Scanning Hints

Contents

Introduction

General Scanning Hints

1. Resolution
2. Brightness
3. "Black & White" vs. Color or Greyscale
4. A note about Hewlett-Packard scanners

Scanning with TWAIN

Introduction

This file is intended to provide users of Arbor Image's line of raster to vector conversion products with information on how to get the best results from their scanners for use with Arbor Image software. The quality of the vector conversion you end up with depends on the quality of the raster image you start with.

Since scanners and their software differ greatly from one manufacturer to another, familiarizing yourself with your scanner and its software is the best first step in achieving the best possible results. Be sure to read the documentation that came with your scanner, and the relevant sections of your Arbor Image software's User Manual.

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General Scanning Hints

1. Resolution (DPI)

In most cases, the optimum scan resolution for use with Arbor Image raster-to-vector software will be 300 dpi. Lower or higher resolution is certainly possible, but not usually desireable. Lower resolutions usually result in poorer quality conversions, while higher resolutions do not usually improve the conversion quality enough to justify the increased file size.

Remember that the HS model of the software will import a raster 6 1/2" wide if scanned at 300 dpi (1950 pixels). If you were to scan at 600 dpi, you are still restricted to 1950 pixels so you would be limited to a drawing half as wide (3 1/4"). The PF model will import a scan up to 11 inches wide at 300 dpi (3300 pixels), and the LF version will import a scan up to 100 inches wide at 300 dpi (30000 pixels)

When to use higher resolution: There will be times when greater detail will be required than can be achieved with a 300 dpi scan. This will, of course, depend entirely on the quality of scan you are able to achieve (which will depend on the quality of the original and the capabilities of your scanner). Before increasing the DPI, however, try increasing the Brightness during the scanning process to improve line definition (see below).

When to use a lower resolution: When using the HS or PF models of the software, it may occasionally be necessary to scan a larger image that your model can import (see above). In many cases, you may be able to go as low as 200 dpi if the drawing is clean and not too highly detailed. Some adjustment of the vectorization parameters will probably be necessary.

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2. Brightness

To get the best possible conversion, you need to start with the best scan you can get. The most common scanning problem we encounter is a lack of definition, detail and line seperation caused by scanning too dark. (This is often most noticable with Text, where letters tend to "run together" and the hollow areas of individual characters tend to be filled.)

Increasing the Brightness during the scanning process can make a great difference. Care must be taken not to increase the brightness too much, however, as a loss of information can result. Some experimentation will probably be necessary to determine what settings will work best for you. Your scanner's software may also include Contrast or Threshhold adjustments that could be of some help in this regard. Consult your scanner's documentation for information on how to adjust these settings.

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3. "Black & White" vs. Color or Greyscale

Both Draftsman 2002 and Draftsman Cutting Shop work best with black & white raster input for automatic vectorization. Your scanner's software might call this "Black & White," "Line Art," "Black & White Drawing," "2 Color" or "2 Grey," or "1 bit per Pixel."

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