Many people are happy when they purchase their first scanner because they can now attach images to the Email they send to friends and family. Little do they know that the art of scanning photographs into clear, crisp image files of a small size (50 KB or less) requires skill and an understanding of their scanner hardware and image editing software.

(NOTE: The small file size as given above is recommended because it only requires about 10 seconds to transmit a file of this size through their modem; hence, neither sender nor receiver will grow impatient waiting. The 10 second time is calculated as follows for a typical 56.6 Kbps modem connection:  50 KBytes x 8 bits/Byte / 40,000 bits/sec = 10 sec. The discussion below reveals that if you're not careful, you could easily spend 100 times longer than the above 10 seconds waiting for the file to transmit to the recipient!)

Large image files result from scanning photos because the (default configuration) settings of the scanner are set to yield beautiful pictures when the image is printed out locally on an ink jet printer. This large file size is required in order to capture all the details in the photo. But for Email attachments, a small file size is needed to speed up the transmission (at the sacrifice of image quality when printed out by the recipient). Unfortunately, a new user does not appreciate the trade-offs fully enough in the beginning; hence, much frustration is experienced on his/her part and that of recipients.

The problem with making a small image file when using a scanner is that a normal, scanned 4" x 6" photo will result in a huge file (e.g., over 6 MB) if certain techniques are not utilized at all stages of the acquisition.

Below is a list of tips and subjects that beginners might find useful to read and study up on. Much of this information applies to digital cameras, also. For further information, consult your scanner and image editing user guides.

A 4" x 6" photo scanned at 300 dpi (horizontal) x 300 dpi (vertical) in 256 colors will result in a 6.5 MB file - 4 x 6 x 300 x 300 x 3 = 6.5 MB. If High Color (65 M colors) or True Color (16 MM colors) is desired, then even larger file sizes are created.

o Use these techniques to combat this problem:

- Set the scanner resolution to a smaller value, say, 100 dpi x 100 dpi. (This will make the image 9x smaller.)

- Make the image size smaller than the photo, say, by one half. (This will make the image 4x smaller.)

- Crop out portions of the photo which are not interesting, say, 1" around the edges. (This will make the image about 1.6x smaller.)

Use image editing software to improve brightness, contrast, hue, and sharpness. This will not reduce the file size, per se, but will make it more able to retain image quality across the file compression step in the next step. Watch though, if you make details in the image a whole lot more distinct, the file size will increase.

Hopefully, the image editing software used above employs various levels of .JPG compression, typically 13, to save the file. This step will turn a 2 MB image file into, say, a 30 KB file with very little loss in quality when viewed on-screen.