I tried to read this paragraph from a website, but i don not understand why "32nd pixel store the bits needed for reconstructing the byte value needed to create the original string."
This is trying to put the message into alpha (transparency)(ARGB)
In this code below, why need to embed both integer and byte
int imageWidth = img.getWidth(), imageHeight = img.getHeight(),
imageSize = imageWidth * imageHeight;
if(messageLength * 8 + 32 > imageSize) {
JOptionPane.showMessageDialog(this, "Message is too long for the chosen image",
"Message too long!", JOptionPane.ERROR_MESSAGE);
return;
}
embedInteger(img, messageLength, 0, 0);
byte b[] = mess.getBytes();
for(int i=0; i<b.length; i++)
embedByte(img, b[i], i*8+32, 0);
}
private void embedInteger(BufferedImage img, int n, int start, int storageBit) {
int maxX = img.getWidth(), maxY = img.getHeight(),
startX = start/maxY, startY = start - startX*maxY, count=0;
for(int i=startX; i<maxX && count<32; i++) {
for(int j=startY; j<maxY && count<32; j++) {
int rgb = img.getRGB(i, j), bit = getBitValue(n, count);
rgb = setBitValue(rgb, storageBit, bit);
img.setRGB(i, j, rgb);
count++;
}
}
}
private void embedByte(BufferedImage img, byte b, int start, int storageBit) {
int maxX = img.getWidth(), maxY = img.getHeight(),
startX = start/maxY, startY = start - startX*maxY, count=0;
for(int i=startX; i<maxX && count<8; i++) {
for(int j=startY; j<maxY && count<8; j++) {
int rgb = img.getRGB(i, j), bit = getBitValue(b, count);
rgb = setBitValue(rgb, storageBit, bit);
img.setRGB(i, j, rgb);
count++;
}
}
}