Rochester Institute of Technology RIT Scholar Works Theses 1988 Performance analysis of text-oriented printing using PostScript Thomas Kowalczyk Follow this and additional works at: https://scholarworks.rit.edu/theses Recommended Citation Kowalczyk, Thomas, "Performance analysis of text-oriented printing using PostScript" (1988). Thesis. Rochester Institute of Technology. Accessed from This Thesis is brought to you for free and open access by RIT Scholar Works. It has been accepted for inclusion in Theses by an authorized administrator of RIT Scholar Works. For more information, please contact [email protected]. Rochester Institute ofTechnology School ofComputer Science and Technology Perfonnance Analysis of Text-Oriented Printing Using POSTSCRIPT® by Thomas L. Kowalczyk A thesis, submitted to The Faculty ofthe School ofComputer Science and Technology, in partial fulfillment ofthe requirements for the degree of Master ofScience in Computer Science Approved by: Guy Johnson Professor and Chairman of Applied Computer Studies Dr. Vishwas G. Abhyankar instructor Frank R.Hubbell instructor October 10, 1988 Thesis Title: Performance Analysis of Text-Oriented Printing Using POSTSCRIPT® I, Thomas L. Kowalczyk, hereby grant permission to the Wallace Memorial Libra.ry, of R.I.T., to reproduce my thesis in whole or in part under the following conditions: 1. I am contacted each time a reproduction is made. I can be reached at the fol1mving address: 82 Brush Hollow Road Rochester, New York 14626 Phone # (716) 225-8569 2. Any reproduction will not be for commercial use orprofit. Date: October 10,1988 i Pennission Statement Apple, Appletalk, LaserWriter, and Macintosh are registered trademarks of Apple Computer, Inc. Fluent Laser Fonts and Galileo Roman are trademarks of CasadyWare Inc. Helvetica, Palatino, and Times are registered trademarks of Linotype Co. ITC Avant Garde, ITC Bookman, ITC Garamond, ITC Zapf Chancery, and ITC Zapf Dingbats are registered trademarks of International Typeface Corporation POSTSCRIPT is a registered trademark of Adobe Systems Incorporated. Interpress in a registered trademark of Xerox Corp. u Trademarks Abstract POSTSCRIPT is a page description language which is used to transmit printing information from a host computer (i.e. Apple Macintosh) to a printer (i.e. Apple LaserWriter Plus). It has the ability to describe pages consisting of text, vector graphics, and scanned bit-map images. Printing text is the area of concentration for this thesis. Specifically several variables that affect the printing speed of a common POSTSCRIPT printer, the Apple LaserWriter Plus, are looked at when printing text in a variety of fonts, sizes, and orientations. The variables that affect printer performance include: - use of outline vs. bit-map fonts; - the outline font rasterization process; - the use of pre-cached bit-map fonts; - background outline font rasterization; - arbitrary scaling and rotation; - downloading host-resident fonts; - Adobe and Third Party host-resident downloadable fonts vs. printer-resident fonts; - Appletalk vs. RS-232 communications interfaces; - use of the POSTSCRIPT show, ashow, and widthshow instructions; - targeting the POSTSCRIPT instructions at a particular engine resolution; - print engine overhead A sequence of POSTSCRIPT files were transmitted to the Apple LaserWriter Plus printer. The experiments were carefully constructed to exercize each of the variables listed above. Performance measurements were carefully recorded and analyzed. Where applicable, improvements were proposed to improve printer performance. in Abstract Tfl!?lP of Contents Page Permission Statement ' Trademarks n Abstract ' Table of Contents iv 1. Introduction 1 1.1. Background 1 1.2 "PDL" Defined 1 1.3 History of Interpress and POSTSCRIPT 2 1.4 A Comparison of Outline vs. Bitmap Fonts 4 1 .5 Text, Vector Graphics, and Bitmap Images 8 1.5.1 Text 8 1.5.2 Bitmap Images 9 1.5.3 Vector Graphics 10 2. Problem Description 13 2.1 Variables that Affect Performance 14 problem description and expected results 2.1.1 Font Formats: Outlines vs. Bitmaps 14 2.1.1.1 Outline Font Rasterization and Caching 15 2. 1 . 1 .2 Pre-Cached Bit-Maps 15 2.1.1.3 Background Outline Font Rasterization 16 2. 1 . 1 .4 Effect of Scaling and Rotation 17 2. 1 . 1 .5 Variations of Font Style 19 iv Table of Contents (continued) Page 2.1.2 Downloaded Fonts 20 2.1.2.1 Downloaded Bitmaps vs. 21 Printer Resident (Cached) Bitmaps 2.1.2.2 Adobe Downloaded Outlines vs. 22 Printer Resident (Internal) Outlines 2. 1 .2.3 Adobe Downloaded Outlines vs. 23 Third Party Downloaded Outlines 2.1.2.4 Appletalkvs.RS-232 25 2.1.3 Methods of Printing Strings 26 "Targeting" 2.1.4 Resolution vs. Total 27 Resolution Independence 2.1.5 Effect of Varied Page Complexity on POSTSCRIPT 28 Processing Time 2. 