Photographic Glossary-J


Stair-like lines that appear where there should be smooth straight lines or curves. Jaggies can occur for a variety of reasons, the most common being that the output device (display monitor or printer) does not have enough resolution to portray a smooth line. In addition, jaggies often occur when a bit-mapped image is converted to a different resolution. This is one of the advantages vector graphics has over bit-mapped graphics -- the output looks the same regardless of the resolution of the output device. The effect of jaggies can be reduced somewhat by a graphics technique known as antialiasing. Antialiasing smoothes out jagged lines by surrounding the jaggies with shaded pixels. In addition, some printers can reduce jaggies with a technique known as smoothing.
The smaller the pixels and the greater their number, the less apparent the "jaggies".
Also known as pixelization.

A programming language developed by SUN. Among other features, it allows the programming of interactive software for the Internet.

A scripting language, developed by Netscape® Communications. Javascript is the language that allows the images on the top of this page to hi-light as you roll your cursor over them. Javascript code can be placed directly onto web pages.

Japan Camera Inspection and Testing Institute. Organisation in Japan to monitor export quality of Japanese made cameras, in 1992, may be because of the global localisation programs, most lower end and some mid-range cameras are made and produced in countries outside Japan and their duty is relieved.

JPEG compression
A standard developed by JPEG for reduction in the amount of data required to represent an image and therefore the hard disk space needed to store it. The techniques involved in compression may result in loss of actual data, which may result in irregular rasterization of an image or granularity. JPEG compression is defined only for still-image compression, although a number of variants referred to as "motion JPEG" are used in digital videography. JointPhotographicExperts Group (the committee that established the baseline algorithms), .jpg. . A JPEG is a graphic image file created by choosing from a range of compression qualities (actually, from one of a suite of compression algorithms). When you create a JPEG or convert an image from another format to a JPEG, you are asked to specify the quality of image you want. Since the highest quality results in the largest file, you can make a trade-off between image quality and file size. There are several versions of JPEG, some proprietary. JPEG analyses images in blocks of 8 X 8 pixels in size, and selectively reduces detail within each block. At higher compression ratios, the block pattern becomes more visible and there may be noticeable loss of detail. The actual effect depends on the size of the image when output on a monitor or printer and on the type of subject. This is why you can get as many images into the digital cameras. The results in decompression of the files can cause "blockiness," the “jaggies," or " pixelization " in some digital images. The higher the compression ratio the more the pixelization or "blockiness" occurs. The greater the pixel count, the less pixelization may occur.

The new JPEG compression standard that will be used in digital cameras and software starting in 2001. It will feature higher compression but will less image quality loss.

A storage device for multiple optical disc, and one or more discs drives. It will automatically select or changeover as needed. Also Kodak's term for Photo CD's automated disc library.

In composition, to place two objects close together or side by side for comparison or contrast. Often helpful in showing scale in an image.