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Why is the size of some PDF files bigger than expected?

Posted: Tue Jun 22, 2021 10:45 am
by Patent Information Marketing
Users of Espacenet worldwide can download "original documents" in PDF format for more than 105 countries.

The size of a PDF file is sometimes bigger than the original document publication made available by the patent office or the file downloaded from classic Espacenet. The reason for this is explained below.

Patent document facsimiles are delivered by patent offices to the EPO in different formats (e.g. PDF, ST33, HTML-TIFF and XML-TIFF). The files are stored by the EPO in our prior-art facsimile repositories. These facsimiles are converted and assembled page by page in two standard formats, which are used to display original documents in EPO patent search tools depending on compatibility as follows:
  • a greyscale TIFF format, which is displayed by OPS, classic Espacenet and Global Patent Index (GPI). When using the download feature of classic Espacenet and GPI, this format is converted on the fly to PDF
  • a higher-quality PNG format, sometimes with colour, which is displayed by new Espacenet. However, depending on the incoming format and quality, the file size can be between 1.9 and 8 times the size of the basic black-and-white version. When the download feature of new Espacenet is used, a PDF file constructed from PNG is delivered and may therefore be much bigger than the original document publication provided by the patent office

While the "original document" downloads in Espacenet do not correspond to the "Original File Publications" as produced by the original publishing patent offices, they are faithful representations of the original publications, going back to the publication of 1623 of Robert Mansell (GB162300024A), when electronic formats clearly did not exist. For full legal certainty, we recommend using the official publication channels of the patent offices.

Kind regards,

Andrée Lahaye
Patent Information Marketing