Computer Fundamentals: Module 7: Digital Media

Bit

(Short for binary digit), the smallest unit of data a computer can process.

wireframe drawing

A 3D object composed of individual lines.

Digital Graphics

A bitmap graphic (or bitmap for short) is a grid of pixels that forms an image. The simplest bitmap graphic has only two colors, with each pixel being black or white. Bitmaps become more complex as they include more colors. Photographs or pictures with shading can have millions of colors, which increases file size. Bitmaps are appropriate for detailed graphics, such as photographs and the images displayed on a display screen. In contrast, a vector graphic groups and layers simple objects to create an image. When you work with a vector graphic, you interact with a collection of lines, not a grid of pixels. Vector images are appropriate for simple drawings, such as line art and graphs, for fonts, and for animations. You create and edit bitmaps using graphics apps such as Adobe Photoshop and Windows Paint. Bitmap-editing programs are also called painting programs. You use drawing programs such as Adobe Illustrator to create and edit vector images.

Machine learning

A branch of AI that uses statistics to help machines learn from data, identify patterns, and make decisions to progressively improve their performance without much human intervention.

codec

A device or program that encodes and usually compresses digital media data for storage and then decompresses the data for playback. Short for compressor/decompressor.

set-top box

A device that allows you to view streaming media on your TV set; examples include Apple TV, Roku, and Google Chromecast.

TV stick

A device, usually the size of a USB drive, that connects to a television to provide access to the Internet and to streaming apps.

byte

A field size for Number fields that allows entries only from 0 to 255.

motion-sensing game consoles

A game console that allows players to interact with the system through body movements. Input is usually accomplished through a combination of spoken commands, natural real-world actions and gesture recognition.

Vector graphics

A graphic consisting of shapes, curves, lines, and text created by mathematical formulas.

Bitmap graphics

A grid of square colored dots, called pixels, that form a picture; also, a file containing a graphic that consists of a bitmap.

mixed reality

A hybrid of virtual reality and augmented reality, simulations that let you see the real world while interacting with realistic virtual objects.

keyframe

A location on a timeline that marks the beginning or end of a movement, effect, or transition.

digital devices

A machine that reads and produces digital, or binary, data.

analog

A machine that reads or produces physical signals in their original form, such as a camera or tape player.

analog devices

A machine that reads or produces physical signals in their original form, such as a camera or tape player.

video consoles

A meeting among several geographically separated people who use a network or the Internet to transmit audio and video data; also called a web conference.

lossless compression

A method of reducing graphics file size in which none of the original file data is discarded; TIF, PNG, and GIF files can be compressed using lossless compression. See also Lossy compression.

lossy compression

A method of reducing graphics file size in which some of the original file data is discarded; the lost data is generally not noticeable; JPEG files use lossy compression. See also Lossless compression.

binary number system

A number system consisting of only two digits: 0 and 1.

graphic

A picture, shape, design, graph or chart, diagram, or video.

Sampling software

A program that breaks sound waves into separate segments, or samples, and stores each sample numerically.

holograms

A projected image that appears three-dimensional.

license filter

A search engine tool that lets you search for pictures that you can use, share, or even modify for personal or commercial use.

real-time animation

A security feature that sets Windows Defender to constantly monitor your computer for virus and spyware activity.

animated GIF

A series of slightly different GIF images displayed in sequence to achieve animation effects.

Simulations

A sophisticated computer animation that is useful for training and teaching in many fields, particularly in areas in which learning can be dangerous or difficult.

Compression

A space-saving technique used to store data in a format that takes less space.

Smart TVs

A television that can connect to the Internet and stream TV shows and movies from subscription streaming services.

stop motion animation

A type of animation where animators move real-life objects through a sequence of poses and capture the movements one frame at a time. When you play the frames in sequence, the objects seem to move.

