DesignSpark Electrical Logolinkedin
Menu Search
Ask a Question

25 Oct 2017, 15:47

DesignSpark AR app - OCR module for Unity

The DesignSpark AR app has broken new ground both in making RS Components the first international distributor to provide the majority of their product catalogue as 3D models in Augmented Reality, AND to provide the first of its kind integration of Google's Tesseract OCR engine into a Unity (C#) project.







Unity mobile developers can now import this wrapper as a package into their C# project and build-in accurate optical text recognition, courtesy of Google's open source Tesseract OCR engine. Help documentation to import a Unity package is available here:

Read more about the DesignSpark AR app development journey here:

Apply here to test the DesignSpark AR app:


DOWNLOAD Unity wrapper for Google Tesseract

Become a DesignSpark member or Login now to complete the form and get the download link to the Unity package.

A curious mind with a passion for 3D CAD & rapid prototyping.

25 Oct 2017, 15:47


August 20, 2018 10:32

Also getting the "" error, tried the platform on both iOS and Android. Anyone solved this?

0 Votes

June 1, 2018 07:53

Hello, nice wrapper, I still have 2 questions.

1) What is the version of tesseract?

2) Is there any chance you could set font to recognize or some machine learning way?


0 Votes

June 20, 2018 07:56

@vratisalvino you just call tesseract.Version(); its version 3.05.00 ;-)

[Comment was deleted]

April 12, 2018 14:16

Hi all,

Make sure to choose the right target platform 'Android/iOS' in File > Build Settings. This is to enable the platform dependent compilation in Unity.

Next, here are a couple steps to demo the plugin on Android (courtesy of user 'gtzpower' on the Unity forum):

1. Set Android as your build target
2. Import the Unity wrapper which is downloadable from the above article.
3. Next, import this package:
4. Build and run the Demo scene to your Android device (it does not work in the Unity editor)

The "TestImage.jpg" is passed into Tesseract and should have it's text printed on the screen.

Further help can be sought on the Unity AR/VR forums:

0 Votes

April 12, 2018 07:48

I have the same problem with "" as Deathpyre @N1ck @Deathpy reshamain, any help is wellcome

0 Votes

March 20, 2018 07:57

Hi, I want to read simple math equations with numbers and operators. Bit i want to read them from camera. How can i achieve this plugin?

I have passed this image in Demo script and it is working fine. I need to read from camera. Please help me with that.

0 Votes

April 12, 2018 07:48

@TalhaDX Can you please share your working project? I can't even manage to have a working demo. thank you

April 12, 2018 07:34

@TalhaDX Hi, can you please share your project? I just get the demo script working. I get an error loading "".

June 7, 2018 08:27

@joxevc having the same issue since one day. Anyone has any update on this error ?

March 6, 2018 08:52

When I export my app for iOS and try to run it on an iOS device, the build fails with an Apple Match-O Linker (id) Error. Lots of undefined symbols in TesseractOCR apparently - any ideas why that might be? I am using a very simple setup where I just constantly update a string to use Tesseract with my camera texture ...

0 Votes

March 5, 2018 09:04

Im not sure what my issue is... I try to run TesseractWrapper.Init and it gets an error of just "" which makes the handle null. Anyone have an idea?

March 6, 2018 09:06

I'm having this issue too. After digging around in the VS dubugger, Init() fails with a message of "". I will be digging deeper and will post any updates.

April 3, 2018 08:00

@N1ck @Deathpyre did you guys come up with a fix for this. im having the same error

March 2, 2018 09:06

For those getting the 'tesseractClass' does not exist error, you will likely notice that tesseractClass is declared at the top of the file ONLY for iOS and Android. Make sure your target platform is set to one of those 2 in your build settings.

March 5, 2018 09:19

@gtzpower Just came here to say this, but it looks like you beat me to it :). I ended up copy/pasting the statement in the #elif in the class declaration just to quiet the console error until I switched build platforms.

February 27, 2018 08:32

I am also getting the same issue as @alok100 mentioned. Cannot understand why it is happening. Any lead will be appreciable. Thanks in advance.

March 2, 2018 09:05

Found how to solve the issue. In the build settings, switch to Android/iOS. Then the error will be gone.

February 9, 2018 16:15

Hi 'alok100', see line 49 of your code. This is where the problem lies, the compiler is not able to find a function with the name 'tesseractClass'. Take a look at how you defined the function initially, as they are case sensitive. Maybe, it's 'TesseractClass'? I'd suggest posting queries like these directly on the Unity forums, where there is a larger developer community available to help:

@shamain: I'll be looking into the issue you've reported next.

0 Votes

[Comment was deleted]

February 9, 2018 08:57

getting error Assets/tesseract/TesseractWrapper.cs(49,10): error CS0103: The name `tesseractClass' does not exist in the current context

0 Votes

[Comment was deleted]

[Comment was deleted]

[Comment was deleted]

[Comment was deleted]

[Comment was deleted]

January 31, 2018 09:08

Hi There,
First big thanks for the ocr plugin. When i import the package to unity and built a sample android app i see "unable to load" message in log and no detected text. What would be the issue here ?.

0 Votes

June 7, 2018 08:25

@shamain did you figure out to resolve the issue ? I am facing the same problem

January 10, 2018 11:38

Great article Joy! Looking forward to seeing the advances in the app in the future.

0 Votes