Glossary 213RAM Random-access memory. RAM is that part of your
computer that temporarily stores all data while you are working
on an image or a letter to Granny. Unlike data stored on a
hard drive, this data is volatile. If you lose power or turn off
your computer, the information disappears. Most computer
motherboards feature several raised metal and plastic slots
that hold a RAM chip in the form of DIMMs (Dual In-Line
Memory Modules). The more RAM you have, the better it is
for digital imaging work, but there are economic considerations
too. As I write this, RAM is inexpensive, but prices can
fl uctuate.
Resolution A digital photograph’s resolution, or image quality,
is measured by the image’s width and height as measured in
pixels. When a slide or negative is converted from silver grain
into pixels, the resulting digital image can be made at different
resolutions. The higher the resolution of an image—the more
pixels it has—the better the visual quality. An image with a
resolution of 2048 × 3072 pixels has better resolution and
more photographic quality than the same image digitized at 128
× 192 pixels.
RGB Red, Green, Blue. Color monitors use red, green, and
blue signals to produce all the colors that you see on the screen.
The concept is built around how these three colors of light blend
together to produce all visible colors.
RIP Raster image processor. A process that prepares image
data for the screen or printer.
ROM Read-only memory. The memory in your com-
puter from which you can only read data. It’s a one-way
street.
Saturation Often referred to as chroma. A measurement of the
amount of gray present in a color.
Search engine Because the actual number of Web sites on the
World Wide Web is big and getting bigger every day, fi nding the
Exacta Collectors home page (www.ihagee.org) might be impos-
sible without a way to search for the word “Exacta.” That’s the
function of search engines: you type in a word or words and a
list of Web sites whose descriptions contain those keywords
appears.
Selection tool One of the most important tools found in an
image-enhancement program. Selection tools allow you to high-
light or select portions of an image that will have an effect
applied to them.
Serial port On the back of a computer, an outlet that is used
to connect peripheral devices such as modems and printers. The
serial port sends and receives data 1 bit at a time.