2.3.3 Understanding data compression:

• What is the purpose of data compression?

  Reduce data size
• Lossy compression permanently loses some data, resulting in smaller file sizes compared to lossless compression.

  True
• Data compression is needed to save storage space
• Lossless compression ensures no data is lost during compression and decompression.


  True
• Match the type of data compression with its characteristics:

  Lossless ↔️ Preserves original data

  Lossy ↔️ Significant file size reduction

  Transform coding ↔️ Converts data to frequency domain
• Predictive coding stores the difference between predicted and actual values
• What type of compression is used when some quality loss is acceptable for smaller file sizes?

  Lossy compression
• Transform coding converts data into a frequency domain representation and discards less perceptible high-frequency components.


  True
• Vector quantization represents data using a limited set of "code vectors
• Lossless compression ensures that the original data can be perfectly reconstructed after compression.


  True
• How does run-length encoding compress data?

  Replaces identical consecutive characters with a count and the character
• Lossless compression techniques are commonly used for text files, software, and other data where preserving the exact original content
• In lossless compression, the original data can be perfectly reconstructed
• What type of file commonly uses lossy compression?

  Multimedia file
• Order the following steps to explain why data compression is needed.

  1️⃣ Data compression reduces file size

  2️⃣ More data can be stored on limited media

  3️⃣ Data transmission requires less bandwidth

  4️⃣ Upload and download times are reduced
• What is the primary goal of lossy compression?

  Reduce file size
• What does transform coding do in lossy compression?

  Converts data to frequency domain
• Lossy compression techniques are commonly used for multimedia files to achieve smaller file sizes at the cost of some quality loss.


  True
• Lossy compression techniques permanently remove some data from the original file in order to achieve significantly smaller file sizes
• What does predictive coding store instead of original values?

  Differences between predicted and actual values
• Which lossy compression technique reduces resolution or color depth by removing pixel data?

  Subsampling
• Lossless compression is a type of data compression where the original data can be perfectly reconstructed from the compressed data
• Huffman coding assigns shorter codes to more frequently occurring characters to reduce file size.


  True
• What is the primary purpose of data compression?

  Reduce data size
• What is the key difference between lossless and lossy compression?

  Lossy compression permanently loses data
• Data compression reduces the time needed to transmit files over networks
• Match the data compression type with its characteristic.

  Lossless ↔️ Original data is perfectly reconstructed

  Lossy ↔️ Some data is permanently lost
• Transform coding converts data into a frequency domain representation and discards less perceptible high-frequency components.


  True
• Lossy compression techniques permanently remove some data from the original file to achieve significantly smaller file sizes
• What does predictive coding store in lossy compression?

  The difference between predicted and actual values
• Subsampling reduces image resolution by removing pixel data.

  True
• Lossless compression ensures that the original data can be perfectly reconstructed from the compressed data.
• Huffman coding assigns shorter codes to more frequent characters.


  True
• Match the compression algorithm with its definition:

  Run-length encoding ↔️ Replaces consecutive identical characters

  Huffman coding ↔️ Assigns shorter codes to more frequent characters
• Transform coding converts data into a frequency domain representation.


  True
• Data compression for storage reduces file size to optimize storage space.


  True
• What are the benefits of data compression for transmission?

  Lower bandwidth costs
• Lossless compression allows the original data to be perfectly reconstructed from the compressed file.


  True
• Lossless compression ensures the original data can be perfectly reconstructed from the compressed data
• Compressing data saves storage space on devices with limited memory.


  True