How to convert The int array to byte array？ so that I can make a bitmap by byte array instead of byte array

Question

I have an int[] intArray, i can make a bitmap like :

Bitmap bitmap = Bitmap.createBitmap(intArray, width, height, Bitmap.Config.ARGB_8888);

Now, i want to use byte[] to make this bitmap, so i try convert int[] to byte[], but it does't work, the bitmap it make seems lack some color

public static byte[] intArrayToByteArray(int[] intArray) { byte[] ba = new byte[intArray.length * 4];

    for(int i = 0, k = 0; i < intArray.length; i++) {
        int temp= intArray[i];
        for(int j = 0; j < 4; j++, k++) {
            ba[k] = (byte)((temp>> (8 * j)) & 0xFF);
        }
    }
    return ba;

}

public static Bitmap byteArrayToBitmap(byte[] byteArray, int width, int height) {
    ByteBuffer buffer = ByteBuffer.wrap(byteArray);
    Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
    bitmap.copyPixelsFromBuffer(buffer);
    return bitmap;
}

the bitmap it make seems lack some color by this way.

But if I make bitmap by int[] firstly, and then converted bitmap to byte[], and the byte[] seems to be correct!! This way is not good.

So does somebody has a way convert int[] to byte[], so that we can use byte[] to make a bitmap indtead of using int[].

Answer 1

You need set alpha = false -> bitmap.setHasAlpha(false)

public static Bitmap byteArrayToBitmap(byte[] byteArray, int width, int height) {
    ByteBuffer buffer = ByteBuffer.wrap(byteArray);
    Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
    bitmap.setHasAlpha(false);
    bitmap.copyPixelsFromBuffer(buffer);
    return bitmap;
}