Substituting outline fonts for bitmap fonts in archived PDF files

As collections of archived digital documents continue to grow the maintenance of an archive, and the quality of reproduction from the archived format, become important long-term considerations. In particular, Adobe s PDF is now an important final form standard for archiving and distributing electro...

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Main Authors: Probets, Steve, Brailsford, David F.
Format: Article
Published: John Wiley & Sons ltd 2003
Subjects:
Online Access:https://eprints.nottingham.ac.uk/195/
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author Probets, Steve
Brailsford, David F.
author_facet Probets, Steve
Brailsford, David F.
author_sort Probets, Steve
building Nottingham Research Data Repository
collection Online Access
description As collections of archived digital documents continue to grow the maintenance of an archive, and the quality of reproduction from the archived format, become important long-term considerations. In particular, Adobe s PDF is now an important final form standard for archiving and distributing electronic versions of technical documents. It is important that all embedded images in the PDF, and any fonts used for text rendering, should at the very minimum be easily readable on screen. Unfortunately, because PDF is based on PostScript technology, it allows the embedding of bitmap fonts in Adobe Type 3 format as well as higher-quality outline fonts in TrueType or Adobe Type 1 formats. Bitmap fonts do not generally perform well when they are scaled and rendered on low-resolution devices such as workstation screens. The work described here investigates how a plug-in to Adobe Acrobat enables bitmap fonts to be substituted by corresponding outline fonts using a checksum matching technique against a canonical set of bitmap fonts, as originally distributed. The target documents for our initial investigations are those PDF files produced by (La)TEXsystems when set up in a default (bitmap font) configuration. For all bitmap fonts where recognition exceeds a certain confidence threshold replacement fonts in Adobe Type 1 (outline) format can be substituted with consequent improvements in file size, screen display quality and rendering speed. The accuracy of font recognition is discussed together with the prospects of extending these methods to bitmap-font PDF files from sources other than (La)TEX.
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spelling nottingham-1952020-05-04T20:32:06Z https://eprints.nottingham.ac.uk/195/ Substituting outline fonts for bitmap fonts in archived PDF files Probets, Steve Brailsford, David F. As collections of archived digital documents continue to grow the maintenance of an archive, and the quality of reproduction from the archived format, become important long-term considerations. In particular, Adobe s PDF is now an important final form standard for archiving and distributing electronic versions of technical documents. It is important that all embedded images in the PDF, and any fonts used for text rendering, should at the very minimum be easily readable on screen. Unfortunately, because PDF is based on PostScript technology, it allows the embedding of bitmap fonts in Adobe Type 3 format as well as higher-quality outline fonts in TrueType or Adobe Type 1 formats. Bitmap fonts do not generally perform well when they are scaled and rendered on low-resolution devices such as workstation screens. The work described here investigates how a plug-in to Adobe Acrobat enables bitmap fonts to be substituted by corresponding outline fonts using a checksum matching technique against a canonical set of bitmap fonts, as originally distributed. The target documents for our initial investigations are those PDF files produced by (La)TEXsystems when set up in a default (bitmap font) configuration. For all bitmap fonts where recognition exceeds a certain confidence threshold replacement fonts in Adobe Type 1 (outline) format can be substituted with consequent improvements in file size, screen display quality and rendering speed. The accuracy of font recognition is discussed together with the prospects of extending these methods to bitmap-font PDF files from sources other than (La)TEX. John Wiley & Sons ltd 2003 Article PeerReviewed Probets, Steve and Brailsford, David F. (2003) Substituting outline fonts for bitmap fonts in archived PDF files. Software -- Practice and Experience, 33 . pp. 885-899. PDF (LA)TEX bitmap fonts outline fonts
spellingShingle PDF
(LA)TEX
bitmap fonts
outline fonts
Probets, Steve
Brailsford, David F.
Substituting outline fonts for bitmap fonts in archived PDF files
title Substituting outline fonts for bitmap fonts in archived PDF files
title_full Substituting outline fonts for bitmap fonts in archived PDF files
title_fullStr Substituting outline fonts for bitmap fonts in archived PDF files
title_full_unstemmed Substituting outline fonts for bitmap fonts in archived PDF files
title_short Substituting outline fonts for bitmap fonts in archived PDF files
title_sort substituting outline fonts for bitmap fonts in archived pdf files
topic PDF
(LA)TEX
bitmap fonts
outline fonts
url https://eprints.nottingham.ac.uk/195/