For images like this one (images with text of low contrast), what parameters should I change for a better result?

I tried the default values with dhe.py and ying.py, it did help enhance the contrast a little bit but not much. I'm wondering whether the author knows better about how to tune some parameters in the program to get a better result for images like the one I provided.
Thank you very much for the code and for your help!
For images like this one (images with text of low contrast), what parameters should I change for a better result?
I tried the default values with dhe.py and ying.py, it did help enhance the contrast a little bit but not much. I'm wondering whether the author knows better about how to tune some parameters in the program to get a better result for images like the one I provided.
Thank you very much for the code and for your help!