I am working in OCR android Application. Now I can take images and extract word easily using google vision API but the result is not 100% according to the angle of capturing the image. and illumination. So I tried to make some image processing techniques on image before extracting text. but I search a lot but I can't deiced what is the best image processing technique to use.(blurring,filtering) to smooth image and improve its quality. So if there is any libraries or guide line to follow up with it in this subject. How to improve image quality before extracting text
I testes this libraries for OCR operation