CS Unit 3
What are the 3 color channels that make up a pixel according to the RGB color scheme?
Red Green Blue
The art and science of hiding information by embedding messages within other, seemingly harmless messages is called _____________.
Steganography
What is steganography and what is it used for?
Steganography is the art of sending secret messages in imperceptible(impossible to perceive or detect) ways. It is used for including secret (but decipherable) messages along with other data so that only a number of specific people can read the secret message.
How many different values can be represent using 4 bits
binary 1111 (decimal = 15)
The art of protecting information by transforming it into an unreadable format. It also means secret writing is called _______________.
cryptography
________any system based on discontinuous data or events. Computers are digital machines because at the basic level they can distinguish between just two values, 0 and 1.
digital
_____________ (DSP) refers to manipulating analog information
digital signal processing
_____________ is to copy data (usually an entire file) from a main source to a peripheral device
download
___________ is a problem solving approach (algorithm) to find a satisfactory solution where finding an optimal or exact solution is impractical or impossible.
heuristic
______ is a base-16 number system that uses sixteen distinct symbols 0-9 and A-F to represent numbers from 0 to 15.
hexadecimal
Data compression techniques in which no data is lost is called __________.
lossless compression
_______________________ is data compression techniques in which some amount of data is lost. This technique attempts to eliminate redundant information.
lossy compression
One million pixels, used in reference to the resolution of a graphics device is called ___________.
megapixel
__________________ is one million pixels, used in reference to the resolution of a graphics device
megapixel
What are filename extensions? What are they used for?
A filename extension is the 3 letters after the dot at the end of a filename. They are used to indicate how the contents are to be interpreted.
What is the number base of the octal number system?
8
What is the range of values (expressed in decimal) that each color channel can have?
0-255 (256 possible combinations)
What is the number base of decimal?
10
What is the value of 14 in binary?
1110
How many different digits are used in the Hexadecimal number system?
16
What is the number base of hexadecimal?
16
What is the representation of the photograph in bits called?
A model
What is the difference between a raster image and an ASCII representation of a text document?
A raster image is an image representation based on a division into pixels and ASCII is a collection of 8 bit codes used to represent a string of symbols/letters.
The code for representing English characters as numbers, with each letter assigned a number from 0 - 127 is called ____.
ASCII
A formula or set of steps for solving a particular problem
Algorithm
A device or system that represents changing values as continuously variable physical quantities is called _________.
An analog
_______relies on sharing resources online on the Internet rather than having data and process located on a personal computer.
Cloud computing
Data compression techniques in which some amount of data is lost. This technique attempts to eliminate redundant information.
Lossy compression
What is the process of capturing the photograph? (It is basically making the photograph or object.) What is that process called?
Modeling
Optical character recognition, the branch of computer science that involves reading text from paper and translating the images into a form that the computer can manipulate is known as
OCR
What is the octal and hexadecimal value of 1101 (base-2)?
Octal= 15 Hexadecimal=D
Why do you think they named this chapter Ghosts in a Machine? Explain.
People thought they were able to delete or hide things on their computer, but in reality it was still there. Also people were able to find out how to uncover or find "deleted" things.
This color model uses varying intensities of (R)ed, (G)reen, and (B)lue light that are added together in to reproduce a broad array of colors is called ______.
RGB
What is the meaning of rendering?
The model is turned into an image by rendering the model; this is what happens when you transfer the bits representing a digital photograph to a computer screen or printer.
Representing an image is a two stage process. What is the two stage process in reproducing an image electronically?
The scene is translated into bits, creating a digital model. Then the model is rendered as a visible image.
_______ is short for a picture element, a single point in a graphic image. Also short for "picture element", the fundamental unit of a digital image, typically a tiny square or dot that contains a single point of color of a larger image.
pixel
The rectangular area of a display screen actually being used to display images is called _________________.
raster
____________ is electronic junk mail or junk newsgroup postings
spam
To transmit data from a computer to a network or a mainframe is called ____.
upload
