Imaging and Concept
Imaging and Concept
Bitmap and vector are two different types of images. Vector art and bitmap art are different in the way they are stored in the art files. Bitmap art utilizes pixels that are saved in a file as a series of numbers. Pixels create several dots of color in order to create the image, which is how the human eye sees pictures. Vector art, on the other hand, saves the image as lines with coordinates of their starting and ending points. This creates the simple images, and research has demonstrated that this is the way the human brain sees and stores images.
Bitmap Images
To understand how a bitmap image displays, it’s important to understand the computer display screen. The display is made up of rows and columns of tiny blocks, or pixels. In a bitmap image, each pixel is assigned at least one bit to indicate whether the pixel should reflect the background color, the foreground color, or some other color.
In the case of a page of black and white text, let’s consider a single letter. The many pixels that make up that letter only require one bit of data each. Either the pixel will be black or white: 1 or 0.
When a bitmap displays a colored image, such as a lake scene, there are several shades of gradation in colors and lighting. In this case, each pixel in the bitmap might have 16, 24, or 48 bits of information associated with it. The more bits, the greater the resolution of the bitmap – and the larger the file.
Because bitmaps store so much information in the highest resolutions, they make very beautiful images. However, a bitmap image doesn’t rescale well. If blown up using a graphics program, the bitmap image becomes blocky and blurred. If reduced, it loses clarity.
Compression techniques are used to shrink the file size of the bitmap while maintaining as much data as is necessary to render a good picture. One such format is the 8-bit .GIF format, which uses a pallette of 256 colors. The advantage of the compressed .GIF is that it is a smaller file that can be resized with satisfactory results, as it uses lossless compression. The disadvantage is that it cannot faithfully reproduce images containing more than 256 colors.
Photographs saved in the bitmap format that need to be reduced for Internet use can be converted to the JPEG (JAY-peg) format. While this is a lossy compressionformat, it is capable of displaying more than 256 colors and does a better job of rendering photographs.
Because bitmap images are built pixel-by-pixel, they can be easily edited. Zooming in on a bitmap image in any graphics program allows the user to add, delete, or change the color of individual pixels. For this reason, logos, favicons and icon images are frequently built in the bitmap format.
Guide by Anonymous