imge.js

import React from 'react';
import { StyleSheet,View, Image, Dimensions } from 'react-native';

export default function App() {
  return (
    <View>
      <Image 
        source={require('..assets/images/my_image.png')}
        style = {styles.im}
      />            
   </View>
  );
}

const styles = StyleSheet.create({
  im:{
    width:Dimensions.get('window').width,
    height:Dimensions.get('window').height/2
  }
});