Scan Images for Use in Photoshop Elements 12 - dummies

Scan Images for Use in Photoshop Elements 12

By Barbara Obermeier, Ted Padova

You can’t do much in Photoshop Elements until you bring in some pictures to work on. Sometimes that involves scanning images.

Scanners connect through the same ports as cameras and card readers. (The exception is a SCSI, or Small Computer Systems Interface device; SCSI is another type of connection port, almost nonexistent today.) Most scanners today use either USB or FireWire. Low-end scanners sold now are typically USB devices.

Even the lowest-end scanners provide 16-bit scans that help you get a little more data in the shadows and highlights. As with a digital camera, a scanner’s price is normally in proportion with its quality.

All scanning software provides you with options for determining resolution and color mode before you start a new scan:

  • Resolution: An image’s resolution determines how many pixels it contains. Indeed, resolution is measured in ppi, or pixels per inch.

    Images displayed on the web use low resolutions because monitors don’t need lots of pixels to display images clearly. Also, images download faster the lower their resolutions are, and fast download times are ideal for the web. A good-looking print requires a higher resolution because printers and paper require more pixels than monitors do to render an image clearly.

  • Color mode: RGB, Grayscale, or Bitmap (line art).

You should decide what output you intend to use and scan originals at target resolutions designed to accommodate a given output. Some considerations include the following:

  • Scan the artwork or photo at the size and resolution for the final output. If you have a 3-x-5 photo that needs to be 1.5 x 2.5 inches on a web page, scan the original with a 50-percent reduction in size at 72 ppi (the desired resolution for images on the web).

  • Size images with the scanner software. If you have a 4-x-6 photo that needs to be output for prepress and commercial printing at 8 x 12 inches, scan the photo at 4 x 6 inches at 600 ppi (a resolution that’s large enough to increase the image size to 200 percent and still have a 300 dpi image, which is the desired resolution for a print).

  • Scan properly for line art. Line art is 1-bit black and white only and should be used for scanning not only black-and-white artwork but also text. When you print line art on a laser printer or prepare files for commercial printing, the line art resolution should match the device resolution.

  • For example, printing to a 600 dpi (dots per inch) laser printer requires 600 ppi for a 1-bit line-art image.

  • Scan grayscale images in color. In some cases, it doesn’t matter, but with some images and scanners, you can get better results by scanning in RGB (red, green, and blue) color and converting to grayscale by using the Hue/Saturation dialog box or the Convert to Black and White dialog box.

  • Scan in high bit depths. If your scanner is capable of scanning in 16- or 32-bit, by all means, scan at the higher bit depths to capture the most data.