问题
I want to scan a VIN barcode, which in Code 39 format, using the camera of iphone/ipad. I tried zxing and zbar, but they don't work well. Most of time they can not recognize the barcode. Can anyone show me a better way to do that? or is there anything I can do to increase the result, because I only need scanning Code 39 (for VIN car).
回答1:
use Zbar to accomplish this. In order to get enough resolution to scan, you will want to scan the barcode in landscape mode. Here are my settings (tested & working)
// ADD: present a barcode reader that scans from the camera feed
ZBarReaderViewController *reader = [ZBarReaderViewController new];
reader.readerDelegate = self;
reader.supportedOrientationsMask = ZBarOrientationMaskAll;
ZBarImageScanner *scanner = reader.scanner;
//disable other codes to improve performance
[scanner setSymbology: 0
config: ZBAR_CFG_ENABLE
to: 0];
[scanner setSymbology:ZBAR_CODE39 config:ZBAR_CFG_ENABLE to:1];
//only scan vertically, in the middle of the screen (also improves performance)
[reader setScanCrop:CGRectMake(0, 0.4, 1, 0.2)];
[reader setShowsZBarControls:NO];
[reader setShowsHelpOnFail:NO];
//VERY IMPORTANT: reset zoom. by default, the screen is partially zoomed in and will cause a loss of precision
reader.readerView.zoom = 1.0;
reader.readerView.allowsPinchZoom=NO;
reader.readerView.showsFPS=YES;
reader.readerView.tracksSymbols=YES;
//scan landscape only (this also improves performance)
[scanner setSymbology:ZBAR_CODE39 config:ZBAR_CFG_X_DENSITY to:0];
[scanner setSymbology:ZBAR_CODE39 config:ZBAR_CFG_Y_DENSITY to:1];
That should pretty much do it! Good luck!
Edit/Note:the iOS framework now includes a barcode scanner as of iOS 7. I used this implementation to get better and easier results than using Zbar.
来源：https://stackoverflow.com/questions/11340418/free-sdk-for-scanning-barcode-code-39-format-in-ios