Android Example OCR OFFLINE - Tesseract

joilts · Dec 1, 2016

roberto64 said:
hello joilts, or Picasso used to trasfomare the image and tesseract ocr for riconoscimeto of letters and numbers with no success, if you can help me with some examples to you already, but unfortunately not familiar java vb net.
greetings Roberto

Roberto, I do not have permission to share the code for this project, but you can find examples at Internet as here. For more details about the javaccp libraries, you can access this link.
Here is a sample code I found at internet (unfortunately I do not have the original link):

B4X:

IplImage grayImg = cvCreateImage(cvGetSize(orgImg),orgImg.depth(),1);
            cvCvtColor(orgImg,grayImg,CV_BGR2GRAY);
cvThreshold(grayImg,grayImg,127, 255, CV_THRESH_OTSU+CV_THRESH_BINARY);   
cvErode(grayImg,grayImg,null,1);
cvDilate(grayImg,grayImg,null,1);

Hope it helps.

roberto64 · Dec 1, 2016

thanks for your time, unfortunately not familiar java, thanks anyway

joilts · Dec 1, 2016

roberto64 said:
thanks for your time, unfortunately not familiar java, thanks anyway

Unfortunately my solution was based on inline java code. I wrote a sample to encapsulate transformation functions in a b4a class. See if it helps a little. You have to save image in same place at device and send image path, name, extension and a name for the image to be saved after transformation. It´s an exemple and the best solution looking for performance is to create a single method to do all transformations U need and avoid many reads and saves. I had no time to test this code (sorry for that).

B4X:

Sub Class_Globals
   
End Sub

'Initializes the object. You can add parameters to this method if needed.
Public Sub Initialize

End Sub


Public Sub GrayImage(dir As String, fileName As String, extension As String, newFileName As String)
     Private NativeMe As JavaObject
Try
Try
        NativeMe.InitializeContext
        File.Copy(dir,fileName&extension,global.dir, "1_"&fileName&extension)
        Dim path As String = dir
        Dim name As String = "/1_"&fileName
        NativeMe.RunMethod("converttoGray",  Array (path,name,extension,global.dir, newFileName ))
Catch
    Log("error")
End Try
Catch
    Log("error")
End Try
End Sub


Public Sub ThesImage(dir As String, fileName As String, extension As String, newFileName As String)
     Private NativeMe As JavaObject
Try
Try
        NativeMe.InitializeContext
        File.Copy(dir,fileName&extension,global.dir, "1_"&fileName&extension)
        Dim path As String = dir
        Dim name As String = "/1_"&fileName
        NativeMe.RunMethod("ThrsholdImage",  Array (path,name,extension,global.dir, newFileName ))
Catch
    Log("error")
End Try
Catch
    Log("error")
End Try
End Sub



Public Sub DilateImage(dir As String, fileName As String, extension As String, newFileName As String)
     Private NativeMe As JavaObject
Try
Try
        NativeMe.InitializeContext
        File.Copy(dir,fileName&extension,global.dir, "1_"&fileName&extension)
        Dim path As String = dir
        Dim name As String = "/1_"&fileName
        NativeMe.RunMethod("DilateImage",  Array (path,name,extension,global.dir, newFileName ))
Catch
    Log("error")
End Try
Catch
    Log("error")
End Try
End Sub

Public Sub ErodeImage(dir As String, fileName As String, extension As String, newFileName As String)
     Private NativeMe As JavaObject
Try
Try
        NativeMe.InitializeContext
        File.Copy(dir,fileName&extension,global.dir, "1_"&fileName&extension)
        Dim path As String = dir
        Dim name As String = "/1_"&fileName
        NativeMe.RunMethod("ErodeImage",  Array (path,name,extension,global.dir, newFileName ))
Catch
    Log("error")
End Try
Catch
    Log("error")
End Try
End Sub



