Android Question show image directory/location


I make a program (" Leaf disease detection ") which is an android app connected to MATLAB.
I successfully created a php file as a communication from matlab to b4a app (vice versa) with the help of Xampp
(NOTE: I also use WEBVIEW in uploading image)

I get trouble in location of an image. I mean for example an image located in my SD CARD/INTERNAL STORAGE in a folder named as (ex: pic_there). My problem is " If I manually put its location ( ex: storage/emulated/0/pic_there/name.jpg ). The app get crash. But if I use the WebExtras for webview to loadthe image, it works. Or file chooser, it also works.

My purpose is to have an Exact Folder to locate all the image captured or and I want it to assign in program. But I dunno what is the location..
I tried to show the logs of File chooser directory but it only shows ("content directory")


I will upload the build program If the app works fine already As well as the Matlab sources