Hey Larry,
thank you for looking into this.
https://www.imagemagick.org/discourse-server/viewtopic.php?t=26785
This old thread from imgmagick reflects the same...
https://www.adobe.io/content/dam/udp/en/open/standards/tiff/TIFFphotoshop.pdf
Page 11 mentions Layers...
This is the text from page 11
"""
Image Source Data Introduction This section describes the Adobe
Photoshop specific image source data tag. This section has the layer and
mask information found in a typical layered Photoshop file. Field:
ImageSourceData Tag: 37724 (935C.H) Type: UNDEFINED Count: number of
bytes for section The section starts with a character string of "Adobe
Photoshop Document Data Block" including the null termination character.
The remainder of the count, after subtracting the length of the above
mentioned string, is a series of tagged data types in the following
format: 4 bytes Signature ‘8BIM’ 4 bytes Type various types (see below)
4 bytes Length length in bytes, variable for each type, padded to a 4
byte offset The various types are mentioned here with further
documentation in the Photoshop File Formats.pdf. The available types
are: ‘Layr’ Layer Data ‘LMsk’ User Mask Same as Global layer mask info
table ‘Patt’ Pattern ‘Anno’ Annotations
"""
Does this eventually help at least understanding what adobe is doing there ?
All the best
Johannes
Am 15.08.20 um 8:10 am schrieb Larry Gritz:
OK, the layered.tif is definitely not a multi-subimage file. It seems
that it's just one subimage (maybe the merged layers?) but there is a
special data block in the header containing encoded PhotoShop
information, which presumably contains whatever PS needs to represent
the layer information. But unfortunately, it's a proprietary tag that
is not documented. I'm not sure how we could reliably write TIFF files
and embed that data.
-- lg
On Aug 12, 2020, at 11:18 PM, Johannes Hezer
<[email protected]
<mailto:[email protected]>> wrote:
Hey Larry,
attached is an archive with 5 files, one layered.tif from PS, then
all three seperate and one created with oiio --siappendall, called
multipage_tif...
Thanks, for looking into this.
All the best
Johannes
Am 12.08.20 um 17:16 pm schrieb Larry Gritz:
I'm not quite sure what a "multi layered tiff" is, from PS's
perspective. Do you have an example of a TIFF file (doesn't have to
have been written by OIIO) that does correctly behave in the way you
want when opened by PS? Send it to me and maybe I can see how
exactly it's laid out and figure out what is the missing ingredient.
-- lg
On Aug 12, 2020, at 6:09 AM, Johannes Hezer
<[email protected]
<mailto:[email protected]>> wrote:
Hey,
I was wondering if anybody has achieved writing a tiff that works
in PS as a multi layered tiff.
oiiotool a.tif b.tif c.tif --siappendall -o out.tif creates a
multipage tif, which apparently opens fine in almost any tif
enabled program on the planet, but ps only reads in the first page...
Any ideas?
All the best
Johannes
--
Larry Gritz
[email protected] <mailto:[email protected]>
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--
Larry Gritz
[email protected] <mailto:[email protected]>
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