#If JAVA

import static org.bytedeco.javacpp.opencv_core.IplImage;
import static org.bytedeco.javacpp.opencv_core.cvCreateImage;
import static org.bytedeco.javacpp.opencv_core.cvGetSize;
import static org.bytedeco.javacpp.opencv_imgproc.CV_BGR2GRAY;
import static org.bytedeco.javacpp.opencv_imgproc.CV_THRESH_OTSU;
import static org.bytedeco.javacpp.opencv_imgproc.CV_THRESH_BINARY;
import static org.bytedeco.javacpp.opencv_imgproc.CV_THRESH_TRUNC;
import static org.bytedeco.javacpp.opencv_imgproc.CV_THRESH_BINARY_INV;
import static org.bytedeco.javacpp.opencv_imgproc.cvThreshold;
import static org.bytedeco.javacpp.opencv_imgproc.cvCvtColor;
import static org.bytedeco.javacpp.opencv_imgproc.cvErode;
import static org.bytedeco.javacpp.opencv_imgproc.cvDilate;
import org.bytedeco.javacpp.BytePointer;
import static org.bytedeco.javacpp.lept.PIX;
import static org.bytedeco.javacpp.lept.pixRead;
import static org.bytedeco.javacpp.lept.pixDestroy;
import static org.bytedeco.javacpp.opencv_imgcodecs.cvLoadImage;
import static org.bytedeco.javacpp.opencv_imgcodecs.cvSaveImage;



public static void converttoGray(String path, String filename, String extension, String result_name) {
        IplImage orgImg = new IplImage();
        orgImg = cvLoadImage(""+path+filename+extension);
        if (orgImg != null) {
            IplImage grayImg = cvCreateImage(cvGetSize(orgImg),orgImg.depth(),1);
            cvCvtColor(orgImg,grayImg,CV_BGR2GRAY);
            cvSaveImage(path+result_name+extension, grayImg);
        }
}


public static void ThrsholdImage(String path, String filename, String extension, String result_name) {
        IplImage orgImg = new IplImage();
        orgImg = cvLoadImage(""+path+filename+extension);
        if (orgImg != null) {
            IplImage grayImg = cvCreateImage(cvGetSize(orgImg),orgImg.depth(),1);
            //Threshold binary
            cvThreshold(grayImg,grayImg,127, 255, CV_THRESH_OTSU+CV_THRESH_BINARY);    
            cvSaveImage(path+result_name+extension, grayImg);
        }
}

public static void ErodeImage(String path, String filename, String extension, , String result_name) {
        IplImage orgImg = new IplImage();
        orgImg = cvLoadImage(""+path+filename+extension);
        if (orgImg != null) {
            IplImage grayImg = cvCreateImage(cvGetSize(orgImg),orgImg.depth(),1);
            cvErode(grayImg,grayImg,null,1);
            cvSaveImage(path+result_name+extension, grayImg);
        }
}

public static void DilateImage(String path, String filename, String extension, , String result_name) {
        IplImage orgImg = new IplImage();
        orgImg = cvLoadImage(""+path+filename+extension);
        if (orgImg != null) {
            IplImage grayImg = cvCreateImage(cvGetSize(orgImg),orgImg.depth(),1);
            cvDilate(grayImg,grayImg,null,1);
            cvSaveImage(path+result_name+extension, grayImg);
        }
}

#END IF

roberto64 · Dec 1, 2016

thank you very much test tomorrow.
regards

roberto64 · Dec 2, 2016

hello joilts, bad value B4A version: 6.31
Parsing code. (0.01s)
Compiling code. (0.11s)
Compiling code layouts. (0.01s)
Organizing libraries. (0.00s)
Generating R files. (0.14s)
Compiling code debugger engine. (2.06s)
Compiling generated Java code. error
javac 1.8.0_102
src \ B4A \ example \ immaginecls.java: 283: error: illegal start of type
public static void ErodeImage (String path, String filename, String extension,, String result_name) {
^
1 error
and also
public static void DilateImage (String path, String filename, String extension,, String result_name) {
IplImage orgImg IplImage = new ();
orgImg = cvLoadImage ( "" + path + filename + extension);
if (orgImg! = null) {
IplImage grayImg = cvCreateImage (cvGetSize (orgImg), orgImg.depth (), 1);
cvDilate (grayImg, grayImg, null, 1);
cvSaveImage (path + result_name + extension, grayImg);
}
}

thanks for your help

roberto64 · Dec 2, 2016

** Activity (main) Create, isFirst = true **
** Activity (main) Resume **
Error occurred on line: 18 (Immaginecls)
java.lang.RuntimeException: Method: converttoGray not found in: b4a.example.main
at anywheresoftware.b4j.object.JavaObject$MethodCache.getMethod(JavaObject.java:366)
at anywheresoftware.b4j.object.JavaObject.RunMethod(JavaObject.java:119)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at anywheresoftware.b4a.shell.Shell.runVoidMethod(Shell.java:753)
at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:343)
at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:247)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:134)
at anywheresoftware.b4a.BA.raiseEvent2(BA.java:157)
at anywheresoftware.b4a.BA.raiseEvent(BA.java:153)
at anywheresoftware.b4a.objects.ViewWrapper$1.onClick(ViewWrapper.java:78)
at android.view.View.performClick(View.java:4639)
at android.view.View$PerformClick.run(View.java:19252)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:146)
at android.app.ActivityThread.main(ActivityThread.java:5511)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1283)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1099)
at dalvik.system.NativeStart.main(Native Method)

