Extract invoice data with C# and OCR

using GdPictureOCR gdpictureOCR = new GdPictureOCR();
using GdPictureImaging gdpictureImaging = new GdPictureImaging();
// Load the source document.
int imageId = gdpictureImaging.CreateGdPictureImageFromFile(@"C:\temp\source.png");
// Configure the OCR process.
gdpictureOCR.ResourceFolder = @"C:\GdPicture.NET 14\Redist\OCR";
gdpictureOCR.AddLanguage(OCRLanguage.English);
gdpictureOCR.SetImage(imageId);
// Run the OCR process.
string ocrResultId = gdpictureOCR.RunOCR();
string keyValuePairsData = "";
for (int pairIndex = 0; pairIndex < gdpictureOCR.GetKeyValuePairCount(ocrResultId); pairIndex++)
{
    keyValuePairsData += $"| Key: {gdpictureOCR.GetKeyValuePairKeyString(ocrResultId, pairIndex)} | " +
                         $"Value: {gdpictureOCR.GetKeyValuePairValueString(ocrResultId, pairIndex)} | " +
                         $"Document Type: {gdpictureOCR.GetKeyValuePairDataType(ocrResultId, pairIndex).ToString()} | " +
                         $"Confidence Level: {Math.Round(gdpictureOCR.GetKeyValuePairConfidence(ocrResultId, pairIndex), 1).ToString()}% |\n";
}
// Write the output to the console.
Console.WriteLine(keyValuePairsData);
// Release unnecessary resources.
gdpictureImaging.ReleaseGdPictureImage(imageId);
gdpictureOCR.ReleaseOCRResults();

Using gdpictureOCR As GdPictureOCR = New GdPictureOCR()
Using gdpictureImaging As GdPictureImaging = New GdPictureImaging()
    ' Load the source document.
    Dim imageId As Integer = gdpictureImaging.CreateGdPictureImageFromFile("C:\temp\source.png")
    ' Configure the OCR process.
    gdpictureOCR.ResourceFolder = "C:\GdPicture.NET 14\Redist\OCR"
    gdpictureOCR.AddLanguage(OCRLanguage.English)
    gdpictureOCR.SetImage(imageId)
    ' Run the OCR process.
    Dim ocrResultId As String = gdpictureOCR.RunOCR()
    Dim keyValuePairsData = ""
    For pairIndex As Integer = 0 To gdpictureOCR.GetKeyValuePairCount(ocrResultId) - 1
        keyValuePairsData += $"| Key: {gdpictureOCR.GetKeyValuePairKeyString(ocrResultId, pairIndex)} | Value: {gdpictureOCR.GetKeyValuePairValueString(ocrResultId, pairIndex)} | Document Type: {gdpictureOCR.GetKeyValuePairDataType(ocrResultId, pairIndex).ToString()} | Confidence Level: {Math.Round(gdpictureOCR.GetKeyValuePairConfidence(CStr(ocrResultId), CInt(pairIndex)), CInt(1)).ToString()}% |" & vbLf
    Next
    ' Write the output to the console.
    Console.WriteLine(keyValuePairsData)
    ' Release unnecessary resources.
    gdpictureImaging.ReleaseGdPictureImage(imageId)
    gdpictureOCR.ReleaseOCRResults()
End Using
End Using