics_window()->save_screenshot(fn);
+  bool ok = wf->get_graphics_window()->save_screenshot(fn, "from pview");
   if (!ok) {
     cerr << "Could not generate screenshot " << fn << "\n";
   }