Restoring the appearance of scans of damaged physical documents

A computer-implemented method for restoring appearances of scans of damaged physical documents, the computer-implemented method comprising:

• receiving a scanned image of a physical document that includes ink writing;
• for individual pixels of the scanned image, measuring a decrease in darkness from the respective individual pixel by scanning pixels at multiple angles away from the respective individual pixel;
• assigning scores to the multiple angles based on the decrease in darkness at individual angles;
• determining likelihoods that the individual pixels are part of a stroke based on the assigned scores;
• determining a curve based on the likelihoods that the individual pixels are part of the stroke;
• and
• restoring an appearance of the scanned image of the physical document by changing colors of pixels of the scanned image of the physical document to make pixels on or near the curve darker.

A computer-implemented method for restoring appearances of scans of damaged physical documents, the computer-implemented method comprising:

• removing ink bleed and adding ink based on determining an ink bleed model by analyzing colors of pixels in a scanned image of a physical document;
• reconstructing gaps in strokes based on analyzing pixel color at multiple angles around individual pixels in the scanned image of the physical document to determine whether the individual pixels are part of the strokes;
• and
• enhancing an appearance of the scanned image by comparing pixels that are not already close to a background color or ink color with other nearby pixels and, based on the nearby pixels, adjusting colors of the pixels that are not already close to the background color or ink color.