DocuMate 252 Scanner User’s Guide 107Scanning with the ISIS InterfaceTo adjust the Custom Document settings:1. Click the Custom Document button and click the Definebutton.The dialog box for Custom settings opens.Mode—Click the arrow and choose a scan mode.Black and White—The scanning pixels are all the samesize and are either black or white. Use this setting forletters, memos, pen and ink drawings, and other black andwhite material. This setting produces the smallest file sizefor scanned items.256-Level Gray—Scans the image using up to 256 trueshades of gray. Use this setting to scan black and whitephotographs and other higher quality black and whiteimages. You can also scan a color photo with this setting toturn its colors into gray shades. The file size is about onethird the size of a color scan.24-Bit Color—Scans the image in full color. Use thissetting to scan color photographs and other color images.The file size is the largest of the scan mode options.Dither—Only available if the Mode is Black and White. Clickthe menu arrow and choose a Halftone option or Diffusionfrom the list.Halftone—Converts the image so it appears to consist ofgray tones. Halftones produce simulated gray tones byusing black and white pixels of different sizes and is oftenused to produce newspaper and magazine images. Usethis setting for lower resolution black and white images. Thehalftone settings also produce small file sizes.Diffusion—Also converts the image to gray tones, butdiffuses the grays to nearby pixels to give the image agrainy, film-like texture. Diffusion is useful for viewingimages on a black-and-white screen.The preview imageshows the effect of your Dither selection so you can seewhich one is best for scanning.
