Develop Reference

How to decode a very large image on android?

I am decoding an image(ARGB) that is 8000x8000 pixels, so in uncompressed form it reaches
(2 + 2 + 2 + 2) * (8000 * 8000) = 488 MB
and crashes the android. I don't want to sample the image because I am converting the bitmap to byte array and sending it in a PUT request. I have tried "decodeRegion" but I don't know how to stitch the data(i.e. byte arrays) back together , since they have the head info at start and just concatenating them isn't helping.

Use an HTTP client library that allows you to upload from a file or stream, so that you do not need to decode the image and try to hold it in memory. OkHttp has options for this; see this recipe for streaming a POST request, this recipe for POSTing a file, or this recipe for multipart POSTs. Those techniques should be adaptable to a PUT request.

Why are you reading in a large image, decoding it, then posting the byte array? That's the wrong way to do it.
If your API actually requires the decoded bytes, fix it. More likely it wants the file's raw data. In which case you just need to use any networking API that gives you an OutputStream, and read in the file's data 1 MB at a time, reading it from the File's InputStream and writing it to the socket's OutputStream

Posting jpeg file as text in Android

I have a photo (jpeg) format in an Android device. Instead of posting the file as a file using HTTP I prefer to convert that to a string and post it as string using http to a spreadsheet. I understand jpeg files are encoded and opening them as string shows funny characters. My question is if I send these characters as string using http, can I get them back on the other side using a binary file editor and save them as jpeg?

One thing you can do is, on client side:
1.Convert image to byte array.
Path path = yourImageFile.toPath();
byte[] byteArray = Files.readAllBytes(path);
2.Encode the byteArray to Base64 String.
String encodedString = Base64.encodeBase64URLSafeString(byteArray);
3.That's it, send via http.
I'm not really sure what you mean by a binary file editor, but from server side you can retrieve the image like this (if using Java):
byte[] decodedByte = decodedBase64.decodeBase64(encodedString);
FileOutputStream out = new FileOutputStream("newPathToYourImage");
out.write(decodedByte);
out.close();

How to read base64 encoded picture from rails by android

I want to send an base64 encoded picture from ruby on rails to android.
Sending the data to rails included the picture encoding and decoding works, the data transfer from rails back to android works also, but I can't decode the picture, which was encoded by rails. I always get a NullpointerException at the following marked line:
imageOutFile = new FileOutputStream(file);
byte[] bytes = Base64.decode(imageString, Base64.URL_SAFE);
Bitmap bitmap = BitmapFactory.decodeByteArray(bytes, 0, bytes.length);
**bitmap.compress(Bitmap.CompressFormat.JPEG, 100, imageOutFile);**
The encoded string looks like the following (it's the shortest one):
_9j_4AAQSkZJRgABAQEASABIAAD_4Se-RXhpZgAASUkqAAgAAAALAA4BAgAUAAAAkgAAAA8BAgAUAAAApgAAABABAgAJAAAAugAAABIBAwABAAAAAQAAAA==
Another string is this:
_9j_4AAQSkZJRgABAQEAAQABAAD_2wBDAAEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQH_2wBDAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQH_wAARCAHgAoADASIAAhEBAxEB_8QAHAABAQEBAQEBAQEAAAAAAAAAAAoICQcGAgED_8QARRAAAQIBCAYIBAQEBwACAwAAAAYHBQEECAkZOIe3AxQVFqfWAhhWV1iWl9cXaNXnERIjJRM2VfAkJic1UZSkUmchMjf_xAAXAQEBAQEAAAAAAAAAAAAAAAAACQEH_8QAMxEBAAAEAwUGBQMFAAAAAAAAAAEGB1YCGJYDcbHV1ggXQUam8AURFjFRYaG1IYGRxcb_2gAMAwEAAhEDEQA_AIPwAAAAAAACo6rguPM3iPm-vCXEqOq4LjzN4j5vrwDbQAAAAAAABLnWM33Hqw4yoQ5UYS51jN9x6sOMqEOBiMAAAAAAAAqOq4LjzN4j5vrwlxKjquC48zeI-b68A20AAAAAAAAS51jN9x6sOMqEOVGEudYzfcerDjKhDgYjAAAAAAAAKjquC48zeI-b68JcSo6rguPM3iPm-vANtAAAAAAAAEudYzfcerDjKhDlRhLnWM33Hqw4yoQ4GIwAAAAAAACo6rguPM3iPm-vCXEqOq4LjzN4j5vrwDbQAAAAAAABLnWM33Hqw4yoQ5UYS51jN9x6sOMqEOBiMAAAAAAAAqOq4LjzN4j5vrwlxKjquC48zeI-b68A20AAAAAAAAS51jN9x6sOMqEOVGEudYzfcerDjKhDgbYsbvmb4PfdIWN3zN8HvukdtABxLsbvmb4PfdIWN3zN8HvukdtABxLsbvmb4PfdIWN3zN8HvukdtABxLsbvmb4PfdId
In Logcat I get a message like this, after the failed decoding:
--- decoder->decode returned false
I encode the string with the following method and send the string with a json object to android. The picture was uploaded with the uploader of CarrierWave.
Base64.urlsafe_encode64(File.read("public#{picture_path.to_s}"))

