fix onnx for dynamic shape (#8812)

tools/infer/predict_det.py

@@ -143,7 +143,9 @@ class TextDetector(object):
 
         if self.use_onnx:
             img_h, img_w = self.input_tensor.shape[2:]
-            if img_h is not None and img_w is not None and img_h > 0 and img_w > 0:
+            if isinstance(img_h, str) or isinstance(img_w, str):
+                pass
+            elif img_h is not None and img_w is not None and img_h > 0 and img_w > 0:
                 pre_process_list[0] = {
                     'DetResizeForTest': {
                         'image_shape': [img_h, img_w]

tools/infer/predict_rec.py

@@ -173,9 +173,10 @@ class TextRecognizer(object):
         imgW = int((imgH * max_wh_ratio))
         if self.use_onnx:
             w = self.input_tensor.shape[3:][0]
-            if w is not None and w > 0:
+            if isinstance(w, str):
+                pass
+            elif w is not None and w > 0:
                 imgW = w
-
         h, w = img.shape[:2]
         ratio = w / float(h)
         if math.ceil(imgH * ratio) > imgW: