Scale Invariant Region Selection and SIFT Sung-Eui Yoon ( ) - - PowerPoint PPT Presentation

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Scale Invariant Region Selection and SIFT Sung-Eui Yoon ( ) - - PowerPoint PPT Presentation

CS688: Web-Scale Image Search Scale Invariant Region Selection and SIFT Sung-Eui Yoon ( ) Course URL: http://sgvr.kaist.ac.kr/~sungeui/IR Announcements Parts of my book are updated One of students is invited to each class 5


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CS688: Web-Scale Image Search

Scale Invariant Region Selection and SIFT

Sung-Eui Yoon (윤성의)

Course URL: http://sgvr.kaist.ac.kr/~sungeui/IR

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Announcements

  • Parts of my book are updated
  • One of students is invited to each class
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Class Objectives (Ch. 2.4)

  • Scale invariant region selection
  • Automatic scale selection
  • Laplacian of Gradients (LoG)

Difference of Gradients (DoG)

  • SIFT as a local descriptor
  • At last time, we discussed:
  • Different conferences
  • Image descriptors that are invariant to various

changes

  • Harris corner detector
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Other Descriptors

  • GIST: a kind of SIFT in a global scale
  • SURF: an acceleration using the integral

image, i.e., summed area table

  • CNN features
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80M Tiny Images

  • Just use 32 by 32 images
  • It works well even for recognition with a

simple recognition method (nearest neighbor search) with using 80M data

  • Indicates the importance of data
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PA1 (Optional)

  • Objective
  • Understand how to extract SIFT features and to

use related libraries (OpenCV, vlfeat, … )

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Class Objectives (Ch. 2.4) were:

  • Scale invariant region selection
  • Automatic scale selection
  • Laplacian of Gradients (LoG)

Difference of Gradients (DoG)

  • SIFT as a local descriptor
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Next Time…

  • Basic deep learning and its applications to

computer vision

  • Intro to object recognition
  • Bag-of-Words (BoW) models
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Homework for Every Class

  • Go over the next lecture slides
  • Come up with one question on what we have

discussed today

  • 1 for typical questions (that were answered in the class)
  • 2 for questions with thoughts or that surprised me
  • Write questions 3 times before the mid-term exam
  • Write a question about one out of every four classes
  • Multiple questions in one time will be counted as one time
  • Common questions are compiled at the Q&A file
  • Some of questions will be discussed in the class
  • If you want to know the answer of your question,

ask me or TA on person