Detection of physical tampering on documents

A method comprising:

• obtaining, by one or more hardware processors, an image of a document;
• identifying, by the one or more hardware processors, a plurality of contours in the image;
• eliminating, by the one or more hardware processors, one or more first contours from the image based on at least one of a size threshold or a curvature threshold;
• subsequent to the eliminating, determining, by the one or more hardware processors, a number of contours remaining in the image;
• and
• determining, by the one or more hardware processors, whether the document has been physically manipulated based on the number of contours remaining in the image.

A non-transitory machine-readable medium having stored thereon machine-readable instructions executable to cause a machine to perform operations comprising:

• obtaining an image of a document;
• identifying a plurality of contours in the image;
• determining, for each contour in the plurality of contours in the image, a size attribute of the contour;
• eliminating, from the plurality of contours, one or more contours based on the size attribute of the one or more contours;
• determining, for a first contour in the plurality of contours, a curvature attribute;
• determining whether to eliminate the first contour from the image based on the curvature attribute;
• and
• determining whether the document has been physically manipulated based on a number of contours remaining in the image.