At some point it can be necessary to generate a barcode and encode into it the data, which size exceeds the capacity of barcode, making impossible to put all the data into one barcode. To solve this problem, you should divide the source data into several data blocks and encode these data blocks into several barcodes. You also will have to mark the data blocks so that they can be united back into the source data.
There is Structure Append technology for two-dimensional barcodes, which allows you to divide the source data into data blocks and get back the original data from these data blocks.
Structure Append technology for DataMatrix and QR Code barcodes allows you to split the source data up to 16 data blocks and encode these data blocks into 16 DataMatrix or QR Code barcodes.
For Aztec barcodes you can split the source data up to 26 data blocks and encode them into 26 Aztec barcodes.
For PDF417 barcodes the Structure Append technology allows you to split the source data to 99999 data blocks.
And for Code16K barcodes the Structure Append technology allows 9 data blocks.
Each barcode with a data block contains the position of the data block in the source data, so barcodes with data blocks in the image can be arranged in random order.
This feature can be used to place barcodes on an image in most optimal way.
Here is C# code that allows you to generate an Aztec barcode with text "VintaSoft Barcode .NET SDK is the professional 1D & 2D barcode reader and barcode generator library for .NET, WPF and WEB.":
/// <summary>
/// Generates Aztec barcode as raster image.
/// </summary>
public void GenerateAztecBarcode()
{
// create the barcode writer
Vintasoft.Barcode.BarcodeWriter barcodeWriter = new Vintasoft.Barcode.BarcodeWriter();
// set barcode writer settings
barcodeWriter.Settings.Barcode = Vintasoft.Barcode.BarcodeType.Aztec;
barcodeWriter.Settings.Value = "VintaSoft Barcode .NET SDK is the professional 1D & 2D barcode reader and barcode generator library for .NET, WPF and WEB.";
// get barcode as image
using (System.Drawing.Image barcodeImage = barcodeWriter.GetBarcodeAsBitmap())
{
// save the barcode image to a file
barcodeImage.Save("aztec-barcode.png");
}
}
Here is the image of generated Aztec barcode:
Here is C# code that allows you to read data encoded into generated Aztec barcode:
/// <summary>
/// Recognizes Aztec barcode in image.
/// </summary>
/// <param name="barcodeImageFilePath">A path to a barcode image file.</param>
public void RecognizeAztecBarcode()
{
// create barcode reader
using (Vintasoft.Barcode.BarcodeReader reader = new Vintasoft.Barcode.BarcodeReader())
{
// specify that reader must search for Aztec barcodes
reader.Settings.ScanBarcodeTypes = Vintasoft.Barcode.BarcodeType.Aztec;
// specify that reader must search for horizontal barcodes only
reader.Settings.ScanDirection = Vintasoft.Barcode.ScanDirection.Horizontal;
// read barcodes from image file
Vintasoft.Barcode.IBarcodeInfo[] barcodeInfos = reader.ReadBarcodes("aztec-barcode.png");
// if barcodes are not detected
if (barcodeInfos.Length == 0)
{
System.Console.WriteLine("Barcodes are not found.");
}
// if barcodes are detected
else
{
// get information about recognized barcodes
System.Console.WriteLine(string.Format("{0} barcode(s) found:", barcodeInfos.Length));
System.Console.WriteLine();
for (int i = 0; i < barcodeInfos.Length; i++)
{
Vintasoft.Barcode.IBarcodeInfo barcodeInfo = barcodeInfos[i];
System.Console.WriteLine(string.Format("[{0}:{1}]", i + 1, barcodeInfo.BarcodeType));
System.Console.WriteLine(string.Format("Value: {0}", barcodeInfo.Value));
System.Console.WriteLine(string.Format("Region: {0}", barcodeInfo.Region));
System.Console.WriteLine();
}
}
}
}
Here is the result of reading data from generated Aztec barcode:
1 barcode(s) found:
[1:Aztec]
Value: VintaSoft Barcode .NET SDK is the professional 1D & 2D barcode reader and barcode generator library for .NET, WPF and WEB.
The Aztec barcode has a square shape and this may cause a non-optimal use of space in the image if the barcode should be placed in a rectangular region.
So next we divide the text of the barcode into 4 data blocks, instead of one barcode, we create 4 barcodes and place these 4 barcodes horizontally in order to optimally use the space of rectangular shape intended for positioning the barcode.
Here is C# code that allows to divide the text "VintaSoft Barcode .NET SDK is the professional 1D & 2D barcode reader and barcode generator library for .NET, WPF and WEB."
into 4 data blocks, generate 4 Aztec barcodes with these data blocks and place Aztec barcodes horizontally:
/// <summary>
/// Generates several Aztec barcodes with structure append information and aligns barcodes horizontally.
