DataMatrixDemodulationMode
Specifies the mode the function should use to demodulate (determine which cells are on and which cells are off) the Data Matrix barcode.
Elements
| Name | Value | Description |
|---|---|---|
| IMAQ_AUTO_DETECT_DEMODULATION_MODE | -2 | The function 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. |
| IMAQ_HISTOGRAM | 0 | The function 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. |
| IMAQ_LOCAL_CONTRAST | 1 | The function 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. |
| IMAQ_COMBINED | 2 | The function 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 function will use the threshold to determine if the cell is on or off. If the cell pixel values are close to the threshold, the function will use the IMAQ_LOCAL_CONTRAST 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. |
| IMAQ_ALL_DEMODULATION_MODES | 3 | The function tries IMAQ_HISTOGRAM, then IMAQ_LOCAL_CONTRAST and then IMAQ_COMBINATION, stopping once one mode is successful. |
| IMAQ_DATA_MATRIX_DEMODULATION_MODE_SIZE_GUARD | 0xFFFFFFFF | Reserved |