1 .5. 1 Effect on the Inter-Page Time Delay 28 Program sec 2.1.5.2 Effect on the Compilation and Rasterization 29 of Text Pages 2.2 Performance Measurement and Calculation 30 2.2.1 Communications 31 2.2.2 Interpretation (Compilation) and Rasterization 35 2.2.3 Print Engine Paper Ejection 44 2.3 Programming Tasks 45 2.3.1 Extraction of Font Widths from 45 Apple Laser Writer Plus 2.3.2 Batch Composition Program 47 2.3.3 Downloadable POSTSCRIPT Bitmap Font Program 49 2.3.4 Installing Downloadable POSTSCRIPT Outline Fonts 54 2.4 Assumed RIP Architectural Model 55 v Table of Contents Tahlp of Contents (continued) Page 3. Analysis of Experimental Results 59 3.1 Font Formats: Outlines vs. Bitmaps 59 3.1.1 Red Time Outline Font Rasterization and Caching 59 3. 1 . 1 .A Experimental Results 3.1. LB Analysis 3.1. l.C Proposed Improvements 3.1.2 Pre-Cached Bit-Maps 65 3. 1 .2.A Experimental Results 3.1.2.B Analysis 3. 1 .2.C Proposed Improvements 3.1.3 Background Outline Font Rasterization 67 3 . 1 . 3 . A Experimental Results 3.1.3.B Analysis 3.1.3.C Proposed Improvements 3.1.4 Effect of Scaling and Rotation 71 3. 1 .4.A Experimental Results 3.1.4.B Analysis 3.1 .4.C Proposed Improvements 3.1.5 Variations ofFont Style 78 3.1.5.A Experimental Results 3.1.5.B Analysis 3. 1 .5.C Proposed Improvements 3.2 Downloaded Fonts 81 3.2.1 Downloaded Bitmaps vs. Printer Resident 81 (Cached) Bitmaps 3.2. 1 .A Experimental Results 3.2. LB Analysis 3.2. 1 .C Proposed Improvements 3.2.2 Adobe Downloaded Outlines vs. 86 Printer Resident (Internal) Outlines 3.2.2.A Experimental Results 3.2.2.B Analysis 3.2.2.C Proposed Improvements vi Table of Contents Table of Contents (continued) Page 3.2.3 Adobe Downloaded Outlines vs. 91 Third Party Downloaded Outlines 3.2.3.A Experimental Results 3.2.3.B Analysis 3.2.3.C Proposed Improvements 3.2.4 Appletalk vs. RS-232 97 3.2.4.A Experimental Results 3.2.4.B Analysis 3.2.4.C Proposed Improvements 3.3 Methods of Printing Strings 102 3.3.A Experimental Results 3.3.B Analysis 3.3.C Proposed Improvements "Targeting" 3.4 Resolution vs. Total Resolution Independence 111 3.4.A Experimental Results 3.4.B Analysis 3.4.C Proposed Improvements 3.5 Effect of Varied Page Complexity on POSTSCRIPT 115 Processing Time 3.5. 1 Effect on the Inter-Page Time Delay Program sec 115 3 . 8 . 1.A Experimental Results 3.8. LB Analysis 3.8. l.C Proposed Improvements 3.5.2 Effect on the Compilation and Rasterization 118 of Text Pages 3.8.2.A Experimental Results 3.8.2.B Analysis 3.8.2.C Proposed Improvements 4. Conclusions 123 4.1 Scan Converting Outline Fonts vs. Caching Bitmap Fonts 123 Hints" 4.2 Scan Converting Font Outlines with "Quality Applied 124 4.3 Font Style Complexity 124 4.4 Downloading Fonts 125 4.5 Methods of Printing Strings 125 4.6 Resolution Targeting 126 vii Table of Contents TflhiP of Contents (continued) Page 4.7 Printer Induced Delays 127 5. Glossary 6. References 133 7. Bibliography 1. Equipment and Software Tools Evaluation Equipment Configuration 1 . 1 POSTSCRIPT 2. Support Programs 2.1 PostScript Font Widths 2.1.1 Font Extraction Program the Laser Writer Plus 2. 1 .2 Printed Font Width Tables from Apple Width Table CH 2. 1 .3 Times-Roman Font (AS File) 2.2 Generation of POSTSCRIPT Text Pages 2.2. 1 Batch Composition Pseudo-Code "Content" 2.2.2 Input Data File "Style" 2.2.3 Input Markup File 2.2.4 Text PostScript File 2.2.5 Printed Text and Timing Pages from the Apple Laser Writer Plus viu Table of Contents 1. Introduction 1.1 Background An electrtonic publishing system is made up of three main parts: the front-end, the RIP, and the print engine. Figure 1.1 is a block diagram of a typical electronic publishing system. Page Description External Bit-Map fe- Front Language ^ Print n formi ri n n RIP W w' Input End Engine Engine Control Electronic Publishing System Block Diagram figure 1.1 The front-end provides interfaces to the user and to other computer systems. The user interface handles input of text, graphics, and bit-map (scanned) images, and provides the merging and page layout of these pieces in either a batch or interactive (WYSIWYG) mode. The computer interface provides a communications interface with other information input systems (ie. word processors, illustration stations). This information is filtered by the front-end to yield the internal page format of the electronic publishing system. Ultimately, the output of the front-end language" processor" is the "page description (PDL) file which is sent to the "raster image (RIP). The PDL file describes the marks on the printed page.