ZBar vs. zxing - QR recognition comparison

Question

Can anyone tell which library is better in small QR Codes recognition under low lighting conditions? Platform is iPhone 4/iOS 5 I tried both Barcodes (zxing) and the ZBar apps and it seems that zxing was noticeably better in recognizing the codes under "hard" conditions. That said, it wasn't a very large sample test.

Any inputs on the actual image recognition capabilities (speed+quality) of both libraries would be helpful.

TIA.

Answer 1

I have found that Zxing very good on the later iPads and iPhones. The iPad 2 camera was very slow with Zxing, but the later cameras were much faster and have better focusing, which improved speed considerably.

One "hack" I did with Zxing on iPad 2 is to change the rectangle in code. I would progressively zoom out on each attempt, so rather than use the rectangle shown I would expand it out in steps, so I would check 5 times for each scan. The results were much much improved. On the iPad 3 etc this was not so necessary, but still I have the code in there and it is fast.

I have used both ZBar and ZXing in Windows using scanners (300 DPI), and found dense QRCodes a problem for ZXIng and had to include ZBar support. Implementing ZBar support was very tricky and had to write my own API, if anyone is interested.

Answer 2

As for me ZXing is better. I have used them both at work for iOS application.

1. With ZBar I had problems with large QRCodes.

2. ZXing works fine on iPhone 4 and 3GS, but Zbar works worse on 3GS, some times it just can't capture the code.

Answer 3

I've used both of them. You have to use ZXing if you want scan data matrix codes. But if you don't need data matrix, using ZBar is a fast and easy way. Also, there is a built-in scanner API in iOS 7, AVCaptureMetaDataOutput that scans 1D and 2D codes except data matrix. I'd prefer AVCaptureMetaDataOutput because of simplicity. Here is a guide for AVCaptureMetaDataOutput.

Answer 4

You should take a look at this link. Performance wise, using the ZBar defaults will create issues with large v40 QRCodes - the solution is to set the videoQuality property to UIImagePickerControllerQualityTypeHigh instead of the default 640x480 (Apple docs). As per documentation, the barcode module size need to be at least 3 pixels in size to scan. I tried both SDK around a year ago, I like the ZXing sample app, but in the end prior to appstore submission, I found it generated a lot of warning messages that I find hard to remove. Switching to ZBar allowed me to cleanup the message and add capability to scan several 1D Barcode types to my app. As mentioned the default settings will not give you optimal performance but you need to look into the options, turn off the ones you don't need, stripped bare it should perform reasonably well.

I am pretty happy with ZBar at the moment but will likely switch if ZXing support for other barcode types particularly DataMatrix, PDF417, Aztec and Maxi Code become available.