A Novel Multiresolution Spatiotemporal Saliency Detection Model and Its Applications in Image and...
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- Slide 1
- A Novel Multiresolution Spatiotemporal Saliency Detection Model
and Its Applications in Image and Video Compression Chenlei Guo
Liming Zhang Image Processing 2010
- Slide 2
- Outline Introduction Phase Spectrum of Quaternion Fourier
Transform (PQFT) Detect Proto-Objects in the Spatiotemporal
Saliency Map Hierarchical Selectivity (HS) Experiment Result
Applications in Image and Video Coding Conclusions and
Discussions
- Slide 3
- Introduction Most traditional object detectors need training
Graph-based visual saliency detection can be very powerful but it
demands a very high computational cost Most of the models only
consider static images
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- Phase Spectrum of Quaternion Fourier Transform(PQFT) (1/3)
Locations with less periodicity or less homogeneity create pop out
proto objects in the reconstruction of the images phase spectrum An
early saliency detection model : PFT
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- Quaternion Representation (2/3) Define the input image captured
at time t as F(t) r(t), g(t), b(t) are color channels of F(t)
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- Calculate the Saliency Map By PQFT (3/3) 2-D gaussian
filter
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- Detect Proto-Objects (1/3)
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- Alpha (2/3)
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- Gamma (3/3)
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- How PQFT Select Visual Resolution PQFT simulates the human
vision system(HVS)
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- Hierarchical Selectivity Set hierarchical level
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- Experiment Results Video Sequence Natural Images Psychological
Patterns
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- Video Sequence (1/3)
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- Video Sequence (2/3)
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- Video Sequence (3/3)
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- Natural Image
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- Evaluation Method - ROC True Positive Rate(TPR), False Positive
Rate(FPR) Receiver Operating Characteristic (ROC) ROC curve =
TPR/FPR ROC area = area beneath ROC curve The larger ROC area is,
the better the prediction power of a saliency map.
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- Psychological Patterns (1/3)
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- Psychological Patterns (2/3)
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- Psychological Patterns (3/3)
- Slide 21
- Applications in Image and Video Coding Multiresolution Wavelet
Domain Foveation Model (MWDF) Evaluate the performance of the
HS-MWDF model in Image and video compression
- Slide 22
- Multiresolution Wavelet Domain Foveation Model (MWDF) JPEG 2000
has included the region-of-interest(RoI) coding in drafts A better
way to find RoI:use Hierarchical Selectivity
- Slide 23
- Multiresolution Wavelet Domain Foveation Model (MWDF)
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- The Performance of HS-MWDF in Image Compression We use HS-MWDF
model as a front end before standard compression (JPEG 2000) Set n
fov => we only use the first n OCAs found by PQFT Auto fov =>
let the program itself decide the number
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- The Performance of HS-MWDF in Video Compression
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- Conclusion and Discussion Extend PFT model to PQFT model PQFT
model is independent of parameters and prior knowledge, and is fast
enough to meet real- time requirements Develop a model called
HS-MWDF as a front end before the image/video encoder Problems:
Cant deal with closure patterns well Only considers bottom-up
information Insert the model into the image/video encoders
- Slide 28
- References