3.10 AP Classroom Questions

A person wants to transmit an audio file from a device to a second device. Which of the following scenarios best demonstrates the use of lossless compression of the original file?

A device compresses the audio file before transmitting it to a second device. The second device restores the compressed file to its original version before playing it.

A list of binary values (0 or 1) is used to represent a black-and-white image. Which of the following is LEAST likely to be stored as metadata associated with the image?

A duplicate copy of the data

Which of the following is an advantage of a lossless compression algorithm over a lossy compression algorithm?

A lossless compression algorithm can guarantee reconstruction of original data, while a lossy compression algorithm cannot.

A library of e-books contains metadata for each book. The metadata are intended to help a search feature find books that users are interested in. Which of the following is LEAST likely to be contained in the metadata of each e-book?

An archive containing previous versions of the e-book

A user wants to save a data file on an online storage site. The user wants to reduce the size of the file, if possible, and wants to be able to completely restore the file to its original version. Which of the following actions best supports the user's needs?

Compressing the file using a lossless compression algorithm before uploading it

Digital images are often represented by the red, green, and blue values (an RGB triplet) of each individual pixel in the image. A photographer is manipulating a digital image and overwriting the original image. Which of the following describes a lossless transformation of the digital image?

Creating the negative of an image by creating a new RGB triplet for each pixel in which each value is calculated by subtracting the original value from 255. The negative of an image is reversed from the original; light areas appear dark, and colors are reversed.

A group of students take hundreds of digital photos for a science project about weather patterns. Each photo file contains data representing the level of red, green, and blue for each pixel in the photo. The file also contains metadata that describes the date, time, and geographic location where the photo was taken. For which of the following goals would analyzing the metadata be more appropriate than analyzing the data?

Determining the chronological order of the photos Determining whether two photos were taken at the same location on different days

A digital photo file contains data representing the level of red, green, and blue for each pixel in the photo. The file also contains metadata that describes the date and geographic location where the photo was taken. For which of the following goals would analyzing the metadata be more appropriate than analyzing the data?

Determining the likelihood that the photo was taken at a particular public event

The file name of the photo The date and time the photo was taken The geographic location where the photo was taken Assume that all of the photos that have been taken on the phone are accessible. Which of the following can be determined using the photo data described above? I. The number of photos that were taken at a particular geographic locationII. The number of photos that were taken in the last yearIII. The name of the person who took the most recent photo

I and II only

For which of the following goals would it be more useful to computationally analyze the metadata instead of the data? To determine if a caller frequently uses a specific word To estimate the number of phone calls that will be placed next Monday between 10:30 A.M. and noon. To generate a list of criminal suspects when given the telephone number of a known criminal

II and III only

For example, the string "This_is_the_best_wish" can be encoded as "%#_#_%E_BEST_W#H" by replacing all instances of "TH" with "%" and replacing all instances of 'IS" with "#". For which of the following strings is it NOT possible to use byte pair encoding to shorten the string's length?

Level_Up

A programmer is developing software for a social media platform. The programmer is planning to use compression when users send attachments to other users. Which of the following is a true statement about the use of compression?

Lossy compression of an image file generally provides a greater reduction in transmission time than lossless compression does.

In which of the following situations would it be most appropriate to choose lossy compression over lossless compression?

Storing music files on a smartphone in order to maximize the number of songs that can be stored

Which of the following statements about the Internet is true?

The Internet is designed to scale to support an increasing number of users.

A camera mounted on the dashboard of a car captures an image of the view from the driver's seat every second. Each image is stored as data. Along with each image, the camera also captures and stores the car's speed, the date and time, and the car's GPS location as metadata. Which of the following can best be determined using only the data and none of the metadata?

The number of bicycles the car passed on a particular day

The time the message was posted The name of the user who posted the message The names of any users who comment on the message and the times the comments were made For which of the following goals would it be more useful to analyze the data instead of the metadata?

To determine the topics that many users are posting about

A media librarian at a movie studio is planning to save digital video files for archival purposes. The movie studio would like to be able to access full-quality videos if they are needed for future projects. Which of the following actions is LEAST likely to support the studio's goal?

Using lossy compression software to reduce the size requirements of the data being stored

j ← LENGTH(myList) REPEAT UNTIL(j = 1) { IF(myList[j] = myList[j - 1]) { REMOVE(myList, j) } j ← j - 1 } For which of the following contents of myList will the procedure NOT produce the intended results?

[10, 10, 20, 20, 10, 10] [30, 50, 40, 10, 20, 40]