Signature Brushes

Having seen a digitised signature on a friend’s blog, I decided to make one of my own. The result is the signature image that you see on the right part of this blog. Instead of using the method that he suggested, I decided to do it using a different method. This was primarily because most of the tutorials used tools that were not at my disposal. So, this is my technique for creating a signature brush using only Gimp and Inkscape.

1. We need the raw signature, which can be obtained through a variety of means. I used a sharpie and scribbled my John Hancock on a piece of white paper. Then, I used my digital camera to take a photo of the raw signature. This raw photo will need to be processed.
2. The photo needs to be cleaned up first. This can be done in Gimp using the Colour-Threshold settings to clearly define the paper and writing. The resultant image will be a largely black and white image.
3. The signature now needs to be cropped. Once again, using Gimp, the signature is selected using the selection tool. Then, using Image-Crop to Selection the signature is cropped and everything outside the signature is removed.
4. Being now cleaned and cropped, the signature can be imported into Inkscape using File-Import. Then, using Path-Trace Bitmap and setting it to Brightness Cutoff mode, the signature is converted from a bitmap into a vector image.
5. As a vector image, the signature can be made a little artsy by using the Path-Simplify command in Inkscape. This reduces the number of points in the vector image and smooths the stroke edges. This can be repeated a number of times for artistic effect. The resultant image looks like it is painted.
6. Using File-Export Bitmap from Inkscape, the vector image is saved as a raster PNG file. This PNG file should be sufficiently large in size in order to allow the signature to be resized without too much distortion.
7. This PNG can be imported into Gimp for final post processing. The image is flattened using Image-Flatten Image and converted into grayscale using Image-Mode-Grayscale. This is an important step to ensure that the brush works correctly.
8. Finally, the resultant black signature on white background, is exported as a Gimp brush. Use the File-Save As command to save the image as a Gimp brush (*.gbr) format image. This image should be saved in the ~/.gimp-2.4/brushes subdirectory. Then, refresh the brushes and it is ready for use.

And the result is the signature brush as seen in the image above. I can use this brush to insert a signature into any of my future photographs, like how artists of old used to scrawl their names into the corner of their paintings. My signature brush is 900 pixels across, which should be good for use in any decent sized image.