(Random Access Memory) The short term chip-based memory in a computer that applications load into to run.

The series of lines of information such as the parallel and horizontal scan lines that form a television or video display image.

This is a resolution - dependant image that is produced using pixels. The quality of a low - resolution image decreases as you zoom in to the image. Photoshop is raster software.

A scanning pattern, generally from left to right while progressing from top to bottom of the imaging sensor or the display monitor. Generally comprised of two fields composed of odd and even lines.

Converting mathematical and digital information into a series of dots by an imagesetter for the production of negative or positive film.

The RAW image format is the data as it comes directly off the CCD, with no in-camera processing is performed.

"The most common image format amongst digital cameras is JPEG, it's a format which produces relatively small files from large amounts of image data by discarding certain information, as JPEG uses a "lossy compression algorithm". The only other common alternative is TIFF, this produces an uncompressed 24-bit per pixel image often in the multiple megabytes, certainly for a 3 megapixel camera in excess of 8 MB per image, not really practical. Each pixel of a CCD can only see one colour, depending on the CFA (colour filter array) placed over the CCD this is either Red/Green/Blue or Cyan/Magenta/Green/Yellow. The cameras internal image processing engine then interpolates colours from the value of neighboring pixels to calculate a full 24-bit colour for each pixel. RAW is simply the raw data as it comes directly off the CCD, no in-camera processing is performed. Typically this data is 8, 10 or 12 bits per pixel. The advantage being that file sizes are considerably smaller (e.g. 2160 x 1440 x 12 bits = 37,324,800 bits = 4,665,600 bytes), the image has not been processed or white balanced which means you can correct the image, and it's a better representation of the "digital negative" captured. Advantages of RAW format: A true "digital negative", untouched by cameras processing algorithms. No sharpening, gamma or level correction applied, no white balance and no colour correction applied. Lossless yet considerably smaller than TIFF. Records data over a wider bit range (typically 10 or 12 bits) than JPEG or 8-bit TIFF. Disadvantages of RAW format: Requires proprietary acquire module (typically TWAIN) or plug-in to open images. Images can take 20-40 seconds to process on an average machine. No universally accepted RAW standard format, each manufacturer (even each camera) differs."

The red glow from a subject's eyes caused by light from a flash reflecting off the blood vessels behind the retina in the eye. The effect is most common when light levels are low, outdoor at night, or indoor in a dimly-lit room.

To change the resolution of an image.

Refers to the sharpness and clarity of an image. The term is most often used to describe monitors, printers, and bit-mapped graphic images. In the case of dot-matrix and laser printers, the resolution indicates the number of dots per inch. For example, a 300-dpi (dots per inch) printer is one that is capable of printing 300 distinct dots in a line 1 inch long. This means it can print 90,000 dots per square inch. For graphics monitors, the screen resolution signifies the number of dots (pixels) on the entire screen. For example, a 640-by-480 pixel screen is capable of displaying 640 distinct dots on each of 480 lines, or about 300,000 pixels. This translates into different dpi measurements depending on the size of the screen. For example, a 15-inch VGA monitor (640x480) displays about 50 dots per inch. Printers, monitors, scanners, and other I/O devices are often classified as high resolution, medium resolution, or low resolution. The actual resolution ranges for each of these grades is constantly shifting as the technology improves.

A process that enlarges an image by adding extra pixels without actually capturing light from those pixels in the initial exposure.

The true resolution of an image based on the number of photosites on the surface of the image sensor.

The resolving power of a lens is a measure of its ability to closely spaced objects so they are recognizable as individual objects. It is determined by photographing a series of closely spaced lines, measuring the spacing between the most closely spaced lines that appear separate on film. The resolving power is expressed as the number of lines pairs per millimeter.

(Red. Green, Blue) The additive primary colours used to display images on a monitor.

A storage format used with gray-scale images.