Image Processing and Analysis

Image Processing

Agenda

• Gray-Level Operations– Look-up Tables– Brightness and Contrast

• Color Space Operations

• Frequency Filtering

• Basic Morphology

• Particle Filtering and Parameters

• Gray-Level Morphology

Modifying Gray Values

Gray Level Perception (1)

Gray Level Perception (2)

Creating LuT (Look-up Tables)

LuT: Linear

LuT: Logarithmic

LuT: Exponential

LuT: Square

LuT: Square Root

LuT: Power x

LuT: Power 1/x

LuT: Equalize

LuT: Inverse

Exercise 4.4

Brightness and Contrast

Exercise 4.5

Color Models: RGB

Source: Adobe Technical Guides

Color Models: HSL (HSI)

Source: Adobe Technical Guides

Converting RGB to HSL (HSI)

Example: NI Vision Assistant

Example: LabVIEW

Spatial Image Filtering

FilterKernel

Filter Kernel Impact (Smoothing)

97 108 42 58 56

67 73 56 81 50

58 67 75 65 65

50 67 50 16 73

34 34 40 252 255

New value: 99

Filter Kernel Impact

Exercise 4.7

• Kernel Families:– Smoothing– Gaussian– Gradient– Laplacian

Smoothing Filter

Gaussian Filter

Gradient Filter (0)

PrewittKernel

Gradient Filter (1)

Gradient Filter (4)

PrewittKernel

Gradient Filter: Sobel Kernel

Laplace Filter (0)

Laplace Filter (1)

Laplace Filter (6)

Laplace Filter (7)

Frequency Filtering

FFT Spectrum (Image)

Exercise 4.8

Standard and Optical Display

FFT Truncate (Low Pass)

Exercise 4.9

FFT Truncate (High Pass)

FFT Attenuate (Low Pass)

FFT Attenuate (High Pass)

Morphology Functions

Thresholding

Erosion

Binary Morphology: Structuring Element

Structuring Element Configuration

1 1 1 1 1 0 0 0 0 0 0 01 1 1 1 1 1 0 0 0 0 0 01 1 1 1 1 1 0 0 0 0 0 01 1 1 1 1 1 1 0 0 0 0 01 1 1 1 1 1 1 0 0 0 0 01 1 1 1 1 1 1 0 0 0 0 01 1 1 1 1 1 1 0 0 0 0 01 1 1 1 1 1 1 0 0 0 0 01 1 1 1 1 1 0 0 0 0 0 01 1 1 1 1 1 0 0 0 0 0 01 1 1 1 1 1 0 0 0 0 0 01 1 1 1 1 1 0 0 0 0 0 0

Exercise 4.13

Dilation

Opening

Closing

Proper Opening

Proper Closing

Hit-Miss Function

Hit-Miss Function (2)

Inner Gradient (Internal Edge)

Outer Gradient (External Edge)

Total Gradient

Thinning

Thickening

Auto-Median

Outline

• Gray Values and Look-up Tables (LuTs)

• Color Spaces and Models

• Spatial Filtering

• Frequency Filtering

• Basic Morphology

• Particle Filtering and Parameters

• Gray Level Morphology

Remove Particle: Low Pass

Remove Particle: High Pass

Exercise 4.14

Reject Border

Exercise 4.15

Particle Filtering

Exercise 4.16

Basic Particle Analysis

Complex Particle Analysis

Particle Parameter

Fill Holes

Exercise 4.17

Convex

Exercise 4.18

Separation

Exercise 4.19

Skeleton L

Exercise 4.20

Skeleton M

Skiz Function

Outline

• Gray Values and Look-up Tables (LuTs)

• Color Spaces and Models

• Spatial Filtering

• Frequency Filtering

• Basic Morphology

• Particle Filtering and Parameters

• Gray Level Morphology

Gray-Level Erosion

Exercise 4.21

Gray-Level Dilation

Square and Hexagon

Gray-Level Opening

Gray-Level Closing

Gray-Level Proper Open

Gray-Level Proper Close