Text is textual material in the mainstream sense; data in ordinary ASCII or EBCDIC representation. Hypertext refers to connections between files or within files that enable direct movement from one position to another.
Audio is the recording or sequence of sound. Computers (and audio compact discs and digital audio tape) handle sound by storing a sequence of discrete samples. The continuous sound waveform from the original source is sampled tens of thousands of times a second. Each sample represents the intensity of the sound pressure wave at that instant. Apart from the sampling frequency, the other parameter is the digital encoding of each sample including the number of bits used.
Graphics or images are data representing a two- dimensional scene. Images are represented on the screen by individual dots called pixels. The word pixel comes from the words picture element. A pixel is the smallest unit on the screen that can be turned on and off or made different shades. Images are usually taken from the real world via a digital camera, frame grabber or scanner.
This demonstrates the ability to edit a bitmap graphic at the pixel level. Notice the greater level of ‘pixellation’ as the image is stretched. Original image - 100% 200% 400% 600% 800% Each image has been zoomed in to the varying degrees indicated.
There are different types of graphics software for – drawing, and painting A drawing program allows users to design and illustrate objects and products. A paint program allows the user to simulate the art of painting on the screen.
Drawing programs create vector images. The images are created using mathematical coordinates. The mathematical formulae are stored in memory. Some drawing programs are – CorelDraw Adobe Illustrator Macromedia Freehand Sketcher AutoSketch
Painting programs create raster or bitmap images. The images are made up of little dots (pixels). There is a one-to-one relationship between the image and what is stored in memory. Some painting programs are – Paintbrush Adobe Photoshop PaintShop Pro Corel PhotoPaint
Animation is the illusion of smooth movement generated by a series of static graphics, each slightly different from the previous one, being rapidly presented to the eye. Cel-based animation involves a process by which each individual frame is drawn separately and then played back at a suitable speed and a specific sequence. Path-based animation identifies the starting point, end point and the path to be followed by an object.
Video combines real dynamic (moving) graphics and sound into the one file. Video can be captured using a standard (analogue) video camera and then using a video capture card or frame grabber to collect and convert the images to digital data, and then saved on CD-ROM or DVD. Digital video cameras capture the images and automatically save them in a digital format. Images can be saved in a variety of file formats including.avi,.mpg, QuickTime’s.mov files, and.dvi