Java tutorial
//package com.java2s; //License from project: Open Source License import android.graphics.Bitmap; import android.support.annotation.NonNull; import java.io.ByteArrayOutputStream; public class Main { @NonNull public static byte[] bitmapToByteArray(@NonNull Bitmap bitmap) { ByteArrayOutputStream out = null; try { out = new ByteArrayOutputStream(bitmap.getWidth() * bitmap.getHeight()); bitmap.compress(Bitmap.CompressFormat.JPEG, 100, out); return out.toByteArray(); } finally { if (out != null) try { out.close(); } catch (Exception ignore) { } } } }