Making Still Images

• Still images may be small or large, or even full screen, colored, placed at random on the screen, evenly geometric, or oddly shaped.


• Still images are generated by the computer in two ways: as bitmaps and as vector-drawn graphics.


• Bitmap are used for photo-realistic images and for complex drawings requiring fine detail. Vector-drawn objects are used for lines, boxes, circles, polygons, and other graphic shapes that can be mathematically expressed in angles, coordinates, and distances.


• Many image file formats already use compression within the file itself, for example, GIF, JPEG, and PING.

Bitmaps

• A bit is an electronic digit that is either on or off, black or white, or true (1) or false (0).


• This is referred to as binary, since only two states (on or off) are available. A map is a two-dimensional matrix of these bits.


• A bitmap, then, is simple matrix of the tiny dots that form and image and are displayed on a computer screen or printed

Clip Art

• Clip art is available on CD-ROMs and through online services. A clip art collection may contain a random assortment of images, or it may contain a series of graphics, photographs, sound, and video related to a single topic.

Vector Drawing

• Most multimedia authoring systems provide vector-drawn objects such as lines, rectangles, ovals, polygons, complex drawings created from those objects, and text.


• Computer-aided design (CAD) programs have traditionally used vector-drawn object systems for creating the highly complex and geometric renderings needed by architects and engineers.


• Programs for 3-D animation also use vector-drawn graphics.

3-D drawing and Rendering

• Creating objects in three dimensions on a computer screen can be difficult for designers comfortable with squares, circles, and other x (width) and y (height) geometries on two-dimensional screen.


• Dedicated software like Tek’s Lightwave and Autodesk’s help you render three-dimensional scenes and complete with directional lighting.


• A scene contains many different objects. Objects are created by modeling them using 3-D application.


• To model an object you must start with a shape.


• Once you have created 3-D object, you can apply textures and colors to it to make it seem more realistic.


• In modeling your scene, you can also set up one or more lights that will create diffuse or sharp shades and shadows on your objects.


• There is several way of shading; Flat, Gouraud, Phong, and ray tracing.


• When you have completed the modeling of your scene or an object in it, you then must render it for final output.

Computerized Color

There are two basic methods of making color:

• Additive Color
  1. A color is created by combining colored light sources in three primary colors: red, green and blue (RGB). This is the process used for TV or computer monitor.


• Subtractive Color
  1. Subtractive color is the process used to create color in printing. The printed page is made up of tiny halftone dots of three primary colors: cyan, magenta, yellow and black (CMYK).

Image File Formats

• Macintosh Format


• Windows Format


• Cross-Platform Formats