Acrobat Widths-Only CIDFont Tutorial

Adobe Developer Technologies

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Acrobat Widths-Only CIDFont TutorialbbcTechnical Note #5412ADOBE SYSTEMS INCORPORATED Corporate Headquarters345 Park AvenueSan Jose, CA 95110-2704(408) 536-6000http://partners.adobe.comApril 12, 2001 Copyright 2001 Adobe Systems Incorporated. All rights reserved. NOTICE: All information contained herein is the property of Adobe Systems Incorporated. No part of this publication (whether in hardcopy or electronic form) may be reproduced or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written consent of the Adobe Systems Incorporated. PostScript is a registered trademark of Adobe Systems Incorporated. All instances of the name PostScript in the text are references to the PostScript language as defined by Adobe Systems Incorporated unless otherwise stated. The name PostScript also is used as a product trademark for Adobe Systems’ implementation of the PostScript language interpreter. Except as otherwise stated, any reference to a “PostScript printing device,” “PostScript display device,” or similar item refers to a printing device, display device or item (respectively) that contains PostScript technology created or licensed by Adobe Systems Incorporated and not to devices or items that purport to be merely compatible with the PostScript language.Adobe, the Adobe logo, Acrobat, the Acrobat logo, Acrobat Capture, Acrobat Catalog, Acrobat Exchange, Acrobat Search, ...

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• Publié par: Ficir
• Nombre de lectures: 12
• Langue: English

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Acrobat WidthsOnly CIDFont Tutorial

Technical Note #5412

ADOBE SYSTEMS INCORPORATED Corporate Headquarters 345 Park Avenue San Jose, CA 95110-2704 [phone] http://partners.adobe.com

April 12, 2001

Copyright 2001 Adobe Systems Incorporated. All rights reserved.

NOTICE: All information contained herein is the property of Adobe Systems Incorporated. No part of this publication (whether in hardcopy or electronic form) may be reproduced or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written consent of the Adobe Systems Incorporated.

PostScript is a registered trademark of Adobe Systems Incorporated. All instances of the name PostScript in the text are references to the PostScript language as deÞned by Adobe Systems Incorporated unless otherwise stated. The name PostScript also is used as a product trademark for Adobe Systems’ implementation of the PostScript language interpreter.

Except as otherwise stated, any reference to a “PostScript printing device,” “PostScript display device,” or similar item refers to a printing device, display device or item (respectively) that contains PostScript technology created or licensed by Adobe Systems Incorporated and not to devices or items that purport to be merely compatible with the PostScript language.

Adobe, the Adobe logo, Acrobat, the Acrobat logo, Acrobat Capture, Acrobat Catalog, Acrobat Exchange, Acrobat Search, Distiller, Illustrator, Photoshop, PostScript, and the PostScript logo are trademarks of Adobe Systems Incorporated.

Apple, Macintosh, and Power Macintosh are trademarks of Apple Computer, Inc., registered in the United States and other countries. ActiveX, Microsoft, Windows, and Windows NT are either registered trademarks or trademarks of Microsoft Corporation in the United States and other countries. UNIX is a registered trademark of The Open Group. All other trademarks are the property of their respective owners.

This publication and the information herein is furnished AS IS, is subject to change without notice, and should not be construed as a commitment by Adobe Systems Incorporated. Adobe Systems Incorporated assumes no responsibility or liability for any errors or inaccuracies, makes no warranty of any kind (express, implied, or statutory) with respect to this publication, and expressly disclaims any and all warranties of merchantability, Þtness for particular purposes, and noninfringement of third party rights.

Chapter 1

1.1 1.2 1.3

Contents

Acrobat WidthsOnly CIDFont Tutorial . . . . . . . . . . . . 1

Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Differences Between CIDFonts & WidthsOnly CIDFonts . . . . . . . . . . . . . . . . . . . 1 Installing & Using WidthsOnly CIDFonts . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

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1.1 Introduction

Widths-only CIDFont Þles are almost identical to genuine CIDFont Þles, except that they have a special/WidthsOnly keywordin the header, and provide only advance widths for each CID. Hence, they are referred to as widths-only CIDFonts.

Widths-only CIDFonts are used by Acrobat Distiller, Version 4.0 and later, when it encounters a PostScript Þle that contains a reference to a font whose outlines are not otherwise available. Widths-only CIDFonts allow Acrobat Distiller to create a metrically-correct PDF Þles.

