How can I convert an image into a Base64 string

Question

What is the code to transform an image  maximum of 200 nbsp KB  into a Base64 String   I need to know how to do it with Android  because I have to add the functionality to upload images to a remote server in my main app  putting them into a row of the database  as a string   I am searching in Google and in Stack Overflow  but I could not find easy examples that I can afford and also I find some examples  but they are not talking about to transform into a String  Then I need to transform into a string to upload by JSON to my remote server

User · Answer

If you re doing this on Android  here s a helper copied from the React Native codebase   import java io ByteArrayOutputStream  import java io Closeable  import java io FileInputStream  import java io FileNotFoundException  import java io IOException  import java io InputStream   import android util Base64  import android util Base64OutputStream  import android util Log      You probably don t want to do this with large files     will allocate a large string and can cause an OOM crash   private String readFileAsBase64String String path      try       InputStream is   new FileInputStream path       ByteArrayOutputStream baos   new ByteArrayOutputStream        Base64OutputStream b64os   new Base64OutputStream baos  Base64 DEFAULT       byte   buffer   new byte 8192       int bytesRead      try         while   bytesRead   is read buffer    gt  -1            b64os write buffer  0  bytesRead                 return baos toString          catch  IOException e          Log e TAG   Cannot read file     path  e            Or throw if you prefer       return           finally         closeQuietly is         closeQuietly b64os      This also closes baos           catch  FileNotFoundException e        Log e TAG   File not found     path  e          Or throw if you prefer     return            private static void closeQuietly Closeable closeable      try       closeable close        catch  IOException e

User · Answer

Put the image file path into this method public static String getFileToByte String filePath       Bitmap bmp   null      ByteArrayOutputStream bos   null      byte   bt   null      String encodeString   null      try          bmp   BitmapFactory decodeFile filePath           bos   new ByteArrayOutputStream            bmp compress Bitmap CompressFormat JPEG  100  bos           bt   bos toByteArray            encodeString   Base64 encodeToString bt  Base64 DEFAULT             catch  Exception e         e printStackTrace              return encodeString

User · Answer

Below is the pseudocode that may help you   public  String getBase64FromFile String path        Bitmap bmp   null      ByteArrayOutputStream baos   null      byte   baat   null      String encodeString   null      try               bmp   BitmapFactory decodeFile path           baos   new ByteArrayOutputStream            bmp compress Bitmap CompressFormat JPEG  100  baos           baat   baos toByteArray            encodeString   Base64 encodeToString baat  Base64 DEFAULT             catch  Exception e                e printStackTrace              return encodeString

User · Answer

Here is code for image encoding and image decoding   In an XML file   lt TextView     android layout width  wrap content      android layout height  wrap content      android text  yyuyuyuuyuyuyu      android id    id tv5    gt    In a Java file   TextView textView5  Bitmap bitmap   textView5    TextView  findViewById R id tv5    bitmap   BitmapFactory decodeResource getResources    R drawable logo    new AsyncTask lt Void  Void  String gt           Override     protected String doInBackground Void    voids            ByteArrayOutputStream stream   new ByteArrayOutputStream            bitmap compress Bitmap CompressFormat JPEG  70  stream           byte   byteFormat   stream toByteArray                Get the Base64 string         String imgString   Base64 encodeToString byteFormat  Base64 NO WRAP            return imgString              Override     protected void onPostExecute String s           textView5 setText s           execute

User · Answer

I make a static function  Its more efficient i think  public static String file2Base64 String filePath            FileInputStream fis   null          String base64String    quot  quot           ByteArrayOutputStream bos   new ByteArrayOutputStream            try               fis   new FileInputStream filePath               byte   buffer   new byte 1024   100               int count   0              while   count   fis read buffer      -1                    bos write buffer  0  count                             fis close              catch  Exception e                e printStackTrace                      base64String   Base64 encodeToString bos toByteArray    Base64 DEFAULT           return base64String          Simple and easier

