Add `crops = results.crops()` dictionary (#4676)

* adding get cropped functionality

* Add target logic in existing functions

* Crops cleanup

* Add dictionary keys: conf, cls, box

* Bug fixes - avoid return after first image

Co-authored-by: Glenn Jocher <glenn.jocher@ultralytics.com>

models/common.py

@@ -365,6 +365,7 @@ class Detections:
         self.s = shape  # inference BCHW shape
 
     def display(self, pprint=False, show=False, save=False, crop=False, render=False, save_dir=Path('')):
+        crops = []
         for i, (im, pred) in enumerate(zip(self.imgs, self.pred)):
             str = f'image {i + 1}/{len(self.pred)}: {im.shape[0]}x{im.shape[1]} '
             if pred.shape[0]:
@@ -376,7 +377,9 @@ class Detections:
                     for *box, conf, cls in reversed(pred):  # xyxy, confidence, class
                         label = f'{self.names[int(cls)]} {conf:.2f}'
                         if crop:
-                            save_one_box(box, im, file=save_dir / 'crops' / self.names[int(cls)] / self.files[i])
+                            file = save_dir / 'crops' / self.names[int(cls)] / self.files[i] if save else None
+                            crops.append({'box': box, 'conf': conf, 'cls': cls, 'label': label,
+                                          'im': save_one_box(box, im, file=file, save=save)})
                         else:  # all others
                             annotator.box_label(box, label, color=colors(cls))
                     im = annotator.im
@@ -395,6 +398,10 @@ class Detections:
                     LOGGER.info(f"Saved {self.n} image{'s' * (self.n > 1)} to {colorstr('bold', save_dir)}")
             if render:
                 self.imgs[i] = np.asarray(im)
+        if crop:
+            if save:
+                LOGGER.info(f'Saved results to {save_dir}\n')
+            return crops
 
     def print(self):
         self.display(pprint=True)  # print results
@@ -408,10 +415,9 @@ class Detections:
         save_dir = increment_path(save_dir, exist_ok=save_dir != 'runs/detect/exp', mkdir=True)  # increment save_dir
         self.display(save=True, save_dir=save_dir)  # save results
 
-    def crop(self, save_dir='runs/detect/exp'):
-        save_dir = increment_path(save_dir, exist_ok=save_dir != 'runs/detect/exp', mkdir=True)  # increment save_dir
-        self.display(crop=True, save_dir=save_dir)  # crop results
-        LOGGER.info(f'Saved results to {save_dir}\n')
+    def crop(self, save=True, save_dir='runs/detect/exp'):
+        save_dir = increment_path(save_dir, exist_ok=save_dir != 'runs/detect/exp', mkdir=True) if save else None
+        return self.display(crop=True, save=save, save_dir=save_dir)  # crop results
 
     def render(self):
         self.display(render=True)  # render results