Digital Information: Lossy Data Compression

Question 1

how do lossy Algorithms reduce file sizes

Answer 1

by discarding less important information

Question 2

what are things that commonly used lossy Algorithms and why

Answer 2

images, videos, audio recordings bc they are rly complex

Question 3

what are techniques used by computers to reduce the file size of images

Answer 3

chroma subsampling and discrete cosine transformation

Question 4

chroma subsampling

Answer 4

keeping the brightness while reducing the amount of color information in an image

Question 5

why is chroma subsampling effective

Answer 5

bc ppl are good noticing brightness differences but bad at noticing color differences

Question 6

what file formats use chroma subsampling

Answer 6

JPEG and MPEG

Question 7

discrete cosine transformation

Answer 7

simplify the details in the brightness layer

Question 8

what are techniques used by computers to reduce the file size of audio files

Answer 8

perceptual audio coding

Question 9

perceptual audio coding

Answer 9

algorithms can analyze an audio file and discard the sounds that are outside our hearing capacity

Question 10

temporal masking

Answer 10

when a sudden sound can mask (hide) other sounds for a period after it occurs—and even a bit before

Question 11

why does perceptual audio coding work

Answer 11

The computer sees those hidden sounds in the recorded audio file, but our ears can’t hear them, so audio compression algorithms can safely discard that information or represent it with fewer bits