1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
|
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BoxLayout;
import javax.swing.ImageIcon;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import org.opencv.core.Core;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.highgui.HighGui;
import org.opencv.imgcodecs.Imgcodecs;
class ChangingContrastBrightnessImage {
private static int MAX_VALUE_ALPHA = 500;
private static int MAX_VALUE_BETA_GAMMA = 200;
private static final String WINDOW_NAME = "Changing the contrast and brightness of an image demo";
private static final String ALPHA_NAME = "Alpha gain (contrast)";
private static final String BETA_NAME = "Beta bias (brightness)";
private static final String GAMMA_NAME = "Gamma correction";
private JFrame frame;
private Mat matImgSrc = new Mat();
private JLabel imgSrcLabel;
private JLabel imgModifLabel;
private JPanel controlPanel;
private JPanel alphaBetaPanel;
private JPanel gammaPanel;
private double alphaValue = 1.0;
private double betaValue = 0.0;
private double gammaValue = 1.0;
private JCheckBox methodCheckBox;
private JSlider sliderAlpha;
private JSlider sliderBeta;
private JSlider sliderGamma;
public ChangingContrastBrightnessImage(String[] args) {
String imagePath = args.length > 0 ? args[0] : "../data/lena.jpg";
matImgSrc = Imgcodecs.imread(imagePath);
if (matImgSrc.empty()) {
System.out.println("Empty image: " + imagePath);
System.exit(0);
}
// Create and set up the window.
frame = new JFrame(WINDOW_NAME);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// Set up the content pane.
Image img = HighGui.toBufferedImage(matImgSrc);
addComponentsToPane(frame.getContentPane(), img);
// Use the content pane's default BorderLayout. No need for
// setLayout(new BorderLayout());
// Display the window.
frame.pack();
frame.setVisible(true);
}
private void addComponentsToPane(Container pane, Image img) {
if (!(pane.getLayout() instanceof BorderLayout)) {
pane.add(new JLabel("Container doesn't use BorderLayout!"));
return;
}
controlPanel = new JPanel();
controlPanel.setLayout(new BoxLayout(controlPanel, BoxLayout.PAGE_AXIS));
methodCheckBox = new JCheckBox("Do gamma correction");
methodCheckBox.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
JCheckBox cb = (JCheckBox) e.getSource();
if (cb.isSelected()) {
controlPanel.remove(alphaBetaPanel);
controlPanel.add(gammaPanel);
performGammaCorrection();
frame.revalidate();
frame.repaint();
frame.pack();
} else {
controlPanel.remove(gammaPanel);
controlPanel.add(alphaBetaPanel);
performLinearTransformation();
frame.revalidate();
frame.repaint();
frame.pack();
}
}
});
controlPanel.add(methodCheckBox);
alphaBetaPanel = new JPanel();
alphaBetaPanel.setLayout(new BoxLayout(alphaBetaPanel, BoxLayout.PAGE_AXIS));
alphaBetaPanel.add(new JLabel(ALPHA_NAME));
sliderAlpha = new JSlider(0, MAX_VALUE_ALPHA, 100);
sliderAlpha.setMajorTickSpacing(50);
sliderAlpha.setMinorTickSpacing(10);
sliderAlpha.setPaintTicks(true);
sliderAlpha.setPaintLabels(true);
sliderAlpha.addChangeListener(new ChangeListener() {
@Override
public void stateChanged(ChangeEvent e) {
alphaValue = sliderAlpha.getValue() / 100.0;
performLinearTransformation();
}
});
alphaBetaPanel.add(sliderAlpha);
alphaBetaPanel.add(new JLabel(BETA_NAME));
sliderBeta = new JSlider(0, MAX_VALUE_BETA_GAMMA, 100);
sliderBeta.setMajorTickSpacing(20);
sliderBeta.setMinorTickSpacing(5);
sliderBeta.setPaintTicks(true);
sliderBeta.setPaintLabels(true);
sliderBeta.addChangeListener(new ChangeListener() {
@Override
public void stateChanged(ChangeEvent e) {
betaValue = sliderBeta.getValue() - 100;
performLinearTransformation();
}
});
alphaBetaPanel.add(sliderBeta);
controlPanel.add(alphaBetaPanel);
gammaPanel = new JPanel();
gammaPanel.setLayout(new BoxLayout(gammaPanel, BoxLayout.PAGE_AXIS));
gammaPanel.add(new JLabel(GAMMA_NAME));
sliderGamma = new JSlider(0, MAX_VALUE_BETA_GAMMA, 100);
sliderGamma.setMajorTickSpacing(20);
sliderGamma.setMinorTickSpacing(5);
sliderGamma.setPaintTicks(true);
sliderGamma.setPaintLabels(true);
sliderGamma.addChangeListener(new ChangeListener() {
@Override
public void stateChanged(ChangeEvent e) {
gammaValue = sliderGamma.getValue() / 100.0;
performGammaCorrection();
}
});
gammaPanel.add(sliderGamma);
pane.add(controlPanel, BorderLayout.PAGE_START);
JPanel framePanel = new JPanel();
imgSrcLabel = new JLabel(new ImageIcon(img));
framePanel.add(imgSrcLabel);
imgModifLabel = new JLabel(new ImageIcon(img));
framePanel.add(imgModifLabel);
pane.add(framePanel, BorderLayout.CENTER);
}
private void performLinearTransformation() {
Mat img = new Mat();
matImgSrc.convertTo(img, -1, alphaValue, betaValue);
imgModifLabel.setIcon(new ImageIcon(HighGui.toBufferedImage(img)));
frame.repaint();
}
private byte saturate(double val) {
int iVal = (int) Math.round(val);
iVal = iVal > 255 ? 255 : (iVal < 0 ? 0 : iVal);
return (byte) iVal;
}
private void performGammaCorrection() {
//! [changing-contrast-brightness-gamma-correction]
Mat lookUpTable = new Mat(1, 256, CvType.CV_8U);
byte[] lookUpTableData = new byte[(int) (lookUpTable.total()*lookUpTable.channels())];
for (int i = 0; i < lookUpTable.cols(); i++) {
lookUpTableData[i] = saturate(Math.pow(i / 255.0, gammaValue) * 255.0);
}
lookUpTable.put(0, 0, lookUpTableData);
Mat img = new Mat();
Core.LUT(matImgSrc, lookUpTable, img);
//! [changing-contrast-brightness-gamma-correction]
imgModifLabel.setIcon(new ImageIcon(HighGui.toBufferedImage(img)));
frame.repaint();
}
}
public class ChangingContrastBrightnessImageDemo {
public static void main(String[] args) {
// Load the native OpenCV library
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
// Schedule a job for the event dispatch thread:
// creating and showing this application's GUI.
javax.swing.SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
new ChangingContrastBrightnessImage(args);
}
});
}
}
|
