Difference between revisions of "Capturing Handwriting"

Revision as of 23:29, 31 July 2017

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Overview

The best way to transform actual human handwriting into something that the AxiDraw can plot is to capture that handwriting in real time. In real-time capture, you use your computer to record each stroke as it is written, and then save the resulting set of paths as a vector artwork file. This method can also be used when replicating handwriting. For example when replicating historical signatures, it is necessary to trace along the strokes of existing writing and to capture that again in real time.

This page discusses some approaches to real-time capture, as well as some alternatives. Naturally, these same approaches can be used for capturing sketching and other non-handwriting types of artwork as well.

Capturing a signature with jSignature

For very small amounts of text — for example a single signature — a convenient software tool is jSignature. jSignature can create and save an SVG file which can be opened in Inkscape. jSignature can be used from your computer, smartphone, or tablet.

To use it from your computer, sign your signature, and then select "SVG" from the "Extract signature data as" pop-up menu. It should then display your signature as an image below that pop-up menu. Right-click on the image, and select from the menu there "Save image as..." (the exact wording of this option will vary depending on your browser), and save the result with a name like "signature.svg". You can then open up this SVG file from within Inkscape and print to the AxiDraw. For other platforms (smartphone and tablet), you'll need to send the signature to your desktop computer, by a means such as e-mail, before proceeding.

Capturing with a simple graphics tablet

One solution for capturing writing is to use a dedicated graphics tablet such as a Wacom Bamboo or Wacom Intuos Draw. These are relatively inexpensive (< $100) input devices with a stylus. You can use the stylus just like a pen, within almost any application that supports drawing and creating vector graphics. (Be sure to use a vector graphics application such as Inkscape or Adobe Illustrator, and not a bitmap graphics application such as Photoshop.)

While you can certainly write freehand on a tablet like this while watching your screen alone, another approach is to trace existing writing or artwork on a piece of paper. You can attach a piece of paper to the top of your graphics tablet and use the stylus on top of that, to trace handwriting or other artwork.

If you are tracing something small (for example a signature), it is sometimes helpful to start with an extra large version of your signature (perhaps, the full size of your tablet's input area), and shrink the result down when you are done. This helps to minimize any artifacts from your tracing.

Capturing with a hybrid graphics tablet/monitor

There are also high end graphics tablets that are more aptly described as computer monitors which accept stylus input. A good example is the Wacom Cintiq, available in various sizes. These tend to be considerably more expensive than a stand-alone tablet, and you may wish to consider a general-purpose tablet computer (e.g., iPad) as an alternative. (Hints on using a tablet computer are in the section below.)

A graphics tablet with a display is excellent for freehand writing since it provides instant feedback. However it requires a different approach if you wish to trace existing writing or artwork. Use a scan or photograph of the handwriting or artwork that you wish to follow, and display it in the background of the area where you are tracing.

Capturing with a tablet computer such as an iPad

Several commercial software utilities now exist that allow you to use your existing touchscreen tablet computer (usually an iPad or Android tablet) as an external monitor for your Mac or Windows computer. This, combined with the addition of a stylus (for example an included or third-party touchscreen stylus or the Apple Pencil on the iPad Pro) can make a very effective graphics tablet -- and at relatively low cost if you already own such a tablet.

Inkscape settings for handwriting capture

We have found the following settings within Inkscape to work well as a starting point for capturing input from a graphics tablet:

• Use the "Pencil" tool (labeled as "Draw Freehand Lines") from the toolbar to trace over your image. You can select this tool with F6 as well.
• There are two "Mode" options available for this tool. Select the default value, "Create regular Bezier path."
• The "Smoothing" parameter controls the amount of automatic smoothing applied to the input as each stroke is drawn. We typically use a value of 30. If the smoothing is too aggressive, feel free to lower this value.
• Set the "Shape" parameter to None. (Other values allow you to apply a width effect to the path, but these only affect how it is drawn on the screen, not how it will plot.)