Graphics, Digital Media and Multimedia PDF

Graphics, Digital Media and Multimedia Chapter 6 Multimedia Part 2 Topics Animation Video Audio Hypertext and Hypermedia Interactive Multimedia 2 Multimedia Computer information can be represented through audio, video, and animation in ad...

Graphics, Digital Media and Multimedia Chapter 6 Multimedia Part 2 Topics Animation Video Audio Hypertext and Hypermedia Interactive Multimedia 2 Multimedia Computer information can be represented through audio, video, and animation in addition to traditional media (i.e., text, graphics/drawings, images). 3 Animation Pictures are manipulated to appear as moving images. The effect is achieved by a rapid succession of sequential images that minimally differ from each other. A frame is one of the many still images which compose the complete moving picture Frame Rate:  Is the frequency (rate) at which consecutive images called frames appear on a display.  Usually ( > 24 frames/sec  standard 30) A 20 second 30fps animation, how many frames? 4 Computer Animation Used in television and movies to create effects that would be diffi cult to achieve without computers Most animations are made with computer- generated imagery (CGI) Tweening: Process of generating intermediate frames between two key frames(images), to give the appearance that the first image evolves smoothly into the second image 5  Video Digital video is a series of bitmap images that, when played back, create the illusion of movement. The quality and overall file size of digital video is determined by its: 1. Frame size: Width x Height. E.g. High-definition (HD) video – 1280 x720 2. Bit depth 3. Frames per second (fps) 6  Data Compression Encoding information using fewer bits than the original representation. Can be: 1) Lossless: Original representation can be recovered  E.g. WinZip, WinRar,  But: not good enough for Multimedia Data! 2) Lossy: Recover a representation similar to the original one (more practical)  Throw away less relevant parts of the data  Examples: MP3, JPEG, MPEG Video  High compression ratios 7  Digital Audio Using a microphone to capture sound in an analog form (Electric Waves) Electric wave is converted into digital data by Audio digitizer (ADC) Sound can be: 1. Sampled – Digitally recorded 2. Synthesized - Generated 8  Synthesizer An electronic instrument that synthetically generates, creates, produces, etc. sounds using mathematical formulas Synthesizer 9  Samplers An electronic instrument which instead of generating sounds, uses recordings (or "samples") of sounds that are loaded or recorded into it by the user 10 Visualizing a Sound Wave Repetitive oscillations of sound vibrations A – Amplitude B – Wavelength C – Frequency 11 Digital Sampling An analog audio signal is continuous without interruption A digital audio signal is sampled at regular intervals 12  Audio Quality 1) The Sampling Rate:  Number of samples taken per second (frequency)  Measured in Hertz (Hz) 2) The sample size (Bit Depth)  Bits used to represent a sample  Measured in bits 3) The number of channels  Mono or Stereo 13  Audio Digitizer - ADC Captures sound(Analog) and stores it as a data file 0 33 80 -122 -56 -21 40 -43 15 47 96 -96 -47 -15 43 -40 21 56 122 -80 -33 0 47 -46 Snapshots 24 52 117 -84 -26 10 42 -66 34 48 85 -78 -24 35 18 -74 32 55 0 -55 -32 74 -18 -35 24 78 -85 -48 -34 66 -42 -10 26 84 -117 -52 -24 46 -47 0 14 Playing back digital audio - DAC Digital data converted to analog wave and played 0 33 80 -122 -56 -21 40 -43 15 47 96 -96 -47 -15 43 -40 21 56 122 -80 -33 0 47 -46 24 52 117 -84 -26 10 42 -66 34 48 85 -78 -24 35 18 -74 32 55 0 -55 -32 74 -18 -35 24 78 -85 -48 -34 66 -42 -10 26 84 -117 -52 -24 46 -47 0 15  Audio Formats Format Description WAV, Uncompressed audio for Windows and AIFF Mac OS MP3 1/10 the size of the original WMA An alternative to MP3 for Windows. AAC Apple’s alternative to MP3 OGG Similar to MP3  open source and freely available 16 HyperText Text which contains links to other texts Information linked in non-sequential ways. 17 HyperText Traversal through pages of hypertext is therefore usually non-linear. 18 HyperMedia Hypermedia is not constrained to be text-based, it can include other media Hypermedia: combines  text, numbers  graphics, animation  sound, music 19 Interactive Multimedia Integration of digital media including electronic text, graphics, moving images, and sound, into a structured digital computerized environment that allows people to interact with the data for appropriate purposes. 20  Interactive Multimedia Visual guide to Hearing: Interactive Ear The Funky Forest  Children manage resources to influence the environment around them using their bodies Interactive Flowers at Expo 2020 Interactive Sliding Screen Expo 2020 21