Technical FAQs

How can I improve the performance and memory usage of scanning/recognition in Barcode Xpress?

Barcode Xpress supports a number of optimization settings that can improve your recognition performance, sometimes up to 40%, along with memory usage. The best way to optimize Barcode Xpress is to fine-tune the properties of the Reader class to be specific to your application’s requirements.

BarcodeTypes

• The best way to increase performance is to limit which barcodes Barcode Xpress should search for. By default, BarcodeTypes is set to UnknownBarcode which targets all 1D barcodes.

MaximumBarcodes

• This property will instruct Barcode Xpress to halt searching after finding a specified number of barcodes. The default value is 100.

Area & Orientation

• If you know the location or orientation of your barcodes in your image, specifying an orientation (such as Horizontal) and area can prevent Barcode Xpress from searching for vertical or diagonal barcodes, or in places where barcodes would not exist.

ScanDistance

• Raising this value increases performance by applying looser recognition techniques by skipping rows of an image. However, this may fail to detect barcodes.

Finally, BarcodeXpress Professional edition does not impose a 40 page-per-minute limit on processing.

Why do I get a “File Format Unrecognized” exception when trying to load a PDF document in ImageGear .NET?

You will need to set up your project to include PDF support if you want to work with PDF documents. Add a reference to ImageGear24.Formats.Pdf (if you’re using another version of ImageGear, make sure you’re adding the correct reference). Add the following line of code where you specify other resources:

using ImageGear.Formats.PDF;

Add the following lines of code before you begin working with PDFs:

ImGearFileFormats.Filters.Insert(0, ImGearPDF.CreatePDFFormat());
ImGearPDF.Initialize();

The documentation page linked here shows how to add PDF support to a project.

We are saving files to the PDF/A standard and are running into a few cases where the file cannot be saved as PDF/A by ImageGear .NET. Why is this, and how do we do it properly?

First, determine whether a PDF document can be converted to PDF/A by creating an ImGearPDFPreflight object from your document, and generating an ImGearPDFPreflightReport object from it:

using (ImGearPDFPreflight preflight = new ImGearPDFPreflight((ImGearPDFDocument)igDocument))
{
    report = preflight.VerifyCompliance(ImGearPDFPreflightProfile.PDFA_1A_2005, 0, -1);
}

The first argument of the VerifyCompliance() method is the standard of PDF/A you want to use. ImageGear .NET is currently able to convert documents to adhere to the PDF/A-1A and PDF/A-1B standards:

PDF/A-1 Standard

ImageGear and PDF/A

There are parts of the PDF/A-2 and PDF/A-3 standards which may allow for more documents to be converted, but ImageGear .NET currently does not support those. This could possibly be why your document cannot be converted in ImageGear .NET.

Once the report is generated, you can access its Status, which will tell you if the document is fixable. You can also access its Code which will let you know if it’s a fixed page or if it has issues; it will return Success if fixed, or some error code otherwise. You can check these conditions to determine whether it’s worth attempting to convert the document:

// If the document is not already PDFA-1a compliant but can be converted
if ((report.Code == ImGearPDFPreflightReportCodes.SUCCESS) ||
(report.Status == ImGearPDFPreflightStatusCode.Fixable))
{
    ImGearPDFPreflightConvertOptions pdfaOptions = new ImGearPDFPreflightConvertOptions(ImGearPDFPreflightProfile.PDFA_1A_2005, 0, -1);
    ImGearPDFPreflight preflight = new ImGearPDFPreflight((ImGearPDFDocument)igDocument);
    preflight.Convert(pdfaOptions);
    saveFile(outputPath, igDocument);
}

// Create error message if document was not converted.
else if (report.Status != ImGearPDFPreflightStatusCode.Fixed)
{
    printAllRecordDescriptions(report);
    throw new ApplicationException("Given PDF document cannot be converted to PDFA-1a standard.");
}

If you want more information on why a document may not be convertible, you can access the preflight report for its records and codes. A preflight’s "Records" member is a recursive list of preflight reports. A preflight report will have a list of reports under Records, and each of those reports may have more reports, etc. You can recursively loop through them as seen below to output every reason a document is not convertible:

    private static void printAllRecordDescriptions(StreamWriter file, ImGearPDFPreflightReport report)
    {
        foreach (ImGearPDFPreflightReport rep in report.Records)
        {
            file.WriteLine(rep.Description);
            file.WriteLine(rep.Code.ToString() + "\r\n");
            printAllRecordDescriptions(file, rep);
        }
    }

Ultimately, the failure of a document to convert to PDF/A is non-deterministic. While some compliance failures can be corrected, in combination they may not be correctable. Therefore, the unfortunate answer is that to determine if it can be converted, conversion must be attempted.

After restarting the Prizm Services, you may notice that the http://localhost:18681/admin status page shows a status of “unhealthy” and in the Internal Services section, the mongo-manager-service is showing a clock, and the text-service is showing a red x.

How can this be fixed?

Reason:

This will typically occur when the mongo-manager-service detects an unclean shutdown and the cache gets corrupted.

How to Verify:

You can do a search in the C:\Prizm\logs\mongod.log file on Windows or the /usr/share/prizm/logs/mongod.log file on Linux for the word "unclean" and you may find the following error:

Detected unclean shutdown -
C:\Prizm\cache\mongo-manager-service\data\mongod.lock is not empty.

