I'm developing an android app to recognize text in particular plate, as in photo here: 
I have to recognize the texts in white (e.g. near to "Mod."). I'm using Google ML Kit's text recognition APIs, but it fails. So, I'm using OpenCV to edit image but I don't know how to emphasize the (white) texts so OCR recognize it. I tried more stuff, like contrast, brightness, gamma correction, adaptive thresholding, but the cases vary a lot depending on how the photo is taken. Do you have any ideas? Thank u very much.