Compression Standard Interview Preparation Guide Download PDF
Compression Standard frequently Asked Questions by expert members with experience in Compression Standard. These interview questions and answers on Compression Standard will help you strengthen your technical skills, prepare for the interviews and quickly revise the concepts. So get preparation for the Compression Standard job interview
28 Compression Standard Questions and Answers:
1 :: Explain what is lossless source coding?
- A data compression technique, which reverts an exact copy of original file.
- Lossless Source Coding is used for compressing text files in modems.
- Lossless Source Coding is a building block for designing lossy compressors.
- Lossy compression is implemented for images, sound and video files for effective data compression.
- Many compression techniques have a lossless mode.
- The lossless source coding involves a sequence of fixed length symbols.
- Each of these symbols is easily manipulated independently.
- Lossless Source Coding is used for compressing text files in modems.
- Lossless Source Coding is a building block for designing lossy compressors.
- Lossy compression is implemented for images, sound and video files for effective data compression.
- Many compression techniques have a lossless mode.
- The lossless source coding involves a sequence of fixed length symbols.
- Each of these symbols is easily manipulated independently.
2 :: Can you explain information theory plays an important role in field of compression
- Information Theory is about quantification of information.
- It is used in compressing data.
- Entropy is a key measure of information.
- It is expressed in terms of average number of bits that are required to store a message.
- Entropy is used to quantify the uncertainty which is a process in predicting the random variable values.
- Lossless data compression, Lossy data compression and channel coding are the fundamental topics of information theory.
- It is used in compressing data.
- Entropy is a key measure of information.
- It is expressed in terms of average number of bits that are required to store a message.
- Entropy is used to quantify the uncertainty which is a process in predicting the random variable values.
- Lossless data compression, Lossy data compression and channel coding are the fundamental topics of information theory.
3 :: Do you know instantaneous variable length codes?
- A code that maps source symbols into a set of variable number of bits.
- A VL code compresses the sources and decompresses with zero error.
- By implementing a right coding strategy, an identically distributed source might be compressed almost close to its entropy.
- This process is in contrast to fixed length coding methods.
- Examples of variable-length codes are Huffman coding, LempelZiv code.
- A VL code compresses the sources and decompresses with zero error.
- By implementing a right coding strategy, an identically distributed source might be compressed almost close to its entropy.
- This process is in contrast to fixed length coding methods.
- Examples of variable-length codes are Huffman coding, LempelZiv code.
4 :: Can you explain what is file compression and why is it necessary to compress files?
- File compression is a process to reduce the disk space to store that file.
- File compression enables data to be transferred quickly.
- Disk space needed on internet servers is reduced. This allows the servers to store more files / information with less disk space.
- File compression reduces the amount of time on internet to upload or download a file.
- Compression hides data so that not all computers can read the information stored.
- File compression is a mandatory preference for some of the internet servers to transfer files.
- File compression enables data to be transferred quickly.
- Disk space needed on internet servers is reduced. This allows the servers to store more files / information with less disk space.
- File compression reduces the amount of time on internet to upload or download a file.
- Compression hides data so that not all computers can read the information stored.
- File compression is a mandatory preference for some of the internet servers to transfer files.
5 :: What is unique decipherability?
- Data symbols are encoded with coding schemes for fixed length codes.
- Every coding scheme has unique code.
- This unique encoded character ensures unambiguous.
- The encoded strings have fixed length.
- The fixed length codes are always uniquely decipherable.
- Every coding scheme has unique code.
- This unique encoded character ensures unambiguous.
- The encoded strings have fixed length.
- The fixed length codes are always uniquely decipherable.
6 :: Do you know non-binary Hoffman Codes?
- The non-binary Hoffman code elements are derived from an alphabet ’m’ is > 2 letters.
- All the symbols ‘m’ which occur least frequently will be having the same length.
- The lowest probability of the symbols ‘m’ will differ only in the last position.
- The letters that combine have code words of the same length.
- The symbols that have lowest probability will have code words with long length.
- All the symbols ‘m’ which occur least frequently will be having the same length.
- The lowest probability of the symbols ‘m’ will differ only in the last position.
- The letters that combine have code words of the same length.
- The symbols that have lowest probability will have code words with long length.
7 :: Tell me what are the parameters that are used in silence compression?
- Silence compression is used in compressing sound files.
- It is equivalent to run length coding on normal data files.
- The parameters are:
1. A threshold value. It is a parameter that specifies, below which the compression can be considered as silence.
2. A silence code followed by a single byte. It indicates the numbers of consecutive silence codes are present.
3. To specify the start of a run of silence, which is a threshold.
- It is equivalent to run length coding on normal data files.
- The parameters are:
1. A threshold value. It is a parameter that specifies, below which the compression can be considered as silence.
2. A silence code followed by a single byte. It indicates the numbers of consecutive silence codes are present.
3. To specify the start of a run of silence, which is a threshold.
8 :: Do you know what is rate distortion theory?
- Distortion theory is about trade-offs between the rate and distortion.
- It is applied for compression schemes.
- An average number of bits are utilized to represent each sample value.
- If the rate of bits is decreased it is known as increase in distortion.
- If the rate of bits to represent each value is increased it is known decrease in distortion.
- It is applied for compression schemes.
- An average number of bits are utilized to represent each sample value.
- If the rate of bits is decreased it is known as increase in distortion.
- If the rate of bits to represent each value is increased it is known decrease in distortion.
9 :: What is Huffman Coding?
- An entropy encoding algorithm.
- It uses variable length code table for encoding source symbol.
- It uses variable length code table for encoding source symbol.
10 :: What is Shannon Fano Coding?
- It is used to construct a prefix code that is based on a set of symbols.
- It suboptimal. The lowest expected code word length will not be achieved.
- It suboptimal. The lowest expected code word length will not be achieved.