Image Processing in Java

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Image Processing in Java

• lyon

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Introduction

• Observer-observable DPs
• Review of HW solution
• Input of values to the system

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Agenda
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Overview

• public int filterRGB (int rgb)
• int red (rgb 0xff0000) gtgt16
• int green (rgb 0xff00) gtgt 8
• int blue rgb 0xff
• int gray (red green blue) / 3
• return (
• 0xff000000
• (gray ltlt 16)
• (gray ltlt 8) gray)

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Review of Arrays
public static void print(double a) for
(int i 0 i lt a.length i) for (int j
0 j lt a0.length j) System.out.print(ai
j" ") System.out.println()
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Row-Major
If arrays are row major, then increment the row
more quickly public void print() for
(int j 0 j lt 3 j) for (int i
0 i lt 3 i)
System.out.print(aij" ")
System.out.println()
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Row vs Column Major
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Simulating 2D arrays
public int getPixel(int x, int y) return
pelsywidth x
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Drawing in Java
public void repaint() public void repaint(long
t) public void repaint(int x, int y, int w, int
h) public void repaint(long t, int x, int y, int
w, int h)
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Damage Control
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ImageFrame-a series of methods that ease image
processing
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• public class ImageFrame extends ShortCutFrame
• public short r
• public short g
• public short b
• public int width 128
• public int height 128
• public ImageFrame(String title)
• public void setImage(Image i)
• public Image getImage()
• public void short2Image()
• public void image2Short()
• public void openGif()
• public void openGif(String fn)
• public static void main(String args)

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FilterFrame-Sample
26. public void gray() 27. for (int x0
x lt width x) 28. for (int y0 y lt
height y) 29. rxy (short) 30.
((rxy gxy bxy) /
3) 31. gxy rxy 32.
bxy rxy 33. 34.
short2Image() 35.
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TestPatterns
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SnellWlx
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GrabFrame

• public class GrabFrame extends FilterFrame
• public void grab(Container f)
• public void testPattern()

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TestPattern
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Homogeneous Point Processing

• Every point is treated the same
• Input size of image is same as output size
• Good application of statistics!

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PMF

• Add the total number of pixels of a particular
  value
• Divide by the total number of pixels

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Rules of Prob.

• Sum of all probs1
• CMF is sum of all values up to a point.

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Histogram Computations
histArray new double256 for (int i0
iltwidth i) for (int j0 j lt height
j) histArrayplaneij 0xFF
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Normalization of PMF
double max 0.0 for(int i0 ilt256
i) if (histArrayi gt max)
max histArrayi // Normalize
for(int i0 ilt256 i) histArrayi
(histArrayi / max)
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The Histogram of the Image
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Summary of Histogram
package gui public class Histogram extends
ClosableFrame public double getPMF()
public double getCMF() public void
printPMF() public void show() public
Histogram(short plane, String title)
public void paint(Graphics g)
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Linear Map and Sample Image
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Negating an Image
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Implementation
for (int y0 y lt height y) rxy
(short) (255 - rxy) gxy
(short) (255 - gxy) bxy
(short) (255 - bxy) short2Image()
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Power law and image processing
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Washed out images can result
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1.5 exponentdarkening
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Darkening Image
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Darkening and the Histogram
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Implementing the power xform
public void powImage(double p) for (int x0
x lt width x) for (int y0 y lt height
y) rxy (short)
(255 Math.pow((rxy/255.0),p))
gxy (short) (255
Math.pow((gxy/255.0),p)) bxy
(short) (255
Math.pow((bxy/255.0),p))
short2Image()
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Changing Brightness and Contrast
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Linear eq and histogram
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Brightening and image
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Computing parameters automatically
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UNAHE
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The CMF
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Adaptive Equalization
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Histogram an AUHE
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LUT Implementation
package gui   public class TransformTable
public TransformTable(int size) public short
getLut() public void setLut(short lut)
public void print()
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The NegateFrame
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Computing Averages
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Two kinds of methods for altering an image

• The direct methods
• The indirect methods.
• The direct methods employ a mapping function,
• Mapping functions are applied to the color planes.

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Indirect Methods

• The indirect method use statistical properties
• Two Kinds of Indirect Methods
• adaptive and nonadaptive