Claims:WE CLAIM:
1. A method for processing an image extracted from a document, the method comprising:
detecting, by an image processing system, one or more edges of the image;
determining, by the image processing system, a missing edge in the image by comparing color gradients of the one or more edges;
reconstructing, by the image processing system, the missing edge by cloning image pixels based on data pixels of an edge, opposite to the missing edge, amongst the one or more edges to obtain a reconstructed image, wherein the reconstructed image includes a reconstructed edge;
identifying, by the image processing system, outer corner points in the reconstructed image based on quadratic corner points, wherein the quadratic corner points are determined based on the one or more edges and the reconstructed edge; and
performing, by the image processing system, an image perspective correction on the reconstructed image, based on the outer corner points, to obtain a processed image.

2. The method as claimed in claim 1 further comprises:
extracting, by the image processing system, at least one unique feature from the processed image;
comparing, by the image processing system, the at least one unique feature with a trained data set to validate the processed image, wherein the trained data set comprises template images and predefined features set; and
storing, by the image processing system, the processed image for future usage upon successful validation.

3. The method as claimed in claim 1, wherein determining the missing edge further comprises:
computing a color gradient along each side of the image; and
comparing the color gradient of each side with remaining sides to detect the missing edge.
4. The method as claimed in claim 1, wherein reconstructing the missing edge further comprises:
extending size of the image along the missing edge until a predetermined offset is reached to obtain an extended image;
determining an empty region in the extended image by moving data pixels based on the predetermined offset; and
cloning the empty region, based on the data pixel of the edge opposite to the missing edge, to reconstruct the missing edge.

5. The method as claimed in claim 4, wherein cloning the empty region further comprises:
computing a color variation between background color and a color of the document; and
applying an edge gradient direction on cloned empty region, wherein the edge image gradient direction is determined based on the color variation.

6. The method as claimed in claim 1, wherein identifying the outer corner points further comprises:
deriving the quadratic corner points by extending lines detected along the one or more missing edges and the reconstructed edge;
filtering redundant quadratic corner points amongst the quadratic corner points to obtain a filtered set of quadratic corner points;
detecting outer corner points in the filtered set of quadratic corner points based on coordinates, along a vertical direction and a horizontal direction, corresponding to each quadratic corner point present in the filtered set of quadratic corner points;
increasing an edge detection filter threshold value of the reconstructed image upon unsuccessful detection of all the outer corner points; and
iterating detection of the outer corner points with the increased edge detection filter threshold value till all the outer corner points are detected.

7. The method as claimed in claim 1, wherein performing the image perspective correction on the reconstructed image further comprises:
performing polygon approximation on the outer corner points;
determining a mass center of the reconstructed image based on the polygon approximation;
computing a perspective transformation for the reconstructed image based on the mass center and a predefined image size; and
applying the perspective transformation to the reconstructed image to obtain the processed image.

8. An image processing system for processing an image extracted from a document, the image processing system comprising:
a processor; and
a memory communicatively coupled to the processor, wherein the memory stores processor-executable instructions, which, on execution, causes the processor to perform operations comprising:
detecting one or more edges of the image;
determining a missing edge in the image by comparing color gradients of the one or more edges;
reconstructing the missing edge by cloning image pixels based on data pixels of an edge, opposite to the missing edge, amongst the one or more edges to obtain a reconstructed image, wherein the reconstructed image includes a reconstructed edge;
identify outer corner points in the reconstructed image based on quadratic corner points, wherein the quadratic corner points are determined based on the one or more edges and the reconstructed edge; and
performing an image perspective correction on the reconstructed image, based on the outer corner points, to obtain a processed image.

9. The system as claimed in claim 8 wherein the instructions further causes the processor to perform operations comprising:
extracting at least one unique feature from the processed image;
comparing the at least one unique feature with a trained data set to validate the processed image, wherein the trained data set comprises template images and predefined features set; and
storing the processed image for future usage upon successful validation

10. The system as claimed in claim 8, wherein operations of determining the missing edge further comprise:
computing a color gradient along each side of the image; and
comparing the color gradient of each side with remaining sides to detect the missing edge.

11. The system as claimed in claim 8, wherein operations of reconstructing the missing edge further comprise:
extending size of the image along the missing edge until a predetermined offset is reached to obtain an extended image;
determining an empty region in the extended image by moving data pixels based on the predetermined offset; and
cloning the empty region, based on the data pixel of the edge opposite to the missing edge, to reconstruct the missing edge.

12. The system as claimed in claim 11, wherein operations of cloning the empty region further comprise:
computing a color variation between background color and a color of the document; and
applying an edge gradient direction on cloned empty region, wherein the edge image gradient direction is determined based on the color variation.

13. The system as claimed in claim 8, wherein operations of identifying the outer corner points further comprise:
deriving the quadratic corner points by extending lines detected along the one or more missing edge and the reconstructed edge;
filtering redundant quadratic corner points amongst the quadratic corner points to obtain a filtered set of quadratic corner points;
detecting outer corner points in the filtered set of quadratic corner points based on coordinates, along a vertical direction and a horizontal direction, corresponding to each quadratic corner point present in the filtered set of quadratic corner points;
increasing an edge detection filter threshold value of the reconstructed image upon unsuccessful detection of all the outer corner points; and
iterating detection of the outer corner points with the increased edge detection filter threshold value till all the outer corner points are detected.

14. The system as claimed in claim 8, wherein operations of performing the image perspective correction on the reconstructed image further comprise:
performing polygon approximation on the outer corner points;
determining a mass center of the reconstructed image based on the polygon approximation;
computing a perspective transformation for the reconstructed image based on the mass center and a predefined image size; and
applying the perspective transformation to the reconstructed image to obtain the processed image.

Dated this 26th day of January, 2016

SWETHA S.N
OF K & S PARTNERS
AGENT FOR THE APPLICANT
, Description:TECHNICAL FIELD

The present subject matter is related, in general to image processing, and more particularly, but not exclusively to a method and system for processing an image extracted from a document.