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MULTIMEDIA Technology Presented by ARLENE N. BARATANG, M. A.
Multimedia Definition l Multimedia refers to the combines use of various types of data in addition to letters and numbers, including static images, video and audio. With advances in computer technology, the use of data such as static images, video, and audio files has become increasingly common. After converting this analog data into digital data according to certain rules, it is used in “Web content”, “hypermedia”, “streaming”, and other media.
Web Content l Is a generic term that refers to information and data accessed on Internet browsers, including static images, video, audio and text.
Hypermedia l Is used as a logical extension of the term “hypertext”, which applies to text, and is a media format that links text, images, audio, and other objects together in an easily accessible manner.
Streaming l Refers to a technology for efficiently distributing and playing back audio files, video, and other Web content. The data is played back while it is being downloaded, so the user does not need to wait for the download to complete. It makes it easier to watch videos and listen to music on the Internet.
PDF l Portable Document Format or PDF is a file format created by Adobe Systems’ Acrobat software. When converting documents created using word processing software into PDF format, the data cab be compressed to reduce the file size. For this reason, it is widely used for distributing electronic documents. PDF files cannot be edited using the original software.
Compression Rate l Refers to the ratio of data compression. The higher the compression rate, the smaller the file size.
JPEG l Abbreviation for “Joint Photographic Experts Group”.
GIF l Abbreviation for “Graphics Interchange Format”.
PNG l Abbreviation for “Portable Network Graphics”.
Capture Card l A “capture card” is an extension card that can import video signals from VCRs and other devices, and convert them into digital data (video) that can be viewed on a computer.
MPEG l Abbreviation for “Moving Picture Experts Group”.
Types of Multimedia File
1. Static Images l l l File Type: JPEG Extension: . jpg , . jpeg Characteristics: A file format for compressing and storing static images. Supports 24 -bit full color (16. 77 million colors) images suited for photographs; used as the image format for digital cameras and other devices. Employs lossy compression so there is deterioration in quality.
Static images. . . l l l File Type: GIF Extension: . gif Characteristics: A file format for compressing and storing static images. Supports 8 -bit color (256 colors) images suited for graphics and other data with limited color variation. Employs lossless compression, so no deterioration in quality.
Static images. . . l l l File Type: BMP Extension: . bmp Characteristics: A file format for storing static images as a collection (or map) of dots. The images are not compressed, so the size of the file is relative to the size of the image and the number of colors. It is the standard format on Windows.
Static images. . . l l l File Type: TIFF Extension: . tif, . tiff Characteristics: A file format for storing static images developed by Microsoft and Adobe Systems, and can save image data of different formats. It can record images regardless of resolution, number of colors, etc. Employs lossless compression so there is no deterioration in quality.
Static images. . . l l l File Type: PNG Extension: . png Characteristics: A file format for compressing and storing static images. Supports 48 -bit color images. Employs lossless compression, so there is no deterioration in quality.
2. Video l l l File Type: MPEG Extension: . mpg Characteristics: A file format for compressing and storing video. It is an international standard format for color video and audio.
Three MPEG formats l MPEG-1 : Used for CDs (Video-CD), DAT (digital audio tape), hard disks and other media that have a data transfer speed of around 1. 5 Mbps. Data is compressed and decompressed by software. Image quality is comparable to VHS videos.
l MPEG-2 : Used for DVDs (DVDVideo), digital satellite broadcasts, etc. that have a data transfer speed of several Mbps. Data is compressed and decompressed by hardware. Image quality is comparable to HDTV.
l MPEG-4 : Used for mobile communication devices (such as mobile phones), video conferencing systems, etc. that have a data transfer speed of several kbps to several dozens of kbps.
SWF l l l File Type: SWF Extension: . swf Characteristics: The video file format created by Macromedia’s (now Adobe Systems) Flash software. Widely used on the Internet for animated video files. A plugin (adobe Flash Player) is required to playback video.
AVI l l l File Type: AVI Extension: . avi Characteristics: A standard composite file format for videos and audio used on Windows. Software called “CODEC” that supports the various video and audio compression formats is required to play AVI files.
Quick. Time l l l File Type: Quick. Time Extension: . mov Characteristics: A video file format created by Apple/ Widely used not only on Macintosh, but also Windows computers. These files provide simultaneous support for various compression and decompression systems not only for audio and video, but also for text.
3. Audio l The types of audio format and their characteristics are summarized below.
MP 3 l l l File Type: MP 3 Extension: . mp 3 Characteristics: A file format for compressing and storing audio data using the part of MPEG-1 that controls sound. The data can be compressed to about 1/10 the size of a music CD (compression rate can be specified). It is used on portable music players and used top distribute music over the Internet.
