improve post process (#5758)

* improve post process

* rm unused code

ppocr/postprocess/rec_postprocess.py

@@ -54,22 +54,24 @@ class BaseRecLabelDecode(object):
         ignored_tokens = self.get_ignored_tokens()
         batch_size = len(text_index)
         for batch_idx in range(batch_size):
-            char_list = []
-            conf_list = []
-            for idx in range(len(text_index[batch_idx])):
-                if text_index[batch_idx][idx] in ignored_tokens:
-                    continue
-                if is_remove_duplicate:
-                    # only for predict
-                    if idx > 0 and text_index[batch_idx][idx - 1] == text_index[
-                            batch_idx][idx]:
-                        continue
-                char_list.append(self.character[int(text_index[batch_idx][
-                    idx])])
-                if text_prob is not None:
-                    conf_list.append(text_prob[batch_idx][idx])
-                else:
-                    conf_list.append(1)
+            selection = np.ones(len(text_index[batch_idx]), dtype=bool)
+            if is_remove_duplicate:
+                selection[1:] = text_index[batch_idx][1:] != text_index[
+                    batch_idx][:-1]
+            for ignored_token in ignored_tokens:
+                selection &= text_index[batch_idx] != ignored_token
+
+            char_list = [
+                self.character[text_id]
+                for text_id in text_index[batch_idx][selection]
+            ]
+            if text_prob is not None:
+                conf_list = text_prob[batch_idx][selection]
+            else:
+                conf_list = [1] * len(selection)
+            if len(conf_list) == 0:
+                conf_list = [0]
+
             text = ''.join(char_list)
             result_list.append((text, np.mean(conf_list)))
         return result_list