You can determine whether a PDF document is PDF/A-compliant
by using the Assembler service. A PDF/A document exists as an archival
format meant for long-term preservation of the document’s content.
The fonts are embedded within the document, and the file is uncompressed.
As a result, a PDF/A document is typically larger than a standard
PDF document. Also, a PDF/A document does not contain audio and
video content.
The PDF/A-1 specification consists of two levels of conformance,
namely A and B. The major difference between the two levels is the
logical structure (accessibility) support, which is not required
for conformance level B. Regardless of the conformance level, PDF/A-1
dictates that all fonts are embedded within the generated PDF/A
document. At this time, only PDF/A-1b is supported in validation
(and conversion).
For the purpose of this discussion, assume that the following
DDX document is used.
<?xml version="1.0" encoding="UTF-8"?>
<DDX xmlns="http://ns.adobe.com/DDX/1.0/">
<DocumentInformation source="Loan.pdf" result="Loan_result.xml">
<PDFAValidation compliance="PDF/A-1b" resultLevel="Detailed" ignoreUnusedResources="true" allowCertificationSignatures="true" />
</DocumentInformation>
</DDX>
Within this DDX document, the DocumentInformation element
instructs the Assembler service to return information about the
input PDF document. Within the DocumentInformation element,
the PDFAValidation element instructs the Assembler service
to indicate whether the input PDF document is PDF/A-compliant.
The Assembler service returns information that specifies whether
the input PDF document is PDF/A-compliant within an XML document
that contains a PDFAConformance element. If the
input PDF document is PDF/A-compliant, the value of the PDFAConformance element’s isCompliant attribute
is true. If the PDF document is not PDF/A-compliant,
the value of the PDFAConformance element’s isCompliant attribute
is false.
注意: Because the DDX document specified in this section
contains a DocumentInformation element, the Assembler
service returns XML data instead of a PDF document. That is, the
Assembler service does not assemble or disassemble a PDF document;
it returns information about the input PDF document within an XML
document.