A great friend and coworker drew my south park caricature. It was a hand drawing so I scanned and get a dirty grey-scale image, not to nice. So to get something cleaner I realized that I will need to vectorize the image. To do so I was looking for some freeware and I found Inkscape. This open-source software is surprisingly great and the vectorizing tool is awesome for someone like me that was facing this problem for the first time. So in the following lines, I will briefly document how to vectorize a bitmap using Inkscape and the help of The Gimp.
- Open the image in The Gimp and select the piece of the image you want to vectorize. Using Ctrl+C and then Ctrl+Shift+V you will create new image and save it (jpg or png will work well).
- Open the Inkscape and Drag&Drop the the new image file into the main window of the Inkscape.
- Select the image and click on menu Path->Trace Bitmap. A pop-up dialog will appear.
- The Trace Bitmap dialog shows several methods to vectorize and a very useful Update button to see a preview of the vectorizing process result. Playing with the parameters for a while will show you all the possibilities.
- When you arrive to a nice result in the preview, you can press OK and the final result will be showed in the main window ready to be edited.
- Usually it's a great idea to select the vectorized result and apply a simplification because the number of knots used for the paths during the vectorization process makes editing the strokes almost impossible. To do so click on menu Path->Simplify. Be careful because this algorithm sometimes simplifies too much, but it's usually easy to solve this issues adding some points where the simplification was too aggressive.
- If you have big black shapes, probably the vectorizer will create several white gaps. Increase the Suppress Speckles parameter within the Options tab to remove them.
- Usually the Brightnees cutoff works pretty well, but when the edges of the shapes are well defined by colors use the Color Quantization