Enhance barcodes detection

Use these options to set preprocessing filters to enhance barcode detection.

Preprocessing helps to detect barcodes on the defected or low-resolution images.

Note: The output documents will not be affected by the preprocessing filters: the preprocessed images are temporary and used only for recognition.
Option Description
Enhance image Select this check box to enable this group of settings.

If this check box is not selected, the component performs only the minimum preprocessing: aligns the skewed image by rotating it on a small angle.

If this check box is selected, the following preprocessing filters are available:

  • Deskew: select this check box to detect the angle of the skew of the image and then to rotate it to correct the skew.
  • Despeckle: select this check box to remove small noise from the image before recognition. See Despeckle filter.
  • OCR resolution: select this check box to increase image resolution before recognition. See OCR Resolution.
  • Fill gaps less than: select this check box to remove black objects which have length along the bars direction less than defined. See Fill gaps less than filter.
    Note: This option is applied to 1D barcodes only.
  • Dilate black pixels: select this check box to dilate black objects (like bars) along the bars direction by the specified amount of pixels. See Dilate black pixels filter.
  • Dilate white pixels: select this check box to decrease each black object in the image (like a bar) to horizontal and vertical directions by the specified number of pixels. See Dilate white pixels filter.

When Enhance image check box is selected, the component performs multiple attempts to preprocess and recognize input images. The component preprocesses input images by using every value for every specified range of values for the filters that hold minimum and maximum values; such as Fill gaps less than, Dilate black pixels, and Dilate white pixels.

The set of filters applied during preprocessing depends on barcode Type and Direction specified on the General tab. The Fill gaps less than filter is applied only if 1D barcodes are searched for. The Dilate black pixels filter is applied only if 2D barcodes are searched for, or if the specified barcode direction differs from one of possible vertical or horizontal values. In case barcode type or direction is unknown, the component attempts all applicable combinations.

After applying the combination of preprocessing filters, the component attempts to recognize barcodes in the resulting image. After all recognition attempts are done, the component combines found barcode values from different attempts as if these values were found by a single recognition attempt. During this process of combining barcode values, if two or more directional barcodes of the same direction overlap, then some of these barcodes can be discarded.

Detect best settings Click this button to open the Detect Best Settings dialog box that allows you to test how the component detects barcodes using the specified filters and to detect the optimal preprocessing options.