Create a PDF with custom channel level

Questions and postings pertaining to the usage of ImageMagick regardless of the interface. This includes the command-line utilities, as well as the C and C++ APIs. Usage questions are like "How do I use ImageMagick to create drop shadows?".
Post Reply
luciot
Posts: 5
Joined: 2017-09-08T07:28:55-07:00
Authentication code: 1151

Create a PDF with custom channel level

Post by luciot » 2017-09-08T08:54:59-07:00

Hi to all!
I would like to automate a procedure that I currently do with Photoshop but I do not know if it can be done with IM. Here is the procedure:

1) Create a new RGB image
2) Write some text, then color it
3) Select the text level, invert selection, save the selection
4) Go to the "Channels" tab, click on the new channel just creted and set it to "Flat color"
5) Set the color to "Pantone Yellow C"
6) Save the file as PDF

I hope I have explained it well.
Thanks in advance to all!

snibgo
Posts: 9404
Joined: 2010-01-23T23:01:33-07:00
Authentication code: 1151
Location: England, UK

Re: Create a PDF with custom channel level

Post by snibgo » 2017-09-08T09:47:18-07:00

ImageMagick is a raster image processor. It saves images as raster, ie a number of pixels. I suspect your Photoshop procedure saves the PDF contents as text, or at least as vectors. IM can save images as PDF, but merely by putting a PDF wrapper round the raster images.
snibgo's IM pages: im.snibgo.com

User avatar
fmw42
Posts: 22109
Joined: 2007-07-02T17:14:51-07:00
Location: Sunnyvale, California, USA

Re: Create a PDF with custom channel level

Post by fmw42 » 2017-09-08T09:57:37-07:00

Imagemagick also does not know Pantone colors and is not interactive. If you know the rgb color equivalent to your Pantone color, then you likely can do it all, except as snibgo points out your PDF will be a raster image embedded in a vector shell. Also Imagemagick is command line based and not a GUI tool.

luciot
Posts: 5
Joined: 2017-09-08T07:28:55-07:00
Authentication code: 1151

Re: Create a PDF with custom channel level

Post by luciot » 2017-09-11T02:30:28-07:00

Hi guys! Thanks for your fast reply!! So... I know that IM it's just a command line program. I think it's not possible to do what I have to do, because the additional channel is just an information that it's interpretated by the printer.

I.E. :
The Pantone Yellow C channel is translated by the printer in a command (embossing print)

If I understand what you says, it's not possible to bring this information in the file, right?

Thanks in advance.

snibgo
Posts: 9404
Joined: 2010-01-23T23:01:33-07:00
Authentication code: 1151
Location: England, UK

Re: Create a PDF with custom channel level

Post by snibgo » 2017-09-11T02:34:44-07:00

No, IM can't write Pantone data to the PDF.
snibgo's IM pages: im.snibgo.com

luciot
Posts: 5
Joined: 2017-09-08T07:28:55-07:00
Authentication code: 1151

Re: Create a PDF with custom channel level

Post by luciot » 2017-09-11T02:40:58-07:00

Not even if I could translate the pantone into rgb?

snibgo
Posts: 9404
Joined: 2010-01-23T23:01:33-07:00
Authentication code: 1151
Location: England, UK

Re: Create a PDF with custom channel level

Post by snibgo » 2017-09-11T03:02:56-07:00

You can colour pixels with any colour you want, if you know the RGB (or sRGB) numbers, or CMYK, or whatever.
snibgo's IM pages: im.snibgo.com

luciot
Posts: 5
Joined: 2017-09-08T07:28:55-07:00
Authentication code: 1151

Re: Create a PDF with custom channel level

Post by luciot » 2017-09-11T03:19:04-07:00

But (if I understand) when I save the PDF, I will lose that information because it's rastered in the final result, right? If I open the file with Photoshop I suppose I can't see the additional channels, but only the classic R,G,B...

snibgo
Posts: 9404
Joined: 2010-01-23T23:01:33-07:00
Authentication code: 1151
Location: England, UK

Re: Create a PDF with custom channel level

Post by snibgo » 2017-09-11T04:13:20-07:00

I don't understand the question.

When you create an image with IM, it isn't "rastered in the final result". It is always a raster image (ie pixels). Pixels might have RGB channels, or CMYK, or various others. But IM can't create channels for spot colours.
snibgo's IM pages: im.snibgo.com

luciot
Posts: 5
Joined: 2017-09-08T07:28:55-07:00
Authentication code: 1151

Re: Create a PDF with custom channel level

Post by luciot » 2017-09-11T07:36:30-07:00

Ok, thanks for your help! I need to found another way, but thanks a lot for your reply!

Post Reply