Scanning Images

Photoshop provides direct integration with most scanner control software. And although you can open a previously scanned image, you can also scan images directly into Photoshop. The File ’ Import submenu offers direct access to any installed scanners. This menu will vary with the scanning software currently installed. The TWAIN software is designed to provide universal controls for scanners and other image-capture devices.

After you select a scanner from the submenu, its controlling dialog box will appear. The software for every scanner will vary, but most scanner control software enables you to control attributes such as these:

Type Most interfaces offer you the opportunity to choose among multiple scanners.

Beginner/Advanced Typically you can choose between a Beginner mode that offers limited control using everyday terminology and an Advanced mode that offers precision scanning options.

Resolution Enter a value to determine the pixel count. Be aware that some scanner software refers to resolution in DPI (dots per inch) instead of the PPI (pixels per inch) used by Photoshop. In this case, the terms are synonymous.

B & W or Color Most scanners enable you to select between a grayscale or color scan. Grayscale images are typically one-third of the size of color images of the same dimensions because only one channel of information is being recorded.

Descreen/No Descreen The function will attempt to remove rhythmic interference patterns produced by scanning already-printed images from newspapers or magazines. Use it to reduce or eliminate moir patterns produced by the interference of the image s halftone screen with the sensors of the scanner. The scan can take considerably more time, and when effective, will seem slightly less sharp because moir removal often creates a slight blur in images.

Preview The Preview (often called Overview) feature performs a quick, low-resolution scan that you can use to crop the image to eliminate unwanted areas.

Filter This option applies a sharpening operation to the image after the data has been collected. It s better to use Photoshop s Unsharp Mask filter after the image has been scanned, because it affords more control, and enables you to Undo the effect to compare before and after images on-screen. Sharpening is dependent on image size, printing process, intended use, viewing distance, and subject matter of the photo. It s a mistake to allow a scanner to sharpen images while scanning.

Auto Adjustment Check this box to perform automatic contrast adjustments to the image. In most cases, it s better to scan the image and perform a Levels or Curves adjustment in Photoshop.

Scan Every scanner provides a Scan button to initiate the scanning process. As the scan proceeds, you will usually see a progress bar indicating what percentage of the document has been scanned.

Transparency/Reflective Those scanners that can handle both reflective art (prints) and film ( negatives and transparencies ) will have a control for this setting.

Other Uses for Scanners

Flatbed scanners are designed to scan images that are drawn, painted , or printed on flat sheets of film or paper. They can also be used to scan text if optical character recognition (OCR) software is installed on the computer. OCR software can convert a scanned image of text, usually saved as a TIFF, to an editable text document. OCR software does this by recognizing the shapes of characters and applying conversion algorithms to produce an editable text document of significantly smaller file size. The quality of this process is highly variable. If the text is very clear and in a font that the software can easily discern, the translation into text will be excellent . With some pages, however, the fonts and the print quality will reduce the efficacy of the text conversion.

There are also nontraditional uses for scanners that you might want to try for fun. A scanner can be used to scan three-dimensional objects. Place the object on the bed of the scanner and position the cover over the object (be careful not to break the glass!). Cover the entire scanner with a piece of black cloth to prevent light leaks. You can scan any object that fits on the bed with surprising quality. The depth of field of some flatbed scanners is more than 0.5 inch.

Just for fun, you might also try scanning your hand or even your head. Remain very still during the process of the scan. Or try moving a little to produce some really weird results. Don t stare directly into the light or you ll be seeing stars for a while, and make sure you clean the glass after this twisted little adventure.