Digital Information Review

How many possible values can be created with only 2 bits? A) 4 B) 2 C) 11 D) 3

A

What are the 3 color channels that make up a pixel according to the RGB color scheme? A) Red, Green, and Blue B) Red, Blue, and Yellow C) White, Black, and Gray D) Cyan, Magenta, and Yellow

A

What is the value of 9F in binary? A) 1001 1111 B) 1111 1001 C) 0111 1000 D) 1100 0011

A

Which of the following describes the instructions for a general image filter? A) Given an image: for every (x, y) coordinate in the image Get the current pixel at (x, y) Modify the pixel according to a function Update image at (x, y) with this modified pixel B) Given an image: for every (x, y) coordinate in the image Get the current pixel at (x, y) Add 50 to the red value of the pixel Add 50 to the green value of the pixel Add 50 to the blue value of the pixel Update image at (x, y) with this modified pixel C) Given a pixel: Modify the red value of the pixel according to a function Modify the green value of the pixel according to a function Modify the blue value of the pixel according to a function return the modified pixel D) Given an image: Get the pixel at (0, 0) from the image Modify the pixel according to a function Update image at (0, 0) with this modified pixel

A

Which of the following statements are true about Caesar's Cipher? I: Caesar's Cipher is a form of Symmetric Encryption II: Caesar's Cipher is a "hard" encryption to crack A) I only B) II only C) Both I and II D) Neither I nor II

A

What system is used to encode text to binary?

ASCII Table

Public Key encrypts. Private key decrypts.

Public Key Encryption

What function would you use for a darkness filter?

Math.max

What function would you use for a brightness filter?

Math.min

The building block of a digital image. A pixel is the smallest element of a digital image.

Pixel

Data that is represented in a physical way (Vinyl Record and VCR Cassette)

Analogue Data

One key encrypts and a different key decrypts.

Asymmetric Encryption

What is the number base of the binary number system? A) 10 B) 2 C) 1 D) 0

B

What is the range of values (expressed in decimal) that each color channel can have? A) 1 - 256 B) 0 - 255 C) -128 - 127 D) 0 - 127

B

What is the value of F in decimal? A) 16 B) 15 C) 6 D) 5

B

Which of the following are true about Symmetric Key Encryption? I: The same key is used for both encryption and decryption II: The sender and receiver must exchange a shared key in private before using symmeric key encryption to communicate III: Symmetric key encryption is the most common form of encryption for internet communication A) I only B) I and II only C) I, II, and III D) I and III only

B

Which of the following functions properly removes all green and blue from a pixel and returns the modified pixel? A) var RED = 0; var GREEN = 1; var BLUE = 2; function removeGreenAndBlue(pixel) { pixel[RED] = 255; return pixel; } B) var RED = 0; var GREEN = 1; var BLUE = 2; function removeGreenAndBlue(pixel) { pixel[GREEN] = 0; pixel[BLUE] = 0; return pixel; } C) var RED = 0; var GREEN = 1; var BLUE = 2; function removeGreenAndBlue(pixel) { pixel[GREEN] = 0; pixel[BLUE] = 0; } D) function removeGreenAndBlue(pixel) { pixel.setGreen(0); pixel.setBlue(0); return pixel; }

B

Which of the following instructions would brighten a pixel? Assume R is the red value of the pixel, G is the green value, and B is the blue value. A) R = R + 50; G = G + 50; B = B + 50; B) R = Math.min(R + 50, 255); G = Math.min(G + 50, 255); B = Math.min(B + 50, 255); C) R = R - 50; B = B - 50; G = G - 50; D) R = Math.max(R - 50, 0); B = Math.max(B - 50, 0); G = Math.max(G - 50, 0);

B

Which of the following is true about lossless data compression? A) It is only useful for files being sent over the internet. B) The compressed data can be restored back to its original state C) Once a file is compressed, it cannot be read by anyone else but you D) There only exists one lossless compression algorithm. This algorithm is used regardless of what kind of data is being compressed.

B

In the binary value 100, what is the place value of the 1? A) 100s place B) 2s place C) 4s place D) 1s place

C

We are going to compress this text using the Run Length Encoding compression algorithm: WWWWWWHAAAAAAT?? Which of the following would be the proper compressed text? A) WHAT? B) W6HA6T?2 C) W6H1A6T1?2 D) WHT?

C

What is Data Abstraction? A) Manipulating data to create something new B) Storing data in as little space as possible C) The process of simplifying complicated data into manageable chunks D) Filtering data to gain new knowledge

C

What is a pixel? A) A grid of several colors in a digital image B) Another name for a digital image C) A single tiny dot, or square, of color in a digital image. D) A small picture

C

What is the value of 14 in binary? A) 101 B) 1101 C) 1110 D) 10000

C

Which of the following are true about Public Key Encryption? I: It requires all senders and receivers to have their own public key and their own private key II: A message encrypted with a person's public key can only be decrypted with the same person's private key III: A public key can be shared with anyone IV: Public key encryption is the most common form of encryption for internet communication A) I and II only B) I, II, and IV C) I, II, III, and IV D) I and IV only

C

How many bits are used to encode a character according to the ASCII encoding scheme? A) 2 bits(ex: 10 encodes 'A') B) 4 bits(ex: 1011 encodes 'A') C) 6 bits(ex: 10 0110 encodes 'A') D) 8 bits(ex: 0100 0001 encodes 'A')

D

What types of data should be compressed with the Run Length Encoding algorithm? What types of data does the algorithm perform well with? A) Images B) Videos C) Text with few repeated characters D) Text with many repeated characters

D

Which of the following are examples of encoding information? A) Representing fast food meals as numbers on the menu. For example a number 1 represents a hamburger. B) Assigning a numeric value to every area of a region, for example zip codes in the United States C) Assigning a number to every character of the alphabet so we can represent sentences as series of simple digits. D) All of the above

D

Which of the following is true about lossy compression? A) Lossy compression can compress data down to significantly less bits than lossless compression can B) compressed with lossy compression cannot be restored back to its original state C) Lossy compression throws away a lot of the original data, but humans can't even tell anything is missing. D) All of the above

D

Which of the following pixels has a color value of #ff0000 (expressed in hexadecimal) A) White Pixel B) Blue Pixel C) Green Pixel D) Red Pixel

D

Why do we compress data? A) To save memory space on devices B) To speed up the time it takes to send a file over the internet C) The computation it takes to decompress data is cheaper than the storage space required to store uncompressed data D) All of the above

D

Unscrambling information into a readable form.

Decrypt

Data that can be represent other forms of data and can be interpreted by various technologies.

Digital Data

Scrambling information into an unreadable form

Encrypt

No data lost so it can be decompressed back into the exact original.

Lossless Compression

To save space some information is thrown away.

Lossy Compression

Form of lossless data compression in which runs of data are stored as a single data value and count.

Run Length Encoding

Same key used to encrypt and decrypt

Symmetric Encryption