Chapter Two: Information Technology Basics
Raster Images
Images stored by dividing a picture into rows of pixels and collecting the color values of each pixel, in order, row-by-row.
Vector Images
Images stored by mathematically describing the shapes in the image. A circle might be stored as a center point and the distance from the center point to the circle's edge. A square is stored as four lines, each with a beginning point and a length. More complex shapes can be stored as a set of small lines.
1977 - The Personal Computer Revolution
In 1977, three successful personal computers were released to the public: The Apple II, the TRS-80 Model 1, and the Commodore Pet 2001. These three computers became known as the "1977 trinity." 1977 also saw the release of the Atari 2600, the first popular home video game console. For the first time, computers were marketed to the general public rather than just businesses and hobbyists. Four years later, IBM followed up with the IBM PC, giving birth to the PC/Apple rivalry that still exists today.
1994 - The World Wide Web
Personal computer ownership began to skyrocket in the mid-nineties with the advent and rise of the World Wide Web, which began in 1991. In 1994, the web became public, and the world got a lot smaller. With new technology like email and chatrooms, computers became a viable way of communicating with other people and thus became more popular. In the early 2000s, social media sites like MySpace and Facebook were launched.
Video Codecs
Pieces of software that either compress or decompress digital media.
.png
Portable Network Graphics, or PNG, is a raster file format that supports lossless compression of image files. PNG (.png) was released in 1994 to be an improvement on the GIF file format, and it combined many features of both GIF and JPG formats (like JPG, it can support 24-bit color). PNG was meant to create files that could be shared on the internet or used in applications - it was not intended for use in print media. One feature that PNG files have that JPG files don't is something called an alpha channel, which facilitates different levels of transparency within an image. This allows PNG files to have transparent backgrounds, making them preferable for web design. PNG files, however, cannot be animated like GIF files.
ASCII
Pronounced ask-ee and short for American Standard Code for Information Interchange, the most common format for text files in computers on the internet where each character is represented by a unique 7-bit binary code. Extended ASCII uses an 8-bit binary code and allows for international characters.
A typical computer monitor is which type of display? Raster Vector RGB White
RGB Computer monitors are made up of tiny red, green, and blue lights. This is called an RGB display.
Which type of digital picture is made by storing individual pixel values? Vector Raster High-res Pixel map
Raster
Which of the following is a lossless compression algorithm? PNG MP4 Compression artifact Run-length encoding
Run-length encoding is a common lossless compression algorithm. A compression artifact is when patches of pixels appear to have less visible detail due to the compression. MP4 is a type of audio file. PNG is a type of image file.
.tiff
TIFF stands for Tagged Image File Format. TIFF is a format for storing raster graphics that was created in 1986 to be a standard image format that could be shared across a variety of computer programs. Several corporations worked on its development, including the Aldus Corporation (which became part of Adobe) as well as Microsoft and Hewlett-Packard. Unlike many other image formats, TIFF is not compressed at all. This makes it an ideal format for high-quality printing. However, modern web browsers don't support the format without special plugins, which is why we haven't included an example here.
Color Depth
The amount of memory the computer uses to display colors in a digital image or a digital video. 8-bit color images use one byte of data for each pixel. 24-bit color uses three bytes for each pixel.
Bit Depth
The amount of memory used to store the numeric value of a sound sample during digital sound recording. 8-bit sound uses eight bits (or one byte) to store the value of each sample. 16-bit sound uses two bytes per sample. Generally speaking, the better the bit depth, the better the sound.
Lossy Compression
A compression algorithm, such as JPG, MP3, and MP4, that slightly alters the data to make it easier to store, taking advantage of the limitations of human sight and hearing, and is usually used for images, videos, and audio files.
System Memory
A computer needs memory space available for processing. Processing would be very slow if you had to call up everything to be processed from a mass storage system. Instead, computers are equipped with a system memory that is a storage working space while the computer is running. Random Access Memory (RAM) is this memory system. However, it is volatile memory. RAM clears all data when the computer shuts down. Some RAM types include: Dynamic RAM (DRAM) is a system RAM that is often used for a computer's main processing memory. A DRAM cell is an integrated circuit composed of a capacitor and a transistor. A data bit is held in the capacitor until the electrical charge is discharged which happens continuously at a slow rate. The DRAM is pulsed with a new electrical charge every few milliseconds in order to retain the data bit. Synchronous DRAM (SDRAM) is dynamic RAM that is synchronized to the system bus, the system for communication between the memory and the CPU. Dual Inline Memory Module (DIMM), or RAM stick, is made of several DRAM integrated circuits. They are used for SDRAM in a desktop PC. Small Outline DIMM (SO-DIMM) is a smaller version DIMM that can be used in smaller devices like laptops and tablets.
