How to crop scanned barcode using Zbar?

Question

I am using below code to scan bar code using Zbar sdk.

I go through related question of stackoverflow but that answer is not working for me.

Till now I have done

Answer 1

Try this. If CGRect = CGRectMake(x, y, width, height);, then do:

float A = y / readerView.bounds.size.height;   
float B = 1 - (x + width) / readerView.bounds.size.width;   
float C = (y + height) / readerView.bounds.size.height;   
float D = 1 - x / readerView.bounds.size.width;;  
CGRectMake( A, B, C, D );