实验三

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电子科技大学



学生姓名: 顿 珠
学号:2011019130020
指导教师: 王 军
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EXPERIMENT 3 MULTIMEDIA DATA COMPRESSION
STANDARD——JPEG

Steps
1) Start computer and run desktop\multimedia\experiment3\jpeg.exe
2) Open a bitmap file and click Split\Split to RGB to display the R, G, and B components
of the selected image separately. Compare the R, G, and B components images with the
original one.
3) Click Split\Split to YUV to display the Y, U, and V component of the selected image.
Compare the components images with the original one. What conclusion can you make
from step 2 and step 3?
4) Click DCT&Quan\select 8×8 block or , and select an 8×8 block in the image.
There will be a new window to display the selected block image. Click
DCT&Quan\Y-table. A dialog box will display. Pay attention to the data shown in the
box. What conclusion can you make from these data? Change the selected picture.
How about the result?
5) Click DCT&Quan\U-table or DCT&Quan\V-table. What do you get? Together with
what you get in step 4, what do you learn?
6) Repeat step 3. Then click DCT&Quan\Y-channel (or U-channel, V-channel,
All-channel). Compare the images you get. What do you learn?

7) Close all the pictures you get except the original one. Click Huffman\ select

16×16 block or . There will be a new window to display the selected block image.
Click Huffman\Y Channel Block. A dialog box will display. Pay attention to the data
shown in the box. What conclusion can you make from these data? Read what you get
after click button “See Huffman Coding”.
8)
Close all the windows you get except the original one. Click JPEG\JPEG
Compression. Input 50 in the box, and then click ok. Click Edit\Zoom in +

or to zoom in the image. Compare the compressed image with the
original one. How about the compressed picture and the compression ratio
you get?

9) Repeat step 8 but change the input value to 5, 25, 75, and 100 in turn (or
a value
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arbitrary between 1 and 100
). Compare the results. Which picture you get is better?

And why?

10)
Close all the pictures except the original one. Click Enhanced\DC and
observe the processed image. How about the image you get?

11)
Click Enhanced and select DC and 2AC. How about the image you get in
this step?

12)
Click Enhanced and select Full Frequency. Compare the picture you get
with those in step 10 and step 11. What do you learn?

13)
Close all the pictures except the original one. Click Enhanced\1bit observe
the processed image. How about the image you get?

14)
Click Enhanced and select 4 bits. How about the image you get in this
step?

15) Click Enhanced and select Full Bits. Compare the picture you get with those in step 13
and step 14. What do you learn?