Augmented reality gaming

A type of gaming that integrates visual and audio game content with your real environment.

digital audio

A type of sound that is recorded and stored as a series of 1s and 0s.

augmented reality (AR)

A type of virtual reality that uses an image of an actual place or thing and adds digital information to it.

stock photo galleries

A website that maintains an inventory of photographs and other graphics and makes them available for download.

container

A wrapper that contains parts of a video file including the video, audio, and codec, in a single package.

Common Audio File Formats

AAC and M4P .aac and .m4p Lossy Apple uses these formats for iTunes downloads AIFF (Audio Interchange File Format) .aiff or .aif None Files are large; good to excellent sound quality MP3 .mp3 Lossy Common format for music and audio books; most digital audio devices can play MP3 files WAVE or WAV (Waveform Audio) .wav None Files are large; good to excellent sound quality WMA (Windows Media Audio) .wma Lossless Played using Windows Media Player; also copy-protected

Common Video Containers

AVI (.avi) Files are often larger than others Videos to store on a computer One of the oldest and most accepted formats MP4 (.mp4) Relatively small files and high quality Nearly universal Websites such as YouTube and Vimeo prefer MP4 files Quicktime (.mov) Large files with high quality Playback on Apple devices Developed by Apple Windows Media (.wmv) Small file size with reduced quality Sharing with others and posting on the web Developed by Microsoft

Animation on the Web

Ads, films, TV shows, computer games, and promotional videos use 2-D animation. Websites frequently use it to enhance content. One popular animation method on the web is an animated GIF, a series of slightly different GIF images displayed in sequence to achieve animation effects. For many years, people used Adobe Flash to create static or animated graphics in the SWF format, which was designed for web use. But Flash required users to download a plug-in, a component added to your browser, to play videos. Flash also became a target for malware developers. Currently, most web animations are created with HTML 5, the latest version of the Hypertext Markup Language that is built into browsers. HTML 5 features high-quality playback without the need for additional plug-in software, and is the standard for web animation development. Adobe Flash has been replaced by Adobe Animate CC, which incorporates HTML 5.

Animations

Although you might think the main purpose of animation is entertainment in films and games, animation has other uses. For example, animation can teach medical students a procedure or novice pilots how to maneuver through bad weather. Simulations are sophisticated computer animations that are useful for training and teaching in many fields, particularly in areas in which learning can be dangerous or difficult. A popular use of simple animations is in PowerPoint or Prezi presentations, in which you can animate slide text and objects. PowerPoint transitions, the way one slide moves to another, are a type of animation.

in-betweening

An animation technique using a sequence of images, in which one or more objects are changed slightly between each image. Often shortened to tweening.

2-D animation

An animation that displays 2-D images in rapid sequence to create the illusion of lifelike motion.

3-D animation

An animation that displays 3-D objects or models in rapid sequence to create the illusion of natural motion.

virtual world

An environment simulated by virtual reality software to appear as a real or imagined 3-D space.

digital graphic

An image you can see, store, and manipulate on a computer, tablet, smartphone, or other digital device.

computer-aided design (CAD) software

Applications used by architects, scientists, designers, engineers, and others to create highly detailed and technically accurate drawings that can be shared, modified, and enhanced with speed and accuracy.

3-D CAD software

Applications used by engineers and scientists to create wireframe drawings of objects, which they can rotate to view from multiple angles.

Choose Video File Formats

Are you shooting a video of an event to post on YouTube? Inserting a video in a PowerPoint presentation? Downloading a movie trailer to play on your phone? Each purpose requires a different video file format. Digital video files have two parts: a codec and a container. A codec (short for compressor/decompressor) is software that encodes and usually compresses data for storage and then decompresses the data for playback. Video files typically use lossy compression. A video container bundles the video, audio, codec, and other parts such as subtitles into a single package. Most digital video file formats are named after their container. Video codecs are compatible with only some containers.

