Extracting barcode information from PDF documents

Introduction

In this tutorial, we will look into how to use PassportPDF to extract information embedded in a barcode.

You should have your machine already set up using instructions from our getting started guide.

Extracting barcode information from PDF documents

In the following tutorial, we are going to:

1. Load a document from a URI using DocumentLoadFromURIAsync.
2. Extract barcode information using ImageReadBarcodesAsync or ReadBarcodesAsync depending on the document format.

The document we passed to the API looks like this:

As you can see, there is a barcode on the invoice. It contains a message that we would like to extract. The code we used to extract this information is pretty simple, as shown below:

using PassportPDF.Api;
using PassportPDF.Client;


namespace BarcodeExtraction
{

    public class BarcodeExtractor
    {
        static void displayBarcodesInfo(PassportPDF.Model.ReadBarcodesResponse barcodes)
        {
            foreach (var barcode in barcodes.Barcodes)
            {
                Console.WriteLine("Barcode type : {0}", barcode.Type);
                Console.WriteLine("Barcode symbology : {0}", barcode.Barcode1DSymbology);
                Console.WriteLine("X_left : {0}", barcode.X1);
                Console.WriteLine("Y_top : {0}", barcode.Y1);
                Console.WriteLine("X_right : {0}", barcode.X3);
                Console.WriteLine("Y_down : {0}", barcode.Y3);
                Console.WriteLine("Barcode data : {0}", barcode.Data);
                Console.WriteLine("-------------------");
            }
        }

        static void Main(string[] args)
        {
            GlobalConfiguration.ApiKey = "YOUR-PASSPORT-CODE";
            DocumentApi api = new();

            var uri = "https://passportpdfapi.com/test/invoice_with_barcode.pdf";
            var document = api.DocumentLoadFromURIAsync(new PassportPDF.Model.LoadDocumentFromURIParameters(uri)).Result;

            var imageSupportedFormats = new ImageApi().ImageGetSupportedFileExtensionsAsync().Result;

            if (imageSupportedFormats.Value.Contains(document.DocumentFormat.ToString()))
            {
                ImageApi imageApi = new();

                var barcodes = imageApi.ImageReadBarcodesAsync(new PassportPDF.Model.ImageReadBarcodesParameters(document.FileId, "*")).Result;

                displayBarcodesInfo(barcodes);
            }
            else if (document.DocumentFormat == PassportPDF.Model.DocumentFormat.PDF)
            {
                PDFApi pdfApi = new();

                var barcodes = pdfApi.ReadBarcodesAsync(new PassportPDF.Model.PdfReadBarcodesParameters(document.FileId, "*")).Result;

                displayBarcodesInfo(barcodes);
            }
            else
            {
                var pdfImportSupportedFormats = new PDFApi().GetPDFImportSupportedFileExtensionsAsync().Result;

                if (pdfImportSupportedFormats.Value.Contains(document.DocumentFormat.ToString()))
                {
                    PDFApi pdfApi = new PDFApi();

                    var convertedDocument = pdfApi.LoadDocumentAsPDFFromHTTPAsync(new PassportPDF.Model.PdfLoadDocumentFromHTTPParameters(uri)).Result;

                    if(convertedDocument != null)
                    {
                        var barcodes = pdfApi.ReadBarcodesAsync(new PassportPDF.Model.PdfReadBarcodesParameters(convertedDocument.FileId, "*")).Result;

                        displayBarcodesInfo(barcodes);
                    }
                    
                }
                else
                {
                    Console.WriteLine("Document format not supported!");
                }
            }
        }
    }
}
                                

For a full version of this code with all dependencies included, check out the complete project.

Now, let’s take a look at the response we received.

As you can see, we get a lot of information about the barcode, such as the type of barcode, its symbology, the coordinates, and the message or data embedded. In our case, the data is https://passportpdf.com/.

Final remarks

Using the barcodes reader from PassportPDF, you can read all sorts of barcodes, including:

• Linear barcodes.
• QR codes.
• Micro QR codes.
• Data matrix.
• PDF417.
• Aztec.
• Maxi code.

Also, PassportPDF supports many document formats such as JPEG, PNG, and a hundred more. So you can run the API on most documents that you have.