Scanning: Adobe Photoshop Basics
How Do You Plan To Use The Scanned Image?
How you will be using your image–for instance, whether it will be featured in a Web document or printed in grayscale–determines many of the settings you will use in scanning. Unfortunately, you need to have a pretty good idea of your final product before you begin to scan, so you can make the proper choices along the way. Use the following questions and guidelines to prepare yourself and your materials for scanning. Importing the image into Word Processing, Desktop Publishing, Presentation or other software program, Web page design, High-quality printing, Photo CD
Will You Be Printing The Image? What Type Of Printer Will You Be Using?
Images used in web page design require a very low resolution, 72 dpi (dots per inch), because of the limits of the medium. If you plan to use your images solely for web design, a resolution of 72 dpi is all you need since higher resoultion only means a bigger file and a longer download time. However, if you think you will ever want to print the image, save both high and low resolution versions.
Most grayscale printers create a halftone screen to render the information in your digital images. A general rule of thumb is to scan at a resolution 1-1/2 to 2 times the line frequency of the printer. For example, a typical laser printer has a line frequency of 53 lpi (lines per inch), so scanning at a resolution of 150 dpi should suffice. A dye-sublimation printer (CMYK color) which prints photographic quality color images will give the best images with 300 dpi resolution. As a rule of thumb, if you plan to print quality images scan with a resolution of 300 dpi. Remember: you can always lower the resolution in Adobe Photoshop at a later time.
What Size Image Do You Need?
Your desired final size will determine the size of the initial scan. If you do not know the exact required size, try to estimate as closely as possible. The ideal is to acquire your image at the size you will be using in the final product. (More on adjusting image size in the Adobe Photoshop handout). Scanning Resolution Key: Web pages-72 dpi, Low to medium quality printing-150 dpi, High-quality printing -300 dpi, Photo CD-300 or 600 dpi
Import Image Into Software Program, What File Formats Will The Software Accept?
Adobe Photoshop features a variety of file saving formats; however, not all are readable by the most popular software. For instance, the Mac version of MS Word accepts PICT and TIFF file formats and the Windows version of Word Perfect accepts BMP and TIFF file formats. Consult your software manual to determine which image file format you will need to use.
Where Will You Store Your Images?
Image files can be huge. An uncompressed 300 dpi image can easily take up 2 megabytes. A floppy disk holds 1.4 Megabytes. Many people save their images on a zip drive. You can download saved images from your zip drive into a working document anytime. AZIP drive is available at most office supply stores.