I have to read the file binary ("rb") and then encode it.
Base64.encode64(File.open("public#{picture_path.to_s}", "rb") {|io| io.read})

Send byte array of a Bitmap using http post in android?

In my application I need to call an API Using Http Post to send some information to the web server. So I need to append userid, name, phoneNo and image to the url. I need to convert the image to a byte array and append it to url. I used the following code but it didn't work for me. I just got a byte array like this [B#4055dd90
My code is
Bitmap bitmap1 = ((BitmapDrawable) d).getBitmap();
ByteArrayOutputStream stream = new ByteArrayOutputStream();
bitmap1.compress(Bitmap.CompressFormat.PNG, 100, stream);
byte[] bitmapdata = stream.toByteArray();
Can Some one please help Me ?
Thanks in advance !

Two things:
Images can get pretty big. So, you may be better off using a JPG, as you can compress it (a PNG does not compress). So, you'd use Bitmap.CompressFormat.JPEG and set the amount of compression you want.
When sending in your post, you should encode the byte[] like this: Base64.encodeBase64String( bitmapdata);
Let me know if that works for you. OH, and don't forget to unencode it on your server side.

You can not send the images in the byte array form directly to server. You have to encode it into Base64 String with the help of Base64 Class. Encode Bitmap byte array to Base64 string and send that string to server with the help of HTTPPost method. If you have any doubt then you can comment.

Android: get image from base64binary format

I use web service to get image. The service response contains image in base64Binary format. I try to decode response data with Base64.decode() (http://iharder.sourceforge.net/current/java/base64/). See my code below:
byte[] data = Base64.decode(responseString);
Bitmap bmp = BitmapFactory.decodeByteArray(data, 0, data.length);
imageView.setImageBitmap(bmp);
decodeByteArray always return null.
I try to save data in .png file. I can open this file on my PC and in the Android File Manager application. But preview activity of File Manager couldn't open this file.
Then i try to parse this data using .NET client with Convert.Base64() method. And this image have been processing successfully. Then i compare byte array in image created with android client and .NET client. The differences were in sign of bytes. .NET uses unsigned bytes but Java use only signed bytes. Is this is a reason of my problem?
Is anybody have the same problem in decoding of base64Binary?

Here is one solution, and for me is working (knowing that the format in which the image comes from the server through the web service is base64binary)
decodedIcon[] = null;
byte[] bb = (resposeString).getBytes("utf-8");
decodedIcon = Base64.decodeBase64(bb);
Bitmap bitmap = BitmapFactory.decodeByteArray(decodedIcon, 0,
decodedIcon.length);
//then you get the image view and setImageBitmap(bitmap)
PS:
Base64.decodeBase64 comes from the library org.apache.commons.codec.binary.Base64;
You should have commons-codec-1.3.jar included in the assets folder
the version doesn't have to be 1.3
Thanks to one of my friends for this hint.