Choose Audio File Formats

As with graphics, you can store audio files in a variety of formats, each with a specific purpose. For example, some types of audio formats are for storing music, others are for audio recordings such as Audible books, and others are for podcasts. Some formats use lossy or lossless compression to reduce file size. You can identify an audio file format by looking at the file extension. To create uncompressed audio files such as WAV and AIFF files, you convert real sound waves directly to digital form without additional processing, resulting in accurate sound quality, but very large files. Choose uncompressed audio files to capture and edit pure audio, and then save them in a compressed format. Audio files lose data when they are compressed with lossy compression, giving up quality and fidelity for file size. However, most people cannot detect any difference between uncompressed and lossy compressed audio files. Choose audio files with lossy compression (MP3 or M4P) when you are listening to sound other than music or want to conserve disk space. Audio files with lossless compression have good audio quality and smaller file sizes than uncompressed audio files, but still larger than files with lossy compression. Choose audio files with lossless compression (WMA) if you want to listen to music with accurate audio representation.

live audio feeds

Audio transmitted live, as it happens; you can play the audio directly from the Internet.

Use Digital Media

Because digital media is so appealing, it is a major part of entertainment products such as games and movies. However, it also has uses in education and training. For example, digital videos and virtual reality create simulated experiences when direct training would be difficult or dangerous, such as when learning how to fly jets or perform brain surgery. Businesses of all kinds use digital media in advertising and product support.

Record and Edit Digital Media

Besides downloading or streaming digital media, you can create graphics and animations, record audio, develop original videos, and edit your digital media files. Each of these tasks requires software that ranges from basic to highly sophisticated. For example, if you want to remove some background from a photo, you can modify it in Windows Paint. If you want to blend images or correct color in a photo, you need a more powerful app, such as Adobe Photoshop. You should have an idea of what's involved the next time you want to change a digital media file.

How Computers Represent Images and Sounds

Cameras, musical instruments, and video projectors are analog devices, meaning they read or produce physical signals in their original form. For example, an analog tape recorder captures sound waves directly from a guitar or singer, and then plays the sound waves through an analog speaker. Computers are digital devices, meaning they read and produce numeric data as combinations of 1s and 0s. A digital recorder turns the sound it captures into numbers representing tones, and then generates an electronic signal based on those numbers. Digital media translates analog data into digital data so that anyone with a computer can create, edit, and play the media. Converting analog data to digital data is also called digitizing the data, or changing the data into a form that computers and other digital devices can use. That means you no longer have to be a virtuoso musician or talented artist to produce professional-quality audio and video.

Computer-Aided Technology

Computer-aided technology involves using computers to help design, analyze, and manufacture products. In fields such as manufacturing, interior design, and architecture, people use computer-aided technology to bring their products or designs to life. Architects, scientists, designers, engineers, and others use computer-aided design (CAD) software to create highly detailed and technically accurate drawings. With CAD software, you can share, modify, and enhance drawings with speed and accuracy. Interior designers use CAD software to model proposed room designs. Clothing designers can experiment with fabrics and patterns. Architects use CAD to prototype buildings and create floor plans. Engineers and scientists use 3-D CAD software to create wireframe drawings of objects, which they can rotate to view from many angles. Increasingly, CAD is using artificial intelligence (AI) to help automate design tasks, such as creating precise shapes. In broad terms, AI lets computers perform tasks that require human-level intelligence. Machine learning is a branch of AI that trains machines to learn from data, identify patterns, and make decisions to progressively improve their performance without much human intervention. Engineers can use CAD software with built-in machine learning tools to discover quicker production methods, evaluate the results of using different materials or changing a product's features, and produce design options based on goals and constraints.

digital media

Content you create, produce, and distribute in digital, or computer-readable, form, such as photos, audio, video, and virtual reality.

sound waves

Continuous sound waves created in response to vibrations in the surrounding air, such as a drumstick hitting a drum pad.

resolution dependent

Describes graphics whose image quality deteriorates as their size increases; bitmap graphics are resolution dependent, but vector graphics keep the same quality as their size increases.

