Android Question Read MRZ Data from a passport

[GeoffT660]

I've trying to read the MRZ data at the bottom of the passport using the Text Recognition example https://www.b4x.com/android/forum/threads/b4x-textrecognition-based-on-mlkit.161210/ and suggestions from ChatGPT but the text recognition example doesn't appear to read the MRZ text on a passport well enough. I've adapted the code as follows but does not identify the text I need to read. Any suggestions or other ideas I should try to recognize this data?

Public Sub Recognize (bmp As B4XBitmap) As ResumableSub
    Dim res As TextRecognizerResult
    res.Initialize
    #if B4I
    recognizer.RunMethod("processImage:completion:", Array(ImageToMLImage(bmp), Me.as(NativeObject).RunMethod("createBlock", Null)))
    Wait For Process_Result(Success As Boolean, MLKText As Object)
    res.Success = Success
    If Success Then
        #if B4I
        res.Text = MLKText.As(NativeObject).GetField("text").AsString
        #else if B4A
        #end if
    End If
    #else if B4A
    Dim task As JavaObject = recognizer.RunMethod("process", Array(ImageToMLImage(bmp)))
    Do While task.RunMethod("isComplete", Null).As(Boolean) = False
        Sleep(50)
    Loop
    If task.RunMethod("isSuccessful", Null) Then
        res.Success = True
        Dim Text As JavaObject = task.RunMethod("getResult", Null)
        res.Text = Text.RunMethod("getText", Null)
    Else
        Log(task.RunMethod("getException", Null))
    End If
    #End If
    
    mlKit_TextRecognized(True,res.text)
    Return res
End Sub

Private Sub ImageToMLImage(bmp As B4XBitmap) As Object
    #if B4I
    Dim image As NativeObject
    image = image.Initialize("MLKVisionImage").RunMethod("alloc", Null).RunMethod("initWithImage:", Array(bmp))
    #else if B4A
    Dim image As JavaObject
    image = image.InitializeStatic("com.google.mlkit.vision.common.InputImage").RunMethod("fromBitmap", Array(bmp, 0))
    #end if
    Return image
End Sub

Sub mlKit_TextRecognized (Success As Boolean, Texts As String)
    If Success And Texts.Length > 0 Then
        Dim fullText As String = Texts '.Get(0)
        Dim mrzData As String = ExtractMRZ(fullText)
        lblOutput.Text = "MRZ Data Found:" & CRLF & mrzData
        'Log("MRZ Data Found:" & CRLF & mrzData)
    Else
        lblOutput.Text = "MRZ not detected, please try again."
        Log("MRZ not detected, please try again.")
    End If
End Sub

' Function to extract MRZ data (Assumes ICAO 9303 Format)
Sub ExtractMRZ(inputText As String) As String
    Dim mrzPattern As String = "[A-Z0-9<]{44}" ' Regex for MRZ lines
    Dim Matcher As Matcher = Regex.Matcher(mrzPattern, inputText)
    Dim mrzLines As List
    mrzLines.Initialize

    Do While Matcher.Find
        mrzLines.Add(Matcher.Match)
    Loop
    
    If mrzLines.Size >= 2 Then
        Return mrzLines.Get(0) & CRLF & mrzLines.Get(1) ' Return the two MRZ lines
    Else
        Return "No valid MRZ detected."
    End If
End Sub

 

[drgottjr]

the <<<<<<'s can be a problem. you need a trained reader