How to Read Barcodes from an Image

Features on this page are only available for the Foundational APIs.

Refer to the DecodeFromAnImage sample for an example of decoding from the photo gallery.

The capture methods of the CaptureVisionRouter class are designed to process a single image.

- (DSCapturedResult *)captureFromFile:(NSString *)filePath templateName:(NSString *)templateName error:(NSError **)error;
- (DSCapturedResult *)captureFromFileBytes:(NSData *)fileBytes templateName:(NSString *)templateName error:(NSError **)error;
- (DSCapturedResult *)captureFromImage:(UIImage *)image templateName:(NSString *)templateName error:(NSError **)error;
- (DSCapturedResult *)captureFromBuffer:(NSData *)buffer width:(NSInteger)width height:(NSInteger)height stride:(NSInteger)stride format:(DSImagePixelFormat)format orientation:(NSInteger)orientation templateName:(NSString *)templateName error:(NSError **)error;

Supported Image Types

The following image input types are supported:

1. An image specified by file path.
2. An image in memory (file bytes).
3. UIImage
4. com.dynamsoft.core.basic_structures.ImageData

When decoding with a file path, provide the full file path, including the extension. Supported extensions are “.bmp”, “.jpg”, “.png”, “.gif”, and single-page “.tiff”.

How to Specify Template Name

When using a capture method, templateName is required. You can specify either a preset template or a custom template name.

Use a Preset Template

EnumPresetTemplate.PT_READ_BARCODES_READ_RATE_FIRST is recommended when processing an image.

• Objective-C
• Swift

1. @property (nonatomic, strong) DSCaptureVisionRouter *cvr;
   self.cvr = [[DSCaptureVisionRouter alloc] init];
   DSCapturedResult *capturedResult = [self.cvr captureFromFile:@"Your-file-path" templateName:DSPresetTemplateReadBarcodes];
   

2. let capturedResult = try cvr.captureFromFile("Your-file-path", templateName: PresetTemplate.readBarcodes.rawValue)
   

Use a Customized Template

For details, see Parameters and Settings - Use a Customized Template.

How to Extract Barcode Info

• Objective-C
• Swift

1. NSError *error = nil;
   DSCapturedResult *capturedResult = [self.cvr captureFromFile:@"Your file path" templateName:DSPresetTemplateReadBarcodes];
   DSDecodedBarcodesResult *decodedBarcodesResult = capturedResult.decodedBarcodesResult;
   for (DSBarcodeResultItem *barcodeResultItem in decodedBarcodesResult.items) {
      NSString *barcodeText = barcodeResultItem.text;
      NSString *barcodeFormatString = barcodeResultItem.formatString;
   }
   

2. let capturedResult = try cvr.captureFromFile("Your file path", templateName: PresetTemplate.readBarcodes.rawValue)
   if let decodedBarcodesResult = capturedResult.decodedBarcodesResult {
      guard let barcodeResultItems = decodedBarcodesResult.items, barcodeResultItems.count>0 else
      {
         // result count = 0
         return
      }
      for barcodeResultItem in barcodeResultItems
      {
         // deal with the results
      }
   }
   

• CapturedResult: The largest set of image processing results. DecodedBarcodesResult is one subset of CapturedResult.
• DecodedBarcodesResult: The set of barcode results. It contains an array of BarcodeResultItem objects and additional information.
• BarcodeResultItem: An object that represents a single decoded barcode.