US 8,274,533 B2Granted

Resizing a digital document image via background content removal

AssigneeXerox Corporation

InventorsClaude S. Fillion, Vishal Monga, Zhigang Fan, Ramesh Nagarajan

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Abstract

What is disclosed is a system and method for performing a background deletion that exploits both local and global context to remove background and other white space between objects with the aim of retaining structural relationships between objects in the document. A document image is received and seams are carved through the image. Seams composed of uniform background pixels are identified. Adjacent seams containing background pixels are collected into groups of seams. The background seam groups are classified according to their widths. A target number of seams to be removed for each background seam group is then determined based on the classification. Seam groups which are wider will have at least the same or a greater target number of seams to be deleted therefrom than will seam groups of narrower widths. The document image is then resized by deleting seams from the seam groups based on the assigned target number.

Claims18

Dependent claims

A method for resizing an image of a document in an image processing system, the method comprising:

receiving an image of a document to be resized to a desired target dimension, said image having a plurality of pixels;
carving a plurality of seams from a first edge to a second edge of said image in one of a horizontal and vertical direction based on an importance map generated for said image;
calculating an energy for each of said seams;
identifying seams composed of background pixels based on said seam energy;
grouping adjacent seams together to form background seam groups;
classifying said background seam groups based upon their respective overall seam group width;
determining a target number of seams to be removed from said background seam groups based on a width of said background seam group;
removing said target number of seams from said background seam groups until said image has been resized to a desired target dimension, comprising removing seams of wider background seam groups first before removing seams from progressively narrower background seam groups, each of said background seams groups retaining their ordering by their respective overall seam group width such that, if a background seam group is wider than a next smaller background seam group before resizing, it will not be any narrower than the next smaller seam group after resizing;
and
providing said resized image of said document to an image output device.

7 more elements

A system for resizing an image of a document in an image processing system, the system comprising:

a memory;
a storage medium;
and
a processor in communication with said storage medium and said memory, said processor executing machine readable instructions for performing:
receiving an image of a document to be resized to a desired target dimension, said image having a plurality of pixels;
carving a plurality of seams from a first edge to a second edge of said image in one of a horizontal and vertical direction based on an importance map generated for said image;
calculating an energy for each of said seams;
identifying seams composed of background pixels based on said seam energy;
grouping adjacent seams together to form background seam groups;
classifying said background seam groups based upon their respective overall seam group width;
determining a target number of seams to be removed from said background seam groups based on a width of said background seam group;
removing said target number of seams from said background seam groups until said image has been resized to a desired target dimension, comprising removing seams of wider background seam groups first before removing seams from progressively narrower background seam groups, each of said background seams groups retaining their ordering by their respective overall seam group width such that, if a background seam group is wider than a next smaller background seam group before resizing, it will not be any narrower than the next smaller seam group after resizing;
and
providing said resized image of said document to an image output device.

11 more elements

A computer program product for resizing an image of a document in an image processing system, the computer program product comprising:

a non-transitory computer readable medium for storing instructions that, when executed on a computer, cause the computer to perform a method comprising:
receiving an image of a document to be resized to a desired target dimension, said image having a plurality of pixels;
carving a plurality of seams from a first edge to a second edge of said image in one of a horizontal and vertical direction based on an importance map generated for said image;
calculating an energy for each of said seams;
identifying seams composed of background pixels based on said seam energy;
grouping adjacent seams together to form background seam groups;
classifying said background seam groups based upon their respective overall seam group width;
determining a target number of seams to be removed from said background seam groups based on a width of said background seam group;
removing said target number of seams from said background seam groups until said image has been resized to a desired target dimension, comprising removing seams of wider background seam groups first before removing seams from progressively narrower background seam groups, each of said background seams groups retaining their ordering by their respective overall seam group width such that, if a background seam group is wider than a next smaller background seam group before resizing, it will not be any narrower than the next smaller seam group after resizing;
and
providing said resized image of said document to an image output device.

8 more elements

Dependencies are inferred from the claim text.