/// </summary>
public void GenerateAztecBarcodesWithStructureAppendAndAlignBarcodeHorizontally()
{
// source text
string text = "VintaSoft Barcode .NET SDK is the professional 1D & 2D barcode reader and barcode generator library for .NET, WPF and WEB.";
// count of text blocks
int textBlockCount = 4;
// maximum length of text block
int textBlockLen = text.Length / textBlockCount;
if ((text.Length % textBlockCount) != 0)
textBlockLen++;
// array with barcode images
System.Drawing.Image[] barcodeImages = new System.Drawing.Image[textBlockCount];
// for each text block
for (int i = 0; i < textBlockCount; i++)
{
// calculate text block string
string textBlock = text.Substring(0, textBlockLen);
text = text.Substring(textBlockLen);
// generate barcode image with text block
barcodeImages[i] = GenerateImageOfAztecBarcodeWithStructureAppendInformation(textBlock, i + 1, textBlockCount);
}
// width of image with merged barcodes
int mergedBarcodeWidth = 0;
// for each barcode image
for (int i = 0; i < barcodeImages.Length; i++)
{
// increase width of image with merged barcodes
mergedBarcodeWidth += barcodeImages[i].Width;
}
// calculate height of image with merged barcodes
int mergedBarcodeHeight = barcodeImages[0].Height;
// create image with merged barcodes
using (System.Drawing.Image mergedBarcodesImage = new System.Drawing.Bitmap(mergedBarcodeWidth, mergedBarcodeHeight))
{
// create Graphics for drawing on image with merged barcodes
using (System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(mergedBarcodesImage))
{
// fill image with merged barcodes using white color
g.FillRectangle(System.Drawing.Brushes.White, new System.Drawing.RectangleF(0, 0, mergedBarcodesImage.Width, mergedBarcodesImage.Height));
// the horizontal position of barcode image on image with merged barcodes
int barcodeXPosition = 0;
// for each barcode image
for (int i = 0; i < barcodeImages.Length; i++)
{
// draw barcode image on image with merged barcodes
g.DrawImage(barcodeImages[i], new System.Drawing.PointF(barcodeXPosition, 0));
// change the horizontal position of barcode image on image with merged barcodes
barcodeXPosition += barcodeImages[i].Width;
}
}
// save image with merged barcodes to a file
mergedBarcodesImage.Save("aztec-barcodes-with-structure-append-and-aligned-horizontally.png");
}
// for each barcode image
for (int i = 0; i < barcodeImages.Length; i++)
{
// dispose barcode image
barcodeImages[i].Dispose();
}
}
/// <summary>
/// Generates an image of Aztec barcode, which contains information about the structure append.
/// </summary>
/// <param name="barcodeValue">Barcode value.</param>
/// <param name="symbolPosition">Value position in structure append. Value from 1 to <i>symbolCount</i>.</param>
/// <param name="symbolCount">Count of values in structure append.</param>
/// <returns>An image of Aztec barcode, which contains information about the structure append.</returns>
public System.Drawing.Image GenerateImageOfAztecBarcodeWithStructureAppendInformation(string barcodeValue, int symbolPosition, int symbolCount)
{
// create the barcode writer
Vintasoft.Barcode.BarcodeWriter barcodeWriter = new Vintasoft.Barcode.BarcodeWriter();
// specify that Aztec barcode must be created
barcodeWriter.Settings.Barcode = Vintasoft.Barcode.BarcodeType.Aztec;
// specify that created Aztec barcode should not have padding
barcodeWriter.Settings.Padding = 0;
// specify the barcode values
barcodeWriter.Settings.ValueItems = new Vintasoft.Barcode.BarcodeInfo.ValueItemBase[] {
// create the non-data flag that contains information about structure append
Vintasoft.Barcode.BarcodeInfo.NonDataFlags.CreateAztecStructuredAppendCharacter(symbolPosition, symbolCount, null),
// create a text value item
new Vintasoft.Barcode.BarcodeInfo.TextValueItem(barcodeValue)
};
// return generated barcode image
return barcodeWriter.GetBarcodeAsBitmap();
}
Here is the image of generated Aztec barcodes with data blocks:
The image containing Aztec barcodes with data blocks has rectangular shape and thus can be optimally deployed into a rectangular region.
Here is C# code that allows to recognize data from generated Aztec barcodes and unite the data blocks into original data:
/// <summary>
/// Recognizes Aztec barcodes with structure append information.
/// </summary>
/// <param name="barcodeImageFilePath">A path to a barcode image file.</param>
public void RecognizeAztecBarcodesWithStructureAppend()
{
// create barcode reader
using (Vintasoft.Barcode.BarcodeReader reader = new Vintasoft.Barcode.BarcodeReader())
{
// specify that reader must search for Aztec barcodes
reader.Settings.ScanBarcodeTypes = Vintasoft.Barcode.BarcodeType.Aztec;
// specify that reader must search for horizontal barcodes only
reader.Settings.ScanDirection = Vintasoft.Barcode.ScanDirection.Horizontal;
// read barcodes from image file
Vintasoft.Barcode.IBarcodeInfo[] barcodeInfos = reader.ReadBarcodes("aztec-barcodes-with-structure-append-and-aligned-horizontally.png");
// if barcodes are not detected
if (barcodeInfos.Length == 0)
{
System.Console.WriteLine("Barcodes are not found.");
}
// if barcodes are detected
else
{
// reconstruct barcode info from barcode infos with structure append information
Vintasoft.Barcode.BarcodeInfo.StructuredAppendBarcodeInfo[] reconstructedBarcodeInfos =
Vintasoft.Barcode.BarcodeInfo.StructuredAppendBarcodeInfo.ReconstructFrom(barcodeInfos);
// get information about recognized barcodes
System.Console.WriteLine(string.Format("{0} reconstructed barcode(s) found:", reconstructedBarcodeInfos.Length));
System.Console.WriteLine();
for (int i = 0; i < reconstructedBarcodeInfos.Length; i++)
{
Vintasoft.Barcode.BarcodeInfo.StructuredAppendBarcodeInfo reconstructedBarcodeInfo = reconstructedBarcodeInfos[i];
System.Console.WriteLine(string.Format("[{0}:{1}]", i + 1, reconstructedBarcodeInfo.BarcodeType));
System.Console.WriteLine(string.Format("Value: {0}", reconstructedBarcodeInfo.Value));
System.Console.WriteLine();
}
}
}
}
Here is the result of recognition from generated Aztec barcodes with data blocks:
1 reconstructed barcode(s) found:
[1:Aztec]
Value: VintaSoft Barcode .NET SDK is the professional 1D & 2D barcode reader and barcode generator library for .NET, WPF and WEB.
Aztec barcodes do not require a quite zone around the barcode and this allows to place the barcodes tight to each other.
