Develop Reference

Tesseract character recognition problems in Android (but not on iOS?)

I've build an application that uses Tesseract (V3.03 rc1) to identify some specific text strings. These are, unfortunately, printed on a custom font that requires that I build my own traineddata file. I've built the application on both iOS (using https://github.com/gali8/Tesseract-OCR-iOS for inspiration) and Android (using https://github.com/rmtheis/tess-two/ for inspiration as well).
The workflow for both platforms is as follows:
I select a bounding box on the preview screen for where I can crop out the relevant text, and crop the image accordingly.
I use OpenCV to get a binary image (using OpenCV's adaptive threshold function with the same parameters for both platforms)
I pass this binary image to Tesseract. Both platforms (Android and iOS) use the same traineddata file.
And yet, iOS recognizes the text strings perfectly, while Android keeps misidentifying certain characters (6s for Ss, As for Hs).
On both platforms, I use the same white list string, I disable load_type_dawg and load_system_dawg, and also choose to save the blob choices.
Has anyone encountered this kind of situation before? Am I missing a setting on Android that's automatically handled in iOS? Is there something particular about Android that hasn't crossed my mind?
Any thoughts or advice would be greatly appreciated!

So, after a lot of work, I found out what was wrong with my Android application (thankfully, it wasn't an issue with Tesseract at all). As I'm more familiar with iOS apps than Android, I wasn't sure how I could load the traineddata file onto the application without requiring the user to have the file loaded on their external storage device. I found inspiration in this project (http://www.codeproject.com/Tips/840623/Android-Character-Recognition), as they autoload the trained data file.
However, I misunderstood how it worked. I originally thought that the TessDataManager did a file lookup on the project's local tesseract/tessdata folder in order to get the trained data file (as I do this also on iOS). However, that's not what it does. It, rather, checks the internal file structure (data/data/projectname/files/tesseract/tessdata/traineddatafilegoeshere) to see if the file exists and if it doesn't, it copies over the trained data file it keeps in the Resources/Raw directory. In my case, it defaulted to the eng file, so it never read my custom font file.
Hopefully this helps someone else having similar issues. Thanks to Robin and RmTheis for all of your help!

How to create an MS Word document within an Android app

I want to create a word document within an android app and send that document through mail.
Is there any tutorial for creating a word document in android. I have gone through several other questions on this website but i didn't got a clear answer.
can we do this on Android using Apache POI.
If any any sample example exist then please mention.
Thanks in advance.

You can use any Java library in Android, so I do think this would be the way you could accomplish what you want (using Apache POI).
You can send the attachment by adding it as an extra to the Intent you use to create a mail message (lots of examples of that).

Apache POI looks your best bet, but note that the component that deals with Word docs only supports simple files:
HWPF and XWPF for Word Documents
HWPF is our port of the Microsoft Word 97 (-2003) file format to pure Java. It supports read, and limited write capabilities. It also provides simple text extraction support for the older Word 6 and Word 95 formats. Please see the HWPF project page for more information. This component remains in early stages of development. It can already read and write simple files.
We are also working on the XWPF for the WordprocessingML (2007+) format from the OOXML specification. This provides read and write support for simpler files, along with text extraction capabilities.
You should seriously consider whether you can use a different format for your emails - plain text, or maybe HTML.

What is the best way to add external languages to android application in runtime

Our client application has means of updating a "language file" from a server occasionally. Yet it seems quite a challenge to support it on android..
I tried using inflate( XmlPullParser, ... ) but later found it doesn't support non-binary XML files.
The following are given:
Our app uses #string/resource_id resources to support languages. Basically it supports English, but the requirement is to provide language resources dynamically. That is, if we need to support Greek, or provide a change to the Greek language texts, we should be able to provide that on runtime.
So, on runtime our app connects a service and downloads an XML file, with syntax similar to string.xml in the current language.
What remains is how to change the text resources in the application in a sane manner (not one by one..)
I tried using inflate(with the XmlPullParser parameter) but it seems to be intended for use with binary pre-compiled XML files. To use that it would require to binarize the XML before hand, and that would be less compatible, not to say that aapt.exe tool is less documented, especially in my case.
So, any idea?

Don't know if it can be done everywhere in Android but instead of using native resources reference, maybe you can use the Java Properties class and using the device locale configuration to retrieve the wanted strings programmatically?

Parse Android xml file instead of iOS .strings

So as mobile developers, every time we translate one of our apps we have to translate both Android and iOS strings files. These files contain 90% of the same strings just the file is in a different format.
Does anyone know if there is an NSLocalizedString override to read from Android compatible .xml files? or if this is even possible?
Alternatively, is there a command line tool to convert between the two formats?

This does what you need, but not from the command line.
http://localise.biz/free/converter/ios-to-android
The full system has an API though. If you register you'll be able to pull your translations into .strings or Android XML files from the command line, or programmatically via a simple script.

So it turns out this kind of tool doesn't exist. I created a toolchain and posted it here.
If there is activity I will develop it further.

For a recent project which already had 19 translations, I was also looking for a script to convert the XCode Localizable.strings files to Android Eclipse format.
I found convertLocalizable.rb but I can't work with ruby, so I've created a Javascript based on it, see link below. You have to cut and paste each file but it works great.
Javascript XCode Localizable.strings and Android strings.xml convertor

Here's a simple script that will generate iOS Localizable.strings from Android strings.xml files.

Try Twine - a robust project for converting resources.

Is there a way to add or change Android apps language after packaging it into an APK?

In the case of a windows application(EXE/DLL), we can change or add language resources within the binary without re-compiling it. Can the same be done in case of an Android application? Is there any editor available to make this happen?
My plan is to develop the application in English and then release it to the sales department, where they will be responsible for the localization of the application without compiling and packaging it into a new APK. I just want to split the development part and localization part of the app.

The correct way to localize is to create a string resource for your base language and then have that localized and reimported into your project for every language that you support.
Much more detail can be found in the Localization documentation.
I don't believe there is a safe/supported way to inject localized strings into your app after it's been built.

No. You can not, because once your apk is signed then modifying it after this (you can always do that as apk is just a zip file) will corrupt the signed binary.

When having multiple languages with your application you have to build them into the application itself. Android uses XML files to store strings used within your application. Android allows you to add language localization files containing local specific strings. You can't do this without recompiling your project so you'll want to do it as a future update or right from the start. But you can't have the marketing department do it, that's just not a good idea.

As others have said, the short answer is no. The long(er) answer is sort of. If you pack all your language resources into remote XML that can be updated from the web, then with a little bit of forethought you can do all sorts of live updates to your app's strings, graphics, etc.

So if you want to use the standard R.string method for everything it will be a little difficult. I think it's possible to do something funky with a dynamic classloader for the assets and static dex classes (basically classes of data with just inline byte arrays that can be decoded after). However that would still require compiling. See Custom Class Loading in Dalvik for more info.
Another approach would be more of a standard Java implementation. Java has a class known as ResourceBundle. You could create a ResourceBundle from a property file (key-value plain text, or even property xml). Then these files could be loaded outside the apk, via a network connection or sdcard or other file type resource and deleted as necessary. You will have to write the loader code for it, but that's going to happen with any solution. This solution will be less performant and outside the standard design methods for android but it will solve the problem being asked to solve. Like you won't be able to use R.string or #string/whatever for any of these resources but I think you may be able to write an adapter to such resources (like your own TextView extension and whatever that would allow all of this). It's a matter mostly of how much work you want to invest in solving this actual problem.
Honestly I would opt for trying to distribute whole apks with only the targeted language if you are trying to save space, but then there is no way to change locale for the app at runtime :(