Duotone as RGBA
WarrickF (5 pencils) | Fri, 2011-02-04 15:27Hi Guys,
I'm trying to save a DuoTone image as a raster asset from Photoshop. Eg. PNG.
While I understand that PNG does not support Pantone \ Spot color, all I really need to end up with is a file that represents the same idea.
So for example - the Red represents the % ink to use for Color1 and the G value represents the % ink for color 2.
We're writing custom software to process the information.
It would be nice if there was a commong file format that was easy to process that could represnt something like this.
Does anyone have any ideas? PDF, EPS and PSD are all complex file formats that I don't really want to have to deal with and they seem to be the only format I can save DuoTone in.
Thanks
Warrick
Commenting on this Forum topic is closed.
Why?
If you are producing for screen Pantone colors are not reproduced.
Even if you would start with a psd file with patone colors and you make a png out of it, the colors will be RGB. There is no way that a png can hold pantone colors. The values, yes. But it would be a rgb composite value for the pantone color.
i don't get it
I have no idea why you're trying to do what you're trying to do.
Duotones are specifically designed for print purposes, usually taking a grayscale image and separating it into 2 colors rather than a more typical four color process (CMYK). I could imagine making two RGB images, each image representing the 2 plates of the duotone, and overlaying/multiplying them in an HTML page.
For what purpose, I have no idea. Much simpler to simply export for web your duotone.
Without my sense of direction, I don't know where I'd be.
Unless I'm missing what you are trying to do, I think you may be able to designate each color as a separate spot color channel by indexing the image.
I do this all the time when separating-out full color images to simulated process for screen printing.
Let me know if this is what you are trying to do and I'll give you more details.
Terrell Thornhill
e-zign Design Group
RGBA? PNG? Duotone? Spot? I think we are all left guessing as to the intent of the poster.
Without my sense of direction, I don't know where I'd be.
The problem is a duotone represents two inks - usually black and a spot color. Either of those two colors requires multiple channels to recreate in the RGB color model required for a PNG file. So in order for a duotone to be recreated accurately in RGB (visually) - you're going to need all three channels.
However, this line...
"So for example - the Red represents the % ink to use for Color1 and the G value represents the % ink for color 2."
...sounds to me like maybe all you want is the two plates (channels) that create the duotone and the third channel (B) can be extraneous. If that is the case, you can then split a duotone into the two separate channels (Image > Mode > Multichannel) and copy and paste the channels individually into the separate channels of a new RGB document and then save it as a PNG file.
So if your duotone started with BLACK and PMS 125 as the two channels... your final result would be something like this...
R = BLACK channel data
G = PMS 125 channel data
B = (empty channel)
Of course the final image would look nothing like the original duotone - the colors will be totally different. But the channel data is there.