The ISO 16022 Standard requires so called Quiet Zone around the Data Matrix symbol. The width of this zone shall not be less than 2 Matrix module (cell) size.

In Online Decoder we “artificially” reconstruct Quiet Zone around the submitted symbol (about 20 pixels wide at each side) to ensure compliance with the ISO Standard. That is why our decoder was able to decode submitted symbols, which actually have no Quiet Zone around themselves.