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Conversion from one bitmapped format to another is not generally too difficult. Conversion from one scalable format to another is very difficult. Several commercial software packages claim to perform these tasks, but none has been favorably reviewed by the comp.fonts community.
This section was constructed from postings by Primoz Peterlin and Bert Medley in Sep 1993.
There are several commercial tools that will convert between these formats. There are no shareware or free tools that will do the job. See also ``Why do converted fonts look so bad?''.
Performs conversion between Adobe Type 1, Adobe Type 3 and TrueType formats in both PC-DOS and Mac flavours, as well as simple glyph editing. Currently at version 1.0.7, patches available via CompuServe. Available for Mac and MS Windows. Commercial product, price \$60-80.
Performs font conversion. A stable product, being on a market for a while. Available for PC-DOS/MS Windows only. Commercial product. Atech is supposedly leaving the business.
Comprehensive package, allowing creation of fonts as well as conversion between formats. Available for Mac and MS Windows. Commercial product, price cca. \$270 (PC version).
Available for Mac. Commercial product. More info needed.
Many of the programs in the preceding section claim to be able to convert between other formats as well. And there are probably other commercial programs as well. However, as several people have noted, conversion from one scalable format to another is a bad idea. If the original font was well hinted, the converted font will not be. Of course, if the original was poorly hinted, maybe it won't matter much.
In an effort to settle a long-running and oft-asked question, I'll be blunt: as of today [6/93], THERE ARE NO NON-COMMERCIAL PROGRAMS WHICH WILL CONVERT FROM ONE SCALABLE FORMAT TO ANOTHER. Not from TrueType to PostScript Type 1, Type 3, Type 5, or any other scalable PostScript format. Not from PostScript Type 1 to TrueType. Not to or from Intellifont. Not to or from Sun F3 format.
For specific conversions, check the platform specific parts of the FAQ. Most of the conversions discussed require platform specific tools.
Here is a summary of the conversions discussed (and the section in which they appear):
In addition, Adobe ships a copy of Adobe Font Foundry with all of its fonts which can convert Type 1 fonts into HP LaserJet softfonts.
This section was constructed from postings by Mark Hastings and David Glenn in Aug 1993.
With all commercially available conversion tools, converting fonts between scalable formats almost always results in a font inferior to the original. (The rare case where a converted font is not inferior to the original occurs only when the original is a cheap knock-off, and the automatic hinting of the conversion program is better than automatic hinting used in the original!)
David Glenn contributes the following analysis:
There are a few probable [reasons why converted fonts, especially screen fonts, look inferior to the original]. First off, any font that's converted uses a converting algorithm which will make an exact copy at best. Because no currently available converter even comes close to copying faithfully the manual tweaks and hinting in a font file, you often end up with poor screen fonts and poor output. The only reason that printed output from the converted font looks markedly better than the screen font is that the printed output is at a higher resolution. The converter achieves better results on the higher resolutions because hinting is less important at higher resolutions. Screen fonts are incredibly complex to make well. You have very few pixels to represent a very aesthetic and distinct design. That's why at small sizes almost all typefaces look alike---how do you represent a graceful concave side on the letter ``L'' for Optima with only 12 pixels in height and one in width? You can't. And that's why most fonts look similar at 10pt, unless they're hand hinted by typograhers.
One thing that may come into play when fonts are converted between platforms, for example between PC/Windows format and Mac format, is that fonts are hinted down to a certain number of pixels per em. On a Mac screen (72 dpi) there is a one-to-one correspondence between the ppem and the point size of a font. Under windows, the usual VGA screen is 96dpi and fonts that look good at 8 or 9 pt under windows might look like crap on a Mac 'cuz the fonts weren't hinted below 10 or 11ppem. Also, the conversion programs may have made the appearance worse at some sizes than others.
Whenever you convert fonts from one platform to the other keep in mind that:
This section was constructed from postings by Jason Lee Weiler and Piercarlo Antonio Grandi
Enlarging bitmapped images is easy, but enlarging them without creating very jagged edges is much more demanding. There are several possibilities.