Describe How Computers Represent Images

Digital graphics fall into two main types. Bitmap graphics (also called raster graphics) assign colors to the smallest picture elements, called pixels. Each color is assigned a binary number, such as 00 for black and 11 for white. To a computer, a bitmap image is a list of the color numbers for all the pixels it contains. Vector graphics consist of shapes, curves, lines, and text created by mathematical formulas. Instead of storing the color value for each pixel, vector graphics contain instructions that define the shape, size, position, and color of each object in an image.

Common Video Codecs

DivX AVI video container Commercial video production Provides the highest video quality at the expense of file size H.264 MP4 video container Playing on playback devices or streaming services Common, efficient codec; preferred for YouTube videos H.265 MP4 video container Very high resolution videos New video codec; also called HEVC MPEG-2 MP4 and Quicktime containers DVDs, Blu-ray discs, professional-grade cameras Not used for streaming services MPEG-4 Wide range of compatibility Online streaming services Common codec providing good quality

Digital Media File Formats

File format refers to the organization and layout of data in the file. The file name extension usually reflects the file format. For digital media files, the format determines which programs or devices you can use to open or edit the file. For example, you need a painting program such as Windows Paint to edit a bitmap graphic. Digital media playback devices can often play only certain formats of video and audio files. For example, you can play older iTunes songs only on an Apple device such as an iPhone.

Common Graphics File Formats

GIF .gif (Graphics Interchange Format) Simple web graphics and short web animations Format is limited to 256 colors; supports transparency; small file size makes it good for websites JPEG .jpeg or .jpg (Joint Photographic Experts Group) Photos on the web Images have rich colors, but discard some data to reduce file size, which can affect quality PNG .png (Portable Network Graphics) Logos, icons, and illustrations Images have good quality even when highly compressed; supports 16 million colors; better quality and smaller file size than GIF TIF .tif or .tiff (Tagged Image File Format) High-quality photos and printed graphics Large file size is better suited for print than web use Vector graphics EPS .eps (Encapsulated PostScript) Logos and other illustrations that are frequently resized A standard format for exporting vector graphics without data loss SVG .svg (Scalable Vector Graphics) Illustrations on the web Developed by the World Wide Web Consortium (W3C); allows interactivity and animation

VR gaming system

Hardware necessary for playing virtual reality games.

game console

Hardware that allows you to play video games; examples include Xbox, Nintendo Wii, and Sony PlayStation.

Create Graphics and Animation

If you can't find a graphic you need online, why not create it yourself? Start by capturing images using hardware devices such as: Digital cameras Graphics tablet Flatbed scanner A digital camera creates a digital image of an object, person, or scene. Almost all smartphones contain high-quality digital cameras for taking digital photographs. The latest smartphone cameras such as the iPhone XR have 12-megapixel resolution, include a built-in gyroscope for image stabilization, and work well in low-light settings. They also can identify a picture's geographical location, a feature known as geotagging, and can automatically post photos to online locations, such as your Facebook page or your OneDrive. High-end digital cameras have these features and more. You can use a graphics tablet to create drawings with a pressure-sensitive pen. Architects, mapmakers, designers, and artists use specialized graphics tablets. General-purpose tablets such as the iPad Pro also let you draw and edit graphics. In addition, Windows 10 includes the Windows Ink Workspace with a Sketchpad and Screen sketch. Many laptop computers, such as the Surface Book, allow you to draw on the screen with a digital pen or your fingertip. A scanner converts a printed document into a bitmap file by dividing the image into a grid of tiny cells and assigning colors to each cell. Scanners vary in size and shape and include flatbed, sheet-fed, pen, and handheld types. In addition to capturing images with hardware devices, you can use graphics software to make your own graphics or modify existing ones. You can create bitmap images with painting apps such as Microsoft Paint using brush tools and paint palettes that simulate watercolors, pastels, and oil paints. Paint and other image-editing software let you modify existing images. For example, you can rotate an image on its axis, change its colors, or modify lines and other shapes. At sumopaint.com, you can edit images online free of charge. Drawing programs, such as CorelDRAW, let you create simple vector images. In some programs, you layer graphics to create collages. You can use more advanced programs such as Adobe Illustrator to create sketches, logos, typography, and complex illustrations for web or print use. Use photo-editing software, such as Adobe Photoshop, to enhance and retouch photographs. For example, you can add special effects such as reflections or sepia tones, correct problems such as red-eye or poor lighting, or remove unwanted parts of an image. You can also edit photos on a smartphone using free mobile apps such as Snapseed, VSC, and Adobe Lightroom.

animation

In PowerPoint, an effect applied to an object that makes the object appear, disappear, change, or move.

sampling

In Publisher, a command that lets you copy an element's color and apply it elsewhere.

