DemodulationMode Property

Syntax

CWIMAQDataMatrixReport.DemodulationMode

Data Type

CWIMAQDataMatrixDemodulationModes

You can use the following constants with this data type:

• cwimaqDataMatrixDemodulationModeAll—The method tries cwimaqDataMatrixDemodulationModeHistogram, then cwimaqDataMatrixDemodulationModeLocalContrast and then cwimaqDataMatrixDemodulationModeCombined, stopping once one mode is successful.
  
• cwimaqDataMatrixDemodulationModeAutoDetect—The method will try each demodulation mode and use the one which decodes the Data Matrix barcode within the fewest iterations and utilizing the least amount of error correction.
  
• cwimaqDataMatrixDemodulationModeCombined—The method uses the histogram of the Data Matrix barcode to calculate a threshold. For cells with pixel values that are sufficiently below or above this threshold, the method will use the threshold to determine if the cell is on or off. If the cell pixel values are close to the threshold, the method will use the cwimaqDataMatrixDemodulationModeLocalContrast mode to determine if the cell is on or off. This mode is slower, but works with images that contain a Data Matrix barcode with extremely low cell fill percentages or gross print growth errors.
  
• cwimaqDataMatrixDemodulationModeHistogram—The method uses a histogram of all of the Data Matrix cells to calculate a threshold. This threshold determines if a cell is on or off. This is the fastest mode, but requires images with consistent levels of contrast.
  
• cwimaqDataMatrixDemodulationModeLocalContrast—The method examines each of the cell's neighbors to determine if the cell is on or off. This mode is slower, but works with images that have inconsistent levels of contrast.
  

Purpose

The demodulation mode the function used to locate the Data Matrix barcode.

Remarks

If DemodulationMode is set to cwimaqDataMatrixDemodulationModeAutoDetect in the DataMatrixSearchOptions input parameter, this property indicates the recommended demodulation mode for this image.