Archive Class

The alternate text describing the image

The alternate text provides a meaningful description of the images. For example, "This color image shows a small sailing boat at sunset". This information can be used to read the document to the visually impaired.

The list must contain a description for each page of the input image document. For the conversion of SinglePageDocument, a single description is sufficient. For MultiPageDocument, multiple descriptions may be required.

Alternate text is required for PDF/A level A conformance. It is not advisable to add "dummy" tagging solely for the purpose of achieving level A conformance. Instead, for scanned text documents, the Conversion Service can be used to recognize the characters in the documents (OCR) and tag the image with the recognized structure and text. For other types of images, such as photos, logos or graphics, alternate text descriptions should be written manually by a user.

Default: empty list

The PDF/A conformance of the output document

The supported PDF/A conformance are:

• "PDF/A-1b"
• "PDF/A-1a"
• "PDF/A-2b"
• "PDF/A-2u"
• "PDF/A-2a"
• "PDF/A-3b"
• "PDF/A-3u"
• "PDF/A-3a"

Default value: "PDF/A-2b"

The image conversion options

The language of the output PDF

The language code that specifies the language of the PDF and specifically its AlternateText descriptions. Specifying the language is highly recommended for PDF/A level A conformance.

The codes are defined in BCP 47 and ISO 3166:2013 and can be obtained from the Internet Engineering Task Force and the International Organization for Standardization.

If no code is set, the language will be specified as unknown.

Examples:

• "en"
• "en-US"
• "de"
• "de-CH"
• "fr-FR"
• "zxx" (for non linguistic content)

Default: (unknown)