Re: Setting a rectangle to OCR

Hi all.

I am relatively new to this so...

I have a letter that gets scanned into our imaging system from various scanners.  Some are set at 200dpi and some at 300dpi.  All TIFF CCITT (Group 4)  The below code works fine for 300dpi but I get "Invalid zone coordinates" when a 200dpi image is used.

What's the best way to handle this for any resolution?  I don't want to OCR the entire document, I only care about a little piece of it. 

Thanks is advance.

Public Sub OCR(ByVal filename As String)

        'Start up the Ocr engine
        Try
            rasterOcr.StartUp()
        Catch ex As Exception
            msg = "ERROR: " & ex.Message.ToString
        End Try

        'Type the path of the Leadtools Bin folder.
        RasterCodecs.CodecsPath = "C:\Program Files\LEAD Technologies, Inc\LEADTOOLS 14.5\Bin\Dotnet\v11"

        'Initialize a new RasterCodecs object
        Dim codecs As RasterCodecs = New RasterCodecs

        'Load a temporary image
        Dim rasterImage As IRasterImage = codecs.Load(filename)

        Try
            'add the image to the the ocr raster object
            rasterOcr.AddPage(rasterImage, -1)
        Catch ex As Exception
            msg = "Error: " + ex.Message + ". The engine could not add a new page to the document"
        Finally
            rasterImage.Dispose()
        End Try

        'add zone
        Dim zoneData As RasterOcrZoneData = New RasterOcrZoneData

        With zoneData
            .Rectangle = New Rectangle(1400, 1150, 1000, 350)
            .FillMethod = Leadtools.Ocr.RasterOcrFillMethod.Default
            .RecognizeModule = Leadtools.Ocr.RasterOcrRecognizeModule.Auto
            .CharacterFilter = Leadtools.Ocr.RasterOcrCharacterFilter.Default
            .Type = Leadtools.Ocr.RasterOcrZoneType.FlowText
            .Flags = Leadtools.Ocr.RasterOcrZoneFlags.None
            .DisableEvents()
            .SectionName = "t303data"
        End With

        Dim buffer As String = ""
        Try
            rasterOcr.AddZone(0, 0, zoneData)
        Catch ex As Exception
            msg = "Error: " + ex.Message
        End Try

        'get the data
        Dim strPath As String = Path.GetTempPath

        If strPath = "" Then
            'could not determine TEMP directory
            strPath = "C:"
        End If

        Dim strFile As String = strPath & "\ocrtemp.rdf"

        If File.Exists(strFile) Then
            'delete it, will get recreated later
            File.Delete(strFile)
        End If

        With rasterOcr
            .RecognitionDataFileName = strFile
            .SpellLanguageID = RasterOcrLanguage.English
        End With

        Try
            'recognize the image in the rectangle we created
            'and save the results to a string variable
            rasterOcr.Recognize(0, 1)
            Dim strResult As String = rasterOcr.SaveResultsToMemory
            mvarCheckNumber = GetCheckNumber(strResult)
            mvarCheckDate = GetCheckDate(strResult)
            mvarCheckAmount = GetCheckAmount(strResult)
            'If mvarCheckNumber.Length > 0 And mvarCheckDate.Length > 0 Then
            '    GetDCSData(mvarCheckNumber, mvarCheckDate)
            'End If
        Catch ex As Exception
            msg = "Error: " + ex.Message + " in saving recognition result to memory"
        End Try

        ' Shut down the RasterOcr engine
        rasterOcr.ShutDown()
        rasterOcrZoneData = Nothing

    End Sub

It sort of helped [:)]

Just setting the X & Y resolution still generated the error but it did give me an idea.

I figured out what the ratio was for where I wanted the rectangle and did this (works every time regardless of resolution so far):

               'Load a temporary image
                Dim rasterImage As IRasterImage = codecs.Load(filename)

                Dim RecLeft As Integer = rasterImage.XResolution * 4.667
                Dim RecTop As Integer = rasterImage.YResolution * 3.833
                Dim RecWidth As Integer = rasterImage.XResolution * 3.333
                Dim RecHeight As Integer = rasterImage.YResolution * 1.167

                'add the image to the the ocr raster object
                rasterOcr.AddPage(rasterImage, -1)

                rasterImage.Dispose()

            'add zone
            Dim zoneData As RasterOcrZoneData = New RasterOcrZoneData
            With zoneData
                .Rectangle = New Rectangle(RecLeft, RecTop, RecWidth, RecHeight)
                .FillMethod = Leadtools.Ocr.RasterOcrFillMethod.Default
                .RecognizeModule = Leadtools.Ocr.RasterOcrRecognizeModule.Auto
                .CharacterFilter = Leadtools.Ocr.RasterOcrCharacterFilter.Default
                .Type = Leadtools.Ocr.RasterOcrZoneType.FlowText
                .Flags = Leadtools.Ocr.RasterOcrZoneFlags.None
                .DisableEvents()
                .SectionName = "t303data"
            End With

Thanks for pointing me to the XResolution and YResolution though.

Regards