Chapter 8 Digital Media

Digital Sound Digital Audio Basics Portable Audio Players MIDI Music Speech Recognition and Synthesis Chapter 8: Digital Media

Digital Audio Basics Sampling a sound wave Chapter 8: Digital Media Figure 8-1 Chapter 8: Digital Media

Digital Audio Basics Sampling rate refers to number of times per second that a sound is measured Figure 8-2 Chapter 8: Digital Media

Digital Audio Basics Sound cards are responsible for transforming bits stored in an audio file into music, sound effects, and narrations Digital signal processor Figure 8-3 Chapter 8: Digital Media

Digital Audio Basics The most popular digital audio formats include AAC, AIFF, MP3, RealAudio, Wave, and WMA Audio or media player software allows you to record and play digital audio files You can embed digital audio files into a Web page Chapter 8: Digital Media

Portable Audio Players Pocket-sized, battery-powered device that stores digital music Zune Digital music is available from a wide variety of sources Formats include AAC, MP3, WAV, and AIFF Figure 8-5 Chapter 8: Digital Media

MIDI Music MIDI (Musical Instrument Digital Interface) specifies a standard way to store music data for synthesizers, electronic MIDI instruments, and computers MIDI-capable sound cards contain a wavetable Set of prerecorded musical instrument sounds Does not produce high-quality vocals Does not have full resonance of “real” sound Chapter 8: Digital Media

MIDI Music MIDI music tends not to have the full resonance of digital audio. Figure 8-7 Chapter 8: Digital Media

MIDI Music Music composition software provides tools for entering notes, specifying instruments, printing sheet music, and saving compositions in formats such as MIDI. Figure 8-8 Chapter 8: Digital Media

Speech Recognition and Synthesis Speech synthesis is the process by which machines produce sound resembling spoken words Text-to-speech software Speech recognition refers to the ability of a machine to understand spoken words Speech recognition software Chapter 8: Digital Media

Speech Recognition and Synthesis Figure 8-10 Chapter 8: Digital Media

Bitmap Graphics Bitmap Basics Scanners and Cameras Image Resolution Color Depth and Palettes Image Compression Bitmap Graphics Formats Chapter 8: Digital Media

Bitmap Graphics Composed of a grid of dots Color of each dot is stored as a binary number Figure 8-11 Chapter 8: Digital Media

Scanners and Cameras To scan an image, turn on the scanner and start your scanner software. Place the image face down on the scanner glass, and use the scanner software to initiate the scan. The scanned image is saved in RAM and can then be saved on your computer’s hard disk. Figure 8-12 Chapter 8: Digital Media

Scanners and Cameras The controls for a digital camera are very similar to those for an analog, or film, camera. To take a photo, simply point and shoot. Figure 8-13 Chapter 8: Digital Media

Scanners and Cameras Digital cameras use storage medium Solid state storage Transfer images using: Card readers Direct cable transfer Infrared port Media transfer Docking station E-mail Figures 8-14 and 8-15 Chapter 8: Digital Media

Scanners and Cameras Graphics software is used to modify or edit bitmap graphics Modify individual pixels to Retouch photographs Wipe out red eye Erase rabbit ears Require a bit of storage space Figure 8-16 Chapter 8: Digital Media

Image Resolution Expressed as the number of horizontal and vertical pixels Higher resolutions contain more data (larger file size) and are higher quality Bitmaps do not have a fixed physical size Figure 8-17 Chapter 8: Digital Media

Image Resolution File size of bitmaps can be reduced by cropping Bitmaps are resolution dependent Figure 8-18 Chapter 8: Digital Media

Image Resolution When you increase the resolution of a bitmap, pixel interpolation may occur Some images may appear pixilated Figure 8-19 Chapter 8: Digital Media

Color Depth and Palettes Color depth is the number of colors available for use in an image Monochrome bitmap Increasing color depth increases file size True Color bitmap (24-bit bitmap) 32-bit bitmap Color palettes are used to control color depth Grayscale palette System palette Web palette Chapter 8: Digital Media

Color Depth and Palettes Figures 8-21 and 8-23 Chapter 8: Digital Media

Image Compression Any technique that recodes data in an image file so it contains fewer bits Lossless compression Lossy compression Run-length encoding File compression utility Figure 8-25 Chapter 8: Digital Media

