Factors Affecting Resource Requirements - Epson Expression 800 User Manual

Basic Scanning

Factors Affecting Resource Requirements

These factors affect the resources required to store a scanned image:
Type of Original
Size
Scaling
Resolution
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 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.
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