How-to Guides - Enable Scale Up for Barcode Recognition

For some barcodes with small module size, Dynamsoft Barcode Reader SDK will automatically enlarge the barcode to a proper size before recognition.

Since version 7.3, Dynamsoft Barcode Reader SDK provides PublicRuntimeSettings->ScaleUpModes#scaleupmodes) with arguments - ModuleSizeThreshold, AcuteAngleWithXThreshold and TargetModuleSize APIs which allow you to set the custom rules for scaling up. To enable it, you need to set PublicRuntimeSettings->ScaleUpModes to SUM_LINEAR_INTERPOLATION or SUM_NEAREST_NEIGHBOUR_INTERPOLATION, then set the rest parameters.

If the module size of the barcode < ModuleSizeThreshold and the acute angle with X of the barcode > AcuteAngleWithXThreshold, the barcode will be enlarged to N times (N=1,2,3…) till N * modulesize >= TargetModuleSize.

Example

Condition: ModuleSizeThreshold = 4, AcuteAngleWithXThreshold = 30, TargetModuleSize = 4

Result:

The module size of the barcode in the image is 2, which is smaller than ModuleSizeThreshold, and the acute angle is larger than AcuteAngleWithXThreshold, so our library will perform scaling up operation. After scaling up, the barcode is enlarged to 2 times since 2 * modulesize >= TargetModuleSize.

For more information about enabling scale up mode, please see ScaleUpModes and How to Set Scale Up Modes.