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Filters and image Processing

You can enhance your scanned pages or raw images by applying a variety of filters and rotation adjustments. This improves their readability for humans and machines alike and streamlines further processing in your backend.

Supported parametric image filters​

You can try out our filters directly on our Web Demo to experience how they work in real-time.

Here is the complete list of all the supported filters:

  • ColorDocumentFilter - Color document filter. This filter is a good starting point for most use cases.
  • ScanbotBinarizationFilter - Automatic binarization filter. This filter is a good starting point for most use cases. It has an OutputMode parameter that can be set to BINARY or ANTIALIASED.
  • CustomBinarizationFilter - Customizable binarization filter. It has a few presets for specific use cases:
    • BinarizationFilterPreset.PRESET_1 - Usually performs well if there are no shadows.
    • BinarizationFilterPreset.PRESET_2, BinarizationFilterPreset.PRESET_3, BinarizationFilterPreset.PRESET_4 - Usually perform well even if there are shadows.
  • BrightnessFilter - Filter for adjusting the image's brightness.
  • ContrastFilter - Filter for adjusting the image's contrast.
  • GrayscaleFilter - Converts color images to grayscale, optionally applying auto-contrast.
  • WhiteBlackPointFilter - Maps the image value channel so that all the pixels darker than the black point are set to 0, all the pixels brighter than the white point are set to 255, and the pixels in between are linearly scaled.
  • LegacyFilter - Applies a filter used for compatibility with older versions of the Scanbot SDK. It takes one of the old filter types as a parameter:
    • ImageFilterType.NONE - Does not apply an image filter and keeps the original colors.
    • ImageFilterType.COLOR - Optimizes the colors, contrast and brightness.
    • ImageFilterType.GRAY - Grayscale filter.
    • ImageFilterType.BINARIZED - Standard binarization filter with contrast optimization. Creates an 8-bit grayscale image with mostly black or white pixels.
    • ImageFilterType.COLOR_DOCUMENT - MagicColor filter. Fixes the white balance and cleans up the background.
    • ImageFilterType.PURE_BINARIZED - A filter for binarizing the image. Creates an image with pixel values set to either pure black or pure white.
    • ImageFilterType.BLACK_AND_WHITE - Black-and-white filter with background cleaning. Creates an 8-bit grayscale image with mostly black or white pixels.
    • ImageFilterType.BACKGROUND_CLEAN - Cleans up the background and tries to preserve photos within the image.
    • ImageFilterType.OTSU_BINARIZATION - A filter for black-and-white conversion using Otsu binarization.
    • ImageFilterType.DEEP_BINARIZATION - A filter for black-and-white conversion primary used for low-contrast documents.
    • ImageFilterType.EDGE_HIGHLIGHT - A filter that enhances edges in low-contrast documents.
    • ImageFilterType.LOW_LIGHT_BINARIZATION - Binarization filter primarily intended to use on low-contrast documents with hard shadows.
    • ImageFilterType.LOW_LIGHT_BINARIZATION_2 - Binarization filter primarily intended to use on low-contrast documents with hard shadows.
    • ImageFilterType.SENSITIVE_BINARIZATION - Binarization filter for poor-quality printed papers.
    • ImageFilterType.PURE_GRAY - Standard grayscale filter. Creates a grayscaled 8-bit image.

Applying filters and rotation to a scanned page​

Processing Scanned Page
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Applying filters and rotation to an image​

Processing an image
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