[CREATE] Clipping Path names in TIFF files

[Liam R E Quin]

On Mon, 2007-05-28 at 02:15 +0200, Simon Budig wrote:
[...]
> - try to encode the name as iso8859-15, which seems to be what photoshop
>   use by default (or is it windows 1250 - that is a bit hazy at the
>   moment, needs some more tests).

Is there a specification for this PhotoShop behaviour anywhere?



> 
> - if this is not possible, because the string contains glyphs outside
>   the iso8859-15 range, we just use UTF-8, and prepend it with
>   0xff 0xfe  (the unicode byte order marker) to make it a bit easier to
>   detect a "free software style" encoded path name.
> 
> I'd like to hear what other people think about this proposal. Any
> alternative suggestions? Do you like the idea?
> 
> I could need help with this problem:
> 
> The name "€name¤§@"  (EURO, "name", CURRENCY, PARAGRAPH, @) gets encoded
> as 80 6E 61 6D 65 A4 A7 40. Can someone identify this encoding? Encoding
> the EURO as 0x80 seems to hint at some windows code page, but the
> currency symbol seems to contradict this.
It might be just broken -- e.g. ISO 8859-1 didn't have a Euro in it,
although AdobeStandardEncoding and/or the old Mac font encoding seem
more likely.  My references are in storage right now unfortunately.

> 
> If this turns out to be a non-standard encoding I suggest to just try to
> encode to iso8859-1, since this is a pretty close "standard" encoding
> (we might need to do some more tests here to really settle this).
What about, e.g. Chinese or Japanese layer names?

An alternative might be to add the information elsewhere in the TIFF
file, e.g. an XDG-ENCODING tag.

> Also: Could someone try to give clipping paths complicated names and
> create tiff files on windows and mac and look if the names show up the
> same on the other platform?
If you send me a sample psd or TIFF file I'll be happy to try.

> On a more theoretical side the current proposal has a problem with path
> names starting with ÿþ (YDIAERESIS, THORN), since we use this as the
> unicode marker. Can anyone imagine this as being a real problem?
A google search for ÿþ* did provide lots of matches, but I think most
of them were either encoding errors or binary files.


-- 
Liam Quin - XML Activity Lead, W3C, http://www.w3.org/People/Quin/
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