Adobe 65045315 Photoshop Elements Manual - Page 328

USING PHOTOSHOP ELEMENTS 10 322 Glossary aliasing The jagged edges seen at the edges of diagonal lines, arcs, and so on, caused by pixels lining up in a saw-tooth pattern. alpha channels Masks, which let you manipulate, isolate, and protect specific parts of an image. In Photoshop Elements, alpha channels are called saved selections. To save an alpha channel, choose Select > Save Selection. To load an alpha channel, choose Select > Load Selection. ambient light The existing lighting conditions under which a photo is taken, without enhancement from a camera flash. animated GIF A series of images in GIF format that create the illusion of movement when they are displayed in sequence over time. anti-aliasing The smoothing of jagged edges in digital images by averaging the colors of the pixels at a boundary. arithmetic coded JPEG A type of file compression used to compress JPEG files. artifact Any unexpected and undesired change to a digital image caused by incorrect settings or faulty processing. Examples include blooming, moire, sharpening, and noise. aspect ratio The ratio of an image's width to its height. It is used to determine how an image fits on a page or monitor. associated Related to an application (also, file association). Each file type has an associated application. For example, PSD files are associated with Adobe Photoshop and Photoshop Elements. You receive an alert if you try to open a file that lacks an associated application. audio caption Voice narration of a photo. Auto Levels An automatic color-correction command. B Background layer The bottom-most layer in an image, usually containing the image data. The Background layer is always locked. If you want to change its stacking order, blending mode, or opacity, you must first convert it to a regular layer. backlight Light coming from a source behind the photographed subject. bas relief In digital photography, the illusion that an image is slightly raised from its background surface. baseline JPEG The standard compression scheme for JPEG files. Baseline JPEG files display in line-by-line passes when viewed on the web. batch processing Performing one or more tasks to a group of files at the same time. bevel A raised or depressed effect around all or part of an image or text. Bevels are created by applying highlight and shadow to the inside and outside edges of its border to simulate three-dimensional depth. bit depth The number of colors used to represent a pixel in an image. A 1-bit image is black and white; an 8-bit image can have 256 colors or shades of gray; a 16-bit image can have 65,536 colors. bitmap image An image consisting of rows and columns of pixels in computer memory. Also called a raster image. Bitmap file formats include BMP, GIF, JPEG, PSD, PICT, and TIFF. (See also "vector graphics" on page 334.) bits/channel Bits per channel. This measurement determines how many tones each color channel can contain. black body A theoretical material that is black when completely cold and that begins to glow in various colors as it is heated. As its temperature (measured in degrees Kelvin) rises, it begins glowing in colors ranging from red (coolest) to white (hottest). (See also "color temperature" on page 324.) Last updated 1/2/2012