Use Smart TVs and Streaming Devices

In addition to viewing streaming video on your computer or mobile device, you can view it on your television set. Smart TVs connect to a Wi-Fi network and let you view Internet content, including TV shows, movies, games, and photos. If you don't have a smart TV, you can connect hardware to your television, such as a TV stick or a set-top box, which lets you stream TV shows and movies from subscription services. Because streaming video is more convenient and less expensive than traditional cable and satellite television content, many people are "cutting the cord" to their cable and satellite television subscriptions. Instead of watching scheduled content, you can create a personal entertainment hub with a smart TV and streaming video service to watch your favorite shows, movies, news, and sports at your convenience.

digital video

Live action captured in digital format by a video camera.

Set up a Gaming System

Most games are played on video consoles with special controllers. A popular choice for video gaming is a game console such as the Xbox, Nintendo Wii, or Sony PlayStation. These systems use handheld controllers as input devices, speakers and a television screen or computer monitor as output devices, a hard drive, and memory cards or optical discs for storage.

stream

Music that you can listen to as it is being downloaded from the web.

megapixels

One million pixels. On a digital camera, the measurement that describes the camera's maximum resolution; the higher the number of megapixels, the higher the resolution of photos, and the larger the picture files.

Define Terms That Describe Data

Remarkably, all computer data is fundamentally composed of 1s and 0s, even movies with sophisticated special effects and musical recordings of full orchestras. To get a handle on how computers represent digital media, you need to know a few terms that describe computer data. The two-digit system of 1s and 0s that computers use is called the binary number system. Computers are binary machines because they are electronic devices, and electricity has two states: on and off. Bit is short for "binary digit," the smallest unit of information a computer handles and the basis of today's computer processing. A bit can have the value of 0 or 1. Bits appear in groups of eight. A group of 8 bits is called a byte. Bytes can represent letters, symbols, and numbers. Bytes are the basic building blocks of digitally representing sounds and colors.

pixels

Short for picture element, an individual point of color on a display screen or printout.

on-demand content

Software that is distributed online for a monthly subscription or an annual fee.

Participate in Mobile Gaming

Some game consoles are self-contained devices that fit in one hand, such as the Sony PlayStation Vita and the Nintendo Switch. These portable consoles are designed for single-player or multiplayer video games. Many use memory cards to store games; others use a cartridge or a miniature optical disc for storage. Mobile computing and smartphones put the world of gaming in the palms of your hands. Phones often come with scaled-down game versions to introduce them to new players. Some games, such as Words with Friends, are designed to be played by people with similar smartphones or on social networks. Mobile games were the first to popularize augmented reality (AR), a type of virtual reality that uses an image of an actual place or thing and adds digital information to it. Augmented reality gaming integrates visual and audio game content with your environment. Unlike VR gaming, which often requires a separate room to create an immersive experience, AR gaming superimposes digital game elements in the real world, as with the breakthrough AR game Pokemon Go. You usually play AR games on smartphones, tablets, and portable consoles.

Describe How Computers Represent Sounds

Sound is produced when vibrations, such as a drumstick hitting a drum pad, cause pressure changes in the surrounding air, creating analog (continuous) sound waves. A process called sampling converts the analog sound waves into digital sound. Sampling software breaks the sound wave into separate segments, or samples, and stores each sample numerically. The more samples taken per second, the higher the sound quality and the larger the file. The quality of an audio file is also determined by its bit rate, which is the number of bits of data processed every second. Bit rates are usually measured as kilobits per second (kbps). As with the sampling rate, the higher the bit rate, the higher the sound quality and the larger the file. Large files take longer to download from a website or load and play on a webpage. They also require more storage space than smaller files. If you are using an audio file in a project and can choose from varying bit rates (such as 128 kbps and 160 kbps) and sampling rates (such as 22,050, 44,100, and 88,200), choose a file that balances quality and size.

live video streaming

Streaming video content transmitted live, as it happens; you can view the media as it arrives.

