android 图片像素格式

https://blog.51cto.com/u_16099263/6670634

• ARGB8888
  ARGB8888各通道的排列顺序验证：https://blog.csdn.net/afei__/article/details/81415286

import android.app.Activity;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.util.Log;
import android.widget.ImageView;

import java.nio.Buffer;
import java.nio.ByteBuffer;

public class MainActivity extends Activity {

    private static final String TAG = "MainActivity";
    private ImageView displayIv;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Bitmap bitmap = Bitmap.createBitmap(1, 1, Bitmap.Config.ARGB_8888);
        bitmap.eraseColor(0xff336699); // AARRGGBB
        byte[] bytes = new byte[bitmap.getWidth() * bitmap.getHeight() * 4];
        Buffer dst = ByteBuffer.wrap(bytes);
        bitmap.copyPixelsToBuffer(dst);
        // ARGB_8888 真实的存储顺序是 R-G-B-A
        Log.d(TAG, "R: " + Integer.toHexString(bytes[0] & 0xff));
        Log.d(TAG, "G: " + Integer.toHexString(bytes[1] & 0xff));
        Log.d(TAG, "B: " + Integer.toHexString(bytes[2] & 0xff));
        Log.d(TAG, "A: " + Integer.toHexString(bytes[3] & 0xff));
        displayIv = (ImageView) findViewById(R.id.display_iv);
        displayIv.setImageBitmap(bitmap);
    }

}

ARGB8888各通道的排列顺序为RGBA