Read Data Matrix Code Concepts

The Read Data Matrix Code step consists of two phases:

Phase during which you specify an region of interest in the image, which helps to locate the region occupied by the barcode. This phase is optional, but it can increase the performance of the second phase by reducing the size of the search region.
Phase during which the region you specify is analyzed to decode the barcode.

The following factors can cause errors in the search and decoding phase:

Very low resolution of the image
Very high horizontal or vertical light drift
Contrast of the modules in the image
High level of noise or blurring
Inconsistent printing or stamping techniques—such as misaligned barcode elements—inconsistent element size, or elements with inconsistent borders.
Quiet zone that is too small or contains too much noise

Note The minimum quiet zone for a Data Matrix barcode is equal to one module width on all four sides of the barcode.