Display thinking for deepseek r1 (#4904)

### What problem does this PR solve?
#4903
### Type of change

- [x] New Feature (non-breaking change which adds functionality)

deepdoc/vision/operators.py

@@ -108,7 +108,7 @@ class NormalizeImage(object):
 
     def __init__(self, scale=None, mean=None, std=None, order='chw', **kwargs):
         if isinstance(scale, str):
-            scale = np.float32(scale) if scale != 'None' else None
+            scale = eval(scale)
         self.scale = np.float32(scale if scale is not None else 1.0 / 255.0)
         mean = mean if mean is not None else [0.485, 0.456, 0.406]
         std = std if std is not None else [0.229, 0.224, 0.225]