java获取图片像素点的RGB值

package com.yang.rm.system;

import java.awt.AWTException;
import java.awt.Dimension;
import java.awt.Rectangle;
import java.awt.Robot;
import java.awt.Toolkit;
import java.awt.image.BufferedImage;
import java.io.File;

import javax.imageio.ImageIO;

public class ReadColorTest {
/**
* 读取一张图片的RGB值
*
* @throws Exception
*/
public void getImagePixel(String image) throws Exception {
int[] rgb = new int[3];
File file = new File(image);
BufferedImage bi = null;
try {
bi = ImageIO.read(file);
} catch (Exception e) {
e.printStackTrace();
}
int width = bi.getWidth();
int height = bi.getHeight();
int minx = bi.getMinX();
int miny = bi.getMinY();
System.out.println("width=" + width + ",height=" + height + ".");
System.out.println("minx=" + minx + ",miniy=" + miny + ".");
for (int i = minx; i < width; i++) {
for (int j = miny; j < height; j++) {
int pixel = bi.getRGB(i, j); // 下面三行代码将一个数字转换为RGB数字
rgb[0] = (pixel & 0xff0000) >> 16;
rgb[1] = (pixel & 0xff00) >> 8;
rgb[2] = (pixel & 0xff);
System.out.println("i=" + i + ",j=" + j + ":(" + rgb[0] + ","
+ rgb[1] + "," + rgb[2] + ")");
}
}
}

/**
* 返回屏幕色彩值
*
* @param x
* @param y
* @return
* @throws AWTException
*/
public int getScreenPixel(int x, int y) throws AWTException { // 函数返回值为颜色的RGB值。
Robot rb = null; // java.awt.image包中的类，可以用来抓取屏幕，即截屏。
rb = new Robot();
Toolkit tk = Toolkit.getDefaultToolkit(); // 获取缺省工具包
Dimension di = tk.getScreenSize(); // 屏幕尺寸规格
System.out.println(di.width);
System.out.println(di.height);
Rectangle rec = new Rectangle(0, 0, di.width, di.height);
BufferedImage bi = rb.createScreenCapture(rec);
int pixelColor = bi.getRGB(x, y);

return 16777216 + pixelColor; // pixelColor的值为负，经过实践得出：加上颜色最大值就是实际颜色值。
}

/**
* @param args
*/
public static void main(String[] args) throws Exception {
int x = 0;
ReadColorTest rc = new ReadColorTest();
x = rc.getScreenPixel(100, 345);
System.out.println(x + " - ");
rc.getImagePixel("D:\\car.jpg");
}

}

i=76,j=554:(189,157,118)
i=76,j=555:(171,139,100)
i=76,j=556:(176,144,105)
i=76,j=557:(183,153,117)
i=76,j=558:(172,145,115)
i=76,j=559:(114,87,57)
i=76,j=560:(156,127,93)
i=76,j=561:(173,143,105)
i=76,j=562:(164,132,94)
i=76,j=563:(170,138,99)
i=76,j=564:(170,136,99)
i=76,j=565:(167,135,97)
i=76,j=566:(174,144,108)
i=76,j=567:(158,128,90)
i=76,j=568:(183,151,112)
i=76,j=569:(185,153,115)
i=76,j=570:(206,177,145)
i=76,j=571:(134,107,78)
i=76,j=572:(113,88,58)
i=76,j=573:(190,165,135)
i=76,j=574:(154,130,104)
i=76,j=575:(94,68,41)
i=76,j=576:(182,151,120)
i=76,j=577:(190,157,122)
i=76,j=578:(170,137,102)
i=76,j=579:(167,136,105)
i=76,j=580:(149,123,98)
i=76,j=581:(91,69,46)
i=76,j=582:(134,109,89)
i=76,j=583:(139,114,94)
i=76,j=584:(127,102,80)
i=76,j=585:(126,101,81)
i=76,j=586:(111,85,68)
i=76,j=587:(111,85,70)
i=76,j=588:(113,88,68)
i=76,j=589:(119,94,72)
i=76,j=590:(142,118,92)
i=76,j=591:(140,116,88)
i=76,j=592:(151,127,101)
i=76,j=593:(86,64,41)
i=76,j=594:(103,82,65)
i=76,j=595:(114,93,76)
i=76,j=596:(110,85,63)
i=76,j=597:(166,139,110)
i=76,j=598:(172,142,108)
i=76,j=599:(139,107,69)
i=76,j=600:(173,141,100)
i=76,j=601:(205,172,131)
i=76,j=602:(142,108,71)
i=76,j=603:(201,168,133)
i=76,j=604:(165,134,103)
i=76,j=605:(136,109,79)
i=76,j=606:(147,122,92)
i=76,j=607:(144,118,91)
i=76,j=608:(142,116,93)
i=76,j=609:(140,114,91)
i=76,j=610:(121,94,67)
i=76,j=611:(168,139,109)
i=76,j=612:(159,126,91)
i=76,j=613:(167,133,95)
i=76,j=614:(191,154,110)
i=76,j=615:(197,159,120)
i=76,j=616:(198,167,136)
i=76,j=617:(102,76,51)
i=76,j=618:(110,89,72)
i=76,j=619:(116,97,83)
i=76,j=620:(127,109,95)
i=76,j=621:(92,74,62)
i=76,j=622:(102,85,75)
i=76,j=623:(94,80,71)
i=76,j=624:(96,81,74)
i=76,j=625:(95,80,73)
i=76,j=626:(107,90,82)
i=76,j=627:(99,82,74)
i=76,j=628:(100,83,73)
i=76,j=629:(110,93,83)
i=76,j=630:(105,88,78)
i=76,j=631:(104,90,81)