comp sci chapter one

cie exam board

how many bits are in a byte

8

what does resolution mean

number of pixels per inch

what is colour depth

the number of colours displayed in an image

more colours means what?

There will be more bits per pixel

how does a ADC work

we sample the analog sound, measure and record the amplitude, which is then stored as a binary number, After a certain time interval, this is repeated 

 what happens when the sample rate is increased 

more binary numbers need to be stored and the file size is larger. But it provides better quality 

what happens when sample rate is decreased 

the file size is smaller bc less bits stored, sound quality decreases 

what's lossy compression 

when a file is decompressed it's not identical to the original, some data has been lost

what's lossless compression

when a file is decompressed, it's identical to the original.

when is lossy compression used 

with sound or image files

when is lossless compression used 

for text files, when all data is essential and cannot be lost 

what are vector graphics made up of 

geographical shapes

what are bitmaps made up of 

pixels

which is more realistic: bitmaps or vector graphics?

bitmaps- as vector graphics have a limit on the number of geometrical shapes