绘制图形直方图 [英] Drawing a graphical histogram
本文介绍了绘制图形直方图的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我正在研究一个项目，我希望显示一个看起来像条形图的单线直方图，条形图中的每一行代表一个像素及其灰度值。
我有一个充满灰度值的数组，我只需要将它们放入这个直方图中并让它显示代表值的行..有点像这样
IMAGE [最小化] [最大化] [关闭]
图片直方图
我
（已加载图片）II
III
IIII
[开放] [保存]
以下是加载数组的代码......我只需要获得一些代码，这些代码将使用这些灰度值并将它们表示为上面的条形。
public void showImage（File fileName）{
Scanner scan;
try {
scan = new Scanner（fileName）;
typefile = scan.next（）;
iname = scan.next（）;
width = scan.nextInt（）;
height = scan.nextInt（）;
maxshade = scan.nextInt（）;
array = new int [width] [height];
for（int r = 0; r< array.length; r ++）{
for（int c = 0; c< array [r] .length; c ++）{
array [r] [c] = scan.nextInt（）;
imageArray = array;
repaint（）;
} catch（FileNotFoundException e）{
e.printStackTrace（）;
}
}
我知道我必须做点什么喜欢......
int hist [] = new int [256];
for（int r = 0; r< array.length; r ++）
for（int c = 0; c< array [r] .length; c ++）
hist [array [R] [C]] ++;
但我不知道从那里去哪里或如何绘制图表。
解决方案
类似
也许??
<个人而言，我仍然使用 JFreeChart 之类的东西，但这是一个有趣的小练习。 。
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.geom.Rectangle2D;
import java.util.Map;
import java.util.TreeMap;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
公共类TestHisogram {
//http://stackoverflow.com/a/12520104/714968
public static void main（String [] args）{
EventQueue.invokeLater（新的Runnable（）{
@覆盖
公共无效的run（）{
新TestHisogram（）;
}
}）;
}
public TestHisogram（）{
//对于这个例子，我只是随机化了一些数据，你需要
//需要自己加载它...
int width = 256;
int height = 256;
int [] [] data = new int [width] [height];
for（int c = 0; c< height; c ++）{
for（int r = 0; r< width; r ++）{
data [c] [r] = （int）（256 * Math.random（））;
}
}
地图<整数，整数> mapHistory = new TreeMap< Integer，Integer>（）;
for（int c = 0; c< data.length; c ++）{
for（int r = 0; r< data [c] .length; r ++）{
int value = data [c] [r];
int amount = 0;
if（mapHistory.containsKey（value））{
amount = mapHistory.get（value）;
金额++;
}其他{
金额= 1;
}
mapHistory.put（value，amount）;
}
}
JFrame frame = new JFrame（Test）;
frame.setDefaultCloseOperation（JFrame.EXIT_ON_CLOSE）;
frame.setLayout（new BorderLayout（））;
frame.add（new JScrollPane（new Graph（mapHistory）））;
frame.pack（）;
frame.setLocationRelativeTo（null）;
frame.setVisible（true）;
}
protected class图扩展JPanel {
protected static final int MIN_BAR_WIDTH = 4;
private Map< Integer，Integer> mapHistory;
public Graph（Map< Integer，Integer> mapHistory）{
this.mapHistory = mapHistory;
int width =（mapHistory.size（）* MIN_BAR_WIDTH）+ 11;
尺寸minSize = new尺寸（宽度，128）;
Dimension prefSize = new Dimension（width，256）;
setMinimumSize（minSize）;
setPreferredSize（prefSize）;
}
@Override
protected void paintComponent（Graphics g）{
super.paintComponent（g）;
if（mapHistory！= null）{
int xOffset = 5;
int yOffset = 5;
int width = getWidth（） - 1 - （xOffset * 2）;
int height = getHeight（） - 1 - （yOffset * 2）;
Graphics2D g2d =（Graphics2D）g.create（）;
g2d.setColor（Color.DARK_GRAY）;
g2d.drawRect（xOffset，yOffset，width，height）;
int barWidth = Math.max（MIN_BAR_WIDTH，
（int）Math.floor（（float）width
/（float）mapHistory.size（）））;
System.out.println（width =+ width +; size =
+ mapHistory.size（）+; barWidth =+ barWidth）;
int maxValue = 0;
for（整数键：mapHistory.keySet（））{
int value = mapHistory.get（key）;
maxValue = Math.max（maxValue，value）;
}
int xPos = xOffset;
for（整数键：mapHistory.keySet（））{
int value = mapHistory.get（key）;
int barHeight = Math.round（（（float）value
/（float）maxValue）* height）;
g2d.setColor（new Color（key，key，key））;
int yPos = height + yOffset - barHeight;
//矩形条=新矩形（xPos，yPos，barWidth，barHeight）;
Rectangle2D bar = new Rectangle2D.Float（
xPos，yPos，barWidth，barHeight）;
g2d.fill（bar）;
g2d.setColor（Color.DARK_GRAY）;
g2d.draw（bar）;
xPos + = barWidth;
}
g2d.dispose（）;
}
}
}
}
I am working on a project and I would like to display a single line histogram that looks like a bar graph except each line in the bar graph represents a pixel and its greyscale value.
