Adobe FrameMaker to Microsoft Word Document Conversion Part 3: Bitmap to vector conversions

Transcription

1 FrameMaker to Word Conversions 1 Part 3: Bitmap to vector conversions Adobe FrameMaker to Microsoft Word Document Conversion Part 3: Bitmap to vector conversions 1 Introduction This Part 3 document follows on from Adobe FrameMaker to Microsoft Word Document Conversion Part 2: Delivered Graphics. From Part 2, the delivered graphics files should have been assessed for quality and suitability. Typical outcomes could be: Graphic is good can be reused as is requires simple bitmap editing Graphic is poor or too complicated for simple bitmap editing needs to be drawn afresh needs to be regenerated It is an investment for the future to change all the bitmap images into vector drawings. Although this is the ideal, resource constraints often force minimum time solutions and compromises. Part 3 deals with bitmap image conversion to a vector (line) drawing. 2 Bitmap to vector conversions Mention bitmap to vector conversion and in many meetings someone will say I know/have a program that does that. This is not usually a solution statement. On investigation one often finds the proposer has never used the program. Those that have probably didn t use the program on technical drawings. Bitmap tracing programs do good jobs on tracing artworks, such as a tiger s head. For this work it doesn t matter so much if a line varies in thickness, has bumps, isn t straight and is not at a defined angle e.g. horizontal. All these things matter for a technical drawing. If a bitmap trace of a line is done it follows the outline created by the black squares of the bitmap. The traced line created is a shape with a black fill, not a line at all. It can be useful to trace a bitmap image. The tracing can be more readable than the bitmap it traced and is a better template for a redraw than the bitmap. Having a vector drawing allows rotation to correct line slope caused by the original paper drawing not being square in the scanner. Bitmaps can be rotated, but the resampling involved normally degrades the quality. 3 Tracing Programs These programs can be part of a drawing package or a standalone program. Both types are covered here. Figure 1 is the bitmap test image. Often the programs will have the ability to trace with lines or curves and smooth out the image serrated edge. Some programs will be able to reduce the number of drawing points, effectively smoothing out the drawn shapes.

2 FrameMaker to Word Conversions 2 Part 3: Bitmap to vector conversions Figure 1. Test image (300 dpi at this magnification) Several programs were used to trace the Figure 1 image. Each trace was done with an out of the box product performance. No attempt was made to optimise the tracing performance. The results are shown in Annex A. Out of the small number of programs tested Inkscape and KVEC gave the best results for the test image. Inkscape is open source software and is being continuously improved. As it is free and has a comprehensive set of drawing tools it rates as the best buy for volunteer editors. KVEC is a dedicated tracing program with a lot of tracing options as shown on the product Website. If you want the best quality trace, KVEC just has the edge and is available at modest cost.

3 FrameMaker to Word Conversions 3 Part 3: Bitmap to vector conversions 4 Using Traced Image If the tracing is good enough the vector graphic can be used in the standard. Generally the text will need to be replaced by crisp typed text. One can edit the traced lines to improve the drawing. Selecting a line shape and increasing the width of the line forming the shape can increase the line shape thickness. Lines can also be modified by editing the points that define the line shape or deleting the line shape and replacing it with a vector line. Alternatively the traced drawing can be used as the template to redraw the drawing. To do this easily, a drawing package that uses layers is best. Layers are like several sheets of tracing paper one on top of each other. Drawing on one layer doesn t affect the content on other layers. Figure 2 shows the idea. Figure 2. Trace over using layers 5 Comments The quality and speed of the best tracing programs makes it practical to trace all the images. If the results are acceptable these vector drawings can be used in place of the bitmaps. As noted, replacing the traced text with typed-in text greatly improves the look of the text entries. Substantive drawing changes can be done by redrawing from scratch or using the drawing software layers feature to trace over a template on another layer

4 FrameMaker to Word Conversions 4 Part 3: Bitmap to vector conversions Annex A Tracing program results (normative) A.1 Xara Xtreme Pro

5 FrameMaker to Word Conversions 5 Part 3: Bitmap to vector conversions A.2 KVEC

6 FrameMaker to Word Conversions 6 Part 3: Bitmap to vector conversions A.3 Corel Trace 12

7 FrameMaker to Word Conversions 7 Part 3: Bitmap to vector conversions A.4 Adobe Illustrator CS Result wasn t useable A.5 Inkscape Download at

8 FrameMaker to Word Conversions 8 Part 3: Bitmap to vector conversions A.6 Corel DESIGNER 9 (2002) Obsolete! Shows how tracing performance has improved since Replace by Corel Designer Technical Suite 12 (Corel Trace 12)

9 FrameMaker to Word Conversions 9 Part 3: Bitmap to vector conversions Annex B Trace Optimising (informative) B.1 Introduction Volunteer editors normally have a day-job, whose description doesn t include the requirement to become proficient at bitmap tracing. Any improvements to the software out of the box bitmap tracing are a labour of love. A bitmap-tracing tutorial for Inkscape can be found at A 2-page explanation of the KVEC tracing parameters can be found at There are some neat things here. For example, the KVEC gapfill parameter controls whether the vectorizer can 'jump' over gaps while tracing an object. What this can do is join a line that has become a dashed line, as a result of the digitisation missing bits (literally), into a solid line. All very complicated though. The following clauses show the various trace results of using the Corel Trace program preset modes of: Outline Advanced Outline Centreline Centreline Outline These traces show tradeoffs between the various vectorisation parameters. The optimum trace setting mode will be dependent on the bitmap being traced. To emphasise the tracing mode differences, the traces are expanded to 150 % of the actual size. Notice how the centreline modes cause a sag in the 40 C line and a bow in the 72 hr line.

10 FrameMaker to Word Conversions 10 Part 3: Bitmap to vector conversions B.2 Corel Trace in Outline mode

11 FrameMaker to Word Conversions 11 Part 3: Bitmap to vector conversions B.3 Corel Trace in Advanced Outline mode

12 FrameMaker to Word Conversions 12 Part 3: Bitmap to vector conversions B.4 Corel Trace in Centreline mode

13 FrameMaker to Word Conversions 13 Part 3: Bitmap to vector conversions B.5 Corel Trace in Centreline Outline mode Author: Mick Maytum has been a technical document proof-reader, press programmer in the early days of electronic printing and has worked with (Windows) FrameMaker for 15 years. Currently he is lead editor for the ITU-T Study Group 5, editor for IEC SC 37 WG 4, Chair of the IEEE PES SPDC SC 3.7(Web and Electronic Documentation) and controls the SPDC and IEEE SPD Forum Web sites. He may be contacted at m.j.maytum@ieee.org.