Department of Computer Science and Engineering, Hanyang University
Digital Image ProcessingDigital Image Processing
Sampling & Quantization
Image Enhancement
Image Restoration
Image Coding( or Image Data Compression)
Image Understanding( or Computer Vision)
Department of Computer Science and Engineering, Hanyang University
Sampling & QuantizationSampling & Quantization
Department of Computer Science and Engineering, Hanyang University
Subsampling & aliasingSubsampling & aliasing
aliasing
Department of Computer Science and Engineering, Hanyang University
Sub-Nyquist samplingSub-Nyquist sampling
H ½, v ½ Org.
Circular Zone Plate
aliasing
Department of Computer Science and Engineering, Hanyang University
Image EnhancementImage Enhancement
Goal to accentuate certain image features for subsequent
analysis or for image display
Input : image Output : image
Department of Computer Science and Engineering, Hanyang University
Image EnhancementImage Enhancement
Techniques contrast/edge enhancement histogram equalization pseudo coloring noise filtering edge sharpening smoothing
Applications processing of remote-sensed image via satellite radar, SAR, Ultrasonic image processing
Department of Computer Science and Engineering, Hanyang University
Image RestorationImage Restoration
Goal to remove or minimize known/unknown degradations in
image
Department of Computer Science and Engineering, Hanyang University
Blur modelBlur model
estimate or recover f(x,y) from g(x,y)
deconvolution problem
modeldiscrete;or
),(),(),;,(),(
nHfg
yxnddfyxhyxg
),( yxn
Department of Computer Science and Engineering, Hanyang University
Enhancement by integrationEnhancement by integration
Department of Computer Science and Engineering, Hanyang University
Image RestorationImage Restoration
Techniques deblurring noise filtering correction of geometric distortion inverse filtering Least mean square(Wiener) filtering
Applications remote-sensed image processing noise cancellation
Department of Computer Science and Engineering, Hanyang University
Image Data CompressionImage Data Compression Goal
to reduce the amount of data required to represent images
Input : image Output : bit-stream data
“010100101100110101001 . . . .”
moving image:1,0001,0008(bits/sample)330 frame/sec = 72107 bit/sec
Department of Computer Science and Engineering, Hanyang University
2-2-D Image Compression, JPEGD Image Compression, JPEG
(a) 27.9 dB at 0.125 bpp (b) 31.5 dB at 0.25 bpp (c) 34.8 dB at 0.5 bpp
Image quality by JPEG
Department of Computer Science and Engineering, Hanyang University
33D Mesh CompressionD Mesh Compression
Original ‘Bunny’
12 bpc 8 bpc10 bpc
Model # of Vertex
# of Triangle
Original (byte)
Compressed (byte)
12 bpc 10 bpc 8 bpc
Bunny 34835 69473 2,879,786 57,952 37,642 24,842
Compression ratio 50 : 1 77 : 1 116 : 1
Department of Computer Science and Engineering, Hanyang University
Image Data CompressionImage Data Compression Techniques
Error-free coding( or lossless coding) Lossy compression Image Compression Standard
JPEG, H.261, H.263, MPEG-1,2,4 etc Applications
Transmission teleconferencing ,TV system, remote sensing via
satellite Storage
VOD(video on demand), Video CD, DVD(digital video disk), medical imaging, educational and business documents
Department of Computer Science and Engineering, Hanyang University
Standard Application Bit rate
JPEG Still-image Variable
H.261 Visual telephony and video conferencing p64 kbps
H.263 < 64 kbps
MPEG-1 Full motion video on digital storage media 1.5 Mbps
MPEG-2 Higher resolution video than MPEG-1 2 Mbps
HDTV Terrestrial broad cast 20 Mbps
Image Coding StandardsImage Coding Standards
Department of Computer Science and Engineering, Hanyang University
MPEGMPEG
MPEG-1 1992 Video CD Includes Audio Layer III (MP3)
MPEG-4 Part 1: 1998 Part 2: 1999 (addition still under development) Audio visual object Mobile telephony (IMT-2000) Interactivity Content –Based Interactivity
Department of Computer Science and Engineering, Hanyang University
MPEG-7 2001 (addition still under development) Content Description Interface Metadata language and schemes for search & retrieval
Department of Computer Science and Engineering, Hanyang University
Content-based Image RetrievalContent-based Image Retrieval
Image retrieval
Find similar images from
image database
Used features
Color
Texture
Shape
Query
Retrieved
Department of Computer Science and Engineering, Hanyang University
Query Image
Image Data List
Retrieval Results
Texture Option
Department of Computer Science and Engineering, Hanyang University
Video retrieval Scene change detection and key frame extraction Extracted key frame from a movie clip
Content-based Video RetrievalContent-based Video Retrieval
Department of Computer Science and Engineering, Hanyang University
Video retrieval Automatic indexing Index from a news sequence
Content-based Video RetrievalContent-based Video Retrieval
Department of Computer Science and Engineering, Hanyang University
Media Framework Tech.Media Framework Tech.
MPEG-21 All electronic creation, delivery and trade of digital
multimedia content Transparent usage of various content types on various
devices connected through various network
Department of Computer Science and Engineering, Hanyang University
WatermarkingWatermarking
the process of embedding information into a host signal without changing perceived characteristics of the host
WatermarkEmbedding
Image/Document
* Filtering* Lossy Compression* Forgery* Cropping & Scaling* Geometric Distortion
WatermarkInformation
WatermarkGeneration
Key
WatermarkDetection
* Copy Protection* Fingerprinting* Authentification
Key
DecodedWatermark
Department of Computer Science and Engineering, Hanyang University
Image UnderstandingImage Understanding
Goal to interpret or describe the meaning contained in the
image
Input : image Output : interpretation(description)
““KAISION”KAISION”
““circle”circle”
Department of Computer Science and Engineering, Hanyang University
Stereo Vision (disparity map)Stereo Vision (disparity map)
기준 영상 ( 좌 ) 기준 영상 ( 우 )
변위 참 값 ( 붉은색 : 가리워짐 )
구한 변위 지도 ( 검은색 : 가리워짐 )
Department of Computer Science and Engineering, Hanyang University
ModelModel image
Input scene
Scene matching result
Scene Matching (1)Scene Matching (1)
Department of Computer Science and Engineering, Hanyang University
Model
Input image Edge image
Scene matching result
Scene Matching (2)Scene Matching (2)
Department of Computer Science and Engineering, Hanyang University
– 크기 , 반지름
Fruit ClassifierFruit Classifier
Apple Orange Water Mellon
Department of Computer Science and Engineering, Hanyang University
Edge Detection
256)(256 Image Original Lena (a) 10) high 5, low 2,(Operator Canny (b)
Department of Computer Science and Engineering, Hanyang University
Segmentation
(a) Aerial Original Image (b) Segmented Image