Macro PDF417 is a special feature that serves to divide files that are too large to be encoded in a single barcode into smaller encodable segments. Macro PDF417 is an implementation of the PDF417 standard that is capable of encoding very large amounts of information into multiple PDF417 barcodes. These labels can be then scanned by a Macro PDF-compatible scanner to reassemble them into a single massive of data. Each Macro PDF segment has a common file ID with the other segments thus constituting a barcode sequence. If file IDs do not match, the scanner will interpret such segments as those corresponding to different barcode sequences. To reassemble segments in the correct order, each barcode label must have a unique segment index that allows the scanner to identify how to reassemble barcode segments in the correct order even after reading them in a non-sequential order.
You can find the detailed description of classes and properties that are used in Aspose.BarCode for PDF417 generation and recognition:
Macro PDF417 can be used to divide information from a large file into multiple blocks that get encoded in a sequence of PDF417 barcodes and then can be reassembled together in the correct order.
Encoding Character Set
See the article PDF417 Barcode Family for the information about character sets supported for encoding in PDF417 barcodes.
Available configurations may contain from 1 to 30 columns with input information, 2 columns with metainformation (i.e. row indicator, the number of rows and columns), and finally, start and stop patterns. The number of rows can range from 3 to 90. The main distinction between Macro PDF417 and Basic PDF417 is the capability to encode additional metadata about barcode contents. This redundancy corresponding to auxiliary metadata allows reading such barcodes with laser scanners, as well as reducing image quality requirements.
Macro PDF417 barcodes contain additional control data used to facilitate this distributed representation. It allows decoders to correctly reassemble and validate encoded segments regardless of the scanning order.
Macro PDF417 serves to link multiple PDF417 barcodes. See the information about PDF417 sizing in the article PDF417 Barcode Family.
Encoding Capacity and Data Density
The capacity of Macro PDF417 is theoretically unlimited as it allows binding together up to 99,999 PDF417 labels. See more details about Basic PDF417 capacity in the article PDF417 Barcode Family.
The same error correction mechanism as in Basic PDF417 is applied. See more information in the article PDF417 Barcode Family.
Advantages and Limitations
Macro PDF allows representing multiple files in logical and consecutive sequences of PDF417 barcode segments. Up to 99,999 PDF417 barcodes can be linked or concatenated and then scanned in any sequence to enable the correct reconstruction of the original file.