Graphics Fundamentals: Importing Files into Photoshop

Photoshop has the ability to open dozens of different file formats. Files such as JPEGs and GIFs are easily opened and edited within Photoshop’s ample resources, but there are times when you need to do more than merely open them to make them useful. Sometimes, you’re bringing in a file from an external source, such as a digital camera or scanner. This process, known as importing, allows Photoshop to bring in images from other sources.

Import Guidelines
In this article, we’ll look at some of the situations when you need to use importing to get your file into Photoshop. First, we’ll examine the flexible EPS format and tell you why it’s one of the most prevalent file formats used for graphic design. Then, we’ll talk about importing images from your scanner using TWAIN technology. Finally, we’ll look at how Photoshop brings in photos from your digital camera.

Importing EPS Files
EPS, or Encapsulated PostScript, is a specially designed file format that allows vector and raster information to be saved together. This means that a single EPS file may contain both images made up of pixels and objects comprised of vector paths. The primary users of this format are graphic designers, who often need to bring their artwork into Photoshop for finishing touches after designing it in illustration programs such as Adobe Illustrator or Macromedia FreeHand. However, since most graphics applications can save in the EPS format, it has become the bridge into Photoshop for many applications that can’t save files as a standard file format such as TIFF or JPEG.

Rasterizing Your EPS File
While you can open an EPS using the Open command on the File menu, it’s treated differently before being processed as an image. When you open an EPS file in Photoshop, the vector paths are converted to pixels. Because EPS files don’t save any specific resolution or size data, you must tell Photoshop how to open this file by inputting your desired settings. This process is known as rasterization, which is often used in the Photoshop world.
To rasterize an EPS file, first launch Photoshop and select Open from the File menu. Locate your EPS file (with the .eps file extension) and click Open. The Rasterize Generic EPS Format dialog box displays, as shown in Figure A. This dialog box allows you to enter the data Photoshop needs to rasterize the file. You can set the width, height and resolution of your file using the text boxes and dropdown menus.


Figure A

Resolution Considerations
Before we continue, let’s have a quick word on resolution. EPS files aren’t saved at any specific resolution. This means that the vector elements in your file can be rasterized at any resolution without any loss in quality. However, if your file contains any raster elements (images), you can only rasterize the file in Photoshop at the maximum resolution of the images. Anything beyond that maximum resolution results in pixelation, which means your image data has been stretched too far.

Note: If you’re unsure of what the maximum resolution of your placed images is, the easiest way to find out is to open them in Photoshop, independent of the EPS file. Once opened, select Image > Image Size and note the number in the Resolution text box. That’s your maximum resolution for that image. Make sure you check all of the images contained in your document, using the lowest resolution as your rasterizing target point.

When choosing the resolution for your EPS file, first consider the existing resolution of the raster images in your file, then decide the target resolution of your file. For example, if you’re printing on an inkjet printer, 300 or 600 dpi does fine. If you’re prepping an image for the Web, 72 dpi is the standard. Don’t add unnecessary file size that can bog down your computer. Remember that you can always start over if you aren’t satisfied with your results.

More EPS Options
There are more options in the Rasterize Generic EPS Format dialog box that deserve note. The first is the chance to designate the color space of your file. This is an important choice because color is rendered differently depending on its color space. The main color spaces are RGB (Red, Green, Blue) and CMYK (Cyan, Magenta, Yellow, Black), Grayscale and LAB (Luminosity, Alpha, Beta). For 99 percent of your EPS files, you’ll use RGB and CMYK. The rule of thumb is RGB for the Web and CMYK for printing.

Photoshop can also control the amount of pixelation in your images when rasterizing. If you select the Anti-aliased check box in the Rasterize Generic EPS Format dialog box, Photoshop smoothes the rough edges between pixels to make them blend together. This almost always results in better looking images, so make sure this option is selected.

When you’re done making your choices, click OK to rasterize your file. Photoshop uses the in-formation you entered to process the EPS information and brings the file to your screen. Once it’s opened in Photoshop, you can save it in any file format you desire.

Tags
Posted on: May 24, 2003

2 Comments on Graphics Fundamentals: Importing Files into Photoshop

  1. Hello, I need to open 20 very large eps files at a time and convert them to jpeg format. I am trying to create a droplet to do so but the rasterize dialog box opens for each image rather than the action within the droplet just happening behind the scenes without me needing to do anything. Can you tell me how to create the action so that the rasterization is always the same for each image without any prompts needed? Thanks

  2. I’ve been trying for a year to import a single jpeg into a photoshop file. I have physics degree so I’m not stupid – I just think software writers always skip the most basic issues – it happens everywhere.

    Stan Arnold

Leave a comment

Your email address will not be published.


*