PDF/A
ComPDFKit SDK supports analyzing the content of existing PDF files and making a series of modifications to generate documents compliant with the PDF/A standard.
During the process of converting a PDF file to one that complies with the PDF/A standard, features unsuitable for long-term archiving, such as encryption, outdated compression schemes, missing fonts, or device-dependent colors, will be replaced with equivalent elements that conform to the PDF/A standard. Since the conversion process applies only the necessary changes to the source file, minimal information loss occurs.
This example demonstrates how to convert an existing PDF file into a document compliant with the PDF/A-1a standard:
document.convertType(PDFDocumentType.PDFTypeA1a);
What is PDF/A?
PDF/A (Portable Document Format Archival) is a PDF file format standard specifically designed for the long-term preservation of electronic documents. Its purpose is to ensure that documents maintain readability and accessibility over time, meeting the requirements for archiving and long-term preservation. The PDF/A standard is defined by the International Organization for Standardization (ISO) and has become the international standard for electronic document archiving.
PDF/A Versions
Version | Release Date | Standard | Based On |
---|---|---|---|
PDF/A-1 | 2005-09-28 | ISO 19005-1 certified | PDF 1.4 |
PDF/A-2 | 2011-06-20 | ISO 19005-2 certified | PDF 1.7 (ISO 32000-1: 2008) |
PDF/A-3 | 2012-10-15 | ISO 19005-3 certified | PDF 1.7 (ISO 32000-1: 2008) |
PDF/A-4 | 2020-11 | ISO 19005-4 certified | PDF 2.0 (ISO 32000-2: 2020) |
Features of PDF/A
Self-Containment: PDF/A documents should be self-contained, meaning they include all necessary elements and resources, such as fonts, images, and other embedded files. This ensures that the document can be rendered and displayed independently in different environments.
Font Embedding: PDF/A requires that fonts used in the document must be embedded to prevent issues with missing fonts on different systems, ensuring correct document display.
No Compression: PDF/A typically disallows the use of compression algorithms that are unstable for long-term preservation, such as JPEG2000. This helps ensure the reliability and stability of the document.
No Encryption: PDF/A mandates that documents cannot use encryption to guarantee future accessibility and readability. This also ensures that documents are not password-protected and inaccessible for decryption.
Metadata: PDF/A encourages or requires the inclusion of metadata, such as document information, author, title, etc., to provide basic description and management information for the document.
Color Management: The PDF/A standard provides support for color management to ensure consistent display of colors across different devices.