Question

我可以将图像隐藏在另一个内部并显示原始图像，但现在需要为进程添加密码

public BufferedImage encodeImage(String key, BufferedImage cover, BufferedImage secret) {
    int height = secret.getHeight();
    int width = secret.getWidth();
    byte[] bytes = getImageBytes(secret);
    bytes = encrypt(bytes, key.getBytes());
    // get byte array for width, height, and message (8 bytes = 1 bit)
    byte[] widthArray = getBytesFromInt(WIDTH_BITS/8, width);
    byte[] heightArray = getBytesFromInt(HEIGHT_BITS/8, height);
    byte[] messageLengthArray = getBytesFromInt(MESSAGE_LENGTH_BITS/8, bytes.length);

    byte[] imageArray = getImageBytes(cover);

    // hide bytes with offset of previous bit lengths added up
    hideBytes(imageArray, messageLengthArray, 0);
    hideBytes(imageArray, widthArray, MESSAGE_LENGTH_BITS);
    hideBytes(imageArray, heightArray, MESSAGE_LENGTH_BITS + WIDTH_BITS);
    hideBytes(imageArray, bytes, MESSAGE_LENGTH_BITS + WIDTH_BITS + HEIGHT_BITS);

    return cover;
}

但我无法使用相同的流程来检索秘密图片

更新：但是我不能使用相同的过程来检索秘密图像

   public BufferedImage decodeImage(String key, BufferedImage bimg) {
        byte[] imageArray = getImageBytes(bimg);
        int length = 0, height = 0, width = 0;

        // loop through all encoded length bits and store value in corresponding variable
        for (int i = 0; i < (MESSAGE_LENGTH_BITS + WIDTH_BITS + HEIGHT_BITS); i++) {
            if (i < MESSAGE_LENGTH_BITS)
                length = (length << 1) | (imageArray[i] & 1);
            else if (i < MESSAGE_LENGTH_BITS + WIDTH_BITS)
                width = (width << 1) | (imageArray[i] & 1);
            else
                height = (height << 1) | (imageArray[i] & 1);
        }

        byte[] result = new byte[length];

        // skip all encoded lengths (message_length, width and height bits)
        int index = MESSAGE_LENGTH_BITS + WIDTH_BITS + HEIGHT_BITS;

        // loop til length of message and grab each LSB from image
        for (int i = 0; i < result.length; i++) {
            for (int j = 0; j < 8; j++) { // each bit
                // shift by 1 and grab last bit of next image byte
                result[i] = (byte) ((result[i] << 1) | (imageArray[index] & 1));
                index++;
            }
        }

        // swap blue with red to follow RGB sequence from BGR
        for (int i = 0; i < result.length; i+=3) {
            byte temp = result[i];
            result[i] = result[i+2];
            result[i+2] = temp;
        }


        // create image
        BufferedImage b = new BufferedImage(width, height, BufferedImage.TYPE_3BYTE_BGR);
        WritableRaster raster = b.getRaster();
        raster.setDataElements(0, 0, width, height, result);

        return b;
    }

密码处理仅对具有秘密图像的数据进行异或

public static byte[] encrypt(byte[] key, byte[] plainText) {
    byte[] result = new byte[plainText.length];
    for (int i = 0; i < plainText.length; i++) {
        result[i] = (byte) (plainText[i] ^ key[i]);
    }
    return result;
}

该过程中的其他方法隐藏方法和int到字节并从图像

获取字节

private void hideBytes(byte[] bimg, byte[] bytes, int offset) {
    for (int i = 0; i < bytes.length; i++) {
        int character = bytes[i];
        for (int j = 7; j >= 0; j--) {  // 8 bits per character
            // get corresponding bit
            int bit = (character >> j) & 1;

            // get last image byte, set last bit to 0 ( AND 0xFE) then OR with bit
            bimg[offset] = (byte) ((bimg[offset] & 0xFE) | bit);
            offset++;
        }
    }
}

    private byte[] getBytesFromInt(int size, int number) {
    byte[] b = new byte[size];

    for (int i = size-1, shift = 0; i >= 0; i--, shift += 8)
        b[i] = (byte) ((number & (0x000000FF << shift)) >> shift);

    return b;
}

private byte[] getImageBytes(BufferedImage bimg) {
    WritableRaster raster = bimg.getRaster();
    DataBufferByte dbb = (DataBufferByte) raster.getDataBuffer();
    return dbb.getData();
}

在图像steganogrpahy中添加密码步骤

0 个答案: