Chapter 2. Scanning Concepts

2.2 Image Type
Depending on the contents of your documents, basically, we can classify them into three image types.

2.2.1 Line Art
Line Art image type is used for documents containing lines, text and detailed drawings. If OCR (Optical Character Recognition) software is used for document management, you should choose Line Art image type and keep the resolution at 300 dpi or above.

2.2.2 Halftone
Halftone is an image type which simulates shades of gray or color by varying the numbers of dots printed or displayed. When choosing the halftone image type, the scanner will recognize each point in the images as either black or white, thus dark areas are recognized as many black dots, while white areas fewer black dots.

2.2.3 Photo
Photo image type is used for images with continuous tone that have a lot of gray shades or colors that must be kept. Photo contains more information than other image types. But it also uses a lot of disk space and system memory.