2014.03.21 23:28 "[Tiff] Spot colors in TIFF", by Oncaphillis

2014.03.23 08:36 "Re: [Tiff] Spot colors in TIFF", by Leonard Rosenthol

What program(s) are you planning on having read this document? If it¹s not Photoshop, then using Photoshop private data won¹t be useful. If it¹s Photoshop, then you would be better off writing a standard format (such as PDF) or native format (PSD).

Leonard

On 3/22/14, 11:10 AM, "Oncaphillis" <oncaphillis@snafu.de> wrote:

Thanks for the info,

I had a closer look at the tif I'm currently trying to analyse.

TiffTagViewer http://www.awaresystems.be/imaging/tiff/astifftagviewer.html was a specially helpful. (see screenshot under http://www.oncaphillis.net/tifftags.png. Seems like the file simply defines 7 samples per pixel (CMYK+3 Spot Colors in my case). The "ExtraSamples" Tag define these 3 additional samles as undefined. The Rest of the info one would need is stuffed into the "PhotoShop" Tag.

Described here:

>http://www.adobe.com/devnet-apps/photoshop/fileformatashtml/#50577413_pgfI >d-1039502

Does anyone know if there is code available that helps one parse the "PhotoShop" data block?

Thanks again

O.

On 03/22/2014 12:39 AM, Chris Cox wrote:

Photoshop writes layer data, and descriptions of the additional alpha channels in application specific TIFF tags that most other applications won't read.

PDF and PSD/PSB are the only other formats that really support spot colors. DCS/EPS can hold spot channels, but only for final output - it's not that portable.

On 3/21/14 4:28 PM, "Oncaphillis" <oncaphillis@snafu.de> wrote:

I'll have to generate images in CMYK+SpotColor format (e.g PANTONE etc.) format and would like to store in TIFF. Photoshop supports this kind of data but I couldn't find anything about the TIFF file organisation. All tools I used under linux seem to ignore the additional layers. Some just complain about an unknown TAG 37724 (0x935c) for which I couldn't find anything usefull.

tiffsplit doesn't split the tiffs at all, so it doesn't seem to be a multi-layer TIFF.

Are there any informations available for this format? Alternatively it would be o.k. for me to use another bitmap image format supported by other paint programs which supports spot colors for which better docs are acailable.