Read barcode/QR code from existing pdf file

[sauravvijay13]

Hi Team,

Is there a way to read barcode/QR code which is present in an existing pdf file.

Thanks,
Saurav

[Betsy]

Hi,

Thanks for your inquiry.
Sorry that Spire.PDF doesn't support to read barcode/QR code which is in PDF file. But you can save the PDF as image and then read the barcode/QR code by Spire.Barcode.

Sincerely,
Betsy
E-iceblue support team

[sauravvijay13]

Hi Betsy,

Thanks for the quick reply.
Can you help me with any site source / example showing how to read a barcode from pdf document.

Regards,
Saurav

[Betsy]

Dear Saurav,

Please download Spire.Office and then reference the corresponding dlls from it. And then convert PDF to image by Spire.PDF, here is a guide for your reference: http://www.e-iceblue.com/Tutorials/Spir ... ution.html. Then, read the barcode/QR code by Spire.Barcode, here is sample code.

Code: Select all

string[] datas = Spire.Barcode.BarcodeScanner.Scan("barcode.png");

Wish it can help you. If there is any question, welcome to get it back to us.

Sincerely,
Betsy
E-iceblue support team

[sauravvijay13]

Hi Betsy,

Solution did work. Many thanks for the help.

But it takes around 2-3 minutes to scan a single image. Is there any way to boost up the performance??

Regards,
Saurav

[Betsy]

Dear Saurav,

Thanks for your reply.
Please try to use the method SaveAsImage(int pageIndex) to save the PDF as image, as I tested this method and found it is faster than the method SaveAsImage(int pageIndex, int dpiX, int dpiY), if the issue still exists, please provide us your sample document for investigation.

Sincerely,
Betsy
E-iceblue support team

[sauravvijay13]

Hi Betsy,

Thanks for the reply.
I'm already using SaveAsImage() method. This is what im doing.

Code: Select all

        public void ReadBarCode()
        {
            PdfDocument documemt = new PdfDocument();
            documemt.LoadFromFile(@"E:\DOC_2.pdf");
            Bitmap image = (Bitmap)documemt.SaveAsImage(0, PdfImageType.Bitmap, 400, 400);
            string[] datas = Spire.Barcode.BarcodeScanner.Scan(image);
            foreach (var item in datas)
            {
                Console.WriteLine(item);
            }

            documemt.Close();
        }


I want to know of there is any way to convert a particular area of pdf to image rather then just having the whole page to be converted as pdf.
Let's say i have my barcode on top left region of the page. SO in that case can i just not convert that part to image and scan for barcode??
Will this improve the performance.??

Thanks,
Saurav

[Betsy]

Dear Saurav,

Sorry that there is no way to convert a particular area of pdf to image.
Also, please try to use the method SaveAsImage(int pageIndex) to save the PDF as image, as I tested this method and found it is faster than the method SaveAsImage(int pageIndex, PdfImageType type, int dpiX, int dpiY), like this

Code: Select all

Bitmap image = (Bitmap)doc.SaveAsImage(0);

Sincerely,
Betsy
E-iceblue support team

[Betsy]

Dear Saurav,

I find another way to achieve your target. If the barcode/QR code is image on PDF file, you can extract the image, here is the guide: http://www.e-iceblue.com/Tutorials/Spir ... -in-C.html. And then read the barcode/QR code by Spire.Barcode.
If there is any question, welcome to get it back to us.

Sincerely,
Betsy
E-iceblue support team

[sauravvijay13]

Hi Betsy,

Thanks for the solution. But i dont know how to save the barcode as an image in pdf file. This is what i am using right now to create a barcode.

Code: Select all

public void CreateBarCode()
        {
            PdfDocument pdf = new PdfDocument();
            pdf.LoadFromFile(@"E:\doc.pdf");
            PdfDocument pdf1 = new PdfDocument();
            PdfPageBase page;
            for (int i = 0; i < pdf.Pages.Count-1; i++)
            {
                page = pdf1.Pages.Add(pdf.Pages[i].Size, new Spire.Pdf.Graphics.PdfMargins(0));
                pdf.Pages[i].CreateTemplate().Draw(page, new System.Drawing.PointF(0, 0));
             
                PdfCodabarBarcode barcode1 = new PdfCodabarBarcode("00:12-3456/7890");
                barcode1.BarcodeToTextGapHeight = 1f;
                barcode1.EnableCheckDigit = true;
                barcode1.ShowCheckDigit = true;
                barcode1.TextDisplayLocation = TextLocation.Bottom;
                barcode1.TextColor = Color.Green;
                barcode1.Draw(page, new PointF(2, 10));
               
            }
            pdf1.SaveToFile("DOC_4.pdf");       
        }


Can you please let me know what i need to change to save barcode as an image.

Also Betsy for the previous solution to use

Code: Select all

SaveAsImage(int pageIndex)

did speed up the processing but now the

Code: Select all

BarcodeScanner.Scan()

does not return correct result.

Please let me know what I can do to proceed further.

Thanks,
Saurav

[sauravvijay13]

Hi Besty,

Many thanks for the suggestion. I got the solution to save barcode as an image and extracting the same from pdf. It really works fast as well.

I have one doubt though. What if i have multiple images in my pdf page. In that case is there any way to filter out the unwanted images. Because i dont want to scan all the images since only one of them contains the barcode.

Thanks,
Saurav

[Betsy]

Dear Saurav,

Thanks for your feedback.
Sorry that there is no way to filter out the unwanted images. If there is other issue, please let me know.

Sincerely,
Betsy
E-iceblue support team