Add CoreML inference (#6195)

* Add Apple CoreML inference

* Cleanup

models/common.py

@@ -420,9 +420,12 @@ class DetectMultiBackend(nn.Module):
             im = Image.fromarray((im[0] * 255).astype('uint8'))
             # im = im.resize((192, 320), Image.ANTIALIAS)
             y = self.model.predict({'image': im})  # coordinates are xywh normalized
-            box = xywh2xyxy(y['coordinates'] * [[w, h, w, h]])  # xyxy pixels
-            conf, cls = y['confidence'].max(1), y['confidence'].argmax(1).astype(np.float)
-            y = np.concatenate((box, conf.reshape(-1, 1), cls.reshape(-1, 1)), 1)
+            if 'confidence' in y:
+                box = xywh2xyxy(y['coordinates'] * [[w, h, w, h]])  # xyxy pixels
+                conf, cls = y['confidence'].max(1), y['confidence'].argmax(1).astype(np.float)
+                y = np.concatenate((box, conf.reshape(-1, 1), cls.reshape(-1, 1)), 1)
+            else:
+                y = y[list(y)[-1]]  # last output
         else:  # TensorFlow (SavedModel, GraphDef, Lite, Edge TPU)
             im = im.permute(0, 2, 3, 1).cpu().numpy()  # torch BCHW to numpy BHWC shape(1,320,192,3)
             if self.saved_model:  # SavedModel