@TypeConverter

build.gradle

apply plugin: 'com.android.application'
apply plugin: 'kotlin-android'
apply plugin: 'kotlin-kapt'
apply plugin: 'kotlin-android-extensions'

android {
    compileSdkVersion 30
    buildToolsVersion "30.0.0"

    defaultConfig {
        applicationId "com.example.roomdemo"
        minSdkVersion 26
        targetSdkVersion 30
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }

    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }

    kotlinOptions {
        jvmTarget = JavaVersion.VERSION_1_8.toString()
    }

}

dependencies {
    implementation fileTree(dir: "libs", include: ["*.jar"])
    implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
    implementation 'androidx.core:core-ktx:1.3.1'
    implementation 'androidx.appcompat:appcompat:1.2.0'
    implementation 'androidx.constraintlayout:constraintlayout:2.0.1'
    implementation 'androidx.recyclerview:recyclerview:1.1.0'
    implementation 'androidx.legacy:legacy-support-v4:1.0.0'
    testImplementation 'junit:junit:4.13'
    androidTestImplementation 'androidx.test.ext:junit:1.1.2'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0'

    // Navigation Component
    implementation 'androidx.navigation:navigation-fragment-ktx:2.3.0'
    implementation 'androidx.navigation:navigation-ui-ktx:2.3.0'

    // Room components
    implementation "androidx.room:room-runtime:2.2.5"
    kapt "androidx.room:room-compiler:2.2.5"
    implementation "androidx.room:room-ktx:2.2.5"

    // Lifecycle components
    implementation "androidx.lifecycle:lifecycle-extensions:2.2.0"
    implementation "androidx.lifecycle:lifecycle-common-java8:2.2.0"
    implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:2.2.0"

    implementation("io.coil-kt:coil:1.0.0-rc3")

}

Converters.kt

class Converters {

    @TypeConverter
    fun fromBitmap(bitmap: Bitmap): ByteArray {
        val outputStream = ByteArrayOutputStream()
        bitmap.compress(Bitmap.CompressFormat.PNG, 100, outputStream)
        return outputStream.toByteArray()
    }

    @TypeConverter
    fun toBitmap(byteArray: ByteArray): Bitmap {
       return BitmapFactory.decodeByteArray(byteArray, 0, byteArray.size)
    }

}

MainActivity.kt

class MainActivity : AppCompatActivity() {

    private val adapter by lazy { MyAdapter() }
    private lateinit var myViewModel: MyViewModel

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        myViewModel = ViewModelProvider(this).get(MyViewModel::class.java)

        recyclerView.adapter = adapter
        recyclerView.layoutManager = LinearLayoutManager(this)

        lifecycleScope.launch {
            val person = Person("John", "Doe", getBitmap())
            myViewModel.insertPerson(person)
        }

        myViewModel.readPerson.observe(this, {
            adapter.setData(it)
        })

    }

    private suspend fun getBitmap(): Bitmap {
        val loading = ImageLoader(this)
        val request = ImageRequest.Builder(this)
            .data("https://avatars3.githubusercontent.com/u/14994036?s=400&u=2832879700f03d4b37ae1c09645352a352b9d2d0&v=4")
            .build()

        val result = (loading.execute(request) as SuccessResult).drawable
        return (result as BitmapDrawable).bitmap
    }

}

MyAdapter.kt

class MyAdapter: RecyclerView.Adapter<MyAdapter.MyViewHolder>(){

    private var person = emptyList<Person>()

    inner class MyViewHolder(itemView: View): RecyclerView.ViewHolder(itemView)

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyViewHolder {
        return MyViewHolder(LayoutInflater.from(parent.context).inflate(R.layout.row_layout, parent, false))
    }

    override fun getItemCount(): Int {
        return person.size
    }

    override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
        holder.itemView.firstName_txt.text = person[position].firstName
        holder.itemView.lastName_txt.text = person[position].lastName
        holder.itemView.imageView.load(person[position].profilePhoto)
    }

    fun setData(person: List<Person>){
        this.person = person
        notifyDataSetChanged()
    }
}

MyDao.kt

@Dao
interface MyDao {

    @Query("SELECT * FROM my_table ORDER BY id ASC")
    fun readPerson(): LiveData<List<Person>>

    @Insert(onConflict = OnConflictStrategy.REPLACE)
    suspend fun insertPerson(person: Person)

}

MyDatabase.kt

@Database(entities = [Person::class], version = 1, exportSchema = false)
@TypeConverters(Converters::class)
abstract class MyDatabase : RoomDatabase() {

    abstract fun myDao(): MyDao

    companion object {
        @Volatile
        private var INSTANCE: MyDatabase? = null

        fun getDatabase(context: Context): MyDatabase =
            INSTANCE ?: synchronized(this) {
                INSTANCE
                    ?: buildDatabase(context).also { INSTANCE = it }
            }

        private fun buildDatabase(context: Context) =
            Room.databaseBuilder(
                context.applicationContext,
                MyDatabase::class.java, "my_database"
            ).build()
    }

}

MyRepository.kt

class MyRepository(private val myDao: MyDao) {

    val readPerson: LiveData<List<Person>> = myDao.readPerson()

    suspend fun insertPerson(person: Person){
        myDao.insertPerson(person)
    }

}

MyViewModel.kt

class MyViewModel(application: Application): AndroidViewModel(application) {

    private val dao = MyDatabase.getDatabase(application).myDao()
    private val repository = MyRepository(dao)

    val readPerson: LiveData<List<Person>> = repository.readPerson

    fun insertPerson(person: Person){
        viewModelScope.launch(Dispatchers.IO) {
            repository.insertPerson(person)
        }
    }

}

Person.kt

@Entity(tableName = "my_table")
data class Person(
    val firstName: String,
    val lastName: String,
    val profilePhoto: Bitmap
){
    @PrimaryKey(autoGenerate = true)
    var id: Int = 0
}

row_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <TextView
        android:id="@+id/firstName_txt"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="24dp"
        android:layout_marginTop="20dp"
        android:text="First Name"
        android:textSize="20sp"
        app:layout_constraintStart_toEndOf="@+id/imageView"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/lastName_txt"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Last Name"
        app:layout_constraintStart_toStartOf="@+id/firstName_txt"
        app:layout_constraintTop_toBottomOf="@+id/firstName_txt" />

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="100dp"
        android:layout_height="100dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        tools:srcCompat="@tools:sample/avatars" />

</androidx.constraintlayout.widget.ConstraintLayout>