Barcode Detection and Generation

You can perceive and understand an image or extract information from images in your application.

The main barcode detection and generation features include the following:

Handling images

You can handle images with the Tizen.Multimedia.Vision.MediaVisionSource class. You can create the source instance using raw buffer data or an instance of the Tizen.Multimedia.MediaPacket class.
Detecting barcodes

You can detect barcodes in an image or from camera preview streams, and then decrypt them to display messages to the user.

Before detecting a barcode, you must define the barcode detection target as a value of the Tizen.Multimedia.Vision.BarcodeDetectionTarget enumeration:
- Detect both 1D and 2D barcodes
- Detect 1D barcodes only
- Detect 2D barcodes only
Generating barcodes

You can encrypt a given message, generate a barcode from it, and save it in a memory or as an image file.

Before generating a barcode, you must define the text visibility as a value of the Tizen.Multimedia.Visibility enumeration:
- Generate barcode without an input message
- Generate barcode with an input message (supports only 1D barcodes)
You must also define the following barcode specifications:
- Barcode type
- QR code specification (if the QR code barcode type is used)
- Image format (if the barcode is saved as a file)
  - JPEG
  - BMP
  - PNG
Optionally, you can change the foreground or the background color for the barcode by setting the ForegroundColor or BackgroundColor properties of the Tizen.Multimedia.Vision.BarcodeGenerationConfiguration class. Their default values are black and white, respectively.

Prerequisites

To enable your application to use the barcode detection and generation functionality, proceed as follows:

Install the NuGet packages for media vision.

To use the methods and properties of the barcode detection and generation classes and to handle camera preview, include the Tizen.Multimedia and Tizen.Multimedia.Vision namespaces in your application:


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using Tizen.Multimedia;
using Tizen.Multimedia.Vision;

Prepare the barcode engines

To initialize the barcode detection and generation engines for use, proceed as follows:

For barcode detection:

Create an instance of the Tizen.Multimedia.Vision.BarcodeDetectionConfiguration class and set the Target property as a value of the Tizen.Multimedia.Vision.BarcodeDetectionTarget enumeration:


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static BarcodeDetectionConfiguration configDetection = new BarcodeDetectionConfiguration();

/// To detect all barcode types
configDetection.Target = BarcodeDetectionTarget.All;

/// To detect only 1D barcodes
/// configDetection.Target = BarcodeDetectionTarget.Barcode1D;
/// To detect only 2D barcodes (QR codes)
/// configDetection.Target = BarcodeDetectionTarget.Barcode2D;

Create an instance of the Tizen.Multimedia.Vision.MediaVisionSource class with raw image buffer data and its corresponding width, height, and color space:


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/// Assume that there is a decoded raw data buffer of the byte[] type, and
/// it has 640x480 resolution with an RGB888 color space
MediaVisionSource source = new MediaVisionSource(bytes, width, height, ColorSpace.Rgb888);

The source stores the barcode to be detected and all related data.

To provide camera preview images, define a camera preview event handler for the Preview event of the Tizen.Multimedia.Camera class and create an instance of that class:


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/// Define a camera preview event handler
static void PreviewCallback(object sender, PreviewEventArgs e)
{
    PreviewData preview = e.Preview;

    SinglePlane singlePlane = (SinglePlane)preview.Plane;
    if (preview.Format == CameraPixelFormat.Rgb888)
    {
        MediaVisionSource source = new MediaVisionSource(singlePlane.Data, preview.width, preview.height, ColorSpace.Rgb888);
    }
}

/// Create the Tizen.Multimedia.Camera instance
static Camera camera = null;
try
{
    camera = new Camera(CameraDevice.Rear);
}
catch (NotSupportedException)
{
    Log.Info("Barcode Sample", "NotSupported");
}

Set the camera display, register the camera preview event handler, and start the camera preview with the StartPreview() method:


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/// Set the camera display
camera.Display = new Display(new Window("Preview"));

/// Register the camera preview event handler
camera.Preview += PreviewCallback;

IList previewFormats = camera.Feature.SupportedPreviewPixelFormats.ToList();
foreach (CameraPixelFormat previewFormat in previewFormats)
{
    camera.Setting.PreviewPixelFormat = previewFormat;
    break;
}

/// Start the camera preview
camera.StartPreview();

For barcode generation, create an instance of the Tizen.Multimedia.Vision.BarcodeGenerationConfiguration class and set its properties:


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static BarcodeGenerationConfiguration configGeneration = new BarcodeGenerationConfiguration();

/// To show message on the generated barcode image
configGeneration.TextVisibility = Visibility.Visible;

/// To hide message on the generated barcode image
/// configGeneration.TextVisibility = Visibility.Invisible;

/// To change the foreground or background color
/// For this example, the foreground and background are set as black and white, respectively
configGeneration.ForegroundColor = Color.Black;
configGeneration.BackgroundColor = Color.White;

Detect barcodes

To detect barcodes, proceed as follows:

To access the camera preview data from which to detect barcodes, create a new instance of the Tizen.Multimedia.Vision.MediaVisionSource class in the camera preview event handler:


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static void PreviewCallback(object sender, PreviewEventArgs e)
{
    PreviewData preview = e.Preview;

