Separating Jpeg

TD
Posted By
Thomas_Dunlap
Dec 18, 2003
Views
345
Replies
5
Status
Closed
I have a four color jpeg that I want to separate the jpeg in to film positives for each color. Each color must have its own film positive artwork printed on acetate in positive form. These must be opaque black with the Pantone PMS number.

I have tried to make 4 layers from the original. Each layer represented one of the colors. I used the magic wand with a tolerance of 100. It still leaves spots between the colors.

Any help would be appreciated.

How to Master Sharpening in Photoshop

Give your photos a professional finish with sharpening in Photoshop. Learn to enhance details, create contrast, and prepare your images for print, web, and social media.

GT
Gene Trujillo
Dec 18, 2003
In order to separate correctly, the colors need to be on their own CHANNELS, not layers.

If you want to manually separate the colors, change the mode to multichannel, then go to the channels palette flyout menu (it looks like a little triangle on the top right) and select "split channels". It will make individual grayscale images out of each of your channels.

As far as making a selection to move the color around, instead of the magic wand, you could try using the pen tool to mark out the selection you want, then convert path to selection. Or using quick mask to paint in your selection, then copy/paste into the correct channel. Or while in CYMK mode, just fill the selections with the appropriate color (C, Y, M, or K).

HTH,

Gene
CW
Colin_Walls
Dec 18, 2003
I’m not an expert in this, but how about …

Why not just open the channels palette and delete 3 out of the 4 channels? That will give you one film. Then repeat for each of the other 3.
CK
Christine_Krof_Shock
Dec 18, 2003
You cannot separate a .jpg file–jpgs give printers the willies!! Try converting the file to cmyk Image>Mode>CMYK and then saving the file as a .tif or .eps (if there is any vector information or clipping paths used in the file).

If you are using 4 separate pantone colors you are going to have to use the multichannel function to get this to plate properly (Image>Mode>Multichannel, then specify spot channels (click in the blue area when you have highlighted a channel and a dialog box will come up allowing you to choose your ink color and solidity) inside of your multichannel document. You will also have to build a black channel if you convert to multichannel directly out of RGB. If you convert out of CMYK the black channel will be generated., Or consider 4 color process and converting your spots to process color (probably cheaper in the long run-but not the same color fidelity as using 4 pantone inks. Check a solid to process swatch book to see how the colors will change.)You will have to save a Multichannel document as a DCS2 document.

You will also want to do a gamut warning before CMYK conversion to check which colors will be out of gamut when you convert this document from RGB (.jpg) to CMYK (.tif/.eps) You may lose color fidelity in the conversion process due to some colors being out of the CMYK gamut. You can adjust in channels to reboost colors.
DM
Don_McCahill
Dec 18, 2003
And, just a note. You will not be using (I hope) Pantone colors if you are separating the image to CMYK colors. The color names will be Process Cyan, Process Magenta, etc. No PMS names or numbers.
TF
Timothy_Foolery
Dec 18, 2003
This thread might be worth looking at also.

Tom Walace "Help! File separation question…" 12/16/03 1:58pm </cgi-bin/webx?13/33>

Master Retouching Hair

Learn how to rescue details, remove flyaways, add volume, and enhance the definition of hair in any photo. We break down every tool and technique in Photoshop to get picture-perfect hair, every time.

Related Discussion Topics

Nice and short text about related topics in discussion sections