OpenCV Android - Detect partial rectangle/paper

Android/Java
1

Hi everyone! I’m new to OpenCV and I’m trying to implement the library on Android, here is my use case:

I need to use the camera to detect a receipt in real time, so far I’ve manage to detect it if the full receip is shown (using rectangle detection) but if I focus my camera only to one part of the receipt it wont detect it as a rectangle and my implemantation fails.

This is my current implementation working and the fail case

B5677017-E37C-4324-A174-98A689D0CF2F
B5677017-E37C-4324-A174-98A689D0CF2F828×878 207 KB

I’ll really appreciate if someone can help me solving this.

Best regards,

Bryan

2

what are you actually interested to retrieve from that receipe ?

though it’s somewhat obvious to look for a rectangular outline, just saying, maybe you do not need the whole rectangle anyway

also, there are insteresting alternative ways to retrieve text from an image, using dnns

3

The thing is that I need to crop the picture to only the receipt, so I get the points and crop the photo after that. Then I send the photo to an endpoint that extracts the info. So I just need to be able to detect and crop the receipe from the rest

4

I guess you could cheat and add a rectangle around the image before detection - then you’d always have a full rectangle