HTML 5

The latest version of the Hypertext Markup Language, which is built into browsers.

Digital Media Concepts

The major types of digital media include graphics, animation, video, audio, and virtual reality. Websites, entertainment products, and business marketing efforts often use a combination of digital media to attract, inform, entertain, and persuade viewers and listeners. If you are involved with efforts to promote a product, service, or yourself, you can use digital media to reach your audience and emphasize your message. A graphic is an image or picture. A digital graphic is an image you can see, store, and manipulate on a computer, tablet, smartphone, or other digital device. Digital graphics can be as simple as a line drawing or as complex as a highly detailed photo or 3-D illustration. You can also use digital graphics to create an animation, a series of images displayed in sequence to create the illusion of movement. Each still image is called a frame. Instead of storing moving images, a digital animation stores data about the color and brightness of each frame. Like animation, a video is a series of still images played quickly enough to appear as continuous motion. While you typically create an animation by drawing illustrations, you create a digital video by capturing live action Digital video usually includes digital audio, sound that is recorded and stored as computer data. Music, speech, and sound effects are types of digital audio. Although digital video can be convincingly realistic, you are still aware of being a viewer watching the video content. Virtual reality (VR), a computer-simulated, 3-D environment that you can explore and manipulate, attempts to remove the barrier between the viewer and the media. With special headsets to display 3-D images that create the illusion of limitless space and depth, VR immerses you in an artificial world.

transitions

The manner in which a slide appears on the screen in place of the previous slide during a slide show.

Animation in Entertainment

The most popular uses of 3-D animation are in ads, films, and computer games. 3-D animation in films is done during the production phase, while the film is being shot, and then incorporated into the final footage. In computer games, 3-D animation is produced as you're playing because you are in control of the characters' movements. This technology is called real-time animation. Real-time animation consumes an incredible amount of computer resources. At 60 frames per second, your computer must handle more than 1 billion bits of information every second to display a 3-D image. The computer also has to track the movements of each player, using even more resources. Because of these requirements, you need a computer with a powerful processor to play games with 3-D animation.

bit rate

The number of bits of data processed every second, usually measured as kilobits per second (kbps).

Resolution

The number of horizontal and vertical pixels in a display device or the sharpness and clarity of an image.

File format

The organization and layout of data in a file

download

The process of transferring (copying) a file from a server, computer, or device to another computer or device.

Virtual reality (VR)

The use of computers to simulate a real or imagined environment that appears as a three-dimensional (3-D) space.

plug-in

Third-party program that extends the built-in functionality of an application or browser.

digitizing

To convert sound to a format your computer can read.

rendering

To transform a wireframe drawing into a solid 3D image.

Stream Digital Media

To watch videos or listen to audio such as audio books, podcasts, and music on your computer, you can download the media files the same way you download graphics files. However, you must transfer the entire video or audio file to your computer, which can take a long time and a lot of storage space. As an alternative, you can stream the media, which means you receive the audio or video content on your computer from a server, and can watch or listen to the media as it arrives. For on-demand content such as TV shows, the original media file is stored on the media distributor's server. If you subscribe to the streaming service, it sends the media to your computer for viewing. Because the file is stored online, you can watch it more than once. Examples of subscription video streaming services include Netflix, Hulu, Amazon Prime video, HBO Go, Chromecast, Roku, and YouTube. With live video streaming, often used for sports events, the content is sent out live, as it happens, and is available only once.

