我用 tcpdf 库在 php 中创建了一个 pdf/a-1b,但没有通过这些错误的验证( http://www.pdf-tools.com/pdf/validate-pdfa-online.aspx ):
pdfaExtension:schemas/ [0] :: 值类型“Schema”中缺少必填字段“valueType”。pdfaExtension:schemas/ [1] :: 值类型“Schema”中缺少必填字段“valueType”。pdfaExtension:schemas/*[2] :: 值类型“Schema”中缺少必填字段“valueType”。
<x:xmpmeta xmlns:x="adobe:ns:meta/" x:xmptk="Adobe XMP Core 4.2.1-c043 52.372728, 2009/01/18-15:08:04">
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
<rdf:Description rdf:about="" xmlns:dc="http://purl.org/dc/elements/1.1/">
<dc:format>application/pdf</dc:format>
<dc:title>
<rdf:Alt>
<rdf:li xml:lang="x-default">PDF Test</rdf:li>
</rdf:Alt>
</dc:title>
<dc:creator>
<rdf:Seq>
<rdf:li>Example Creator</rdf:li>
</rdf:Seq>
</dc:creator>
<dc:description>
<rdf:Alt>
<rdf:li xml:lang="x-default">Example Description</rdf:li>
</rdf:Alt>
</dc:description>
<dc:subject>
<rdf:Bag>
<rdf:li></rdf:li>
</rdf:Bag>
</dc:subject>
</rdf:Description>
<rdf:Description rdf:about="" xmlns:xmp="http://ns.adobe.com/xap/1.0/">
<xmp:CreateDate>2016-06-12T19:59:46+02:00</xmp:CreateDate>
<xmp:CreatorTool>Example Creator</xmp:CreatorTool>
<xmp:ModifyDate>2016-06-12T19:59:46+02:00</xmp:ModifyDate>
<xmp:MetadataDate>2016-06-12T19:59:46+02:00</xmp:MetadataDate>
</rdf:Description>
<rdf:Description rdf:about="" xmlns:pdf="http://ns.adobe.com/pdf/1.3/">
<pdf:Keywords></pdf:Keywords>
<pdf:Producer>Example Producer</pdf:Producer>
</rdf:Description>
<rdf:Description rdf:about="" xmlns:xmpMM="http://ns.adobe.com/xap/1.0/mm/">
<xmpMM:DocumentID>uuid:cf05125b-6fc5-54c8-0218-9e2394589e95</xmpMM:DocumentID>
<xmpMM:InstanceID>uuid:cf05125b-6fc5-54c8-0218-9e2394589e95</xmpMM:InstanceID>
</rdf:Description>
<rdf:Description rdf:about="" xmlns:pdfaid="http://www.aiim.org/pdfa/ns/id/">
<pdfaid:part>1</pdfaid:part>
<pdfaid:conformance>B</pdfaid:conformance>
</rdf:Description>
<rdf:Description rdf:about="" xmlns:pdfaExtension="http://www.aiim.org/pdfa/ns/extension/" xmlns:pdfaSchema="http://www.aiim.org/pdfa/ns/schema#" xmlns:pdfaProperty="http://www.aiim.org/pdfa/ns/property#">
<pdfaExtension:schemas>
<rdf:Bag>
<rdf:li rdf:parseType="Resource">
<pdfaSchema:namespaceURI>http://ns.adobe.com/pdf/1.3/</pdfaSchema:namespaceURI>
<pdfaSchema:prefix>pdf</pdfaSchema:prefix>
<pdfaSchema:schema>Adobe PDF Schema</pdfaSchema:schema>
<pdfaSchema:property>
<rdf:Seq>
<rdf:li rdf:parseType="Resource">
<pdfaProperty:category>internal</pdfaProperty:category>
<pdfaProperty:description>A name object indicating whether the document has been modified to include trapping information</pdfaProperty:description>
<pdfaProperty:name>Trapped</pdfaProperty:name>
<pdfaProperty:valueType>Text</pdfaProperty:valueType>
</rdf:li>
</rdf:Seq>
</pdfaSchema:property>
</rdf:li>
<rdf:li rdf:parseType="Resource">
<pdfaSchema:namespaceURI>http://ns.adobe.com/xap/1.0/mm/</pdfaSchema:namespaceURI>
<pdfaSchema:prefix>xmpMM</pdfaSchema:prefix>
<pdfaSchema:schema>XMP Media Management Schema</pdfaSchema:schema>
<pdfaSchema:property>
<rdf:Seq>
<rdf:li rdf:parseType="Resource">
<pdfaProperty:category>internal</pdfaProperty:category>
<pdfaProperty:description>UUID based identifier for specific incarnation of a document</pdfaProperty:description>
<pdfaProperty:name>InstanceID</pdfaProperty:name>
<pdfaProperty:valueType>URI</pdfaProperty:valueType>
</rdf:li>
<rdf:li rdf:parseType="Resource">
<pdfaProperty:category>internal</pdfaProperty:category>
<pdfaProperty:description>The common identifier for all versions and renditions of a document.</pdfaProperty:description>
<pdfaProperty:name>OriginalDocumentID</pdfaProperty:name>
<pdfaProperty:valueType>URI</pdfaProperty:valueType>
</rdf:li>
</rdf:Seq>
</pdfaSchema:property>
</rdf:li>
<rdf:li rdf:parseType="Resource">
<pdfaSchema:namespaceURI>http://www.aiim.org/pdfa/ns/id/</pdfaSchema:namespaceURI>
<pdfaSchema:prefix>pdfaid</pdfaSchema:prefix>
<pdfaSchema:schema>PDF/A ID Schema</pdfaSchema:schema>
<pdfaSchema:property>
<rdf:Seq>
<rdf:li rdf:parseType="Resource">
<pdfaProperty:category>internal</pdfaProperty:category>
<pdfaProperty:description>Part of PDF/A standard</pdfaProperty:description>
<pdfaProperty:name>part</pdfaProperty:name>
<pdfaProperty:valueType>Integer</pdfaProperty:valueType>
</rdf:li>
<rdf:li rdf:parseType="Resource">
<pdfaProperty:category>internal</pdfaProperty:category>
<pdfaProperty:description>Amendment of PDF/A standard</pdfaProperty:description>
<pdfaProperty:name>amd</pdfaProperty:name>
<pdfaProperty:valueType>Text</pdfaProperty:valueType>
</rdf:li>
<rdf:li rdf:parseType="Resource">
<pdfaProperty:category>internal</pdfaProperty:category>
<pdfaProperty:description>Conformance level of PDF/A standard</pdfaProperty:description>
<pdfaProperty:name>conformance</pdfaProperty:name>
<pdfaProperty:valueType>Text</pdfaProperty:valueType>
</rdf:li>
</rdf:Seq>
</pdfaSchema:property>
</rdf:li>
</rdf:Bag>
</pdfaExtension:schemas>
</rdf:Description>
</rdf:RDF>
我该如何解决这个错误?缺少什么价值?在哪里?
谢谢你