IMAGE PROCESSING METHOD, APPARATUS AND UNIT

• US 20110188778A1
• Filed: 08/09/2010
• Published: 08/04/2011
• Est. Priority Date: 02/28/2008
• Status: Active Grant

• Current Assignee: Inpho GmbH (Trimble Inc.)
• Original Assignee: Inpho GmbH (Trimble Inc.)
• Inventors: Wiesenfarth, Rainer
• Granted Patent: US 8,594,458 B2
• Time in Patent Office: Days
• US Class Current: 382/284
• CPC Class Codes: G06T 3/4038 Image mosaicing, e.g. composing plane images from plane sub-images

Abstract

The invention relates to a method for selecting a seam between two overlapping images of an area of interest. It includes generating a difference value associated with each portion of the overlapping region, wherein the difference value associated with a portion is derived from the difference between at least one property of the portion in the two images It also includes selecting, through the overlapping region, a path between two points located at the edge of the overlapping region based on the sum of the difference values of the portions along the path. The path is set as the seam. The seam may be used for combining the overlapping images into one image. The invention also relates to a unit, an apparatus, a computer program and an image.

Claims

1. A method for selecting a seam between two overlapping images of an area of interest and for combining the two overlapping images into one image, the images defining an overlapping region, the method including:

performing a generating procedure for generating a difference value associated with each portion of the overlapping region, wherein the difference value associated with a portion is derived from the difference between at least one property of the portion in the two images; and

performing a selecting procedure for selecting, through the overlapping region, a path between two points located at the edge of the overlapping region based on the sum of the difference values of the portions along the path, wherein the path is the seam;

performing a combining procedure including combining and blending the images along the seam, wherein the same difference values associated with the portions of the overlapping region are used for selecting the path and for deciding whether a portion is to be blended.

2. The method of claim 1 wherein the difference value associated with a portion is at least one of:

the difference between the radiometric values of the portion in the two images;

the difference between the gradient of the radiometric values at the portion in the two images;

or

a combination of the two preceding differences.

3. The method of claim 1 wherein the two points located at the edge of the overlapping region are each located at an intersection between the edges of the two images.

4. The method of claim 1 wherein the selecting procedure includes selecting the path along which the sum of the difference values is the smallest or the smallest known.

5. The method of claim 1 wherein, in the selecting procedure, selecting a path between the two points is further based on at least one of:

the position in the overlapping region of the portions along the path;

values associated with the portions or some of the portions along the path, wherein the values are coming from an external source;

or

a combination of the two preceding properties.

6. A method for combining a set of overlapping images, the method including:

a mosaicing procedure applied on the set including;

determining whether the set comprises exactly two images, and, if so, combining the two images into one image using the method of claims 1; and

determining whether the set comprises more than two images, and, if so;

(i) splitting the set into two subsets;

(ii) applying on each one of the two subsets the mosaicing procedure to obtain two images; and

(iii) combining the two obtained images into one image in accordance with the method of claim 1.

7. The method of claim 6 wherein the mosaicing procedure applied on the set further includes

determining whether the set comprises one image, and, if so, completing the mosaicing procedure applied on the set.

8. An image processing unit configured to select a seam between two overlapping images of an area of interest and for combining the two overlapping images into one image, the images defining an overlapping region, the unit including:

a generating unit configured to generate a difference value associated with each portion of the overlapping region, the generating unit being configured so that the difference value associated with a portion is derived from the difference between at least one property of the portion in the two images; and

a selecting unit configured to select, through the overlapping region, a path between two points located at the edge of the overlapping region based on the sum of the difference values of the portions along the path;

the image processing unit being configured so that the path is set as the seam; and

a combining unit configured to combine and blend the images along the seam;

wherein the same difference values associated with the portions of the overlapping region are used for selecting the path and for deciding whether a portion is to be blended.

9. The image processing unit of claim 8 further configured so that the difference value associated with a portion is any one of:

the difference between the radiometric values of the portion in the two images;

the difference between the gradient of the radiometric values at the portion in the two images;

or

a combination of the two preceding differences.

10. The image processing unit of claim 8 further configured so that the two points located at the edge of the overlapping region are each located at an intersection between the edges of the two images.

11. The image processing unit of claim 8 wherein the selecting unit is further configured to include selecting the path along which the sum of the difference values is the smallest or the smallest known.

12. The image processing unit of claim 8 wherein the selecting unit is further configured to select a path between the two points is further based on any one of:

the position in the overlapping region of the portions along the path;

values associated with the portions or some of the portions along the path, wherein the values are coming from an external source;

or

a combination of the two preceding properties.

13. An image processing apparatus configured to combine a set of overlapping images, the apparatus including:

a mosaicing unit configured to carry out a mosaicing procedure by;

taking as input the set;

determining whether the set comprises exactly two images, and, if so, combining the two images into one image using the unit of claim 8; and

determining whether the set comprises more than two images, and, if so;

(i) splitting the set into two subsets;

(ii) applying on each one of the two subsets the mosaicing procedure to obtain two images; and

(iii) combining the two obtained images into one image using the unit of claim 8.

14. The image processing apparatus of claim 13 wherein the mosaicing unit is further configured to determine whether the set comprises one image, and, if so, completing the mosaicing procedure applied on the set.