Snapshot
Mike Huhs
Sanjay Jhaveri
Project
„
Digital Camera
User
Interface
Compression and Storage
Courtesy flickr users la_salebete and smet_dk. Used with permission.
Display
Live
Video
Capture
Camera Video
Shoot
Button
Cursor
Last
Picture
Courtesy flickr user christinatinarobinson. Used with permission.
Display
Capture
Camera Video
Click!
Courtesy flickr user christinatinarobinson. Used with permission.
Display
Capture
Courtesy flickr user christinatinarobinson. Used with permission.
Display
Capture
Live
Video
Courtesy flickr user christinatinarobinson. Used with permission.
Storage
ZBT Ram 1
Click!
Compression
Row, Column =
Address
Courtesy flickr users la_salebete and smet_dk. Used with permission.
ZBT Ram 2
Your
Picture
Block Diagram
NTSC
A/D
XVGA
NTSC YCrCb Write
Decode
Control
Courtesy flickr users la_salebete and smet_dk.
Used with permission.
Controls
Control
Data,
Address
line,
column
Address
RAM
Data
Compressed
Image
Controls
Xvga
signals
Image
Compression
Read
Control
RGB
YCrCb
Image
RGB
Convert
User
Inputs
Mouse
Image from Wikimedia Commons, http://commons.wikimedia.org.
Used with permission.
Image Compression
•
2D Discrete Cosine Transform: decomposes image into frequency
components
•
•
•
Apply 1D transform to rows and then to columns
Separately transform 8 x 8 blocks of image
Eye acts as natural low pass filter
•
Only store low frequency components of image
180 150 23 12 5 2 1 2
130 125 54 22 8 3 5 4
89 77 45 19 4 2 0 3
45 33 21 15 8 4 3 1
22 9 12 5 1 2 5 0
17 13 7 10 8 6 2 2
8
3 4 6 2 1 3 0
5
2 8 3 1 2 5 0
8x8
pixels
8x8 Input Matrix
1D DCT
8x8 Transform Matrix
Transpose
1D DCT
Image Compression
From read
module
data_in
data_in valid
From
control
To read
module
get picture
DCT & Memory Control
delete picture
data_out
data_out valid
d
c
t
„
d
c
t
d
c
t
ZBT RAM
i
d
c
t
ZBT Ram can store ~ 5-6 pictures
i
d
c
t
i
d
c
t
Possible Additions
Visual effects such as zoom, rotate, and
blur
„ Watermarked symbol that appears after
processing the image
„
Questions?