Image processing apparatus, control method and program thereof which searches for corresponding original electronic data based on a paper document

1. An image processing apparatus for executing similarity comparison processing of images, comprising:

storage means for storing a plurality of electronic data as comparison destination images;

input means for electronically scanning printed material and inputting electronic data of the printed material as a comparison source image;

extraction means for extracting a plurality of partial regions from the comparison source image;

calculation means for calculating a distance between a center of one of the partial regions and a center of gravity of the source image as a first block distance and calculating a distance between a center of another partial regions and the center of gravity of the source image as a second block distance; and

search means for searching said storage means for an image by using a distance ratio of the first block distance to the second block distance as a first search condition.

2. The apparatus according to claim 1 , wherein said

calculation means calculates a reduction ratio of a partial region of the comparison source image to a partial region of the comparison destination image based on a degree of positional deviation of the partial regions of the comparison source image and the comparison destination image, and

said search means compares, as layout comparison, a size obtained when the partial region of the comparison destination image is reduced based on the reduction ratio with a size of the partial image of the comparison source image.

3. The apparatus according to claim 1 , wherein said search means executes layout comparison using, when a center of gravity of an entire image is defined as an origin, a center of gravity angle, an angle a line that connects the origin and the center of gravity of a partial region makes with a reference line in the entire image and the origin.

4. The apparatus according to claim 1 , wherein said search means executes layout comparison using, when a center of gravity of an entire image is defined as an origin, a center of gravity angle, an angle a line that connects the origin and the center of gravity of a partial region makes with a reference line, and a distance between a center of gravity of the partial region and the origin.

5. The apparatus according to claim 1 , wherein said search means executes layout comparison using an area of an overlapping region where partial regions of the comparison source image and the comparison destination image overlap.

6. The apparatus according to claim 1 , wherein said search means comprises:

determination means for determining whether or not center of gravities of partial regions of the comparison source image and the comparison destination image and a center of gravity of an image are located on an identical line; and

calculation means for, when said determination means determines that the center of gravities are located on the identical line, calculating a reduction ratio of the partial region of the comparison source image to the partial region of the comparison destination image based on a degree of positional deviation between the center of gravities of the partial regions of the comparison source image and the comparison destination image, and

said search means executes layout comparison between a partial image obtained by reducing the partial region of the comparison destination image based on the reduction ratio, and the partial region of the comparison source image.

7. The apparatus according to claim 1 , said search means comprising:

layout comparison means for executing layout comparison between the distance ratio of the comparison source images and a distance ratio of the comparison destination images;

first search means for searching said storage means for images corresponding to the first search condition based on a result of said layout comparison means;

feature amount comparison means for executing feature amount comparison between partial regions of the comparison source image and partial regions of the respective images corresponding to the first search condition searched by said first search means; and

second search means for searching the images searched by said first search means for an image corresponding to the feature amount of the comparison source image based on a result of said feature amount comparison means.

8. A method of controlling an image processing apparatus executed by a CPU, comprising:

an input step of electronically scanning printed material and inputting electronic data of the printed material as a comparison source image;

an extraction step of extracting a plurality of partial regions from the comparison source image;

a calculation step of calculating a distance between a center of one of the partial regions and a center of gravity of the source image as a first block distance and calculating a distance between a center of another partial regions and the center of gravity of the source image as a second block distance; and

a search step of searching storage means for an image by using a distance ratio of the first block distance to the second block distance as a first search condition.

9. A computer-readable storage medium storing a program for making a computer execute similarity comparison processing of images, said program characterized by making the computer execute:

an input step of electronically scanning printed material and inputting electronic data of the printed material as a comparison source image;

an extraction step of extracting a plurality of partial regions from the comparison source image;

a calculation step of calculating a distance between a center of one of the partial regions and a center of gravity of the source image as a first block distance and calculating a distance between a center of another partial regions and the center of gravity of the source image as a second block distance; and

a search step of searching storage means for an image by using a distance ratio of the first block distance to the second block distance as a first search condition.