STUDENT NAME: ________________________________________BLOCK # ______________ DATE __________
1. Spatial Compression
2. Temporal Compression
3. Color Palettes
Spatial compression compresses each
frame of a video. Using spatial
compression techniques alone, the
compression ratio for a digital video can be
from 5:1 to 8:1. The 5:1 ratio means a 5meg uncompressed file will be 1 meg after
compression.
Temporal compression compresses an
image by only storing the changes from one
image to the next, but spatial compression
compresses each individual image. Modern
compression techniques integrate both
types of compression.
The number of colors in the color palette used
for a video can determine the size of the video
file. A video is rendered with a 256-color
palette; its file size is 8.2 Meg. The same file is
rendered with a 16-color palette; its file size is
4.1 Meg.
By combining spatial and temporal
compression, compression ratios as high as
100:1 can be achieved.
1. What would be the size of a video rendered
Suppose a compression technique
compresses a video by a 9:1 ratio through
spatial compression and by
another 10:1 ratio through temporal
compression.
Formula: 8.2 ÷ 4.1 = 16.8 ÷ Megs
1. What would be the compressed size of a
video file that is 126 meg uncompressed
if the compression ratio is:
a. 5:1?
Hint: 5 uncompressed equals 1 compressed.
Answer: _____ Megs
(Round to tenths place)
b. 8:1?
1. To what size would a 180-meg video file
compress?
Hint: 8 uncompressed equals 1 compressed.
Hint: First compress 180 Megs with the 9:1 ratio, then
compress that answer with 10:1 ratio.
Answer: _______Megs
Answer: ______Megs
(Round to hundredths place)
2. What compression ratio would be
needed to reduce the size of a 126-meg
file to 16 meg?
2. What would be the overall compression
ratio for this technique?
at 16 colors if, when rendered at 256 colors,
its file size is 16.8 meg?
Answer: ________ Megs
(Round to tenths place)
2. What would be the size of the same video if
it were rendered with a 65,536-color
palette?
Hint: The file size would be four times
larger. The file size is in question 1.
Do not use the answer to question 1.
Answer: ______Megs
(Round to tenths place)
Answer: ______: ____Ratio
Answer:
______: ___ Ratio
(Round to thousandth place)
DIGITAL VIDEO – 3 MATH/SCIENCE ENRICHMENTS _______/30 PTS.