-4
我是Java的初學者。目前我想分析兩個相似的圖像，並檢查圖像在位置2和4處是否具有不同的像素值。我已經開發了一些代碼，但是在運行時，代碼會產生錯誤，並且不會循環並檢查所有像素值兩個圖像。分析兩個相似圖像上的像素值時發生錯誤
例如，在第9個像素中，位置2和4處的圖像B像素值與圖像A像素值不同。然後，只要代碼注意到兩個圖像像素值之間的差異，它就會輸出說明像素不相同的語句。
下面的代碼：
public class getPixelRGB1
{
private static String[][] img_hex2;
private static String[][] img_hex4;
private static String[][] img2_hex2;
private static String[][] img2_hex4;
public static void main(String[] args) throws IOException
{
FileInputStream image = null;
FileInputStream image2 = null;
getPixelData1 newPD = new getPixelData1();
compareHexaRGB hexRGB = new compareHexaRGB();
try {
BufferedImage img, img2;
File file = new File("eye1.jpg");
File file2 = new File("eye2.jpg");
image = new FileInputStream(file);
image2 = new FileInputStream(file2);
img = ImageIO.read(image);
img2 = ImageIO.read(image2);
int rowcol;
int width = img.getWidth();
int height = img.getHeight();
hexRGB.compareHexaRGB(width, height);
System.out.println("Image's Width: " + width);
System.out.println("Image's Height: " + height);
//hexRGB.check();
int[][] pixelData = new int[width * height][3];
System.out.println("Pixel Data: " + pixelData);
int[] rgb;
int count = 0;
img_hex2 = new String[width][height];
img_hex4 = new String[width][height];
for(int i=0; i<width; i++)
{
for(int j=0; j<height; j++)
{
rgb = newPD.getPixelData(img, i, j);
for(int k = 0; k < rgb.length; k++)
{
pixelData[count][k] = rgb[k];
//img_hex2[i][j] = newPD.getHexa2();
//img_hex4[i][j] = newPD.getHexa4();
}
img_hex2[width][height] = newPD.getHexa2();
img_hex4[width][height] = newPD.getHexa4();
System.out.println("Output: " + img_hex2[i][j]);
System.out.println("Output: " + img_hex4[i][j]);
count++;
System.out.println("\nRGB Counts: " + count);
}
}
int width2 = img2.getWidth();
int height2 = img2.getHeight();
System.out.println("Image's Width: " + width2);
System.out.println("Image's Height: " + height2);
int[][] pixelData2 = new int[width2 * height2][3];
System.out.println("Pixel Data: " + pixelData2);
int[] rgb2;
int counter = 0;
img_hex2 = new String[width2][height2];
img_hex4 = new String[width2][height2];
for(int i=0; i<width2; i++)
{
for(int j=0; j<height2; j++)
{
rgb2 = newPD.getPixelData(img2, i, j);
for(int k = 0; k < rgb2.length; k++)
{
pixelData2[counter][k] = rgb2[k];
}
img2_hex2[width2][height2] = newPD.getHexa2();
img2_hex4[width2][height2] = newPD.getHexa4();
counter++;
System.out.println("\nRGB2 Counts: " + counter);
}
}
}
catch (FileNotFoundException ex) {
Logger.getLogger(getPixelRGB1.class.getName()).log(Level.SEVERE, null, ex);
}
finally
{
try {
image.close();
}
catch (IOException ex) {
Logger.getLogger(getPixelRGB1.class.getName()).log(Level.SEVERE, null, ex);
}
}
hexRGB.check();
}
public String[][] display_imgHex2()
{
return img_hex2;
}
public String[][] display_imgHex4()
{
return img_hex4;
}
public String[][] display_img2Hex2()
{
return img2_hex2;
}
public String[][] display_img2Hex4()
{
return img2_hex4;
}
}
//獲取像素RGB過程
public class getPixelData1
{
private static final double bitPerColor = 4.0;
private static int red;
private static int green;
private static int blue;
private static String hexa2;
private static String hexa4;
public static int[] getPixelData(BufferedImage img, int w, int h) throws IOException
{
int argb = img.getRGB(w, h);
int rgb[] = new int[]
{
(argb >> 16) & 0xff, //red
(argb >> 8) & 0xff, //green
(argb ) & 0xff //blue
};
red = rgb[0];
green = rgb[1]; //RGB Value in Decimal
blue = rgb[2];
System.out.println("\nRGBValue in Decimal --> " + "\nRed: " + red + " Green: " + green + " Blue: " + blue);
//Convert each channel RGB to Hexadecimal value
String rHex = Integer.toHexString((int)(red));
String gHex = Integer.toHexString((int)(green));
String bHex = Integer.toHexString((int)(blue));
System.out.println("\nRGBValue in Hexa --> " + "\nRed Green Blue " + rHex + gHex + bHex);
return rgb;
}
public String getHexa2()
{
//Check position 2 of hexa value for any changes
String hex = String.format("%02X%02X%02X", red, green, blue);
System.out.println("\nString RGB Hexa: " + hex);
hexa2 = hex.substring(1,2);
System.out.println("\nSubstring at position 2: " + hexa2);
return hexa2;
}
public String getHexa4()
{
//Check position 4 of hexa value for any changes
String hex = String.format("%02X%02X%02X", red, green, blue);
System.out.println("\nString RGB Hexa: " + hex);
hexa4 = hex.substring(3,4);
System.out.println("\nSubstring at position 4: " + hexa4);
return hexa4;
}
}
//比較2個圖像處理
public class compareHexaRGB
{
private static int w;
private static int h;
public static void compareHexaRGB(int width, int height) throws IOException
{
w = width;
h = height;
}
public void check()
{
getPixelRGB1 newPD = new getPixelRGB1();
for(int i = 0; i < w; i++)
{
for(int j = 0; j < h; j++)
{
if(newPD.display_imgHex2().equals(newPD.display_img2Hex2()) && (newPD.display_imgHex4().equals(newPD.display_img2Hex4())))
{
System.out.println("Pixel values at position 2 and 4 are the same.");
}
else if(!newPD.display_imgHex2().equals(newPD.display_img2Hex2()) || (!newPD.display_imgHex4().equals(newPD.display_img2Hex4())))
{
System.out.println("Pixel values at position 2 are not the same.");
}
else if(!newPD.display_imgHex2().equals(newPD.display_img2Hex2()) || (!newPD.display_imgHex4().equals(newPD.display_img2Hex4())))
{
System.out.println("Pixel values at position 4 are not the same.");
}
}
}
}
}
錯誤：
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 3
at getPixelRGB1.main(getPixelRGB1.java:79)
所以這是一個NullPointerException！順便說一句，你有一個空值，使用調試器是好東西！你可以輕鬆找到問題的根源！ –