JSON 64bit decoding bitmap from android to place in mysql BLOB - php

Question

Sending a image to mysql using android, json and php
I was able to get my bitmap converted to a properly formatted string using
converting-images-to-json-objects
Here is the code in android
JSONObject values = new JSONObject();
values.put(KEY_CONTRACTUUID, con.UUID);
...
if (con._sig != null) {
String encodedImage = getStringFromBitmap(con._sig);
values.put(KEY_CONTRACTSIGIMAGE, encodedImage);
private static String getStringFromBitmap(Bitmap bitmapPicture) {
/*
* This functions converts Bitmap picture to a string which can be
* JSONified.
*/
final int COMPRESSION_QUALITY = 100;
String encodedImage;
ByteArrayOutputStream byteArrayBitmapStream = new ByteArrayOutputStream();
bitmapPicture.compress(Bitmap.CompressFormat.PNG, COMPRESSION_QUALITY,
byteArrayBitmapStream);
byte[] b = byteArrayBitmapStream.toByteArray();
encodedImage = Base64.encodeToString(b, Base64.DEFAULT);
return encodedImage;
}
now that it is in base64 and a string I need to retrieve it properly to place in my BLOB in mysql
I am not using namevalue pairs or any of that nonsense - simply send it as json and get the json string like so:
$json = json_decode($HTTP_RAW_POST_DATA,true);
echo var_dump(HTTP_RAW_POST_DATA);
...
$varsigimage = $json['sigimage'];
$formatedJSONimage = "{'sigimage': '$varsigimage'}";
var_dump($formatedJSONimage);
$sigImagedecoded = json_decode($formatedJSONimage);
var_dump($sigImagedecoded);
i need to call json_decode on the image to get it out of 64bit to place in the blob correct?
However to do this I need to use the function json_decode, but json_decode assumes I will give it a JSONObject, and since I have many more objects in my $json object, i need to recreate a single JSON object with just the image inside of it, and pass that to the json_decode
but it retuns json_error of type SYNTAX
What am I doing wrong, What is the correct approach of converting the base64 string to a blob?
and yes, I am going to have the same question on getting it out of the blob back to a base64 string

Answer 1

json_decode parses a JSON string and returns an associative array, mimicking the key/value pairs in the JSON string.
It seems like you are missing another step: you need to decode the base64-encoded image string back to a bitmap. e.g. in your code:
$json = json_decode($HTTP_RAW_POST_DATA,true);
echo var_dump(HTTP_RAW_POST_DATA);
...
$varsigimage = $json['sigimage'];
$image_bitmap = base64_decode($varsigimage); // decode the string back to binary
You should now be able to save $image_bitmap as a BLOB in your database.