How to convert a Base64 string into a Bitmap image to show it in a ImageView?

Question

I have a Base64 String that represents a BitMap image.

I need to transform that String into a BitMap image again to use it on a ImageView in my Android app

H

Answer 1

To anyone who is still interested in this question: If: 1-decodeByteArray returns null 2-Base64.decode throws bad-base64 Exception

Here is the solution: -You should consider the value sent to you from API is Base64 Encoded and should be decoded first in order to cast it to a Bitmap object! -Take a look at your Base64 encoded String, If it starts with

data:image/jpg;base64

The Base64.decode won't be able to decode it, So it has to be removed from your encoded String:

final String encodedString = "data:image/jpg;base64, ....";                        
final String pureBase64Encoded = encodedString.substring(encodedString.indexOf(",")  + 1);

Now the pureBase64Encoded object is ready to be decoded:

final byte[] decodedBytes = Base64.decode(pureBase64Encoded, Base64.DEFAULT);

Now just simply use the line below to turn this into a Bitmap Object! :

Bitmap decodedBitmap = BitmapFactory.decodeByteArray(decodedBytes, 0, decodedBytes.length);

Or if you're using the great library Glide:

Glide.with(CaptchaFragment.this).load(decodedBytes).crossFade().fitCenter().into(mCatpchaImageView);

This should do the job! It wasted one day on this and came up to this solution!

Note: If you are still getting bad-base64 error consider other Base64.decode flags like Base64.URL_SAFE and so on

Answer 2

You can just basically revert your code using some other built in methods.

byte[] decodedString = Base64.decode(encodedImage, Base64.DEFAULT);
Bitmap decodedByte = BitmapFactory.decodeByteArray(decodedString, 0, decodedString.length); 

Answer 3

This is a great sample:

String base64String = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAIAAAACACAYAAADDPmHLAA...";
String base64Image = base64String.split(",")[1];
byte[] decodedString = Base64.decode(base64Image, Base64.DEFAULT);
Bitmap decodedByte = BitmapFactory.decodeByteArray(decodedString, 0, decodedString.length);
imageView.setImageBitmap(decodedByte);

Sample found at: https://freakycoder.com/android-notes-44-how-to-convert-base64-string-to-bitmap-53f98d5e57af

This is the only code that worked for me in the past.

Answer 4

To check online you can use

http://codebeautify.org/base64-to-image-converter

You can convert string to image like this way

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Base64;
import android.widget.ImageView;

import java.io.ByteArrayOutputStream;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        ImageView image =(ImageView)findViewById(R.id.image);

        //encode image to base64 string
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.logo);
        bitmap.compress(Bitmap.CompressFormat.JPEG, 100, baos);
        byte[] imageBytes = baos.toByteArray();
        String imageString = Base64.encodeToString(imageBytes, Base64.DEFAULT);

        //decode base64 string to image
        imageBytes = Base64.decode(imageString, Base64.DEFAULT);
        Bitmap decodedImage = BitmapFactory.decodeByteArray(imageBytes, 0, imageBytes.length);
        image.setImageBitmap(decodedImage);
    }
}

http://www.thecrazyprogrammer.com/2016/10/android-convert-image-base64-string-base64-string-image.html

Answer 5

I've found this easy solution

To convert from bitmap to Base64 use this method.

private String convertBitmapToBase64(Bitmap bitmap) {
    ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
    bitmap.compress(Bitmap.CompressFormat.PNG, 100, byteArrayOutputStream);
    byte[] byteArray = byteArrayOutputStream .toByteArray();
    return Base64.encodeToString(byteArray, Base64.DEFAULT);
}

To convert from Base64 to bitmap OR revert.

private Bitmap convertBase64ToBitmap(String b64) {
    byte[] imageAsBytes = Base64.decode(b64.getBytes(), Base64.DEFAULT);
    return BitmapFactory.decodeByteArray(imageAsBytes, 0, imageAsBytes.length);
}

Answer 6

This is a very old thread but thought to share this answer as it took lot of my development time to manage NULL return of BitmapFactory.decodeByteArray() as @Anirudh has faced.

If the encodedImage string is a JSON response, simply use Base64.URL_SAFE instead of Base64.DEAULT

byte[] decodedString = Base64.decode(encodedImage, Base64.URL_SAFE);
Bitmap decodedByte = BitmapFactory.decodeByteArray(decodedString, 0, decodedString.length);