Graphic Designer
A creative artist who designs digital images and illustrations for a wide variety of purposes, including ads, logos, emails, marketing materials, websites, social media, and mobile apps. Graphic designers are creative individuals who design images and illustrations for a wide variety of purposes, including ads, logos, emails, marketing material, websites, social media, and mobile apps. They have refined skills in integrating color, typography, images, and layout. Many designers are also skilled in front-end coding, photography, and the ability to use various design software such as Adobe Photoshop, InDesign, and Illustrator.
RGB Display
A display on a computer monitor that is made up of sets of tiny red, green, and blue (RGB) lights, each set combining to make a pixel. A pixel will display different colors depending on the brightness of each light.
Human-computer Interaction
A field of study that looks at how computers and other kinds of technology interact with humans.
Byte
A group of eight bits joined together. The value of a single byte can range from 0 (eight 0s) to 255 (eight 1s).
Smartphone
A mobile phone that functions as a computer and allows users to access the internet.
Hexadecimal System
A numbering system that uses sixteen digits, 0 through 9, and A through F.
Decimal System
A numbering system that uses ten digits, 0 through 9.
Binary System
A numbering system that uses two digits, 0 and 1.
Compression Artifact
A patch of pixels in a compressed image or video that have less visible detail than the rest of the image.
Digital Data
A physical signal, such as text, numbers, graphics, or sound, interpreted by converting it into binary numbers.
Transistor
A smaller, faster, cheaper, and more durable electronic device that replaced mechanical relays, which were slow and tended to wear down over time.
World Wide Web
A system for making digital resources publicly available over the internet using a web browser that paved the way for email, chatrooms, and social media sites.
File Compression
A way of reducing the size of files, making them easier to store.
Supercomputers
The fastest, most powerful computers that exist at a given time. These computers have processing capabilities designed to solve problems that are too complex for regular computers. They play vital roles in the advancement of national defense, science, and social change.
Wireframes
The first step in designing a 3D model which provides the outline of the model, including only the vertices and lines without including any surfaces, textures, or lighting.
Throughput
The measurement in bits per second that information is transferred through a network from one computer to another. Throughput is measured in Kbps (kilobits per second), Mbps (megabits per second), and Gbps (gigabits per second).
Storage Space
The measurement in bytes of the volume that a storage device can contain. Storage space is measured in kilobytes (1024 bytes), megabytes (1024 kilobytes), gigabytes (1024 megabytes), and terabytes (1024 gigabytes).
color depth
The number of different colors that can be displayed on the screen at a time. Color depth is expressed in bits (a higher bit count increases the number of colors that can be displayed). Common bit depths include: 8-bit (256 possible colors) 16-bit, also called high color (65,536 possible colors) 24-bit, also called true color (16.7 million possible colors) 32-bit, also called true color (16.7 million possible colors and alpha channel)
Frame Rate
The number of images, or frames, that are taken each second during digital video recording. Most digital videos have a frame rate of about 30 frames per second.
Sampling Rate
The number of individual samples taken each second during digital sound recording. Measured in Hertz, the higher the sampling rate, the better the recording. Most modern sound recordings are made at 44.1 kHz.
Resolution
The number of pixels in the width and height of each frame in a digital video recording. The higher the resolution, the clearer the image will be.
Resolution
The number of pixels on a display screen. Resolution is expressed in a width by height formula (e.g., 1920 � 1080). These numbers represent the number of pixels on that axis. A higher resolution means that more information can be shown on the screen at a time. Resolutions are often described using a naming standard, although these standards encompass much more than just resolution size.
processing
The operations performed by a computer to retrieve, transform, or classify information.
Sample
The part of a sound wave that is captured, measured, and assigned a numeric value during digital sound recording.
2007 - Smart Phones
Through the mid 2000s, Internet access was mostly limited to computers and laptops. Then, in 2007, Apple unveiled the iPhone, the world's first smartphone. Now, people could access the Internet anywhere. Smartphones are now extremely common in the developed world, almost completely replacing other kinds of personal telephones.
1959 - Invention of the Microchip
Throughout the 1950s, computers were large and expensive. Most computers were owned by governments, universities, and businesses - they had no place in the typical home. Then, in 1959, researchers at Texas Instruments developed an integrated circuit, or microchip. This new technology allowed an entire computer to be built into a single board, rather than needing large modules for each part of the computer. Microchips paved the way for personal computer ownership.
