Epson Expression 800 User Manual - TWAIN 32 - Page 29

Factors Affecting Resource Requirements These factors affect the resources required to store a scanned image: Type of Original Size Scaling The size of a scanned image depends on the type of original. Color images require up to 24 bits of computer memory or disk space for each pixel or dot in the image. However, grayscale images require only 8 bits per pixel, and black and white line art requires only 1 bit per pixel. Scanning an original as a color image requires three times as much storage as scanning it as a grayscale image, and up to 24 times the storage requirement of a black and white line art image. Scanning a 2 × 2-inch original creates a smaller file than an 8 × 10-inch original. Scaling (enlarging or reducing) an image changes the file size accordingly. For example, scanning an image scaled to 150% of its original size requires 50% more storage than scaling it at 100%. Resolution Resolution is the amount of detail in an image, measured by the number of dots per inch (dpi). The higher the resolution, the larger the file size. Basic Scanning Page 29