Question

I am using the following code to get the R,G,B values for a grayscale image(they all will be the same)
But the output gives me negative values.

Why is this so? I am totally confused.

for (int i=0;i<bb.getWidth();i++){
                            for (int j=0;j<bb.getHeight();j++){
                                    long temp=bb.getPixel(i, j);
                                    int a=(int)temp;
                                    ByteBuffer b = ByteBuffer.allocate(4);
                                    b.putInt(a  );
                                    byte[] result = b.array();                                      
                                    Log.d("gray value is=", String.valueOf((int)result[1]));
                                //  Log.d("gray value is=", String.valueOf(getLastBytes(a)));
                            }
                        }

Here result[1] should correspond to the ‘R’ value. So how is it negative?

Answer 1

Try this

        long temp=bb.getPixel(i, j);
        R = Color.red(temp);
        G = Color.green(temp);
        B = Color.blue(temp);