joilts · Dec 2, 2016

roberto64 said:
** Activity (main) Create, isFirst = true **
** Activity (main) Resume **
Error occurred on line: 18 (Immaginecls)
java.lang.RuntimeException: Method: converttoGray not found in: b4a.example.main
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1099)
at dalvik.system.NativeStart.main(Native Method)

Here is a sample project running. Did some fixes to the code I sent before. You will need to find the right parameters to work with images you use.

roberto64 · Dec 2, 2016

thanks for your time, in the compilation tells me that "the program and was arrested" on my device
thank you

joilts · Dec 2, 2016

roberto64 said:
"the program and was arrested"

Sorry did not understood this part of your message.

roberto64 · Dec 2, 2016

hi, by running the program on my smartphone, see image,
regards

joilts · Dec 2, 2016

roberto64 said:
hi, by running the program on my smartphone, see image,
regards

Roberto, unfortunately I do not understand Italian (my native language is Portuguese), but I tried to google this message and got some links with "Soluzione" attached, like this one. Are you using an Samsung Device with Knox? When searched the message in english, got many links indicating that Knox may be a motive. But as told before, I can be totally wrong in my Italian interpretation.

roberto64 · Dec 2, 2016

jolts I have installed on my Samsung device with Knox, I can not understand the problem later with another smatphone'll try and see if you encounter the same problem.
regards

roberto64 · Dec 3, 2016

joilts problem is not solved even with other smartphones that mistake, I think the problem and the java code,
greetings and thanks

joilts · Dec 3, 2016

roberto64 said:
joilts problem is not solved even with other smartphones that mistake, I think the problem and the java code,
greetings and thanks

I executed this project with no errors on my S4 (without knox) and on my Xperia Z3 compact. I have tested JavaCode also at Android Studio. Unfortunately I have no idea why it does not works to you. The only thing I can came up is that we are not using the same version of javaccp libs. If you wanna try one more time, I have uploaded my Additional Libs Folder to this link. This can be the problem.

roberto64 · Dec 4, 2016

joilts thanks for your time you are great works fine thank you very much excuse me for my English.

roberto64 · Dec 8, 2016

hello, I run your script but as you see the picture that I see are so.
thank you

joilts · Dec 8, 2016

roberto64 said:
hello, I run your script but as you see the picture that I see are so.
thank you

You need to test and find the right parameters for the transformations you need. At my example, I took random values to dilate an erode. You need to find the right values and combine them to get the best and clean black and with image to your images. Here is an example of a Brazilian plate I got from internet.

roberto64 · Dec 8, 2016

I can not understand what the values to change, what part of the code, I tried in vain to change the code on the routines of java "DilateImage" and "ErodeImage"
thank you

joilts · Dec 9, 2016

roberto64 said:
I can not understand what the values to change, what part of the code, I tried in vain to change the code on the routines of java "DilateImage" and "ErodeImage"
thank you

Unfortunately I can´t help you with this. I tested your image with some different configurations and got something near to what you going to need. Try this settings and try to change values to them.

B4X:

IplImage grayImg = cvCreateImage(cvGetSize(orgImg),orgImg.depth(),1);
cvCvtColor(orgImg,grayImg,CV_BGR2GRAY);
cvThreshold(grayImg,grayImg,127, 255, CV_THRESH_OTSU+CV_THRESH_BINARY);    
cvErode(grayImg,grayImg,null,1);
cvDilate(grayImg,grayImg,null,1);
cvSaveImage(path+"/base_pict"+extension, grayImg);

roberto64 · Dec 9, 2016

I thank you for your disponibiltà and the time you're losing me, I tried your routines is fine to do the image B & W, realizing edesso comene works that I can put inside other commands in rurine fact I added "IplConvKernel mat = cvCreateStructuringElementEx (5, 5, 2, 2, CV_SHAPE_RECT);
cvErode (grayImg, grayImg, mat, 1); so I more black letters and numbers, but I noticed that tessdata OCR does not recognize well the numbers and sometimes letters.
I thank you you're great.

Android Example OCR OFFLINE - Tesseract

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