    SinglePlane singlePlane = (SinglePlane)preview.Plane;
    if (preview.Format == CameraPixelFormat.Rgb888)
    {
        MediaVisionSource source = new MediaVisionSource(singlePlane.Data, preview.width, preview.height, ColorSpace.Rgb888);
    }

Detect barcodes in the image using the DetectAsync() method of the Tizen.Multimedia.Vision.BarcodeDetector class:


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    Point point = new Point(0,0);
    Size size = new Size((int)source.Width, (int)source.Height);

    Rectangle roi = new Rectangle(point, size);

    var barcodeLists = await BarcodeDetector.DetectAsync(source, roi, configDetection);

    foreach (Barcode barcode in barcodeLists)
    {
        Log.Info("Barcode sample", $"Barcode type is {barcode.Type}");
        Log.Info("Barcode sample", $"Barcode message is {barcode.Message}");
    }
}

The ROI (region of interest) feature allows you to define a rectangular region of the image in which to detect barcodes. In the above example, the whole image is set as the ROI.

When barcode detection is no longer needed, deregister the camera preview event handler, stop the camera preview, and destroy the camera instance:


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camera.Preview -= PreviewCallback;

camera.StopPreview();
camera.Dispose();

For more information, see the Tizen.Multimedia.Camera class.

Generate barcodes

To generate a barcode, proceed as follows:

To generate the barcode into memory:

To generate a 1D barcode, create a source instance using the GenerateSource() method of the Tizen.Multimedia.Vision.BarcodeGenerator class with a message and a barcode type:


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string message = "0123455";

/// For a Code 128 type barcode
var source = BarcodeGenerator.GenerateSource(message, BarcodeType.Code128);

/// If you want to change the barcode color or change the visibility of the text, give an instance
/// of the Tizen.Multimedia.Vision.BarcodeGenerationConfiguration class as an additional parameter:
/// var source = BarcodeGenerator.GenerateSource(message, BarcodeType.code128, configGeneration);

To generate a QR code:

To create the QR code configuration, create an instance of the Tizen.Multimedia.Vision.QrConfiguration class with the QR code encoding mode as a value of the Tizen.Multimedia.Vision.QrMode enumeration, the QR code error correction level as a value of the Tizen.Multimedia.Vision.ErrorCorrectionLevel enumeration, and the QR code version:


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string message = "Tizen QR";

/// For the UTF8 encoding type
QrConfiguration qrConfig = new QrConfiguration(QrMode.Utf8, ErrorCorrectionLevel.Medium, 30);

Create a source instance using the GenerateSource() method of the Tizen.Multimedia.Vision.BarcodeGenerator class with a message and the QR code configuration:


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var source = BarcodeGenerator.GenerateSource(message, qrConfig);

/// If you want to change the QR code color, give an instance
/// of the Tizen.Multimedia.Vision.BarcodeGenerationConfiguration class as an additional parameter:
/// var source = BarcodeGenerator.GenerateSource(message, qrConfig, configGeneration);

To generate the barcode into a file:

To generate a 1D barcode:

Create an instance of the Tizen.Multimedia.Vision.BarcodeImageConfiguration class with the file format as a value of the Tizen.Multimedia.Vision.BarcodeImageFormat enumeration, the image file resolution, and a path where the file is to be saved:


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int width = 300;
int height = 100;
BarcodeImageFormat format = BarcodeImageFormat.Jpeg;
string path = "/tmp/tizen_barcode.jpg";
BarcodeImageConfiguration imageConfig = new BarcodeImageConfiguration(width, height, path, format);

Generate the barcode using the GenerateImage() method of the Tizen.Multimedia.Vision.BarcodeGenerator class:


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string message = "0123455";
BarcodeType type = BarcodeType.Code128;
BarcodeGenerator.GenerateImage(message, type, imageConfig);

To generate a QR code, create instances of the Tizen.Multimedia.Vision.BarcodeImageConfiguration and Tizen.Multimedia.Vision.QrConfiguration classes as above, and generate the QR code using the GenerateImage() method of the Tizen.Multimedia.Vision.BarcodeGenerator class:


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int width = 300;
int height = 300;
BarcodeImageFormat format = BarcodeImageFormat.Jpeg;
string path = "/tmp/tizen_qr.jpg";
BarcodeImageConfiguration imageConfig = new BarcodeImageConfiguration(width, height, path, format);
Qrconfiguration qrConfig = new QrConfiguration(QrMode.Utf8, ErrorCorrectionLevel.Medium, 30);

string message = "Tizen QR"
BarcodeGenerator.GenerateImage(message, qrConfig, imageConfig);

Barcode specifications

The following tables provide more information on the barcode generation specifications.

Table: Supported barcode types

You can scroll this table.

1D or 2D	Type	Description
1-D	UPC-A	Universal product code with numeric 12-digit
1-D	UPC-E	Universal product code with numeric 6-digit
1-D	EAN-8	International article number with numeric 8-digit
1-D	EAN-13	International article number with numeric 13-digit
1-D	CODE-128	Code 128; supports alphanumeric or numeric-only
1-D	CODE-39	Code 39; supports 34 characters consisting of uppercase letters (A to Z), numeric digits (0 to 9), and special characters (-, ., $, /, %, space)
1-D	INTERLEAVED 2 of 5	Interleaved 2 of 5 with numeric digits
2-D	QR code	Quick Response code

Table: Supported QR code specifications