nesting: Added ability to display tensors of any rank as multiple windows. Added to readme. lowered opencv_python requirement due to char* assertion bug.

README.md

@@ -41,6 +41,16 @@ Python 2.7/3.5+ and PyPy.
 
     w.VideoHandlerThread(callbacks=[redden_frame_print_spam] + w.display_callbacks).display()
 
+#### Display a tensor
+
+    def tensor_from_image(frame, cam_id):
+        ten = tensor_from_pytorch_or_tensorflow(frame)
+        return ten
+    
+    t = wp.VideoHandlerThread(video_source=cam, callbacks=[tensor_from_image] + wp.display_callbacks)
+
+    t.display()
+
 #### Display multiple windows from one source
     import cvpubsubs.webcam_pub as w
     from cvpubsubs.window_sub import SubscriberWindows

cvpubsubs/window_sub/cv_window_sub.py

@@ -28,7 +28,7 @@ class SubscriberWindows(object):
             if isinstance(name, np.ndarray):
                 self.source_names.append(str(hash(str(name))))
                 self.input_vid_global_names = [str(hash(str(name))) + "frame" for name in video_sources]
-            elif len(str(name))<=1000:
+            elif len(str(name)) <= 1000:
                 self.source_names.append(str(name))
                 self.input_vid_global_names = [str(name) + "frame" for name in video_sources]
             else:
@@ -37,7 +37,6 @@ class SubscriberWindows(object):
         self.callbacks = callbacks
         self.input_cams = video_sources
 
-
     @staticmethod
     def set_global_frame_dict(name, *args):
         if len(str(name)) <= 1000:
@@ -47,7 +46,6 @@ class SubscriberWindows(object):
         else:
             raise ValueError("Input window name too long.")
 
-
     def __stop_all_cams(self):
         for c in self.source_names:
             CamCtrl.stop_cam(c)
@@ -69,20 +67,27 @@ class SubscriberWindows(object):
                     RuntimeWarning("Unknown key code: [{}]. Please report to cv_pubsubs issue page.".format(key_input))
                 )
 
+    def _display_frames(self, frames, win_num):
+        for f in range(len(frames)):
+            if frames[f].dtype.num == 17 or len(frames[f].shape) > 3:  # detect nested
+                self._display_frames(frames[f], win_num)
+            else:
+                cv2.imshow(self.window_names[win_num % len(self.window_names)] + " (press ESC to quit)", frames[f])
+                win_num += 1
+
     def update_window_frames(self):
         win_num = 0
         for i in range(len(self.input_vid_global_names)):
             if self.input_vid_global_names[i] in self.frame_dict and not isinstance(self.frame_dict[
-                                                                        self.input_vid_global_names[i]], NoData):
-                if len(self.callbacks)>0 and self.callbacks[i % len(self.callbacks)] is not None:
+                                                                                        self.input_vid_global_names[i]],
+                                                                                    NoData):
+                if len(self.callbacks) > 0 and self.callbacks[i % len(self.callbacks)] is not None:
                     frames = self.callbacks[i % len(self.callbacks)](self.frame_dict[self.input_vid_global_names[i]])
                 else:
                     frames = self.frame_dict[self.input_vid_global_names[i]]
-                if isinstance(frames, np.ndarray) and len(frames.shape)<=3:
+                if isinstance(frames, np.ndarray) and len(frames.shape) <= 3:
                     frames = [frames]
-                for f in range(len(frames)):
-                    cv2.imshow(self.window_names[win_num % len(self.window_names)] + " (press ESC to quit)", frames[f])
-                    win_num += 1
+                self._display_frames(frames, win_num)
 
     # todo: figure out how to get the red x button to work. Try: https://stackoverflow.com/a/37881722/782170
     def loop(self):

requirements.txt

@@ -1,3 +1,3 @@
-opencv_python==4.0.0.21
+opencv_python==3.4.5.20
 localpubsub==0.0.3
 numpy==1.16.1

setup.py

@@ -14,7 +14,7 @@ with open('README.md', 'r', encoding='utf-8') as f:
     readme = f.read()
 
 REQUIRES = [
-    'opencv_python == 4.0.0.21',
+    'opencv_python == 3.4.5.20',
     'localpubsub == 0.0.3',
     'numpy == 1.16.1'
 ]

tests/test_sub_win.py

@@ -89,3 +89,10 @@ class TestSubWin(ut.TestCase):
 
         t1.join()
         t1.join()
+
+    def test_nested_frames(self):
+        def nest_frame(frame, cam_id):
+            frame = np.asarray([[[[[[frame]]]]]])
+            return frame
+
+        w.VideoHandlerThread(callbacks=[nest_frame] + w.display_callbacks).display()