# Astronomical Image Processing

AI and Robotics

Nov 6, 2013 (4 years and 6 months ago)

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Astronomical Image Processing

with

Visual Fortran

Outline

Visual Fortran Graphic Control

Histogram Equalization

Pseudocolouring

Sobel

Edge Detector

Laplacian

Edge Detector

Hough Transform

Visual Fortran Graphic Control

32
-
bit RGB color value

SETCOLORRGB

SETBKCOLORRGB

SETPIXELCOLOR

SETPIXELSCOLOR

Visual Fortran Graphic Control

SAVEIMAGE

INTEGERTORGB

RGBTOINTEGER

Image Enhancing Techniques

IMSL 2D Fourier Transform

Histogram Equalization

Gray scale

Full color

RGBTOHSI

HSITORGB

7.1 Visual Fortran
Graphic Control

32
-
bit RGB color value

alpha channel

binary 1111111 = hex FF

#0000FF

full
-
intensity red,

#00FF00

full
-
intensity green,

#FF0000

full
-
intensity blue,

#FFFFFF

setcolorRGB

setcolorRGB.F90

setBKcolorRGB

setBKcolorRGB.F90

SETPIXELCOLOR

SETPIXELCOLOR.F90

SETPIXELSCOLOR

SETPIXELSCOLOR.F90

7.1.2 Image2010

Image2010

result = SAVEIMAGE (
filename
,
ulxcoord
,
ulycoord
,
lrxcoord
,
lrycoord
)

Put
SAVEIMAGE
together

Image2010

CALL INTEGERTORGB (
rgb
, red,
green, blue)

result = RGBTOINTEGER (red,
green, blue)

Put
INTEGERTORGB and
RGBTOINTEGER

together

Image2010

Histogram
Equalization

Pseudocolouring

7.2
Histogram Equalization

7.3 Edge Detection
Algoritms

7.3.1
Prewittt

7.3.2
Sobel

Edge Detector

Extreme and zero crossing

7.3.3
Laplacian

Edge Detector

3 x 3 mask for 4
-
neighborhoods and 8
-
neighborhood

7.3.4
Hough Transform

Generalized Hough transform

Classical Hough transform

features specified in some
parametric forms

tolerant of gaps

relatively unaffected by image
noise

Straight line searching

An N
3

operation!

Representation in parameter space

y = ax +b

Polar representation

y = ax +b

xcosθ + ysinθ = r

Applications

Driver drowsiness

2D Fourier Forward Transform

Backward (Inverse) Transform

4.2 2D Fourier Transform

High/Low pass Filter

The End

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