Astronomical Image Processing

with Visual Fortran

黃 信 健

OutlineVisual Fortran Graphic Control Histogram EqualizationPseudocolouringSobel Edge DetectorLaplacian Edge DetectorHough Transform

Visual Fortran Graphic Control

32-bit RGB color valueSETCOLORRGBSETBKCOLORRGBSETPIXELCOLORSETPIXELSCOLOR

Visual Fortran Graphic Control

LOADIMAGESAVEIMAGEINTEGERTORGB RGBTOINTEGER

Image Enhancing TechniquesIMSL 2D Fourier Transform

Histogram EqualizationGray scaleFull colorRGBTOHSIHSITORGB

7.1 Visual Fortran Graphic Control

32-bit RGB color value

alpha channelbinary 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 LOADIMAGE

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

Put LOADIMAGE and 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 Algoritms7.3.1 Prewittt Masks

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

①Generalized Hough transform②Classical Hough transform

features specified in some parametric forms

tolerant of gaps relatively unaffected by image

noise

Straight line searching An N3 operation! Representation in parameter spacey = 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 EndNext: sequential and parallel

laplace solvers