MIDI
Unlike an MP3 or WAV, Musical Instrument Digital Interface (MIDI) files don't contain actual audio waves. MIDI is a standard protocol that was created in the late 1980s as way to standardize the exchange of musical information between musical instruments. MIDI files consists of three different components. The first component is the physical connector that connects and transports data between devices. The second is the message format that controls the stored data and connected devices. Lastly, the storage format stores all the data and information. MIDI files are often used with synthesizers and keyboards but can be used with computers and other electronic instruments as well. A MIDI file translates instructions of which notes are to be played, when they are to be played, and how long they are to be held and reproduced. MIDI files have become popular among musicians because they can easily be modified by editing or removing instructions such as pitch or tempo.
Which type of digital picture can be scaled to any size without losing quality? Transparent High-res Vector Raster
Vector
WAV/AIFF
Waveform Audio Files (WAV) are one of the most popular audio formats. WAV was created in 1991 by Microsoft and IBM to be used with Windows 3.1. Apple created its own version of this format in 1988 called Audio Interchange File Format (AIFF). Despite being older formats, they're preferred by professional users due to the ease of editing and sound quality. Since this data is uncompressed, these files can take up a lot of space and are not ideal for mobile devices such as phones or tablets. WAV files are typically used for TV, radio, and other media that requires quality uncompressed audio.
1944 - Harvard Mark 1 Completed
Working together, engineers from Harvard University and IBM created the Harvard Mark 1, which at the time was the most powerful computing machine ever built. It was fifty feet long, weighed five tons, and was built from about 750,000 individual mechanical parts. The Mark 1 was used by the Allies during World War II and assisted in creating simulations for the Manhattan Project. It could perform three additions or subtractions every second and one multiplication every six seconds.
Run-Length Encoding
A common lossless compression algorithm that looks for repeated patterns of bits or bytes and records the pattern and then number of times the pattern is repeated.
Lossless Compression
A compression algorithm, such as GIF, PNG, PDF, and ZIP, that doesn't affect the original data. A file compressed using a lossless compression algorithm, when decompressed, will be exactly the same as the file before compression, bit for bit.
Which of the following transfer rates is the FASTEST? 181 Mbps 1,480 Mbps 1.24 Gbps 1,282 Kbps
1,480 Mbps 1,480 Mbps is equal to 1.48 Gbps, and so it is the fastest transfer rate listed because it is greater than 1.24 Gbps. In summary, 1,480 Mbps > 1.24 Gbps > 181 Mbps > 1,282 Kbps.
Which of the following is the correct binary representation of the number 22? 10111 11000 10110 10101
10110
How many possible values would an 8-bit audio sample have? 65,000 16 256 256,000
256 Bit depth is the amount of memory used to store each value of a sample. The better the bit depth, the better the sound quality. 8-bit sound uses 8 bits (or 1 byte) to store the value of each sample, which means the sample can be 1 of 256 values. None of the other options are possible values of an 8-bit sample.
Video Production Specialist
An IT professional who designs, records, and edits instructional videos, marketing materials, commercials, and other digital video content. Video production specialists are instrumental in the success of many companies today. They create instructional videos, marketing material, commercials, and much more. It's important that video production specialists have the expertise to recommend effective media communication practices and explain video design principles to clients and employers. Many video production specialists receive a bachelor's degree in telecommunication or video production.
Digital Audio Producer
An IT professional who specializes in recording and editing high-quality audio for videos, podcasts, and many other purposes. Digital audio producers specialize in recording and editing high-quality audio for videos, podcasts, and many other purposes. They have extensive knowledge of setting up audio recording and editing equipment in a variety of different scenarios. For example, recording audio in a studio requires different tools than recording audio outdoors. Since there's a lot of overlap with video production, most audio producers have those skills as well.
Ray Tracing
An advanced rendering method that is used to create incredibly realistic lighting effects for things like video games and movies.
Hollerith's Tabulating Machine
An early computing machine that used punched cards and metal pins. It was used to compile the 1890 US census.
Microchip
An electronic device that allowed entire computers to be built into a single board, replacing modules for each part of the computer. Microchips paved the way for personal computer ownership.
Unicode
An international 16-bit encoding standard that accommodates character sets from multiple languages, with each letter, digit, or symbol being assigned a unique numeric value.
