Convert Image object to Base64 String in Android - android

I've seen a huge number of related questions, but none of them actually answer the question, and many just use code snippets out of context with undefined variables.
I need to store images in a database (which to the best of my knowledge I should do using Base64 encoded strings), and use them as Image objects in the android code.
From what I've worked out, I need to convert the Image to a Bitmap, then Bitmap can be turned into a Base64 string. But I can't for the life of me work out how to convert the Image into a Bitmap. Any help is appreciated.
EDIT: While other questions do convert an image from a file location to a string, I don't have a file location. The image is stored solely as an instance of android.media.Image, and I don't know how to access that using a file path or anything similar.
EDIT 2: Okay, so here's my setup: the images will be stored in Firebase database as Base64 encoded strings. When I need them, I will pull the string from there and convert it into an Image object, which is just a variable I have temporarily. They are never stored locally, the only time they're on the actual app they are the Image object.

Just convert your base64 string into bitmap than load that bitmap into imageview using below code
byte[] decodedString = Base64.decode(encodedImage, Base64.DEFAULT);
Bitmap decodedByte = BitmapFactory.decodeByteArray(decodedString, 0, decodedString.length);
image.setImageBitmap(decodedByte);

Related

How to know if a byte array is a valid image

Is there a way to know if a byte array is a valid image?
I am taking a photograph, In OnActivityResult:
Bitmap imageBitmap = (Bitmap) extras.get("data");
imageBitmap.compress(Bitmap.CompressFormat.JPEG, 75, out);
//arrayFotos is an ArrayList
arrayFotos.add(new BeanFotos("", imageBitmap, lastKnwonLocation.getLatitude(), lastKnwonLocation.getLongitude()));
I am storing it in database:
//listaFotos and arrayFotos are the same array, but with different names, because I am storing it in another class in my app
for(int i=0;i<listaFotos.size();i++){
values.clear();
values.put("codficha", codficha);
int bytes=listaFotos.get(i).getFoto().getByteCount();
ByteBuffer buffer = ByteBuffer.allocate(bytes);
listaFotos.get(i).getFoto().copyPixelsToBuffer(buffer);
values.put("foto", buffer.array());
db.insert("fotos", null, values);
}
Later, I need that image to be shown:
byte[] arrayFoto = csr2.getBlob(0);
Bitmap fotoBitmap=BitmapFactory.decodeByteArray(arrayFoto, 0, arrayFoto.length);
The problem is, no matter what i do, the decodeByteArray method always returns null. I have tried with external libraries, and it is always null, so I am thinking maybe I am storing it in the wrong way. The arrayFoto variable is NOT null, I am receiving bytes (84584, to be exact) but the decodeByteArray method returns null.
So, is there a way for me to be sure that the byte array is a correct image?
Thanks.
It seems you are writing the uncompressed Bitmap to the database. You need to compress it to jpeg or png first if you want to be able to decode it using BitmapFactory.
Also, storing images in a database is a bad idea since the cursor window size is limited to 1MB. You should not store binary data in a SQLite db unless it's very small.

how to convert an image into qrcode in android

Actually, I'am developping an application wich should allow users to get photo from the camera and then convert it into qrcode.
I am trying to use xzing library to generate the qrcode and the Base64 java class to convert the image to String.But when I run this application, the class qrcodewriter handles an exception indicating that the data is too big to be converted.I have tried to get some solutions to this problem and the only way that I found is to subdivise the String generated using the Base64 class into substrings and then convert each of these substrings to a subqrcode and finally concatenate these subqrcodes to get the desired result.Can any one help me to find other method that is easier to implement.
Try to resize and compress the image and then convert the compressed image to base64 encoding. This base64 string will be comparatively small. Now generate QR code based on this string. You have to find the trade-off between quality of image and it's size.

