The modulation matrix of 2D barcode contains information about the modulation of cells of the 2D barcode (modulation - measure of the uniformity of reflectance of the dark and light cells respectively). This matrix allows you to visually identify the location of printing problems on an image of 2D barcode.
In version 14.3 of VintaSoft Barcode .NET SDK was added the ability to obtain the modulation matrix using the
ISO15415QualityTest.ModulationMatrix property.
Obtaining of modulation matrix is available for the following barcode types:
- Aztec
- DataMatrix
- QR Code
- Micro QR Code
- Han Xin Code
An example of C#/VB.NET code, which demonstrates how to display the barcode modulation matrix, is available in documentation for
ISO15415QualityTest.ModulationMatrix property.
Also C#/VB.NET code, which demonstrates how to display the barcode modulation matrix, can be seen in VintaSoft Barcode Demo project ([SdkIntsallPath]\VintaSoft\Barcode .NET v14.3\Examples\WinForms\CSharp\BarcodeDemo\).
Here is the screenshot of VintaSoft Barcode Demo application, which shows the modulation matrix for the recognized DataMatrix barcode:
The following are several examples of identifying defects in 2D barcode printing using the analysis of modulation matrix.
Here is an example of modulation matrix for DataMatrix barcode, which has the following problems:
1. Printing defect - vertical stripes
2. Uneven lighting when shooting - low modulation area
Here is an example of modulation matrix for DataMatrix barcode, which has the following problems:
1. Glare from the light source when shooting a barcode
2. A speck or printing defect in the barcode image
3. Printing defect - many columns in the barcode have different widths
Here is an example of modulation matrix for QR Code barcode, which has uneven lighting problem:
