How to: generate CMYK TIFF with additional spot color channels

[banisco]

I've looked at following posts for reference:

"Combining multichannel images" http://imagemagick.org/discourse-server ... hp?t=21159
"Combining Channel Images with custom colors" http://imagemagick.org/discourse-server ... hp?t=28146

The first post is closest to what I need. In Photoshop I've taken a CMYK image with extra spot color channels, split the channels into separate PNG files and then tried to re-assemble them using -channel-fx:

Code: Select all

magick cyan.png magenta.png yellow.png black.png spot_1.png spot_2.png -channel-fx "gray=>cyan | gray=>magenta | gray=>yellow | gray=>black | gray=>10 | gray=>11" -colorspace CMYK combined.tif

The extra channels are dropped from the image. Any suggestions?

Version: ImageMagick 7.0.2-7 Q8 x64 2016-08-06
Visual C++: 180040629
Features: Cipher DPC Modules OpenMP
Delegates (built-in): bzlib cairo flif freetype jng jp2 jpeg lcms lqr openexr pangocairo png ps rsvg tiff webp xml zlib

[fmw42]

IM 7 can deal currently with multiple channels in MIFF format, as I understand. But I do not know that it has writers to send more than 4 (cmky) channels to TIFF or any other common image format. It probably also does not know explicitly about spot channels. If you are trying to send each image to a layer in tiff, that is fine, but then you don't need -channel-fx.

But I will defer to the Imagemagick developers for more word on writing to formats that support multiple channels

[Marvin]

Hallo!
This post is already a bit old, but I'm looking for the same. I need to add an additional channel (with a custom name, not alpha) to a tiff image.
I'm surprised how difficult this is, because the tiff-secification says it is possible to add custom channels and PhotoShop is able to do it.
Now I'm looking for a way to automate it....

Does anyone know whether it is now possible with ImageMagick?
Or maybe the original author found a way?

I am very grateful for any help.

[fmw42]

Reading from and writing to additional channels in TIFF is not currently possible with ImageMagick as far as I know. But it has had some work on it, though I do not know of any time frame for it to be finished.