Repair the bug in the inference script for LaTeX OCR (#13750)

* test

* dataprocess_abspath2relpath

* repair bug in infer/predict_rec for latexocr

tools/infer/predict_rec.py

@@ -510,7 +510,7 @@ class TextRecognizer(object):
         shape = (1, 1, 3)
         mean = [0.7931, 0.7931, 0.7931]
         std = [0.1738, 0.1738, 0.1738]
-        scale = 255.0
+        scale = np.float32(1.0 / 255.0)
         min_dimensions = [32, 32]
         max_dimensions = [672, 192]
         mean = np.array(mean).reshape(shape).astype("float32")