1890 - Hollerith's Tabulating Machine
At the end of the 19th century, the population of the United States was rapidly growing. Because there were so many people, the 1880 census took seven years to compile, and it was predicted that the 1890 census would take nearly twice as long. To solve this problem, the government hired Herman Hollerith to devise a solution. Hollerith created an electromechanical tabulating machine to process the census data. It worked by punching data into paper cards, then inserting them into the machine. Inside the machine, small metal pins would pass through the holes into a vial of mercury, completing an electrical circuit. This in turn powered an electric motor, which turned the appropriate gear in the machine to keep track of the count. Using this machine, the entire census was compiled in two and a half years.
Given the numerical value 1010101.11, which of the following number systems is MOST likely represented? Binary Decimal Octal Hexadecimal
Decimal
DivX
DivX is a movie encoding codec that's used on many DVD movies by utilizing a certain type of MPEG-4 file. It's used to compress an entire movie so that it can fit on a single DVD. There's also an HD version called DivX HD which can compress a high-definition movie onto a single DVD as well.
1947 - First Transistor Developed
Early computers sent signals via mechanical relays. Relays were metal switches that would physically move to make and break electrical circuits, representing 1s and 0s. Because the parts had to physically move, they were slow and tended to wear down over time. In 1947, scientists at Bell Laboratories invented the transistor. Transistors contain silicon, a semiconductor that can be made to sometimes conduct electricity and sometimes not. Because they didn't have any moving parts, silicon transistors were smaller, faster, cheaper, and more durable than mechanical relays.
Which single digit has the highest value in the hexadecimal number system? F 0 9 G H
F The hexadecimal number system uses sixteen digits - the numerals 0 through 9 followed by the letters A through F.
.gif
GIF, or Graphics Interchange Format, was originally released in 1987 by CompuServ. Pronounced either with a hard G ("gif") or a soft G ("jif"), GIF is a lossless format that's often used for web images. Because it stores image data using indexed color, the range is limited to 256 colors. This is in contrast to other file formats that have millions of colors to draw from, meaning that images won't have as much nuance as other file formats. This also means that it's not the ideal format to store and share digital photos because the limited color palette will cause the photos to look grainy and unclear. The limited palette is instead ideal for icons and buttons on the web because they don't require thousands of colors to look good.
Which of the following notational systems is MOST likely used to represent a MAC address? Octal Decimal Hexadecimal Binary
Hexadecimal The hexadecimal number system uses sixteen digits - the numerals 0 through 9 and the letters A through F. MAC addresses are typically composed of six groups of two hexadecimal digits separated by hyphens or colons.
Output
Information that a computer returns to a user such as images on a screen, sounds from speakers, and printed pages.
input
Information that a user physically enters into a computer by pressing a key on a keyboard, clicking a mouse, tapping a touch screen, pushing a button on a game controller, speaking into a microphone, etc.
.jpg
JPEG stands for Joint Photographic Experts Group and is one of the most common image file extensions. You may see it written .jpg or .jpeg. The reason for this goes back to earlier days when there was a discrepancy between Mac and Windows file extension naming conventions. Windows only allowed for three-letter extension names, while Apple computers weren't restricted in this way. Though this limit was eventually lifted on Windows, JPG is still how most users refer to the format. JPG is a compressed file type that drastically reduces the file's size by a ratio of 20:1 without sacrificing too much image quality (though it is still a lossy format). It supports 24-bit color which can create a wide variety of shades. This balance makes it a popular format to use on the internet for things like posting to social media and displaying pictures on mobile devices. These types of files are easy to share and can be opened by a wide variety of software both on PCs and Macs.
Bitrate
Kilobits of audio data processed each second.
byte from smallest to largest: megabyte kilobyte terabyte gigabyte
Kilobyte Megabyte Gigabyte Terabyte
MP3/AAC
MP3 is an acronym for MPEG Layer 3 and is a format that uses lossy data compression to reduce file size. It was developed in Europe by an international collaboration of engineers called the Moving Pictures Experts Group (MPEG) that was founded in 1988. Their goal was to create an audio compression tool that could shrink the file without affecting the quality of the audio. They achieved this using auditory masking, which uses one sound to render another sound inaudible. After that, the remaining audio information is then recorded in a space-effective manner, reducing the file size by 75%-95%. In November of 1996, this technology was patented as MP3, MPEG-1, or MPEG-2 Audio Layer 3. The creation of the MP3 format created a digital music frenzy in the mid-1990s due to the high-quality sound reproduction and the ability to store many MP3s in one place. In 1997, a similar format was developed called Advanced Audio Coding (AAC) that uses similar but more complex compression algorithms that allow for better sound quality than an MP3. This format is used by YouTube, Android, iOS, iTunes, and various gaming systems because of its small file size and excellent sound quality.