Detailed information on how to build genuine CIDFont Þles can be found in Adobe Technical Note #5014, ÒAdobe CMap and CID Font Files SpeciÞcation Version 1.0,Ó which is available from the ASN (Adobe Solutions Network) Developer Program at the following URL:

http://partners.adobe.com/asn/developer/technotes/main.html

1.2 Differences Between CIDFonts & WidthsOnly CIDFonts

Widths-only CIDFonts and CIDFonts differ in a small number of ways, enumerated as follows: ● There is a new keyword in the CIDFont header, which is set to true :  /WidthsOnly true def

This keyword, when set to true , tells Acrobat Distiller that this is a widths-only CIDFont, and needs to be treated accordingly.

● The /FontBBox array in the CIDFont header should be set the same as the genuine CIDFont. For the widths-only KozMinPro-Light CIDFont, it is set as follows:

/FontBBox [ 191 272 1104 1071 ] def

This information is used by Distiller, and helps a widths-only CIDFont behave much like the genuine CIDFont.

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 Acrobat WidthsOnly CIDFont Tutorial Differences Between CIDFonts & WidthsOnly CIDFonts

● The charstrings for each CID shall look like those in the following three examples, shown in human-readable form:

 0 1000 hsbw 0 callsubr endchar  0 280 hsbw 0 callsubr endchar  0 1000 hsbw 0 callsubr endchar

Note how the first and third charstrings are identical. These example charstrings are taken from CIDs 0, 1, and 1200 of the CIDFont KozMinPro-Light. CID=0 has a full width (1,000 units), CID=1 has a proportional width (280 units), and CID=1200 has a full width (1,000 units). Compare the above with the charstrings in the genuine CIDFont:

 100 1000 hsbw 0 50 vstem 750 50 vstem 120 50 hstem 830 50 hstem  120 vmoveto 800 hlineto 1000 vlineto 800 hlineto closepath 400  459 rmoveto 318 409 rlineto 636 hlineto closepath 286 450  rmoveto 318 409 rlineto 818 vlineto closepath 668 41 rmoveto  318 409 rlineto 318 409 rlineto closepath 668 859 rmoveto 318  409 rlineto 318 409 rlineto closepath endchar  0 280 hsbw endchar  42 1000 hsbw 0 917 vstem 378 29 hstem 8 378 rmoveto 854 hlineto 30 0  15 6 10 20 rrcurveto 112 78 rlineto 59 75 rlineto 746 hlineto  closepath endchar

Specifically, the hints and contour descriptions are replaced by the same subroutine call (Ò0 callsubrÓ), but the width information remains. Note how the value immediately before the specified width, called the left side bearing value, is changed to 0 (zero) for all charstrings.

● Each hint dictionary shall contain exactly one subroutine, deÞned as follows:

 0 120 rmoveto 1000 hlineto 1000 vlineto 1000 hlineto closepath  return

 The in each charstring references the above subroutine definition. "0 callsubr"

● each hint dictionary shall be set to a value of Ð1, meaning that allThe in /lenIV charstrings are clear, thus lacking Type 1 encryption. N O T E : It is not absolutely necessary to subroutinize the charstrings as described above, but it is recommended for space savings. The basic requirement is that the charstrings must encode the same set width as the corresponding charstring in the genuine CIDFont, and must contain a path that draws a solid em-box relative to the origin.

Lastly, a widths-only CIDFont is named exactly the same as its genuine counterpart.

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 Acrobat WidthsOnly CIDFont Tutorial Installing & Using WidthsOnly CIDFonts

1.3 Installing & Using WidthsOnly CIDFonts

Widths-only CIDFonts must be installed into Acrobat DistillerÕs private CIDFont directory in order to be recognized and used. That directory, for both Macintosh and Windows, is located as follows:  Mac OS: Distiller:Data:psdisk:Resource:CIDFont:  Windows: Distillr\Data\psdisk\Resource\CIDFont\ When widths-only CIDFonts are used, PDF Þles with font references are created. ItÕs not possible to embed widths-only CIDFonts, because the only meaningful information that they contain are advance widths. Bear in mind that there are limitations in how Acrobat substitutes CJKV fonts. If the original font is not available when the PDF Þle is printed or displayed, then a substitution font is selected that may or may not match the original font in weight or style. Substitution of glyphs that use proportional widths is only supported for proportional Latin glyphs (that is, kana glyphs that use proportional widths will not be displayed or printed correctly when a substitution font is used). When thumbnails are automatically created by Distiller, the use of widths-only CIDFonts that conform to these speciÞcations will result in boxes appearing in the thumbnails. If the thumbnails are generated (or regenerated) using the Acrobat Viewer, this problem does not occur, because Acrobat Viewer does not have access to the widths-only CIDFonts.

To ensure that a PDF Þle will be printed and displayed as the original document, the original font, containing all needed outline glyphs, must be embedded in the PDF Þle.

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Acrobat WidthsOnly CIDFont Tutorial Installing & Using WidthsOnly CIDFonts

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