There are two ways to convert photographs into a computer-readable format: 1) Scan them in with a scanner; 2) Shoot them with a digital camera.
A scanner passes tiny light-sensitive elements over the image to be digitized. A white light also passes over the image, and the elements detect the relative levels of reflected light and convert them into digital data. Scanners started out recognizing 8 bits of data per pixel, or picture element – the computer equivalent to the dots you see when you look close-up at a picture in the newspaper. For a black and white image, that translates to 256 distinct shades of gray. In the case of a color photograph, the scanner shines its light through three filters: red, green, and blue (RGB). This captures all the color information it needs to reproduce the photograph as it originally appears. These color scanners were referred to as 24-bit scanners, since they record 8 bits of data for each of 3 colors. This results in 16.8 million colors, which corresponds to the number of colors able to be displayed on a computer monitor or printed on a typical inkjet printer. Today's scanners capture 48 bits of color information, which may seem like overkill. However, the extra data results in vastly increased detail in shadow and highlight areas that will show up even at relative low output resolutions.
Scanners typically connect to your computer through the USB port. All scanners come with some kind of controlling software, and most include some kind of manipulation software, allowing you to at least crop, resize, rotate, and make some degree of color adjustments to your images.
The highest-quality solution to getting pictures directly into your computer is to bypass conventional film photography and use a digital camera. You can transfer the pictures from a digital camera to your computer’s hard disk via an included cable and software. An alternative way, which saves the batteries in your camera, is to use a memory card reader hooked to your computer’s USB port. All digital cameras use flash memory cards to store the pictures you take. These can be removed from the camera and inserted into a card reader like tiny floppy or zip disks, which then show up on your computer as additional disk drives. You can then just drag your photos to your hard drive.
Well, so much for getting the pictures into your computer. How do you actually transfer them over the Internet?
The easiest way to transfer a file over the Internet is to attach it to an email message. Every time you send an email message, you have the option to include what’s known as an attachment. It can be any type of file, not just a photo or graphics file.
A digitized photograph is a data file. It’s not a runnable program. It has been created as output from a scanner or digital camera. In order to view it, your recipient must have a program that can recognize the photo and load it as data. There are many graphics formats for both photo-type scanned graphics (bitmaps) and illustration-type (vector) graphics. These formats are identified by their filename extensions; that is, the three-letter tags that come after the period. The most common bitmap graphic format, and thus the one your photos will most likely embody, is .JPG (pronounced "j-peg"), which is one of the standards for World Wide Web graphics, and thus can be viewed in your internet browser and email program, as well as most consumer photo-viewing programs like Windows Picture and Fax Viewer, Microsoft Photo Editor, Photoshop Elements, or whatever software came with your digital camera.
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