Fonts & Encodings

12.5. potrace

There are two great free software packages for autotracing: AutoTrace, by Martin Weber [344], released in 1998, and potrace, by Peter Selinger [316], which was not released until 2001. Both are SourceForge projects, and it is widely acknowledged that the latter is more powerful and that the former supports more file formats for both input and output.

These software packages can perform autotracing on any bitmap images; they have no special features related to fonts.

If we wish to convert a METAFONT font to PostScript Type 1, there are at least two utilities (mftrace [279], written in Python, and T_EXtrace [326], written in Perl) that take control of the entire process of launching METAFONT, assembling the files, autotracing each glyph, and compiling everything into a PostScript font with correct metrics.

When we are beginning not with a METAFONT font but with a series of images, we can use FontForge. To do so, we first install on our system one of the autotracing packages (AutoTrace or potrace) and declare it to FontForge (File>Preferences). Next, we must perform the following operations:

1. Import the images in the form of masks (File>Import) into the correct positions in the table. We can do so manually or import an entire batch of images at the same time. To import a batch of images, name the images uniHHHH.png (where HHHH is a four-digit hexadecimal number and the image corresponds to the Unicode character in that position), perform File>Import, and choose Series ...