repair bleu score computation (#14626)

Author: liuhongen1234567

configs/rec/PP-FormuaNet/rec_pp_formulanet_l.yml

@@ -69,7 +69,7 @@ PostProcess:
 Metric:
   name: LaTeXOCRMetric
   main_indicator:  exp_rate
-  cal_bleu_score: False
+  cal_bleu_score: True
 
 Train:
   dataset:

configs/rec/PP-FormuaNet/rec_pp_formulanet_s.yml

@@ -53,7 +53,7 @@ Architecture:
     encoder_hidden_size: 2048
     is_export: False
     length_aware: True 
-    use_parallel: True,
+    use_parallel: True
     parallel_step: 3
 
 Loss:
@@ -67,7 +67,7 @@ PostProcess:
 Metric:
   name: LaTeXOCRMetric
   main_indicator:  exp_rate
-  cal_bleu_score: False
+  cal_bleu_score: True
 
 Train:
   dataset:

configs/rec/rec_latex_ocr.yml

@@ -66,7 +66,7 @@ PostProcess:
 Metric:
   name: LaTeXOCRMetric
   main_indicator:  exp_rate
-  cal_bleu_score: False
+  cal_bleu_score: True
 
 Train:
   dataset:

configs/rec/rec_unimernet.yml

@@ -66,7 +66,7 @@ PostProcess:
 Metric:
   name: LaTeXOCRMetric
   main_indicator:  exp_rate
-  cal_bleu_score: False
+  cal_bleu_score: True
 
 Train:
   dataset:

ppocr/metrics/bleu.py

@@ -98,7 +98,10 @@ def compute_bleu(reference_corpus, translation_corpus, max_order=4, smooth=False
     else:
         geo_mean = 0
 
-    ratio = float(translation_length) / reference_length
+    if float(translation_length) == 0 or float(reference_length) == 0:
+        ratio = 1e-5
+    else:
+        ratio = float(translation_length) / reference_length
 
     if ratio > 1.0:
         bp = 1.0