Creative Inkscape effects in practice

The first article of this two-part series [2] introduced the effects toolkit of the leading free vector graphics program, Inkscape. In this article, I'll show how to create some real artworks based on these techniques.

Getting Started

You can start by creating a slightly oriental, shiny pattern (Figure 1, bottom right), which is quite easy to do in Inkscape. For the intricate pattern, you can use a photo from a Persian wall mosaic [3] (Figure 1, top left), which you can trace with Inkscape's vectorizing tool and create the image you see in Figure 1, top right.

Figure 1: From an original photo (1), you can apply the settings shown in Figure 2 to create a vectorized version (2). Then, apply an exclusive-or function (3) and finish with "fat oil" and "mother-of-pearl" effects (4).

This image would end up having too many nodes to manipulate comfortably, so you should reduce it in advance to 1,000 pixels wide.

Peeling Away

The vectorization function Path | Trace Bitmap transforms the golden arabesque pattern in a few mouse clicks to a vector format (Figure 2). Recognizing shapes in photos is a challenge for computers, even if it is easy for humans. Nevertheless, with a proper use of Inkscape's vectorization tool, you can get very good results.

Figure 2: You can use the settings in Path | Trace Bitmap to vectorize the Persian wall mosaic.

Luckily, the original Persian wall mosaic photo, despite its delicacy, is easy to convert, because of the contrast between the blue background and yellow pattern. Therefore, you would not need the Edge detection algorithm (not selected in Figure 2) that finds the edges in images with many similarly colored elements.

The default tracing mode Brightness cutoff with a value of 0.45 is enough to detect the yellow mosaic elements. The turquoise-colored element is considered dark, but that actually works well to give the result (Figure 1, top right) an uncluttered look.

This kind of vectorization renders the image in black-and-white. The Inkscape handbook describes how to generate multicolored images [4].

The complexity of the paths created through vectorization presents one of the challenges of detecting bitmaps: The number of nodes can get so high that it can take Inkscape minutes to display them.

You can control this through the Options tab in Trace bitmap (Figure 2, bottom) by setting the Suppress speckles option for the specified Size , which you can set to 10 pixels, for example.

For Smooth corners and Optimize paths , you should choose the maximum values 1.34 and 5.00 , respectively, for the smoothest possible yet not too complex result.