chapter  4
Compression
Pages 14

If we were to use video data in a direct form, representing each pixel of each frame as a triplet of red, green and blue values expressed with a fixed number of bits, then the amount of data involved would be enormous in every regard: recording, storage, transmission. For instance, recording images of 2880x1620 pixels at 30 frames per second and with 10 bits of color information per channel would require a data rate of approximately 4 gigabits per second. This figure is beyond the capabilities of todays’ cameras. A bandwidth of 4 Gb/s is also exceedingly larger than current typical values for domestic DSL connections, which are in the range of a few tens of Mb/s. Finally, storing 90 minutes of such a movie would require a capacity of 2.6 terabytes, equivalent to more than 500 DVDs.