Zbar barcode reader is not properly scaning code128 format barcodes for ipod touch 4G

i am using ZBAR bar code reader to scan 18-digit code128 format bar codes,it is working well for 5-digit and 12-digit bar codes.But it is not all scanning 18-digit bar codes.I have gone through zbar forums and made some changes to default code to make it work for code128 bar codes. .Can any one please tell me is it problem with ipod camera or do we have any code snippet to make it work?

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Solution

Regarding the iPod Touch 4G issue this is most likely a hardware limitation. The device only has a 0.7MP resolution and no autofocus which makes scanning barcodes much more difficult.

One option is to limit these devices from downloading the app using UIRequiredDeviceCapabilities.

You could try improving frame resolution by filtering first with a sharpen filter before passing to ZBar. Have a look at:

Core Image - https://developer.apple.com/library/ios/documentation/GraphicsImaging/Conceptual/CoreImaging/ci_intro/ci_intro.html
GPUImage - https://github.com/BradLarson/GPUImage