Image identifying apparatus

• US 6,047,085 A
• Filed: 01/17/1997
• Issued: 04/04/2000
• Est. Priority Date: 07/21/1994
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Uno, Teruhiko, Nakagawa, Kazuyo, Takahashi, Hiroshi, Sato, Toshio, Hirasawa, Toshio
• Primary Examiner(s): Au, Amelia
• Assistant Examiner(s): AHMED, SAMIR ANWAR
• Application Number:
  US08/765,814
• Time in Patent Office: 1,173 Days
• Field of Search: 382/103, 382/135, 382/165, 382/164, 382/209, 382/278, 382/167, 358/296, 358/401, 358/448, 358/501, 358/518
• US Class Current: 382/165
• CPC Class Codes: G06T 2207/10024 Color image
• CPC Class Codes: G06T 2207/20104 Interactive definition of region of interest [ROI]
• CPC Class Codes: G06T 7/90 Determination of colour characteristics
• CPC Class Codes: G06V 10/40 Extraction of image or video features

Abstract

Apparatus and method for identifying the color image of an object. The object'"'"'s image is digitized and a cut-off portion of the image containing the object is determined. The cut-off portion image data is normalized. Selected pixels of the normalized image are subjected to an averaging process to provide an averaged image containing R, G, and B color components. H, V, and C components of the averaged image data are computed, and their V, c, and d components are computed from the H, V, and C components. A color feature extractor computes from the c and d component data a parameter representative of the object to be identified. This parameter is provided to a memory controller to retrieve from a memory that stores target images one or more images categorized according to the computed parameter. A matching section matches each retrieved target image with the Vcd component data and determines which target image is most similar.

Claims

1. An apparatus for identifying an image represented by digital image data, comprising:

means for extracting feature data from the digital image data representing predetermined color features of the whole image to be identified;

first means for storing a plurality of categories corresponding to color features;

second means for storing a plurality of target image data grouped based on the color features of the categories respectively;

means for selecting one of the categories corresponding to a color feature of the digital image data from the first storing means;

means for comparing the digital image data with the plurality of target image data grouped by the category selected by the selecting means;

means for determining a most similar target image data in the plurality of image data in the second storing means grouped by the selected categories based on a comparison result by the comparing means; and

means for determining a similarity between the digital image data and the target image data in the second storing means grouped by the selected category by the selecting means.

2. The apparatus of claim 1, wherein the digital image data includes color image data, and further including means, responsive to the digital image data for determining selected ones of the color characteristics includes color value means for determining hue (H), value (v), and chroma (C) values corresponding to the digital image data.

3. The apparatus of claim 2, wherein the color value means includes means for computing values of predetermined color components corresponding to the H, V, and C values.

4. The apparatus of claim 3, wherein the means for extracting includes means for extracting the feature data in accordance with the values of selected ones of the predetermined color components.

5. The apparatus of claim 1, wherein the target image data includes information representative of a size of the at least one target image and the feature data includes information representative of a size of the image to be identified;

and

the means for extracting including means for extracting the image size information of the image to be identified.

6. The apparatus of claim 1, further including:

a data base for storing relative data related to the at least one target image;

a data base controller, responsive to the similarity determining means, for retrieving from the data base the relative data related to the retrieved target image data determined by the similarity determining means to be similar to the digital image data; and

means for displaying the relative data retrieved by the data base controller.

7. The apparatus of claim 6, further including a user interface to enable a user to access the relative data in the data base.

8. The apparatus of claim 3, wherein the similarity determining means includes:

means for computing a first similarity factor between the digital image data and the retrieved target image data for each of the predetermined color components;

means for computing a second similarity factor as a predetermined function of the respective first similarity factors computed for the predetermined color components; and

means for selecting a most similar target image in accordance with the second similarity factor.

9. The apparatus of claim 3, wherein the similarity determining means includes:

means for computing a cumulative difference between the digital image data and the retrieved target image data for each of the predetermined color components; and

means for selecting the target image for which the cumulative difference is smallest.

10. The apparatus of claim 1, wherein the digital image data includes color characteristics of selected pixels of the image to be identified;

and

wherein the extracting means includes;

means for computing an average value of at least a predetermined one of the color characteristics for the selected pixels; and

means, responsive to the computed average value, for providing the extracted feature data.

11. The apparatus of claim 10, further including means for determining selected ones of the color characteristics including hue (H), value (V), and chroma (C) values corresponding to the digital image data and means for computing values of predetermined color components corresponding to the H, V, and C values;

the means for computing an average value includes means for computing an average value for at least one of the predetermined color components for the selected pixels; and

the means for providing being responsive to the computed average value to provided the extracted feature data.

12. The apparatus of claim 10, wherein the color characteristic include R, G, and B component values for each of the selected pixels;

the means for computing an average value includes means for computing an average value of each of the R, G, and B components for the selected pixels; and

the means for providing being responsive to the computed average values of the R, G. and B components to provided the extracted feature data.

13. The apparatus of claim 1, wherein the means for determining a similarity includes means to compute a cumulative difference between the digital image data and retrieved target data and determine similarity on the basis of a minimum cumulative difference.

18. An apparatus according to claim 1, wherein the second means for storing includes:

means for detecting a size of the feature data extracted by the extracting means; and

means for storing the plurality of target image data grouped based on the color features of the categories in accordance with the size detected by the size detecting means.

14. An apparatus for identifying an image represented by digital image data, comprising:

a first circuit, coupled to receive predetermined positions of the digital image data, to compute a category parameter representative of predetermined color features;

a first memory to store a plurality of categories corresponding to color features;

a second memory to store a plurality of target image data grouped based on the color features of the categories respectively;

a memory controller to select one of the categories corresponding to a color feature of the digital image data from the first memory;

a second circuit to compare the digital image data with the plurality of target image data grouped by the category selected by the memory controller for determining a most similar target image data in the plurality of image data in the second memory grouped by the selected categories based on the comparison result; and

a third circuit, coupled to receive the digital image data and the selected category, to determine a similarity parameter representative of a similarity between the digital image data and the target image data in the second memory grouped by the selected category.

15. The apparatus of claim 14, wherein the digital image data includes color image data and the predetermined features representing color characteristics of the whole image to be identified;

and

the apparatus further including a third circuit to determine selected ones of the color characteristics of the image to be identified.

16. The apparatus of claim 15, wherein the third circuit includes circuitry to determine hue (H), value (V), and chroma (C) values of the digital image data and predetermined color components corresponding to the H, V, and C values.

19. An apparatus according to claim 14, wherein the second memory includes:

means for detecting a size of the feature data received by said first circuit; and

means for storing the plurality of target image data grouped based on the color features of the categories in accordance with the size detected by the size detecting means.

17. A system for identifying an image represented by digital image data, comprising:

means for forming a digital image which includes an object to be identified;

means for determining a cut-off portion of the digital image containing the object to be identified;

means for normalizing digital image data corresponding to the cut-off portion of the image;

means for computing average image data for selected pixels of the normalized image data;

means for extracting color features corresponding to predetermined ones of a predetermined color components, the color features representing the digital image;

a first memory to store a plurality of categories corresponding to color features;

a second memory to store a plurality of target image data grouped based on the color features of the categories respectively;

means for selecting one of the categories corresponding to a color feature of the digital image data from the first memory; and

means for determining a similarity between the target image data in the second memory grouped by the selected category and the predetermined color components of the digital image data.

20. An apparatus according to claim 17, wherein the second memory includes:

means for detecting a size of the feature data extracted by the extracting means; and

means for storing the plurality of target image data grouped based on the color features of the categories in accordance with the size detected by the size detecting means.