Below are the most common reasons why a document does not pass the security checks (the overall status indicator shows red) in the Document Reader application (SDK):
- The document was moved during the scanning process. The document should be held still during the whole scanning process. Otherwise, errors will occur at every stage of processing: MRZ reading, document type recognition, visual zone OCR and authenticity checks. The impact of document displacement can be reduced by disabling the glare compensation option, but this may raise some other issues, and it is usually recommended only for the extraction of MRZ or barcode data without images. If you need to get images, visual zone OCR results, graphics, or perform authenticity checks, keep the glare compensation option enabled and scan documents as described above.
- Light from external sources. Light from external sources may get into the reader when scanning with the lid up or no lid at all. It may significantly affect the scanning process, especially authenticity checks in UV: external light can excessively illuminate some document areas. The impact of this factor can be reduced by enabling the smart UV option (disabled by default), however, it will increase the processing time and may cause issues when processing document photocopies with the lid up.
- Holograms and/or glossy laminate on the document. Mostly, they affect the OCR of the visual zone and document type recognition. Their impact is reduced by the glare compensation option (enabled by default).
- The document is not valid. Usually, documents have only an expiry date. However, some documents (e.g., visas) may be issued in advance and also have a “valid from” date. Thus, if the document is not yet valid, the overall check status will be marked as red.
- The document is a specimen. If the document number contains only zeros, the country code is invalid (e.g., UTO for Utopia), or a document holder's name is in the stop-list (e.g., "Test", "Specimen", “Musterman”, "Obrazets", etc.), the overall status indicator will show red.
- Unknown document. The possible reasons why the document type is not recognized are the following: it is a new document that is not yet enrolled into our template database, or the document is fake.
- New document series. Sometimes a new document series is issued on old forms but with some modifications: the layout of the visual zone is slightly different, a new type of laminate or a different ink is used. In such cases, the document is recognized as belonging to the previous series, but some processing errors will occur. This is the case when a more careful manual examination by an expert is required. As in the previous case, this error will no longer occur as soon as we enroll this document into our template database and you install this update.
- Passive Authentication (PA) of the RFID chip failed. This is usually a specific case when a document specimen is scanned. PA fails when we cannot build a certificate chain to a trusted root. In document specimens, this is sometimes done on purpose in order to detect specimens and not allow them to pass the security checks.