Gaming Systems

Today's video games use high-end graphics, powerful processors, and the Internet to create environments that rival reality and bring together players from around the world. Games account for most software sales, currently totaling nearly $138 billion in annual revenue. Computer and video games include role-playing, action, adventure, education, puzzles, simulations, sports, and strategy/war games. On consoles that connect to the Internet, you can interact with other players online and watch TV or movies. Large-scale multiplayer games such as Halo, Doom, Overwatch, Minecraft, and World of Warcraft operate on many Internet servers, with each one handling thousands of players. For a more immersive experience, you can set up a VR gaming system using hardware. These systems run on souped-up desktops and include a headset such as the HTC Vive, the Oculus Rift, or the Oculus Go, controllers, and sensors to track your movements. The Oculus Quest and PlayStation VR are VR consoles that you can use instead of a PC. Popular VR games include Robo Recall, Skyrim, The Climb, and Echo Arena. Microsoft offers the HoloLens headsets, though it calls the experience when using them mixed reality, which lets you see the real world while interacting with realistic virtual objects. HoloLens headsets do not require separate sensors because they include cameras and sensors to track motion. HoloLens headsets use holograms, projected images that appear three-dimensional, to allow you to superimpose virtual objects and characters onto scanned images of real objects in the room, and then interact with the virtual and real objects. For example, in the game Fragments, you explore a virtual space to solve a crime, looking for clues and interacting with virtual characters who appear to be seated in the room. Instead of purchasing special hardware for gaming, you can also play games on computers, tablets, or smartphones. Simple games may come with the operating system of a computer or mobile device; you can also download them from an app store. Many of these games use 2-D animation. People use game consoles for activities other than entertainment. For example, doctors can practice their fine motor skills on surgery simulators using motion-sensing game consoles, which allow you to interact with the system through body movements. Physical therapists use these consoles along with virtual reality gaming techniques to challenge and motivate patients doing rehabilitation.

Identify Video File Resolutions

Video file formats are one way to describe a video file. Resolution is another. If you've seen videos available for download on the web described as 720p, HD, or 4K, those descriptions refer to resolution. Digital video resolution is given as width × height. The higher the resolution, the sharper the video, and the larger the file size. Video resolutions can be organized into three categories: Standard Definition (SD): Resolutions of 640 × 360 and 720 × 480 High Definition (HD): Resolutions of 1280 × 720 (called 720p) and 1920 × 1080 (called 1080p or Full HD) Ultra High Definition (UHD): The 4K standard provides a resolution of 3840 × 2160 (called 2160p), while the 8K standard provides a resolution of 7840 × 4320 (called 4320p) Although 8K videos provide the highest resolution, that doesn't mean you should download the 8K version of a video when an SD or HD video is available. An 8K video file is 16 times larger than a Full HD video. Files that large take a long time to download and require significant storage space. In addition, only some devices can play UHD files. If you want to watch a 4K video on a 720p display screen, your computer or TV converts the high-resolution video to 720p because that is the best the screen can offer. In most cases, Full HD videos balance high-quality playback with smaller file sizes that download quickly, making them ideal for sharing and posting on websites.

Describe a Virtual World

Virtual reality software simulates a real or imagined environment that appears as 3-D space, also called a virtual world. When playing a VR game, for example, you wear a headset with built-in headphones to experience a virtual world, a 3-D, 360-degree environment. A virtual world is different from other simulations such as video games or movies because it is believable, interactive, and immersive. In a virtual world, a 3-D computer model creates a convincing illusion of depth and space to make you feel you are part of a real scene you can explore. Sensors detect your movements and a head-mounted display adjusts what you see and hear. For example, if you are visiting a virtual version of Paris and enter a café, the sights and sounds in the virtual world change as you move, just as they would in the real world. A virtual world is also different from augmented reality, mixed reality, and some types of virtual reality. If you had an augmented reality app on your phone, for example, and were roaming real-world Paris, you could point the phone at a landmark to display its image overlaid with details about it, including its name and history. The app enhances, or augments, the reality, while a virtual world replaces it. Like augmented reality, mixed reality maintains a connection to the physical world. The goal of mixed reality is to produce an environment where physical and digital objects interact. Many games such as flight and racing simulators have elements of virtual reality. For example, you could use a wide screen, headphones with surround sound, and a realistic joystick in a flight simulation game to experience piloting a jet. However, the game doesn't fully immerse you in a virtual world. If you turn your head away from the screen, you break the illusion of flying a plane.

