ACSC 375 – Multimedia - 2

Lecturer : Dr. Stephania Loizidou Himona

Memory Storage Devices

As you add more memory and storage space to your computer, you can expect your computer needs and habits to keep pace, filling the new capacity. So enjoy the weeks that allow a memory storage upgrade or adding an additional hard disk; the honeymoon eventually ends.

On a multimedia platform, multimedia authoring can consume a great deal of memory – you may need to open many large graphics and audio files, as well as your authoring system, all at the same time to facilitate faster copying/pasting and then testing in your authoring software.

Floppy and Hard Disks

Floppy disks and hard disks are mass-storage devices for binary data, data that can be easily read by a computer. Hard disks can contain much more information than floppy disks, and they operate at a far greater data transfer rates.

A floppy disk is made of flexible mylar plastic coated with a very thin layer of special magnetic material. The disk is formatted to tracks and sectors where data can be written. As the disk spins, data is written along each track in spots that become magnetically charged or not (either ‘on’ or ‘off’). The data is then readable from the disk as a string of binary information. Disks are made in different sizes and with different data densities for use in various drive mechanisms.

Hard disks are the most common mass-storage device used on computers. A hard disk is actually a stack of hard metal platters coated with magnetically sensitive material, with a series of recording heads or sensors that hover a hairsbreadth above the fast-spinning surface, magnetizing or de-magnetizing spots along formatted tracks using technology similar to that used by floppy disks and audio and video tape recording. For making multimedia, you need a large-capacity hard disk drive.

SyQuest drives and Optical Storage Devices are similar to hard drives except that the disk is a removable cartridge. They are among the most useful external and portable storage devices available for multimedia today.

CD-ROM Drives (Compact Disc Read Only Memory) drives have become and integral part of the multimedia development workstation and are an important delivery vehicle for large, mass-production projects. A wide variety of developer utilities, graphic backgrounds, stock photography and sounds, applications, games, reference texts, and educational software are available only on this medium. CD-ROM players have typically been very slow to access and transmit data but new developments have led to double-, triple-, and quadruple-speed drives designed specifically for computer use.

CD-ROM Recorders – With a special compact disc recorder, you can make your own CDs using special CD-recordable (CD-R) blank optical discs to write a disc in most of the formats of CD-ROM and CD-Audio. CD-R discs are made differently than normal CDs but can play in any CD-Audio or CD-ROM player. These write-once CDs make excellent high-capacity file archives, and are used extensively by multimedia developers for premastering and testing CD-ROM projects and titles. Once the data is written onto these CDs, that part of the disc cannot be overwritten or charged.

Videodisc players (commercial, not consumer quality) can be used in conjunction with the computer for superior delivery of multimedia applications. The requirements of your project and budget will dictate your choice of player.

  • Input Devices
  • Output Devices
  • Communication Devices
  • Painting and Drawing Tools

Painting and Drawing Tools are perhaps the most important items in your toolkit because, of all the multimedia elements, the graphic impact of your project will likely have the greatest influence on the end user. If your artwork is amateurish, or flat and uninteresting, both you and your users will be disappointed. Painting software is dedicated to producing excellent bitmapped images. Drawing software is dedicated to producing line art that is easily printed to paper. Drawing packages include powerful and expensive computer-aided design (CAD) software, which is increasingly used for rendering three-dimensional artwork.

Some features in a drawing or painting package include :

  • An intuitive graphic interface with pull-down menus, status bars, palette control, and dialog boxes for quick, logical selection
  • Scalable dimensions, so you can resize, stretch, and distort both large and small bitmaps
  • Paint tools to create geometric shapes from squares to circles and from curves to complex polygons
  • Ability to pour a color, pattern, or gradient into any area
  • Ability to paint with patterns and clip art
  • Customizable pen shapes and sizes
  • Support for scalable text fronts and drop shadows
  • Undo capabilities, to let you try again
  • Painting features such as smoothing coarse-edged objects into the background with anti-aliasing; airbrushing in variable sizes, shapes, densities, and patterns; washing colors in gradients; blending; and masking
  • Zooming, for magnified pixel editing
  • All common color depths : 1-, 4-, 8-, and 16- or 24-bit color, and gray scale
  • Good color management and dithering capability among color depths using various color models such as RGB, HSB, and CMYK
  • Good palette management when in 8-bit mode
  • Good file importing and exporting capability for image formats such as PIC, GIF, TGA, TIF, WIN, AVC, PCX, EPS, PTN, and BMP

