Q3 2nd Summative

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

• A lossless compression algorithm can guarantee that compressed information is kept secure, while a lossy compression algorithm cannot.

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

• A lossless compression algorithm typically allows for faster transmission speeds than does a lossy compression algorithm.

• A lossless compression algorithm typically provides a greater reduction in the number of bits stored or transmitted than does a lossy compression algorithm.

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

• Compressing the file using a lossy compression algorithm before uploading it

• Compressing the file using both lossy and lossless compression algorithms before uploading it

• Uploading the original file without using any compression algorithm

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?

• Lossless compression of video files will generally save more space than lossy compression of video files.

• Lossless compression of an image file will generally result in a file that is equal in size to the original file.

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

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

A certain programming language uses 3-bit binary sequences to represent non negative integers. For example, the binary sequence  101 represents the corresponding decimal value 5. Using this programming language, a programmer attempts to add the decimal values 4 and 5 and assign the sum to the variable total. Which of the following best describes the result of this operation?

• The correct sum of  9 will be assigned to the variable total.

• An overflow error will occur because 3 bits is not large enough to represent either of the values 4 or 5.

• An overflow error will occur because 3 bits is not large enough to represent  9, the sum of 4 and 5.

• A round-off error will occur because the decimal values 4 and 5 are represented as approximations due to the fixed number of bits used to represent numbers.

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

• A lossless compression algorithm can guarantee that compressed information is kept secure, while a lossy compression algorithm cannot.

• A lossless compression algorithm typically allows for faster transmission speeds than does a lossy compression algorithm.

• A lossless compression algorithm typically provides a greater reduction in the number of bits stored or transmitted than does a lossy compression algorithm.

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

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?

• Compressing the image in a way that may lose information but will suffer only a small loss of image quality.

• Creating the gray scale of an image by averaging the amounts of red, green, and blue in each pixel and assigning this new value to the corresponding pixel in the new image. The new value of each pixel represents a shade of gray, ranging from white to black.

• 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.

•  Modifying part of the image by taking the pixels in one part of the picture and copying them to the pixels in another part of the picture.

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 device compresses the audio file by removing details that are not easily perceived by the human ear. The compressed file is transmitted to a second device, which plays it.

• A device transmits the original audio file to a second device. The second device removes metadata from the file before playing it.

• A device transmits the original audio file to a second device. The second device plays the transmitted file as is.

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

• Storing digital photographs to be printed and displayed in a large format in an art gallery

• Storing a formatted text document to be restored to its original version for a print publication

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

•  Storing a video file on an external device in order to preserve the highest possible video quality

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 video file formats that conform to published standards and are supported across many different devices

• Using storage media that can be expanded for additional data capacity

•  Using a system that incorporates redundancy to handle disk failure

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

A student is recording a song on her computer. When the recording is finished, she saves a copy on her computer. The student notices that the saved copy is of lower sound quality than the original recording. Which of the following could be a possible explanation for the difference in sound quality?

• The song was saved using fewer bits per second than the original song.

• The song was saved using more bits per second than the original song.

• The song was saved using a lossless compression technique.

• Some information is lost every time a file is saved from one location on a computer to another location.