I have a array full of greyscale values, I just need to put them into this histogram and have it display the lines which will represent the values.. sort of like this
IMAGE [minimize][maximize][close]
picture histogram
I
(Loaded Picture) I I
I I I
I I I I
[open][save]
And below is the code loading the array... I just need to get some code that will use those greyscale values and represent them as bars like above.
public void showImage(File fileName) {
Scanner scan;
try {
scan = new Scanner(fileName);
typefile = scan.next();
iname = scan.next();
width = scan.nextInt();
height = scan.nextInt();
maxshade = scan.nextInt();
array = new int[width][height];
for(int r = 0; r < array.length; r++){
for(int c = 0; c < array[r].length; c++){
array[r][c] = scan.nextInt();
imageArray = array;
repaint();
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
I know I have to do something like...
int hist[] = new int[256];
for (int r = 0; r < array.length; r++)
for (int c = 0; c < array[r].length; c++)
hist[array[r][c]]++;
But I don't know where to go from there or how to draw my graph.
解决方案
Something like
Perhaps??
Personally, I'd still use something like JFreeChart, but this was a fun little exercise...
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.geom.Rectangle2D;
import java.util.Map;
import java.util.TreeMap;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
public class TestHisogram {
//http://stackoverflow.com/a/12520104/714968
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
new TestHisogram();
}
});
}
public TestHisogram() {
// For this example, I just randomised some data, you would
// Need to load it yourself...
int width = 256;
int height = 256;
int[][] data = new int[width][height];
for (int c = 0; c < height; c++) {
for (int r = 0; r < width; r++) {
data[c][r] = (int) (256 * Math.random());
}
}
Map<Integer, Integer> mapHistory = new TreeMap<Integer, Integer>();
for (int c = 0; c < data.length; c++) {
for (int r = 0; r < data[c].length; r++) {
int value = data[c][r];
int amount = 0;
if (mapHistory.containsKey(value)) {
amount = mapHistory.get(value);
amount++;
} else {
amount = 1;
}
mapHistory.put(value, amount);
}
}
JFrame frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new JScrollPane(new Graph(mapHistory)));
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
protected class Graph extends JPanel {
protected static final int MIN_BAR_WIDTH = 4;
private Map<Integer, Integer> mapHistory;
public Graph(Map<Integer, Integer> mapHistory) {
this.mapHistory = mapHistory;
int width = (mapHistory.size() * MIN_BAR_WIDTH) + 11;
Dimension minSize = new Dimension(width, 128);
Dimension prefSize = new Dimension(width, 256);
setMinimumSize(minSize);
setPreferredSize(prefSize);
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (mapHistory != null) {
int xOffset = 5;
int yOffset = 5;
int width = getWidth() - 1 - (xOffset * 2);
int height = getHeight() - 1 - (yOffset * 2);
Graphics2D g2d = (Graphics2D) g.create();
g2d.setColor(Color.DARK_GRAY);
g2d.drawRect(xOffset, yOffset, width, height);
int barWidth = Math.max(MIN_BAR_WIDTH,
(int) Math.floor((float) width
/ (float) mapHistory.size()));
System.out.println("width = " + width + "; size = "
+ mapHistory.size() + "; barWidth = " + barWidth);
int maxValue = 0;
for (Integer key : mapHistory.keySet()) {
int value = mapHistory.get(key);
maxValue = Math.max(maxValue, value);
}
int xPos = xOffset;
for (Integer key : mapHistory.keySet()) {
int value = mapHistory.get(key);
int barHeight = Math.round(((float) value
/ (float) maxValue) * height);
g2d.setColor(new Color(key, key, key));
int yPos = height + yOffset - barHeight;
//Rectangle bar = new Rectangle(xPos, yPos, barWidth, barHeight);
Rectangle2D bar = new Rectangle2D.Float(
xPos, yPos, barWidth, barHeight);
g2d.fill(bar);
g2d.setColor(Color.DARK_GRAY);
g2d.draw(bar);
xPos += barWidth;
}
g2d.dispose();
}
}
}
}
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