Protect Your PC from Viruses with the McAfee VirusScan! ©2004 SupraSite(tm) all rights reserved.		Welcome to SuprasiteTM Graphics & Design Introduction Web Design PhotoShop Basics Effective Presentations Misc. HTML Scanning: Adobe Photoshop Basics Before You Begin How Do You Plan To Use The Scanned Image? •          Importing the image into Word Processing, Desktop Publishing, Presentation or other software program •          Web page design •          High-quality printing •          Photo CD 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.   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.   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   Will You Be Using An Outside Ser vice Bureau To Make Your Prints Or CD-ROM? Ser vice Bureaus provide fast, high quality printing and CD-ROM burning at a moderate cost. If you plan to use a ser vice bureau you must contact them for their required file specifications. Many will only accept image files of a specific format (e.g. TIFF) and require image size to be compatible with their printer's print area. Please have this information before you scan.   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).   If You Plan To Import The Image Into A 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.   Scanning: Adobe Photoshop Basics Scanning and Saving Adobe Photoshop is a powerful image manipulation program. This document will give you some pointers, but don't be afraid to experiment with new commands, just remember to save first.   From the Aquire Menu - Import The Image   Crop Out Unwanted Space Or Material Cropping selects part of an image to save. Use the Crop Tool to draw a box around the portion of the image you wish to keep. Adjust the box using the squares at the corners or middle of the sides. Once the box is placed properly, press the Return key on the keyboard and the crop will be performed. The Crop Tool can be found by clicking and holding down the mouse button on the upper left icon in the tool pallette. TIP: Crop out any unwanted area to decrease the file size.   •To select the portion to save, choose the rectangular selection tool in the upper left corner of the tool palette. •Drag a selection rectangle around the portion of the image that you would like to save. •Choose Crop from the Edit menu. •Only the portion selected portion of the image should remain.   Changing Image Resolution - Decreases Size of Image Select "Image...Image Size." The top box is the current size and resolution of your image. Type your changes into the bottom box. - Try different combinations of sizes until your image is under 1.4 megs in size. If your image is destined for a web site, its resolution does not need to be greater than 72 dpi since this is currently the maximum resolution for monitors. Acquiring the image at a higher resolution (200 dpi for black and white, 150 dpi for color) gives you more image data to work with as you do your adjustments and manipulations. Once you are finished working on the image, you need to reduce the resolution. Select "Image...Image Size." The top box is the current size and resolution of your image. Type your changes into the bottom box. Use this operation to adjust image size as well. Note: Reasonable quality is maintained when images are reduced in size, but not if size is increased. To increase the size of an image, it is best to re-scan and be sure the scan contains enough pixels to meet your needs. •          Choose Image Size from the Image menu. •          Make sure that Proportions is checked and File Size is unchecked in the Constrain area. •          Set the Resolution to 72 pixels/inch. (When preparing images for use in a laser-printed projects, you may want to use 150, or even 300 pixels/inch.) •          Set the number of pixels that you want to use in your final image by entering a new number in either the Width or the Height boxes. Photoshop will automatically figure the other dimension. •          Click the OK button.   Save Your Image Before you perform any more manipulations, save your image as it was acquired. "File...Save As...". Make sure you are saving to the proper destination.  On the computer, look for the folder with your name on it. You may store your images here temporarily, then transfer them to your storage de vice later. Type in a file name. At this point save the file as a TIFF file. Continue to save as you manipulate the image. TIFF files can be large and slow to process, but you will achieve better results manipulating the image in TIFF form, and compressing the file after you complete your adjustments. TIP: If you plan to edit the image on a PC, add the file format identification extensions to your file name. E.g.: duomo.tif. PCs and Unix need the extension to recognize the file type. Make sure the extension matches the file type, though! •          Use .TIF for TIFF format             Use .PCX for PCX format    Use .GIF for GIF format •          Use .JPG for JPEG format            Use .PCT for PICT format   •          Choose Save As from the File menu •          Enter a filename for your image. •          