Define Resolution and Compression

When using graphics in your work, you should be aware of how certain properties affect quality. Resolution refers to the clarity or sharpness of an image: the higher the resolution, the sharper the image and the larger the file size. For example, the photo of a Paris café in Figure 7-6 has a resolution of 1500 × 1225, which means it has 1500 pixels across and 1225 pixels down the image, for a total of 1,837,500 pixels and 1.13 MB of data. If you are selecting images for a website, you want to use images with a file size small enough so they load quickly, but large enough so they appear sharp and clear. Bitmap graphics are resolution dependent, which means image quality deteriorates as their dimensions increase. If you significantly resize or stretch bitmaps to fit a space they were not designed to fill, the images become blurred and distorted, as shown earlier in Figure 7-6. On the other hand, vector graphics keep the same quality as their dimensions change. On a digital camera, resolution is typically measured in megapixels, or millions of pixels. The higher the number of megapixels, the higher the resolution of your photos, and the larger the picture files. However, high-resolution photos and other complicated graphics can be difficult to copy, download, or send as email attachments, due to their large file size. Compression makes digital media files smaller by reducing the amount of data in the files. Some types of bitmap graphics (JPEG files) use lossy compression, which discards some of the original file data during compression. Fortunately, you usually don't notice the "lost" data. Other types of media files (TIF, PNG, and GIF) can be compressed using lossless compression, which reduces the file size for storage. When opened and viewed, the files are uncompressed and contain all of their original data.

Stream Digital Audio

You can also stream digital audio in the form of audio books, using sites such as Audible, and as audio podcasts, which may include news stories, music, lectures, or radio shows. To stream music, you can use a music streaming service such as Pandora, Spotify, Sound-Cloud, Groove Music, or iHeartRadio. Some streaming services are free and others are paid; the free services usually feature advertisements. As with streaming video, streamed music is not stored on your computer. You can play audio directly from the Internet by connecting to live audio feeds for live sports events, shows, or even police, fire department, and air traffic control feeds using a web browser or a media player.

Choose Graphics File Formats

You can create and store bitmap and vector graphics in several file formats. Each file format is suited for particular uses. Do you need a two-color button for a webpage? Vacation photos for posting on Instagram? A highly detailed photograph that will appear in print? Each use has different requirements.

Graphics

You can use graphics to improve your work by adding dramatic or informative photos to reports and articles. Select illustrations and drawings that reflect the ideas and concepts you want to communicate. On the job, you use logos on business documents and websites to increase brand awareness. In digital content, you might use graphical buttons and icons to trigger actions such as displaying a menu or navigating to a new page. Before you can use graphics on your social media page or in a presentation, you need to acquire them. You can obtain graphics from external sources such as the web, or you can create your own. If you want to add a picture to a document or presentation to illustrate a key point, you can download it, which means to transfer it from the Internet to your computer. The Internet provides a rich source for graphics. Online stock photo galleries such as Shutterstock, openclipart.org, and Fotolia maintain large inventories of photographs and other graphics, which you can download, usually for a fee. Search engines such as Google and Bing help you find websites containing graphics relating to specific topics. To help you find images that you can use legally, Google and Bing let you search using a license filter, which finds only pictures that you can use, share, or even modify for personal or commercial use. Before you download any graphic from an external source, be sure to read the license and follow restrictions on using the image.

How Digital Media Represents the Real World

You need a camera and film to create a physical photo or video, and you need a musical instrument to create a song. To play the video or song, you need a video or music player. In contrast, you use a computer to generate, display, distribute, and play digital media such as still images, animated images, and audio

logos

identifies a person, business, or organization.