WAV l l l File Type: WAV Extension: . wav Characteristics: A file format for storing raw audio sampling data in the same way as CD audio. It is used as the audio data format on Windows
TERMINOLOGY l l l MIDI – abbreviation for Musical Instrument Digital Interface ATRAC 3 – Abbreviation for “Adaptive Transform Acoustic Coding 3. ” AAC – is a file format developed by Apple for compressing and storing audio. Abbreviation for “Advanced Audio Coding”.
TERMINOLOGY… l SDMI – is a file format standardized by a foundation established to protect digital music copyrights and used on mobile players. It is used as a format for music files distributed over the Internet. Abbreviation for “Secure Digital Music Initiative. ”
Archive l An archive is a collection of files that have been packaged together. Archives are used to be free up space by compressing large files, or distribute multiple files as a single package.
Lossy Compression l Lossy compression is a method of data compression in which the compressed images and other files cannot be completely restored to their original state when decompressing the archive.
Lossless Compression l Lossless compression is a method of data compression in which the compressed images and other files can be completely restored to their original state when decompressing the archive.
Compression and Decompression of Information l l When attaching large data such as multimedia files to e-mail or publishing it on a Web page, it is common practice to “compress” it. The seize of the file can be reduced by compressing the data. “Decompress” refers to returning compressed data to its original state. Compression/decompression software is used to accomplish this task
Compression. . . l l l File Type: Lzh Extension: . lzh Characteristics: Format of files compressed with LHA (file compression software). The compressed data can be decompressed and completely restored to its original state.
Compression. . . l l l File Type: Zip Extension: . . zip Characteristics: Format of files compressed with file compression software developed by PKWARE. The compressed data can be decompressed and completely restored to its original state.
1. Graphics Processing l Graphics processing is a task involving the display, processing, and storing of loaded images. In order to implement graphics processing, it is necessary to have an understanding of color and image quality.
Color Representation l l “RGB” and “CMYK” color models are used for displaying color on display devices and for printing in color. Three primary colors of light (RGB). When displaying color on display devices, a single dot is comprised of the three colored lights Red(R), Green (G) and Blue (B). All colors are reproduced by adding together R, G and B light in varying degrees. When all three combined, white is produced. When all three are at zero intensity, black is produced.
Three primary colors of light (RGB) Red (R) Yellow Magenta White Green (R) Cyan Blue (B)
Three primary process colors (CYMK) l When printing in color, the colors are created by mixing Cyan (C), Magenta (M), Yellow (Y). When C, M, and Y are mixed, black is produced. For a solid black, Black (K) is added to create CMYK ink.
Three primary process colors (CYMK) Cyan (C) Blue Magenta (M) Green Black (K) Red Yellow (Y)
Three Elements of Color l l l Hue – The color as described by wavelength. Each hue is represented on the “color circle”. Brightness – The intensity of the color. The higher the brightness, the whiter the color. The lower the brightness, the blacker the color. Saturation – The amount of color displayed. The higher the saturation, the deeper the color. The lower the saturation, the duller the color.
Image Quality l l Pixel. It refers to the dots that comprise an image and is the smallest single component of the image. The higher the number of pixels, the larger the data. Resolution. It is a value that expresses the number of pixels per inch and is a measure of the detail and smoothness of the image. The higher the resolution, the more natural and attractive the image. The lower the resolution, the blurrier the image.
l Contrast. It refers to the gradation of color, and is a measure of the image detail. The higher the contrast, the smoother the image. The lower the contrast, the clearer the colors.
Graphics Software l Graphics software that handle images include “painting” and “drawing” software.
Multimedia Technology Applications l Graphics processing is an applied technology for multimedia expressions. Graphics processing involves the use of computers to create images and videos, and add sound and other effects to artificially create a sense of realism. It is used in games and other forms of entertainment as well as various professional training programs.
Forms of Graphics Processing l Computer Graphics (CG). Refers to the technology for processing and generating images and videos using a computer or the images and videos themselves. Computers are used to create images of imaginary objects and scenes, or to add special effects. Two-dimensional representations are used in tablet paintings, photographic image processing, etc.
l Three-dimensional representations are used to create virtual worlds for video games, simulations of the future urban landscapes, CAD-based industrial designs, etc.
Virtual Reality (VR) l It refers to the technology for creating an artificial (virtual) reality by combining computer graphics with sound effects. People can experience virtual realities like farremoved worlds, past and future locations, etc. , as if they were actually there, while not setting foot outside their current location.
Computer Simulation l It involves using a computer to simulate an event of some kind. Creating various simulated situations enable results to be realized that are otherwise unattainable using actual theories or experiments. For example, it can be applied to predict damage from building fires, or the effects of global warming on climate. The hardware and software used to perform computer simulations are called a “simulator”.
CAD l “CAD” is a system used when designing machines, buildings, electronic circuits, etc. CAD is used to design floor plans and blueprints for buildings and automobiles, televisions and other mechanical products. It is also used to prepare the basic CG data used in media such as commercials and video games.
Collage l It is a composite picture created using a computer to combine pictures of scenes and people that were taken separately.