Oscurecer una imagen para superponer texto en React Native

Estoy intentando superponer un título sobre una imagen, con la imagen oscurecida con una opacidad menor. Sin embargo, el efecto de opacidad también está cambiando el texto superpuesto, haciéndolo más tenue. ¿Alguna solución a esto?

//component for article preview touchable image
/* will require the following
- rss feed and api
- user's keyword interests from parse In home.js
- parse db needs to be augmented to include what they heart
- parse db needs to be augmented to include what they press on (like google news)
*/
var React = require('react-native');
var {
  View, 
  StyleSheet, 
  Text, 
  Image, 
  TouchableHighlight, 
} = React;

//dimensions
var Dimensions = require('Dimensions');
var window = Dimensions.get('window');
var ImageButton = require('../../common/imageButton');
var KeywordBox = require('../../authentication/onboarding/keyword-box');

//additional libraries

module.exports = React.createClass({
  //onPress function that triggers when button pressed
  //this.props.text is property that can be dynamically filled within button 
  /* following props:
    - source={this.props.source}
    - onPress={this.props.onPress}
    - {this.props.text}
    - {this.props.heartText}
    - key={this.props.key} 
    - text={this.props.category} 
    - this.props.selected
  */
  render: function() {
    return (
      <TouchableHighlight 
        underlayColor={'transparent'}
        onPress={this.props.onPress} >
          <Image 
            source={this.props.source} 
            style={[styles.articlePreview, this.border('red')]}>
                  <View style={[styles.container, this.border('organge')]}>
                      <View style={[styles.header, this.border('blue')]}>
                          <Text style={[styles.previewText]}>{this.props.text}</Text>
                      </View>
                      <View style={[styles.footer, this.border('white')]}>
                        <View style={[styles.heartRow, this.border('black')]}>
                          <ImageButton
                              style={[styles.heartBtn, , this.border('red')]}
                              resizeMode={'contain'}
                              onPress={this.onHeartPress}
                              source={require('../../img/heart_btn.png')} />
                          <Text style={[styles.heartText]}>{this.props.heartText + ' favorites'}</Text>
                        </View>
                          <KeywordBox 
                              style={[styles.category, this.border('blue')]}
                              key={this.props.key} 
                              text={this.props.category} 
                              onPress={this.props.categoryPress}
                              selected={this.props.selected} />
                      </View>
                  </View>
          </Image>
      </TouchableHighlight>
    );
  }, 
  onHeartPress: function() {
    //will move this function to a general module
  }, 
  border: function(color) {
      return {
        //borderColor: color, 
        //borderWidth: 4,
      } 
   },
});

var styles = StyleSheet.create({
  heartText: {
    color: 'white', 
    fontSize: 12, 
    fontWeight: 'bold',
    alignSelf: 'center', 
    marginLeft: 5, 
    fontFamily: 'SFCompactText-Medium'
  }, 
  heartRow: {
    flexDirection: 'row', 
    justifyContent: 'space-around', 
    alignSelf: 'center', 
    justifyContent: 'center', 
  }, 
  heartBtn: {
    height: (92/97)*(window.width/13), 
    width: window.width/13, 
    alignSelf:'center', 
  }, 
  category: {
    fontFamily: 'Bebas Neue', 
    fontSize: 10,
    fontWeight: 'bold'
  }, 
  header: {
    flex: 3, 
    alignItems: 'center', 
    justifyContent: 'space-around', 
    marginTop: window.height/30,
  }, 
  footer: {
    flex: 1, 
    flexDirection: 'row', 
    justifyContent: 'space-between', 
    alignItems: 'center', 
    margin: window.height/50,
  }, 
  container: {
    flex: 1, 
    backgroundColor: 'black', 
    opacity: 0.6, 
  }, 
  articlePreview: {
    flex: 1, 
    height: window.height/3.2, 
    width: window.width, 
    flexDirection: 'column'
  }, 
  previewText: {
    fontFamily: 'Bebas Neue', 
    fontSize: 23,
    color: 'white', 
    alignSelf: 'center', 
    textAlign: 'center', 
    margin: 5, 
    position: 'absolute',
    top: 0,
    right: 0,
    bottom: 0,
    left: 0
  }, 

});

SOLUCION a Oscurecer una imagen para superponer texto en React Native

Intente cambiar el estilo del contenedor a

container: {
 flex: 1, 
 backgroundColor: 'rgba(0,0,0,.6)'
},

o

En lugar de aplicar la opacidad a todo el elemento ImageBackground, impleméntelo en la propia imagen Ej.

<ImageBackground style={styles.imageContainer}
                 imageStyle={{ opacity: 0.5 }}
                 source={require('../assets/images/background.png')}>
                <View style={styles.welcomeContainer}>
                    <Image source={require('../assets/images/zeptagram-logo.png')} style={styles.welcomeImage} />
                </View>
            </ImageBackground>