March 1
Batch Processing Files in Photoshop 5.5

How to automate tasks, save time and keep yourself from killing your boss

by David Nagel
Senior Editor

This tutorial can help you out in a number of situations, but two jump to mind right away. The first is a situation where you work for a print publication, and you need to convert a bunch of very large files into smaller JPEGs for Web publication. The second is one in which you lack an animation program, but you need to apply some effects to a number of files to create an interesting animated GIF. Both cases really work best with a large number of files that all need the same end result—conversion to a common format. We'll save the GIF animation tutorial for next week and do the print to Web conversion this week. Let's take a look at each situation, shall we?

Construction Times goes online
You work for a trade magazine called Construction Times. Your publisher has decided to put your buyer's guide online and needs you, the art director, to supply the artwork in Web-ready form. Thoughtful. So immediately you realize that you have hundreds of 300-DPI DCS files you need to convert into 72 DPI JPEGs. What are you going to do, sit there for the next five days retrieving files off the server, opening each one and manually converting them? What's your publisher thinking?

"Maybe Construction Weekly is hiring," you think as you start working on your resume. "I don't get any respect around here anyway. MFA in design and all I do is sit around working on buyer's guides. Pfft. I spit on your buyer's guide!"

Now just settle down over there. Ol' Davey's here to help you out. So here's what I want you to do. First, make sure all your images are in the same folder. Next, create a new folder outside the old one. Cal it whatever you want. In my case, I'm going t call it "Batched Files." (My original folder will be called "Construction Times Images.") Just for the sake of argument, my files will be in DCS 2.0 format, single file, no composite.

What to do
1. Open up Photoshop, and open just one of your images. This will be the file we use to teach Photoshop what we want it to do with the rest of our files. (The file I'll be working with is called "724190.eps" for no particular reason other than it's the first one in my folder in alphabetical order.)

2. Go to your Window Menu and select "Show Actions." Once that appears, click on the little arrow in the top right of the Actions Palette and select New Action. A dialog box will appear. Name your action "Covert DCS," and then click Record (or hit the Return key). You're good to go now. Photoshop is recording every action you take.

3. Convert. If you don't know how to convert a DCS file into a JPEG, have no fear: Dave is here. First, go the Image menu and into the Mode submenu. Select RGB Color. Then go into the Image menu again and select Image Size. Make sure "Resample Image" is selected, and switch your resolution to 72. Then switch your print size to Percent. When you do, you'll notice the number in there is something like 24 (assuming you were working with a 300 DPI image to begin with). This is because you have resampled the image to a smaller size, the the percent is listed as the image's current DPI divided by its original DPI (72/300=0.24, or 24 percent). If you're happy with the physical dimensions of your pictures (all of them), then just leave it be. If you want it half size, change the number to 12 (percent); if you want it quarter size, change it to 6 (percent). Remember that whatever you size it to, this is how all files will be sized. When you're done, click OK.

4. Now, from the File menu, select Save a Copy. Select JPEG as your file type and whatever compression you prefer, and save the file into your new folder. (Make sure you create the folder before you started this process, not now. Otherwise Photoshop will create a new folder for each converted file.)

5. Now close your original image, and click "Don't Save" (otherwise changes will be saved to your DCS file, which would be bad, and you might need to go looking for that job over at Construction Weekly after all).

6. Now click the Stop Recording button in the Actions palette. You're done, and you can start batch processing the rest of your files at any time. To do so, go to the File menu and into the Automate subfolder. Select Batch. Since you recorded yourself saving and closing your file, you don't need to select a destination folder. But you do need to select your source folder (the one with all the DCS files in it). Make sure the Action is set to "Convert DCS" (or whatever you named it). If you plan to be out of the office while you're doing this batch processing, select "Log Errors to File" and click "Save As" to create a log file. (Make sure you don't put the log file into your original images folder.)

7. Watch the batch processing out of the corner of your eye as you head out the door. Pretty Cool, huh?

Want to see last week's tutorial? It's an animated rollover in Adobe ImageReady. Click here to go there.

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