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Instead of using Bitmap  you can also do this through a trivial InputStream  Well  I am not sure  but I think it s a bit efficient   InputStream inputStream   new FileInputStream fileName      You can get an inputStream using any I O API byte   bytes  byte   buffer   new byte 8192   int bytesRead  ByteArrayOutputStream output   new ByteArrayOutputStream     try       while   bytesRead   inputStream read buffer      -1            output write buffer  0  bytesRead           catch  IOException e        e printStackTrace       bytes   output toByteArray    String encodedString   Base64 encodeToString bytes  Base64 DEFAULT

User · Answer

byte   decodedString   Base64 decode result getBytes    Base64 DEFAULT

User · Answer

Convert an image to Base64 string in Android   ByteArrayOutputStream baos   new ByteArrayOutputStream    Bitmap bitmap   BitmapFactory decodeResource getResources    R drawable yourimage   bitmap compress Bitmap CompressFormat JPEG  100  baos   byte   imageBytes   baos toByteArray    String imageString   Base64 encodeToString imageBytes  Base64 DEFAULT

User · Answer

You can use the Base64 Android class   String encodedImage   Base64 encodeToString byteArrayImage  Base64 DEFAULT     You ll have to convert your image into a byte array though  Here s an example   Bitmap bm   BitmapFactory decodeFile   path to image jpg    ByteArrayOutputStream baos   new ByteArrayOutputStream    bm compress Bitmap CompressFormat JPEG  100  baos      bm is the bitmap object byte   b   baos toByteArray        Update    If you re using an older SDK library  because you want it to work on phones with older versions of the OS  you won t have the Base64 class packaged in  since it just came out in API level 8 AKA version 2 2    Check this article out for a workaround   How to base64 encode decode Android

User · Answer

This code runs perfect in my project   profile image buildDrawingCache    Bitmap bmap   profile image getDrawingCache    String encodedImageData   getEncoded64ImageStringFromBitmap bmap     public String getEncoded64ImageStringFromBitmap Bitmap bitmap        ByteArrayOutputStream stream   new ByteArrayOutputStream        bitmap compress CompressFormat JPEG  70  stream       byte   byteFormat   stream toByteArray            Get the Base64 string     String imgString   Base64 encodeToString byteFormat  Base64 NO WRAP        return imgString

User · Answer

If you need Base64 over JSON  check out Jackson  it has explicit support for binary data read write as Base64 at both the low level  JsonParser  JsonGenerator  and data-binding level  So you can just have POJOs with byte   properties  and encoding decoding is automatically handled   And pretty efficiently too  should that matter

User · Answer

Use this code   byte   decodedString   Base64 decode Base64String getBytes    Base64 DEFAULT    Bitmap decodedByte   BitmapFactory decodeByteArray decodedString  0  decodedString length

User · Answer

For those looking for an efficient method to convert an image file to a Base64 string without compression or converting the file to a bitmap first  you can instead encode the file as base64   val base64EncodedImage   FileInputStream imageItem localSrc  use  inputStream -  gt      ByteArrayOutputStream   use  outputStream -  gt              Base64OutputStream outputStream  Base64 DEFAULT  use                   base64FilterStream -  gt                      inputStream copyTo base64FilterStream                  base64FilterStream flush                   outputStream toString                             Hope this helps

User · Answer

Here is the encoding and decoding code in Kotlin    fun encode imageUri  Uri   String       val input   activity getContentResolver   openInputStream imageUri      val image   BitmapFactory decodeStream input   null  null          Encode image to base64 string     val baos   ByteArrayOutputStream       image compress Bitmap CompressFormat JPEG  100  baos      var imageBytes   baos toByteArray       val imageString   Base64 encodeToString imageBytes  Base64 DEFAULT      return imageString    fun decode imageString  String            Decode base64 string to image     val imageBytes   Base64 decode imageString  Base64 DEFAULT      val decodedImage   BitmapFactory decodeByteArray imageBytes  0  imageBytes size       imageview setImageBitmap decodedImage

[android] How can I convert an image into a Base64 string?

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