[Multimedia] 기말고사 개념 정리

 

Lecture 12. Curve and Spline

• Curve
  • Bezier Curve
    • Linear
    • Quadratic
    • Cubic
    • High-order Bezier Curve
      • Limitation
        • 직관적인 제어 불가능
        • Runge's Phenomenon
    • de Casteljau Algorithm
    • Tesslation
• Spline
  • Interpolation
    • Hermite Spline, Catmull-Rom Spline
  • Approximation
    • Bezier Spline
  • Hermite Spline
    • Cubic Hermite Spline
      • Cubic Bezier Curve -> Cubic Hermite Curve 유도 방법
        • Step 1. 파스칼 삼각형으로 계수 구하기
        • Step 2. de Casteljau Algorithm으로 $p(t)$ 구하기
        • Step 3. t로 1차 미분한 p(t)' 구하기
        • Step 4. $ v_0 = p'(t = 0), \quad v_3 = p'(t = 1) $ 구하기
        • Step 5. $p(t)$의 $p_1, p_2$에 대입 후 정리
  • Catmull-Rom Spline 

 

Lecture 13. Image Data Representation

• Images
  • Black & White Image
    • 1 bit per pixel
  • Grayscale Image
    • 8 bits per pixel
  • RGB Image
    • 24 bits per pixel

 

Lecture 14. Human Visual System

• Retina
  • Rod (간상체)
  • Cone (추상체)
    • Tri-stimulus: L (long), M (middle), S (short) 
  • Purkinje Shift (푸르기녜 변환)
• Visual Signal Processing
  • Optic pathway 
  • Receptive fields
    • Center-Surround
• Trichromatic Theory (삼원색 이론)
  • Cone cells: L, M, S
• Hering's Opponent-Colors Theory (대응색 이론)
  • Afterimages (잔상 효과)
• Modern Opponent-Colors Theory (현대 대응색 이론)
• Adaptation (순응)
  • Dark Adaptation (암순응)
    • Rod cell 활성화, 20~30분 소요
  • Light Adaptation (명순응)
    • Cone cell 활성화, 몇 초 소요
  • Chromatic Adaptation (색순응)
• Contrast Sensitivity (대비 민감도)
  • Luminance > Color
• Psychophysics
  • Weber's Law (베버의 법칙) 
    • $\Delta I / I = k$
  • Fechnner's Law (페히너의 법칙)
    • $S = k \ln(I) + C$
  • Stevens' Power Law (스티븐슨의 멱법칙)
    •  $S = k \cdot I^n$

 

Lecture 15. Colorimetry

• Color Apeearance Terminology
  • Color and Hue
    
    • Color (색상)
    • Hue (색조)
  • Brightness and Lightness
    • Luminance (휘도)
    • Brightness (명도)
    • Lightness (밝기)
  • Colorfulness, Chorma and Saturation
    • Colorfulness (선명도)
    • Chroma (채도)
    • Saturation (채도)
  • Color Materials
    • Absorption (흡수)
    • Reflection (반사)
    • Transmission (굴절)
  • Colored Materials Measurement
    • CIE 0/45 geometry
    • CIE 45/0 geometry
  • Metamerism
  • CIE 1931 Colorimetry
    • CIE Standard Observer
    • 2° Observer (2도 관찰자)
    • Color Matching Experiment (등색 실험)
      • RGB -> XYZ
        • Tristimulus Value (삼자극치)
    • CIE 1931 Chromaticity Diagrams (2차원 색도도)
  • CIE 1976 Uniform Chromaticity Scales
  • CIE LAB

 

Lecture 16. Color System, Model and Space

• Color System
  • Munsell Color System
    • H (Hue), V (Value), C (Chroma)
• Color Space
  • RGB Color Spaces
• Color Model
  • RGB Color Model
  • YUV Color Model
    • Y (Luminance), UV (Chrominance)
  • HSV Color Model
    • H (Hue), S (Saturation), V (Value)

 

Lecture 17.Color Appearance Phenomena

• Color Appearance Phenomena
• Simultaneous Contrast (동시 대비)
• Crispening (수축)
• Spreading (동화 현상)
• Bezold-Brucke Shift (베졸트-브뤼케 효과)
• Abney Effect (애브니 효과)
• Helmholtz-Kohlrausch Effect (헬름홀츠-콜라우슈 효과)
• Hunt Effect (헌트 효과)
• Stevens Effect (스티븐스 효과)
• Bartleson-Breneman Effect (바틀슨-브레네만 효과)
• Context and Structural Effects (구조적 효과)
• Color Constancy (색채 항상성)