MPEG-4
MPEG stands for Motion Picture Experts Group and MPEG-4 is one of the most common and widely used codecs. MPEG-4 has gone through several iterations, including MPEG-1 and MPEG-2. The MPEG-4 codec is the newest version. It uses an advanced compression algorithm that can compress a standard 120-minute film into 300MB.
Gigabyte (GB)
One gigabyte is one billion bytes. Therefore, 1 gigabyte equals 1,000 megabytes.
Kilobyte (KB)
One kilobyte is equal to 1,000 bytes.
Megabyte (MB)
One megabyte is one million bytes of information. Therefore, 1 megabyte equals 1,000 kilobytes.
Terabyte (TB)
One terabyte is equal to 1,000 gigabytes.
Aspect ratio
The proportion between the width and height of a resolution. Aspect ratios are used by both display devices and video content. The following are the three most commonly used aspect ratios: 4:3 16:9 16:10
Refresh rate
The refresh rate is the number of times the entire screen is redrawn per second. Refresh rates are measured in Hz. Most monitors support multiple refresh rates. Increasing the refresh rate reduces screen flicker. A desirable range of refresh rate is 60 Hz or higher. Fast-moving graphics require a refresh rate of 120 Hz or higher. The refresh rate must be supported by the video card, the monitor, and the cable being used. By default, Windows shows only supported refresh rates.
Encoded Integers
The representation of integers using a group of bytes. Normally, one bit in one of the byes represents the sign, 1 for negative and 0 for positive. The remaining 31 bits are used to encode the number itself using binary digits.
Encoded Text
The representation of text by assigning a unique binary code to each character.
Storage
The saving of information on memory chips, discs, or other storage media by a computer for later use.
Rendering
The second step in designing a 3D model which converts the models into 2D images on a computer.
Bit
The smallest unit of digital information, represented by a 1 or 0. Each individual one and zero in a binary sequence is a bit.
Processor Speed
The speed at which a computer processes information, as measured by the number of cycles per second (Hertz) that the computer's CPU operates at. Processor speed is measured in kilohertz, megahertz, and gigahertz.
How many bits are in a single byte? four eight twelve sixteen
eight
Which of the following makes videos appear smoother and more fluid? Lower frame rate Higher frame rate Lower resolution Higher resolution
higher frame rate The frame rate is the measure of how many images, or frames, are shown each second. A higher frame rate makes videos appear smoother and more fluid than a lower frame rate. Resolution is the measure of how many pixels wide and tall each frame of a digital video is. The higher the resolution, the clearer the image will be.
Basic Computer System Functions
input, processing, output, storage
Video File Formats
mp4, avi, mov, wmv
Digital sound recordings capture sound waves and divide them into distinct segments. Each segment is assigned a value. What is that value called? Sampling rate Bit depth Resolution Sample height
sample height Sound is caused by vibrating objects which create pressure waves in the air. Digital sound recordings capture this continuous wave and divide it into distinct segments. The recording then assigns a value to each segment. A single segment's value is called its sample height. Recording programs must decide how much memory they should allocate to store the value of each sample. The amount of memory used is called the bit depth. The sampling rate is how many individual samples are taken each second. This is measured in hertz (Hz). Resolution is the measure of how many pixels wide and tall each frame of a digital video is.
Which of the following BEST describes what a kilobyte is a measurement of? Storage space CPU speed Power level Data throughput
storage space Data storage usually refers to the number of bytes. Storage space on a disk is measured in kilobytes (KB), megabytes (MB), gigabytes (GB), and terabytes (TB).
What are pixels that are the exact same between multiple frames called? Run-length encoding Temporal redundancy Compression artifact Lossless compression
temporary redundancy
A consumer wants to add a hard drive to their computer to store video from their camera. Which of the following is the storage capacity of a modern hard disk drive (HDD) purchased from a computer store? 4 gigabytes 1,024 kilobytes 8 megabytes 3 terabytes
terabyte Storage of modern hard disk drives are available in multiples of terabytes. The other capacities are too small to work well for video storage. Listed in order of increased capacity: kilobyte > megabyte > gigabyte > terabyte.
Which kind of file would be hurt most by a lossy compression algorithm? A digital photograph An audio file containing speech An audio file containing music A text document
text document
Which of the following encoding schemes would MOST likely be used to represent an emoji? Binary Hexadecimal Unicode ASCII
unicode
