Adobe 29180155 User Guide - Page 305

ADOBE PHOTOSHOP ELEMENTS 4.0 300 User Guide 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 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. baseline JPEG The standard compression scheme for JPEG files. Baseline JPEG files display in line-by-line passes when viewed on the web. bas relief In digital photography, the illusion that an image is slightly raised from its background surface. 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 A graphics image represented as rows and columns of dots in computer memory. When displayed on a monitor, the dots are translated into pixels; when printed, they are translated into ink dots. Also called a raster image. The edges of the pixels can be discerned in a saw-tooth pattern unless anti-aliasing is used. Bitmap file formats include BMP, GIF, JPEG, PSD, PICT, and TIFF. Compare vector graphics. 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. blending mode A feature that controls how pixels in an image are affected by a painting or editing tool. The blend color is applied to the base (original) color to produce a new color, the result color. When applied to layers, a blending mode determines how the pixels in a layer blend with pixels in layers beneath it. blooming An artifact caused by overflow of color information from one sensor in a camera (corresponding to a pixel) to adjacent ones. Blooming can cause streaks, halos, and loss of detail. blur The softening of the detail in an image or parts of a image. BMP A standard file format for saving bitmap files in Windows. Windows can display BMP files on any type of display device. bounding box A rectangular border around an image, shape, or text that you can drag to rotate or resize.