Image Compression File compression utilities, such as open source 7-Zip, zip one or more files into a new compressed file with a .zip extension. Figure 8-26 Chapter 8: Digital Media

Bitmap Graphic Formats Figure 8-29 Chapter 8: Digital Media

Vector and 3-D Graphics Vector Graphics Basics Vector-to-Bitmap Conversion Vector Graphics on the Web 3-D Graphics Chapter 8: Digital Media

Vector Graphic Basics Contain instructions for re-creating a picture Figure 8-30 Chapter 8: Digital Media

Vector Graphic Basics Vector graphics resize better than bitmaps Vector graphics usually require less storage space than bitmaps Vector graphics are not usually as realistic as bitmap images It is easier to edit an object in a vector graphic than an object in a bitmap graphic Chapter 8: Digital Media

Vector Graphic Basics Figure 8-33 Chapter 8: Digital Media

Vector-to-Bitmap Conversion Rasterization superimposes a grid over a vector image and determines the color for each pixel Tracing software locates the edges of objects in a bitmap image and converts the resulting shapes into vector graphic objects Figure 8-35 Chapter 8: Digital Media

Vector Graphics on the Web SVG (Scalable Vector Graphics) and Flash are vector graphic formats for the Web Flash Animated GIF Advantages of using vector graphics Consistent quality Searchable Compact file size Figure 8-36 Chapter 8: Digital Media

3-D Graphics Stored as a set of instructions Contain locations and lengths of lines forming a wireframe Rendering covers a wireframe with surface color and texture Ray tracing adds light and shadows to a 3-D image Chapter 8: Digital Media

3-D Graphics 3-D graphics are based on a wireframe, which can be rendered into a bitmap image that looks three-dimensional. Figure 8-39 Chapter 8: Digital Media

Digital Video Digital Video Basics Producing Video Footage Video Transfer Video Editing Video Output Desktop, PDA, and Web Video DVD-Video Chapter 8: Digital Media

Digital Video Basics Uses bits to store color and brightness data for each video frame Different kinds of digital videos: Desktop video Web-based video DVD-video PDA video Figure 8-41 Chapter 8: Digital Media

Digital Video Basics Figure 8-42 Chapter 8: Digital Media

Producing Video Footage Use digital or analog video camera to shoot video footage Digital video cameras store footage as a series of bits Analog video cameras store video signals as a continuous track of magnetic patterns Videoconferencing cameras (Web cam) attach directly to a computer Figure 8-43 Chapter 8: Digital Media

Producing Video Footage Figure 8-44 Chapter 8: Digital Media

Video Transfer Transfer video footage by connecting a cable between a video source and computer Video capture converts analog video signals into digital format Figure 8-45 Chapter 8: Digital Media

Video Transfer Video capture software controls the transfer process Figure 8-47 Chapter 8: Digital Media

Video Transfer Raw, uncompressed formats are ideal for editing Video capture software can: Decrease video display size Reduce the frame rate Compress data Chapter 8: Digital Media

Video Editing Linear editing Requires at least two VCRs Nonlinear editing Requires a computer hard disk and video editing software Figure 8-48 Chapter 8: Digital Media

Video Output Figure 8-49 Chapter 8: Digital Media

Video Output Figure 8-50 Chapter 8: Digital Media

Desktop, PDA, and Web Video Desktop videos are usually displayed on a computer screen Some PDAs and smartphones can be configured to play digital video Web-based videos Streaming video Figure 8-51 Chapter 8: Digital Media

Desktop, PDA, and Web Video You can add external or internet videos to a Web page Internet connection speed affects Web videos Web video formats include Flash Video, MPEG4, QuickTime Movie, Windows Movie, and RealMedia Figure 8-52 Chapter 8: Digital Media

DVD-Video Incorporate digital videos onto DVDs with interactive menus DVD authoring software Figure 8-53 Chapter 8: Digital Media

DVD-Video With advance planning, menus are easy to create Output video in DVD-video format A DVD image is a prototype of your DVD Stored on your computer’s hard disk Thoroughly test DVD on your computer before you burn it Recordable vs. rewritable DVDs Chapter 8: Digital Media