Resolution:

1. Stop the Prizm Services.

2. For PrizmDoc 13.3 and above, clear out all subfolders under prizm\cache (leave the prizm\cache folder).

3. For PrizmDoc 13.2 and prior, clear out all files and subfolders under C:\Prizm\services\mongo-manager-service\bin\mongodb\data

4. Start the Prizm Services.

How can I enable content encryption in PrizmDoc Viewer?

First, you need to enable content encryption on the PrizmDoc Server in the central configuration file. To do this, find the viewing.contentEncryption.enabled section and change the value to true. Save the changes to the file and restart the PrizmDoc services for the change to take effect.

The file paths for the central configuration file are:

Linux: /usr/share/prizm/prizm-services-config.yml
Windows: C:\Prizm\prizm-services-config.yml

Next, you need to enable content encryption in the Viewer. To do this, in the index page of your viewer (Default.aspx in C#, index.php in the PHP sample, index.html, etc.), provide the encryption option in the viewer options parameter as follows so that the Viewer can handle encrypted data:

function buildViewerOptions() {
    ...
    var optionsOverride = args.pop(); // always last arg
    var options = {
        ...
        encryption: true
    };
    var combinedOptions = _.extend(optionsOverride, options);
    embedViewer(combinedOptions);
}

For more in-depth information on enabling content encryption in PrizmDoc, please refer to our documentation here.

Is it possible to automatically annotate a document, similar to the Auto-Redaction feature, using PrizmDoc?

An auto-annotation feature isn’t an out-of-the-box feature but with some work, it can be done. This would involve creating a searchTask and using the information from it to programmatically create XML markup that can be used in the MarkupBurner.

To do this you would need to create a searchTask for the pattern you would like to annotate. You can then get the results of the searchTask as JSON which will contain all occurrences of that pattern/search. Each search result will include the selected text, the page on which it occurs, the starting index of the result, and the dimensions and coordinates of the bounding rectangles for that search result.

All this information can be used to construct the markup XML to add the annotations with the markup burner.

Once you have constructed the XML you would post to the MarkupBurner with the XML as the body to burn the document.

I need to store a unique ID with each of my marks. Is the ID returned by Mark.GetID() unique?

The ID generated by Mark.GetID() is only unique for that instance of the viewing session (for example, if you refresh the page, the counter for mark IDs will reset to 1).

If you are saving your marks to markup layers using the SaveMarkupLayers() method, then each mark will have a unique ID generated which will be stored in the “uid” key in the markup layer JSON.

If you are saving your marks as XML, using the SaveMarks() method, then each mark’s unique ID will be stored in the key “nodeId”.

If you want to generate your own unique ID for your marks, you can include the code below in your viewer.js to generate a UUID. A UUID contains 122 randomly generated bits so you shouldn’t need to worry about any duplicate IDs:

    function uuidv4() {
      return ([1e7]+-1e3+-4e3+-8e3+-1e11).replace(/[018]/g, c =>
        (c ^ crypto.getRandomValues(new Uint8Array(1))[0] & 15 >> c / 4).toString(16)
      )
    }

You can store this UID in the marks data using Mark.SetData("ID", uuidv4());.

You can then use Mark.GetData("ID"); to retrieve the ID at a later time.

How accurate is PrizmDoc Viewer’s auto-redaction process? Is there any estimate of the percentage of matches that it will fail to redact?

If you’re performing auto-redaction as described in our documentation, then all matches for the input regular expression will be redacted in the final document. However, it’s difficult to express that confidence in the form of a percentage. PrizmDoc is subjected to a suite of automatic testing to ensure that its services are behaving as intended, including redactions. We never release a new version unless it passes 100% of those tests.

That being said, the primary way that inaccuracy could enter the system is if you’re attempting to redact scanned documents that have been OCRed. In this case, it’s a matter of your OCR software’s accuracy, rather than the accuracy of PrizmDoc’s redaction process. If the searchable text of the document doesn’t accurately reflect the visible text on the page (for example, if a smudged “discovery” is incorrectly recognized as “disccvery”), then the auto-redaction will be unable to recognize it due to the incorrect input it has been given. This isn’t a problem if the documents were not OCRed.

How does the PrizmDoc print function work exactly?

Every page of the specified print range is being loaded and sent to the printer. This occurs in an iframe separate from what is shown in the Viewer so the user does not actually see this happening.

The actual method being used is one of the following, depending on the browser:

• _iframe.contentWindow.document.execCommand('print', false, null);
• _iframe.contentWindow.print();

If you have a copy of ImagXpress, there are cases where calling certain functions will trigger the following message:

"This function is available in another edition of ImagXpress v13.00
control"

What could cause this error?

This error can occur if ImagXpress Standard Edition is licensed on a system, but you’re trying to call operations that are only available in ImagXpress Professional Edition. So, you will need to ensure you’re using the proper license.

This documentation page specifies the functions that are supported for each edition.

This can also occur if you own both Barcode Xpress and ImagXpress Professional. Barcode Xpress includes ImagXpress Standard Edition, so if you install the ImagXpress Professional license first, and then install Barcode Xpress, the included Standard license will overwrite the Professional license. The resolution in this case is to re-install the ImagXpress license to overwrite Standard with Professional.