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我建立了一個小的Java程序,使用最低有效位的方法隱藏圖像中的消息。當輸入一個jpg文件時它工作正常。輸出可能是png或jpg。當輸入一個PNG時,結果看起來非常直觀。隱寫,只有JPG作爲輸入工作,當使用PNG的結果圖像看起來很奇怪
這裏分別原始和結果圖像是:
public abstract class Builder{
public static void leastSignificantBitEncryption(String imageSource, String message, String newPath) {
BufferedImage image = returnImage(imageSource);
//prepare variables
String[] messageBinString = null;
String[] pixelBinString = null;
final byte[] messageBin = message.getBytes(StandardCharsets.UTF_8);
final byte[] pixelsBin = ((DataBufferByte) image.getRaster().getDataBuffer()).getData();
//convert message and image to binary string array
try {
messageBinString = stringToBinaryStrings(messageBin);
pixelBinString = stringToBinaryStrings(pixelsBin);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
String[] messageBinStringCut = splitIn2Bit(messageBinString); //split message binary into 2 bit strings
String[] pixelBinStringNew = pixelBinString.clone(); //insert 2 bit strings in last 2 bits of bytes from bitmap
insert2Bit(messageBinStringCut, pixelBinStringNew);
byte[] pixelsBinNew = stringArrayToByteArray(pixelBinStringNew); //Convert string array to byte array
try { //Create new image out of bitmap
int w = image.getWidth();
int h = image.getHeight();
BufferedImage imageNew = new BufferedImage(w, h, BufferedImage.TYPE_3BYTE_BGR);
imageNew.setData(Raster.createRaster(imageNew.getSampleModel(), new DataBufferByte(pixelsBinNew, pixelsBinNew.length), new Point()));
File imageFile = new File(newPath);
ImageIO.write(imageNew, "png", imageFile);
} catch (IOException e) {
e.printStackTrace();
}
}
private static String[] stringToBinaryStrings(byte[] messageBin) throws UnsupportedEncodingException{
String[] bytes = new String[messageBin.length];
int i = 0;
for(byte b : messageBin) {
bytes[i] = String.format("%8s", Integer.toBinaryString(b & 0xFF)).replace(' ', '0');
i++;
}
return bytes;
}
private static String binaryStringsToString(String[] messageBin) throws UnsupportedEncodingException{
StringBuilder stringBuilder = new StringBuilder();
int i = 0;
while(messageBin[i] != null) {
stringBuilder.append((char) Integer.parseInt(messageBin[i], 2));
i++;
}
return stringBuilder.toString();
}
private static BufferedImage returnImage(String imageSource) {
try{
try {
return ImageIO.read(new URL(imageSource));
} catch (MalformedURLException e) {
return ImageIO.read(new File(imageSource));
}
} catch (IOException ioe) {
ioe.printStackTrace();
return null;
}
}
private static byte[] stringArrayToByteArray(String[] stringArray) {
byte[] byteArray = new byte[stringArray.length];
for(int i = 0; i < stringArray.length; i++) {
byteArray[i] = (byte) Integer.parseInt(stringArray[i], 2);
}
return byteArray;
}
private static String[] splitIn2Bit(String[] inputArray) {
String[] outputArray = new String[inputArray.length * 4];
for(int i = 0; i < outputArray.length; i += 4) {
String[] splitByte = inputArray[i/4].split("(?<=\\G..)");
outputArray[i] = splitByte[0];
outputArray[i + 1] = splitByte[1];
outputArray[i + 2] = splitByte[2];
outputArray[i + 3] = splitByte[3];
}
return outputArray;
}
private static String[] insert2Bit(String[] twoBitArray, String[] insertArray) {
for(int i = 0; i < twoBitArray.length; i++) {
insertArray[i] = insertArray[i].substring(0, 6) + twoBitArray[i];
}
return insertArray;
}
}
此外,識別TestClass:
public class Test {
public static void main(String[] args) {
Builder.leastSignificantBitEncryption("IMAGEPATH OR URL", "MESSAGE", "PATH FOR IMAGE CONTAINING MESSAGE");
Builder.leastSignificantBitDecryption("PATH OF IMAGE CONTAINING MESSAGE", "PATH FOR TXT CONTAINING OUTPUT");
}
}
如果您清理意大利麪代碼,它將更易於閱讀,從而更容易理解並更容易發現問題;既爲你和我們。我可以很容易地檢查5行方法並給出關於正確性的聲明,但是對於40行方法很難。幫你一個忙,把大方法分成小塊。從前11行開始,從文件名中給出位圖 –
將變量移近使用,例如'w'和'h'似乎不會在接下來的16行中使用。這讓我懷疑他們是否被使用過。如果他們沒有使用,刪除它。 –
另外:你說圖片看起來不對。這告訴我問題在於加密方法。解密方法應該與問題無關。去掉它。最後,在我離開這裏之前,有太多的'String's。如果需要位操作的操作使用瞭如此多的字符串和很少的字節,那麼就會出現問題。 –