Method and apparatus for data retrieval in a lightfield database

1. A method of data retrieval in a lightfield database including four-dimensional (4D) lightfield data, comprising:

acquiring a sample data;

determining a plurality of two-dimensional (2D) images from each of a plurality of 4D lightfield data stored in the lightfield database, the plurality of images being arranged according to a distance between the focal plane and the image plane, each 2D image being different from another 2D image in at least one geometrical parameter;

matching the sample data with the determined 2D images according to geometrical parameters of the sample data, comprising at least the focal plane, and geometrical parameters of the 2D images;

selecting one of the 2D images as a target image based on the matching result; and

retrieving the 4D lightfield data from which the target image is determined;

wherein the geometrical parameters comprise at least one of parameter selected from the group consisting of resolution, viewpoint, viewing direction, focal plane, disparity, and image object.

2. The method of claim 1 , wherein the sample data is a 2D image sample.

3. The method of claim 1 , wherein said matching the sample data with the determined 2D images comprises using a geometrical link, wherein the geometrical link is a combined depth map associated to an all-in-focus image determined from a lightfield data, the method further comprising:

for each lightfield data of the lightfield database,

determining an all-in-focus 2D image;

generating a combined depth map associated to the all-in-focus image;

matching the sample data with the all-in-focus image to determine one position having a highest similarity with the sample data;

using the combined depth map to identify the depth of the determined position;

selecting a candidate 2D image of the multiple 2D images which has a focal plane with the depth of the determined position;

calculating a feature distance between the sample data and the candidate image; and

selecting one of the candidate images as the target image which has a smallest feature distance.

4. An apparatus for data retrieval in a lightfield database including four-dimensional (4D) lightfield data, comprising:

an acquiring unit configured to acquire a sample data;

an operation unit comprising a processing device configured to

determine a plurality of two-dimensional (2D) images from each of a plurality of 4D lightfield data stored in the lightfield database, the plurality of images being arranged according to a distance between the focal plane and the image plane, each 2D image being different from another 2D image in at least one geometrical parameter;

match the sample data with the determined 2D images according to geometrical parameters of the sample data and geometrical parameters of the 2D images;

select one of the 2D images as a target image based on the matching result; and

retrieve the 4D lightfield data from which the target image is determined;

wherein the geometrical parameters comprise at least one parameter selected from the group consisting of of resolution, viewpoint, viewing direction, focal plane, disparity of the sample data and the 2D images, and image object captured in the sample data and the 2D images.

5. A non-transitory computer readable storage medium having stored therein instructions for data retrieval in a lightfield database including four-dimensional (4D) lightfield data, which, when executed by a computer, cause the computer to:

acquire a sample data;

determine a plurality of two-dimensional (2D) images from each of a plurality of 4D lightfield data stored in of the lightfield database, the plurality of images being arranged according to a distance between the focal plane and the image plane, each 2D image being different from another 2D image in at least one geometrical parameter;

match the sample data with the determined 2D images according to geometrical parameters of the sample data, comprising at least the focal plane, and geometrical parameters of the 2D images;

select one of the 2D images as a target image based on the matching result; and

retrieve the 4D lightfield data from which the target image is determined;

wherein the geometrical parameters at least one parameter selected from the group consisting of resolution, viewpoint, viewing direction, focal plane, disparity of the sample data and the 2D images, and image object captured in the sample data and the 2D images.

6. The apparatus of claim 4 , wherein the operation unit is further configured to:

match the sample data with the determined 2D images using a geometrical link, wherein the geometrical link is a combined depth map associated to an all-in-focus image determined from a lightfield data; and

for each lightfield data of the lightfield database, to:

determine an all-in-focus 2D image;

generate a combined depth map associated to the all-in-focus image;

match the sample data with the all-in-focus image to determine one position having a highest similarity with the sample data;

use the combined depth map to identify the depth of the determined position;

select a candidate 2D image of the multiple 2D images which has a focal plane with the depth of the determined position;

calculate a feature distance between the sample data and the candidate image; and

select one of the candidate images as the target image which has a smallest feature distance.