Click on the Format box and select a graphics file format from the pull-down menu. •          To save images for the World Wide Web, choose JPEG, or Compuserve GIF. (To save a GIF file, reduce to 256 colors) •          If you are going to use the image in an on-screen presentation: - use PICT for Macintosh •Use PCX or TIFF for PC. •          If you are going to use the image in a laserprinted document, choose TIFF •          Click the OK button Scanning: Adobe Photoshop Basics Manipulation Tools   Color And Contrast Adjustment A few suggestions: •          To adjust Brightness and Contrast, use "Image...Adjust...Levels" in which you see a histogram of your image. Adjust the black, white and gray "Input" triangles to change the contrast and brightness of your image. Moving the black triangle toward the right will darken the image, moving the white triangle toward the left will brighten the image, and the gray triangle will adjust contrast. This method provides much more control than the "Brightness/Contrast" method. •          To perform color adjustments, try "Image...Adjust...Hue/Saturation" or "Image...Adjust...Color Balance." TIP: Increasing " Hue" (moving triangle to right) helps offset the pinkness of an old slide. •          More sophisticated adjustments can be performed using "Image...Adjust...Curves." Here you are given a color information graph. Place multiple points on the graph to increase the brightness of dark pixels and decrease the brightness of bright pixels. TIP: You can adjust Red, Green and Blue together or individually in both "Levels" and "Curves." Hold down the "RGB" bar to select an individual color channel.   To reduce an image to only use 256 colors: •          Select Indexed Color from the Mode menu. •          Select 8 bits/pixel in the Resolution area. •          Select Adaptive in the Palette area. •          Select Diffusion from the Dither area. •          Click the OK button. To reduce an image to only use 256 grays: •          Select Grayscale from the Mode menu. •          Click OK to verify. To reduce an image to only use black and white: •          Select Grayscale from the Mode menu •          Select Bitmap from the Mode menu •          Set the number for Output in the Resolution section to match the number for Input displayed above the Output box. •          If the image is photographic, then choose Diffusion Dither in the Method area. •          If the image is a line drawing, or logo, choose 50% Threshold. Click the OK button.   Removing Dust And Scratches Using the Rubber Stamp tool •          First enlarge the dirty area. •          Hold down the Option key and click once on a spot which you would like to sample. •          Now holding down the mouse button use the cursor like a paintbrush to apply the sampled area to your target spot. •          You can also try "Filter...Despeckle."   Sharpening Your Image Sometimes images lose their crispness when scanned. To sharpen the image, select "Filter...Sharpen...Unsharp Mask." The other "Filter...Sharpen" choices offer shortcuts, but at the expense of control. "Unsharp Mask" allows you to specify how much you want your image Sharpened. We recommend a "Radius" of .5 and a "Threshold" of 1. The amount will vary with each image. Radius is how many pixels should be considered together; and threshold is how different pixels have to be to be sharpened.   Saving The Image As A GIF For web design the GIF image format has the advantage of having a very small file size, thus it loads faster than a JPEG file. In order to save an image as a GIF, choose "File...Export...GIF89a Export." A new GIF file with 256 colors and a new name will be saved to the hard drive and your current file will be left alone. If you continue to make changes to the original image, remember to export it again when you are finished.   Scanning: Adobe Photoshop Basics More PhotoShop Tricks   ·         You can always "undo" your last action by choosing "Edit...Undo." ·         In most of the Photoshop dialogue boxes you can hold down the Option key to turn the "cancel" button into a "reset" button. This allows you to try different settings without leaving the dialogue box. ·         If you really mess up, you can choose "File...Revert" which will restore the image to your most recently saved version. ·         You can select a "brush size" for many of the toolbox functions. Double click on each tool to see its dialogue box and brushes. ·         "File...Preferences...General" lets you change your units to pixels or inches and set desired cursor appearance (Precise or Standard). The "brush size" cursor is a useful way to see what size brush you are using. ·         Using the various selecting tools: marquee, lasso, magic wand, etc., allows you to make changes only in the selected areas without affecting the rest of the image. ·         Most actions and all of the tools have keyboard shortcuts, and there are often many different ways of performing a single action, such as cropping, within the program. Don't be afraid to experiment.
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