US 12,165,299 B2 · Enhancing light text in scanned documents while preserving document fidelity

Abstract

The present disclosure relates to systems, non-transitory computer-readable media, and methods that implement an image filter for enhancing light text and removing document shadows. In particular embodiments, the disclosed systems use a modified adaptive thresholding approach the relies on image gradients to efficiently guide the thresholding process. In addition, the disclosed systems use a machine-learning model to generate a document shadow map. The document shadow map can include text reflections. Accordingly, the disclosed systems remove text reflections from the document shadow map (e.g., by using an interpolated shadow intensity value of neighboring shadow map pixels). In turn, the disclosed systems use the document text mask and the document shadow map cleaned of text reflections to remove shadows from the digital image. Further, the disclosed systems enhance text in the shadow-removed digital image based on contrast stretching.

Claims20

Dependent claims

A non-transitory computer-readable medium comprising instructions that, when executed by at least one processor, cause a computing device to perform operations comprising:

receiving a digital image portraying a scanned document;
generating a document text mask from the digital image utilizing adaptive filtering;
generating a document shadow map of the digital image utilizing a machine-learning model;
generating a modified document shadow map based on the document text mask;
and
generating an enhanced digital image of the scanned document based on the modified document shadow map and the document text mask;
providing, for display within a graphical user interface, a selectable image filter for viewing the enhanced digital image;
and
providing, for display within the graphical user interface, the enhanced digital image in response to identifying a user input indicating a selection of the selectable image filter.

6 more elements

A system comprising:

one or more memory devices comprising:
a machine-learning model for generating document shadow maps of digital images;
and
one or more processors configured to cause the system to:
scan a document to generate a digital image of the document;
generate a document text mask from the digital image utilizing adaptive filtering by:
comparing a pixel color value of a pixel in a gradient image generated from the digital image and an average pixel color value for a group of pixels in an integral image generated from the digital image;
and
determining the pixel in the gradient image corresponds to either a foreground pixel or a background pixel of the document text mask based on the comparison;
generate a document shadow map of the digital image utilizing the machine-learning model;
generate a modified document shadow map by removing text reflections in the document shadow map based on the document text mask;
generate an enhanced digital image of the document based on the modified document shadow map and the document text mask.

9 more elements

Dependencies are inferred from the claim text.

Enhancing light text in scanned documents while preserving document fidelity

Life of this patent

Enhancing light text in scanned documents while preserving document fidelity

Life of this patent

Abstract

Claims20