You can use scale transform to change the size of the image. If scaling is above one , it will zoom the image.
public static Bitmap scaleImage(Bitmap src,float sx,float sy)
{
Matrix matrix = new Matrix();
matrix.postScale(sx, sy);
src=Bitmap.createBitmap(src, 0, 0, src.getWidth(), src.getHeight(), matrix, true);
return src;
}
If you have byte array, you can convert that to Bitmap object and can call this method.
Here is how you can convert it to byte array.
Bitmap.createBitmap(image, w, h, android.graphics.Bitmap.Config.ARGB_8888);