Showing 24 Result(s)

Reading PDF-417 barcodes from scanned images

PDF-417 barcodes are a common type of 2-D barcode and are designed to store more data than a 1-D barcode with built in redundancy and error correction. A PDF-417 barcode actually consists of stacks of 1-D barcodes arranged in columns. Each of the 1-D barcodes is called a cluster and has a numeric value. The …

Image resolution and barcode reading

We often receive emails asking us to explain why our SDK is unable to decode a barcode from an attached image, and the answer is often that the resolution of the image is too low; but why does image resolution play such an important role in the decoding of a barcode? What is resolution? For …

IOS 4.1 code detail

Detailed description of work-around for AVCaptureVideoPreviewLayer problem in IOS 4.1 IOS 4.1 seems to contain a critical bug in the AVCaptureVideoPreviewLayer which causes app’s to freeze when an instance of the class is created. The normal way to use AVCaptureVideoPreviewLayer is as follows:   // Create the session session = [[AVCaptureSession alloc] init];     // Configure …

iPhone OS 4.0

Following testing on iPhone OS 4.0 beta, the following problems were identified in version 7.3.1d of the SDK and have been corrected in version 7.3.1e: 1. Sample XCode application aborting with error EXEC_BAD_ACCESS. 2. Sample XCode applications froze when Cancel button touched in camera view finder. Both of the above problems were corrected by changes to …

Identifying output files when using tiff split

This article explains how to correlate the output files produced during a tiff split process against the barcode values returned by GetBarString. The algorithm shown here assumes default split mode (TiffSplitMode = 0) and handles multiple barcodes on a single page and the possibility of no barcode on the first page. The code below uses …

How do PrefOccurrence and MinOccurrence work

As the toolkit scans the images in a document, it assigns a “hit-count” to each barcode-like pattern it finds. The hit-count for a very clear barcode will typically be in the region 20 to 100, depending on the size of the barcode and the settings used within the sdk. The PrefOccurrence and MinOccurrence properties specify hit-count levels …

Code 39 barcodes with double start/stop patterns

Code 39 barcodes can be generated using either fonts or software such as embedded objects. When using a font, the text should include the start/stop * character at either end of the barcode, but software generated barcodes will often add the * characters automatically. This can sometimes result in barcodes with 2 * characters at either …

Handling Unicode Encoded Barcodes in VB.Net

2-D barcode formats such as PDF-417 can encode a huge character set, which means that the barcode reader toolkit needs to encode characters outside the normal ASCII range. If the Encoding property is set to 2 then the toolkit will use Unicode encoding, whereby characters can be represented by the string &#N; where N is …