Android Tutorial [Example] Add OCR features to your Android application

This example demonstrates how you can use an OCR web service to recognize text in camera images.

The program allows you to take a picture and then send it to OCRWebService.

OCRWebService returns the recognized text in various formats. This is not a free service, however they offer a free trial and their prices are not high.

Camera picture:

Recognized html:

While the response is not perfect, the text can still be extracted.

The web service is a SOAP web service. The request is created by loading a template file and changing its fields. The response is then parsed and the data file is extracted.

In order to run this example you need to create an account and enter your user name and license key.

Updated example written by DonManfred: https://www.b4x.com/android/forum/t...-android-application.27080/page-2#post-656725

 

[susu]

Hi Erel, is it a free service? Because I see this page OCRWebService.com - OCR Web Service enables you to convert scanned documents to Text, Word, or PDF files

Edit: Sorry, I just read all your post and you mentioned that it's not free.

 

[laviniut]

I tried OCR example with a trial account on OCRWebService. But the application is never focusing on camera and when send picture, application stopped with error main_buildrequest (java line: 337) and after is java.lang.OutOfMemoryError.
I have Galaxy S2 and android 4.1.2
Why is that ?

 

[Erel]

You should decrease the picture size. You can change the size of the picture taken with CameraEx.SetPictureSize.

 

[laviniut]

i use this <code
Sub Camera1_Ready (Success As Boolean)
If Success Then
CamEx.SetContinuousAutoFocus
CamEx.SetJpegQuality(90)
CamEx.SetPictureSize(380, 480)
CamEx.CommitParameters
CamEx.StartPreview
Else
ToastMessageShow("Cannot open camera.", True)
End If
End Sub
code/>
but the same error.
i think CameraExClass is not working good for me, because autofocus is not working, and the size of picture taken is same (maximum).

 

[Erel]

Have you checked whether this picture size is supported? You should call GetSupportedPicturesSizes.

You should download the latest CameraEx class for an auto-focus feature.

 

[laviniut]

I updated CameraEx class. Thank you. Now autofocus is working. And yes, size i wanted for picture is not suported. So i have to set other size. But when i use Log(CamEx.GetSupportedPicturesSizes()) the result is [Lb4a.example.cameraexclass$_camerasize;@41240d80
so, how can i get picture sizes ?

 

[laviniut]

Now OCR example with my trial account is working.
but CamEx.SetContinuousAutoFocus is not working. only CamEx.FocusAndTakePicture is working.
i can set and get results with 800x480 picture size.

 

[Erel]

But when i use Log(CamEx.GetSupportedPicturesSizes()) the result is [Lb4a.example.cameraexclass$_camerasize;@41240d80
so, how can i get picture sizes ?

You should write:

Dim l1 As List = CamEx.GetSupportedPicturesSizes

You can then go over the items in the list.

 

[laviniut]

Thank you. is working CamEx.GetSupportedPicturesSizes.

 

[XverhelstX]

You can do offline Optical Character Recognition with RSTessOcr which is available here:

http://www.b4x.com/android/forum/th...-optical-character-recognition-offline.32335/

 

[Magics]

Hi,
I followed this guide and i am registered on Ocrwebservice.com, but i can not figure out how to configure the application with my profile registered in ocrwebservice.com

I found this code in the project source:

Sub BuildRequest (date () As Byte) As String
Dim req As String = template
req.Replace req = ("$ USER $", user)
req.Replace req = ("$ $ LICENSE" license)
req.Replace req = ("$ FILENAME $", tempfile)
Dim about As StringUtils
req.Replace req = ("$ DATE $", su.EncodeBase64 (date))
req.Replace req = ("$ $ LANGUAGE", "ENGLISH")
req.Replace req = ("$ OUTPUT $", "HTML")
Return req
end Sub

The fields "eg: $ USER $ - $ LICENSE $" are to be filled?
Iif the answer is yes.
I could give an example, how do I compile it?

Thanks in advance, Magics

 

[Erel]

You should set the two global variables:

Private user = "ENTER USER", license = "LICENSE" As String

 

[Magics]

Thank you Erel, now I try and let you know!

Magics

 

[sconlon]

I have been trying this example and sending various pictures some with only a few words on them and each in perfect focus. Each time I get a Job successful but no text is displayed and I can see that the 1.XML document contains an error "Recognition failed". It also advises to contact support but before doing that I thought I would ask here in case someone might know what is going wrong. I have attached the latest picture I sent, it is 640x480.

Thanks,
SC

 

[Erel]

I no longer have an account with them so I cannot test it. Sorry.

 

[NJDude]

You can give THIS library a shot.

 

[sconlon]

I contacted their support and got a reply back saying they no longer supported HTML as an output format. I changed it to TXT and it worked fine and the results were quite good.

I will try NJDudes's library as well and see how it performs.

Thanks.

 

[Tadeu Botelho]

I'm really in need of a professional OCR service on android.
I'm having a problem trying to compile the APK to use the OCR service in this example.
I did not change the sources. I just included my trial username and registration key to use the service.
Can someone help me identify?
Thank you

 

[GMan]

The error message is clear: a class file was not found

Try to uncomment the line (its only a log entry) and try again