PCLETTO to TTF?

[tal6499]

Hi,

I am in the process of converting a PCLETTO to TTF.

I have the following data in hand fom PCLETTO:

head Font header (in PCL GT segment)
hhea Horizontal header (in PCL GT segment)
hmtx Horizontal metrics (in PCL GT segment)
maxp Maximum profile (in PCL GT segment

cvt Control Value Table (in PCL GT segment but only required for hinted fonts only, may not be found in ttf)
fpgm Font program (in PCL GT segment but only required for hinted fonts only, may not be found in ttf)
glyf Glyph data (in PCL char definitions)
loca Index to location (in PCL char definitions)
prep CVT Program (in PCL GT segment but only required for hinted fonts only, may not be found in ttf)


According to Microsoft OpenType documentation:
cmap,OS/2 and post table is also required. cmap can be figured out to some extent. But i am curious about post & OS/2.
Whether any other tables are required? Or Will it work if i build the mentioned tables for TTF.


--Note: This post is related to a design decision before actual implementation. I am wondering that PCLETTO to TTF might not be actually possibly. But it would be a great learning experience if its discussed here and a proper solution can be figured out.---

 

[DansDadUK]

>> I am wondering that PCLETTO to TTF might not be actually possibly

If it is possible, I suspect that it will be quite dfifficult to fill in some of the date that is not present in the PCLETTO sof t font, but that IS required in the 'missing' tables.
And I think that you probably need the 'name' table as well as the 'post ' and OS/2' tables.


>> cmap can be figured out to some extent

True; but if your PCLETTO is a 'bound' font (as is quite likely), then you will only be able to reconstruct the parts related to the subset of characters contained in the soft font.


You may be able to get some more advanced advice from the forum run by the company that produces the
'FontCreator' and 'MainType' applications - go to

http://forum.high-logic.com/

and pose the question there.
I suspect that the contributors won't know a great deal about PCLETTO, but you should be able to get good advice on the TrueType aspects.

 

[pcltools]

The latest printer drivers generate unbound PCLETTO fonts. And, they only download the characters that are being used in the document being printed.

Most drivers only use a subset of the available character cells in a single-byte character set. And, when they run out of character cells, they redundantly download the same characters and assign them to the next temporary download font character cell. So, in a 100 page file - you might have capital "A" 20 times.

And, the fonts are incrementally downloaded in batchs of cells and not in one continguous font.

So, the big question is "Why do you need to convert a PCLETTO font that is generated from a TrueType font back into a Truetype font?". The only reasons I can think of is to create a PCL5e/PCL XL interpreter or to capture a TrueType font from a system that you don't have access to? There are already 10+ commercial quality PCL intepreters on the market and another 300+ interpreters looking for this type of conversion to make them compatible with PCL5e/PCL XL printer driver-generated files.

In my opinion this is definately a "Buy", rather than "Build" solution. You're looking at 300+ hrs. of intermediate to senior software engineering time before you arrive at a viable solution. And, I that's highly dependent on the relevancy and size of your suite of PCL5e/6 test files.

We've been converting PCLETTO to TTF for many years. And, HP's new Universal Printer Drivers in Vista, Win7 and beyond generate these fonts in new ways that have caused us to adapt our product to them. It's a moving target.

 

[DansDadUK]

>> It's a moving target

That's a very compelling reason to go for the "Buy" rather than "Build" option.