GetTextLineTop Method (GdPictureOCR)

In This Topic

Returns the top y-coordinate of the bounding box of the specified line, that is a part of a specified OCR result.

This method uses a coordinate system, where the origin is in the top-left corner of the processed image and the units are pixels.

Syntax

Visual Basic
C#
Delphi
JScript
Managed Extensions for C++
C++/CLI

'Declaration
 
Public Function GetTextLineTop( _
   ByVal OCRResultID As String, _
   ByVal TextLineIdx As Integer _
) As Integer

public int GetTextLineTop( 
   string OCRResultID,
   int TextLineIdx
)

public function GetTextLineTop( 
    OCRResultID: String;
    TextLineIdx: Integer
): Integer;

public function GetTextLineTop( 
   OCRResultID : String,
   TextLineIdx : int
) : int;

public: int GetTextLineTop( 
   string* OCRResultID,
   int TextLineIdx
)

public:
int GetTextLineTop( 
   String^ OCRResultID,
   int TextLineIdx
)

Parameters

OCRResultID: The unique result identifier of the executed OCR process obtained by the RunOCR method.
TextLineIdx: The 0-based index of the text line within the specified OCR result. It must be a value between 0 and GetTextLineCount(OCRResultID) - 1.

Return Value

The top y-coordinate of the text line's bounding box, in pixels.

Please always use the GetStat method to determine if this method has been successful.

Remarks

It is recommend to use the GetStat method to identify the specific reason for the method's failure, if any.

Please note, that the origin of the used coordinate system is in the top-left corner of the processed image and the used units are pixels.

Example

How to find out the number of recognized text lines within the OCR result and some of the text line's properties.

VB.NET
C#

Dim caption As String = "Example: GetTextLineTop"
Dim gdpictureOCR As GdPictureOCR = New GdPictureOCR
Dim gdpicturePDF As GdPicturePDF = New GdPicturePDF
'Load the PDF document.
If gdpicturePDF.LoadFromFile("input.pdf", False) = GdPictureStatus.OK Then
    'Set the new origin for better coordinates handling.
    gdpicturePDF.SetOrigin(PdfOrigin.PdfOriginTopLeft)
    gdpicturePDF.SetLineColor(Color.Olive)
    gdpicturePDF.SetLineWidth(2)
    'Select the first page.
    gdpicturePDF.SelectPage(1)
    'Render this page to a 200 DPI image.
    Dim image As Integer = gdpicturePDF.RenderPageToGdPictureImage(200, True)
    If gdpicturePDF.GetStat = GdPictureStatus.OK AndAlso
       gdpictureOCR.SetImage(image) = GdPictureStatus.OK Then
        'Setting up the image is mandatory.
        Dim message As String = Nothing
        'Set up the OCR parameters.
        gdpictureOCR.ResourcesFolder = "C:\Path\To\GdPicture.NET 14\Redist\OCR"
        gdpictureOCR.AddLanguage(OCRLanguage.English)
        'Set up the OCR context and the character list.
        gdpictureOCR.Context = OCRContext.OCRContextSingleBlock
        gdpictureOCR.CharacterSet = ""
        'Run the OCR process.
        Dim resID As String = gdpictureOCR.RunOCR()
        If gdpictureOCR.GetStat = GdPictureStatus.OK Then
            Dim linesCount As Integer = gdpictureOCR.GetTextLineCount(resID)
            If gdpictureOCR.GetStat() = GdPictureStatus.OK Then
                message = message + "The number of recognized text lines: " + linesCount.ToString() + vbCrLf
                For i As Integer = 0 To linesCount - 1
                    message = message + "The line nr." + i.ToString() + " contains " + gdpictureOCR.GetTextLineWordCount(resID, i).ToString() + " words." + vbCrLf
                    message = message + "   The first word index is " + gdpictureOCR.GetTextLineFirstWordIndex(resID, i).ToString() + "." + vbCrLf
                    Dim left As Integer = gdpictureOCR.GetTextLineLeft(resID, i)
                    Dim top As Integer = gdpictureOCR.GetTextLineTop(resID, i)
                    If gdpicturePDF.DrawRectangle(left, top, gdpictureOCR.GetTextLineRight(resID, i) - left, gdpictureOCR.GetTextLineBottom(resID, i) - top, False, True) = GdPictureStatus.OK Then
                        message = message + "   Drawn: yes" + vbCrLf
                    Else
                        message = message + "   Drawn: no" + vbCrLf
                    End If
                Next
                MessageBox.Show(message, caption)
                'Continue with analyzing the result ...
                'Save the page with drawn recognized text lines to the new PDF document.
                If gdpicturePDF.SaveToFile("output.pdf") = GdPictureStatus.OK Then
                    MessageBox.Show("Done!", caption)
                Else
                    MessageBox.Show("The file can't be saved. Status: " + gdpicturePDF.GetStat().ToString(), caption)
                End If
            Else
                MessageBox.Show("The GetTextLineCount() method has failed with the status: " + gdpictureOCR.GetStat().ToString())
            End If
        Else
            MessageBox.Show("The error occurred when running the OCR. Status: " + gdpictureOCR.GetStat().ToString(), caption)
        End If
        'Release the image.
        GdPictureDocumentUtilities.DisposeImage(image)
    Else
        MessageBox.Show("The error occurred when creating or setting up the image. Status: " + gdpicturePDF.GetStat().ToString() + "/" + gdpictureOCR.GetStat().ToString(), caption)
    End If
    'Close the document.
    gdpicturePDF.CloseDocument()
Else
    MessageBox.Show("The file can't be loaded. Status: " + gdpicturePDF.GetStat().ToString(), caption)
End If
'Release resources.
gdpictureOCR.ReleaseOCRResults()
gdpictureOCR.Dispose()
gdpicturePDF.Dispose()