CAD and 3-D Drawing Tools

Because they consist of drawn or vector graphics, computer-aided design can be resized, rotated, and, if there is depth information, spun about in space, with lighting conditions exactly simulated and shadows properly drawn – all by computer number crunching. With CAD software you can watch a drawing go from 2-D to 3-D elevation and stand in front of your work and view it from any angle, making judgments about its design. You can create animated walk-throughs and even sun studies based on geographic location, time of day, and time of year. You can generate realistic 3-D renderings for movie presentations.

Each rendered 3-D image takes from a few seconds to a few hours to complete, depending upon the complexity of the drawing and the number of drawn objects included in it. If you wish to turn a sequence of these renderings into a visually smooth animation movie, walk-through, or flyby, plan to set aside many hours of computation time on your computer!

There are other ways to develop a 3-D look to your images, e.g. set up a photo shoot (video camera, or still camera and scanner to digitize developed photos; lighting effects and shadows; editing programs to clean up the image).

Image Editing Tools

Image editing applications are specialized and powerful tools for enhancing and retouching existing bitmapped images usually destined as color separations for print output. These programs are also indispensable tools for rendering the images used in multimedia presentations. Increasingly, modern versions of these programs also provide features and tools of painting and drawing programs and can be used to create images from scratch as well as images digitized from scanners, video frame-grabbers, digital cameras, clip art files, or original artwork files created with a painting or drawing package.

Here are some features typical of image editing applications and of interest to multimedia developers :

  • Multiple windows provide views of more than one image at a time
  • Conversion of major image-data types and industry-standard file formats
  • Direct inputs of images from scanner and video sources
  • Employment of a virtual memory scheme that uses hard disk space as RAM for images that require large amounts of memory
  • Capable selection tools, such as rectangles, lassos, and magic wands to select portions of a bitmap
  • Image and balance controls for brightness, contrast, and color balance
  • Good masking features
  • Undo and restore features
  • Anti-aliasing capability, and sharpening and smoothing controls
  • Color-mapping controls for precise adjustment of color balance
  • Tools for retouching, blurring, sharpening, lightening, darkening, smudging, and tinting
  • Geometric transformations such as flip, skew, rotate, and distort, and perspective changes
  • Ability to resample and resize an image
  • 24- or 16-bit color, 8- or 4-bit indexed color, 8-bit gray-scale, black and white, and customizable color palettes
  • Ability to create images from scratch, using line, rectangle, square, circle, ellipse, polygon, airbrush, paintbrush, pencil, and eraser tools, with customizable brush shapes and user-definable bucket and gradient fills
  • Multiple typefaces, styles, and sizes, and type manipulation and masking routines
  • Filters for special effects, such as crystallize, dry brush, emboss, facet, fresco, graphic pen, mosaic, pixelize, poster, ripple, smooth, splatter, stucco, twirl, watercolor, wave, and wind

Image editing programs usually come with plug-in modules allowing you to wrap, twist, and otherwise ‘filter’ your images for special effects which are also designed to manipulate typefaces in a graphical way.

OCR Software

Often you will have printed matter and other text to incorporate into your project, but no electronic text file. With an optical character recognition (OCR) software, a flatbed scanner, and your computer you can save many hours of rekeying printed words, and get the job done faster and more accurately than a room of typists.

OCR software turns bitmapped characters into electronically recognizable ASCII text. A scanner is typically used to create the bitmap. Then the software breaks the bitmap into chunks according to whether it contains text or graphics, by examining the texture and density of areas of the bitmap and by detecting edges. The text areas of the image are then converted to ASCII characters using probability and expert system algorithms (99 per cent accuracy!).

Sound Editing Programs

Sound editing tools for both digitized and MIDI sound let you see music as well as hear it. By drawing a representation of a sound in fine increments, whether a score or a waveform, you can cut, copy, paste, and otherwise edit segments of it with great precision – something impossible to do in real time (that is, with the music playing).

Although you can usually incorporate MIDI sound files into your multimedia project without learning any special skills, using editing tools to make your own MIDI files requires that you understand the way music is sequenced, scored, and published (tempos, clefs, notations, keys, and instruments plus a MIDI synthesizer).

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