how to insert an image in mysql -android

Recently I was working on MySql and Sql, where I found I can almost insert everything primitive type data but is it possible to store a jpeg/jpg/bmp/png (image)file in a database. If so then can you please write the code. Don't need to explain the whole thing just the key point.
Thanks
1 Perhaps convert the image to a Byte Array (if it's not bmp, then convert it), then store it in MySql as a Blob type, then when reading it, you can create a Bitmap through the code (I don't know what language you're using) with the Byte Array with what you read, or perhaps just get the code associated with the image and store that and read it.
Converting an image to a Byte Array
2 Use an image hosting API (like Imgur) and have the user's image upload to that site, and just read the URI from the database whenever you want to use it.
Imgur API, Android Example
there is 3 cases how to make it (that is i know)
Save path from SD card like String in database
Save int value if image is in res folder of your app.
Save url like String if image is in Internet.
Sorry for the late response. However, I found a way to convert the image to String and then store it in the mysql.
This answer is just for those who are still looking for a easy solution:
code:
Bitmap bm = BitmapFactory.decodeFile("/path/to/myImage.jpg");
ByteArrayOutputStream baos = new ByteArrayOutputStream();
bm.compress(Bitmap.CompressFormat.JPEG, 100, baos);
byte[] b = baos.toByteArray();
and then:
String encodedImage = Base64.encodeToString(byteArrayImage, Base64.DEFAULT);
Then the encodedImage which is a String format, I can insert into the db.
Hope that helps other who are still looking for the answer.

Android: System.out: "resolveUri failed on bad bitmap Uri:[B#4072aa78" Prompt when resotre image stream to ListView

I have referred couple of similiar articles regarding the message prompted from System.
The image string is a byte array type Bitmap format. It was encoded to string format by using andorid's Base64 class tool. Then it was saved to mysql DB with Blob format.
On my new App, I want reload the Blob image sting to ListView and show the image: I tried two approaches, but all were failed loading image to listview:
a. put the re-loaded Blob imange(it is a string text type) as value of HashMap's key/value pairs. And then,initial an Adaper (ex. SimpleAdapter) to load the key/vales' and then try to show it on ListView(failed).
b. Similar a, but use Base64 decode method to decode the Blob image back to byte array first. And take it as Byte array type as value of hashMap's key/vale pair.(failed)
I have had studied this problem couple of days and no progress for this problem. If I used wrong process before, Please guide me to correct it, thanks !
By the way. the stored Blob image string can be re-loaded and display to ImageView using
imageview.setImageBitmap(bitmap) method without problem. So, the stored image string data is valid bitmap data. However, this method can not be used on ListView.

How do I decode base64 blob to bitmap Android?

I have a Sqlite database in which a base64 code string is stored as a BLOB. I want to fetch this BLOB from the db and decode the base64 and show the image in an ImageView.
I have read about encoding and decoding base64 and this is what I am using now.
String[] image = new String[100000];
if (cursor.moveToFirst()){
int i = 0;
do {image[i] = cursor.getString(1);
i++;}
while (cursor.moveToNext());
String imagebyte = image[0];
byte[] decodedString = Base64.decode(imagebyte, Base64.DEFAULT);
Bitmap decodedByte = BitmapFactory.decodeByteArray(decodedString, 0, decodedString.length);
mImage.setImageBitmap(decodedByte);
But nothing shows up and I don't get any error messages. In order to pinpoint the problem I tried encoding and decoding an image, and then the bitmap showed. Is this the right way to decode it? I am here using cursor.getString(1), I have tried with using getBlob(1) also, but still nothing shows. Should I use getString or getBlob?
Is there an easy way to check validity of the base64 code? THanks!
I have a Sqlite database in which a base64 code string is stored as a BLOB.
Why? Why not just put the image in the BLOB? What are you gaining by Base64-encoding it? It is costing you CPU time, garbage collection time, and storage space.
String[] image = new String[100000];
Why do you think you need 100,000 String objects?
do {image[i] = cursor.getString(1);
i++;}
while (cursor.moveToNext());
Why are you retrieving this column for all rows in your result set, when you are only using one of them? Particularly considering you are obviously doing all of this on the main application thread, and therefore you will eventually crash with an application-not-responding (ANR) error?
Also, if this column is declared in your database a BLOB, are you sure that getString() will work as you expect?
Is this the right way to decode it?
That would depend upon how you encoded it.
Should I use getString or getBlob?
That depends on how you put the data in the table and what data type the column has. They should all match.
But I would just get rid of all the Base64 stuff and store the image byte array in the BLOB column, if you want an image in a table.

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