Factors that Influence the Size of Scanned Documents
Scanning and digitizing documents entails a huge storage space demand, especially when they are image documents. The two factors that determine the size of files the most are bit depth and resolution. For binary scanning the bit depth is usually set at 2 bits, and for grayscale and color scanning it is set at 8 bits and 24 bits respectively. A higher bit depth ensures more information is collected per pixel; and the more information collected for every pixel, the greater the size of the file. Resolution is another metric that determines the size of files. The higher the resolution, the greater will be the size of files scanned. Usually, in most document imaging applications the resolution setting ranges from 100 dpi to 300 dpi. However, in some special cases it can be as high as 600 dpi. The resolution setting for jpeg images, which contain tonal information (grayscale or color), is often lower than that set for bitonal images.
Steps to Minimize the Size of Scanned Documents
What really matters in document scanning is that the output that contains the information that you have captured is usable. So, first decide whether you need to capture the content in binary, grayscale or color. After you have made your choice, experiment with different resolutions on a sample page, and set the scanner to the lowest possible resolution that can produce satisfactory results. Binary scans generally need a higher resolution to produce acceptable results (20+ dpi), whereas for grayscale and color scans a lower resolution suffices (10+ dpi). Experiment with different bit depths and resolution settings and try to find out the effects on image quality and file size, before you pick the right setting for your scan that will minimize the scanned document.
Another Way to Minimize Scanned Document
After you have set the resolution to the lowest extent possible, run a despeckler to reduce the size of TIFF Group 4 images. This will not only eliminate unneeded backgrounds such as a pink background color on a form but will also deskew the images.