string caption = "Example: GetTextLineTop";
GdPictureOCR gdpictureOCR = new GdPictureOCR();
GdPicturePDF gdpicturePDF = new GdPicturePDF();
//Load the PDF document.
if (gdpicturePDF.LoadFromFile("input.pdf", false) == GdPictureStatus.OK)
{
    //Set the new origin for better coordinates handling.
    gdpicturePDF.SetOrigin(PdfOrigin.PdfOriginTopLeft);
    gdpicturePDF.SetLineColor(Color.Olive);
    gdpicturePDF.SetLineWidth(2);
    //Select the first page.
    gdpicturePDF.SelectPage(1);
    //Render this page to a 200 DPI image.
    int image = gdpicturePDF.RenderPageToGdPictureImage(200, true);
    if ((gdpicturePDF.GetStat() == GdPictureStatus.OK) &&
        (gdpictureOCR.SetImage(image) == GdPictureStatus.OK)) //Setting up the image is mandatory.
    {
        string message = "";
        //Set up the OCR parameters.
        gdpictureOCR.ResourcesFolder = "C:\\Path\\To\\GdPicture.NET 14\\Redist\\OCR";
        gdpictureOCR.AddLanguage(OCRLanguage.English);
        //Set up the OCR context and the character list.
        gdpictureOCR.Context = OCRContext.OCRContextSingleBlock;
        gdpictureOCR.CharacterSet = "";
        //Run the OCR process.
        string resID = gdpictureOCR.RunOCR();
        if (gdpictureOCR.GetStat() == GdPictureStatus.OK)
        {
            int linesCount = gdpictureOCR.GetTextLineCount(resID);
            if (gdpictureOCR.GetStat() == GdPictureStatus.OK)
            {
                message = message + "The number of recognized text lines: " + linesCount.ToString() + "\n";
                for (int i = 0; i < linesCount; i++)
                {
                    message = message + "The line nr." + i.ToString() + " contains " + gdpictureOCR.GetTextLineWordCount(resID, i).ToString() + " words.\n";
                    message = message + "   The first word index is " + gdpictureOCR.GetTextLineFirstWordIndex(resID, i).ToString() + ".\n";
                    int left = gdpictureOCR.GetTextLineLeft(resID, i);
                    int top = gdpictureOCR.GetTextLineTop(resID, i);
                    if (gdpicturePDF.DrawRectangle(left, top, gdpictureOCR.GetTextLineRight(resID, i) - left, gdpictureOCR.GetTextLineBottom(resID, i) - top, false, true) == GdPictureStatus.OK)
                        message = message + "   Drawn: yes\n";
                    else
                        message = message + "   Drawn: no\n";
                }
                MessageBox.Show(message, caption);
                //Continue with analyzing the result ...
                //Save the page with drawn recognized text lines to the new PDF document.
                if (gdpicturePDF.SaveToFile("output.pdf") == GdPictureStatus.OK)
                    MessageBox.Show("Done!", caption);
                else
                    MessageBox.Show("The file can't be saved. Status: " + gdpicturePDF.GetStat().ToString(), caption);
            }
            else
                MessageBox.Show("The GetTextLineCount() method has failed with the status: " + gdpictureOCR.GetStat().ToString());
        }
        else
            MessageBox.Show("The error occurred when running the OCR. Status: " + gdpictureOCR.GetStat().ToString(), caption);
        //Release the image.
        GdPictureDocumentUtilities.DisposeImage(image);
    }
    else
        MessageBox.Show("The error occurred when creating or setting up the image. Status: " + gdpicturePDF.GetStat().ToString() + "/" + gdpictureOCR.GetStat().ToString(), caption);
    //Close the document.
    gdpicturePDF.CloseDocument();
}
else
    MessageBox.Show("The file can't be loaded. Status: " + gdpicturePDF.GetStat().ToString(), caption);
//Release resources.
gdpictureOCR.ReleaseOCRResults();
gdpictureOCR.Dispose();
gdpicturePDF.Dispose();

Reference

GdPictureOCR Class
GdPictureOCR Members
GetTextLineCount Method
GetTextLineBottom Method
GetTextLineLeft Method
GetTextLineRight Method
RunOCR Method