Method, apparatus and computer program product for querying by image colors using JPEG image format

• US 5,949,904 A
• Filed: 11/06/1997
• Issued: 09/07/1999
• Est. Priority Date: 11/06/1997
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Delp, Helen Roxlo
• Primary Examiner(s): Tadayon, Bijan
• Assistant Examiner(s): Novik, Dmitry A.
• Application Number:
  US08/965,446
• Time in Patent Office: 670 Days
• Field of Search: 382/181, 382/195, 382/162, 382/165, 382/232, 382/233, 382/235, 382/250
• US Class Current: 382/165
• CPC Class Codes: G06F 16/5838 using colour

Abstract

A method, apparatus and computer program product are provided for querying by image colors using a JPEG format for images from the internet. First an image color is selected. A DCT coefficient is acquired from a JPEG image. The acquired DCT coefficient is compared with the selected image color. A match within the JPEG image is identified responsive to the acquired DCT coefficient being near the selected image color. An average color can be used for querying JPEG formatted images from the internet.

Claims

1. A method for querying by image colors using Joint Photographic Experts Group (JPEG) format for images comprising the steps of:

selecting an image color;

acquiring a plurality of Discrete Cosine Transform (DCT) coefficients from a JPEG image;

converting said acquired plurality of DCT coefficients to a selected coordinate system of said selected image color;

comparing said converted DCT coefficients with said selected image color; and

identifying a match within the JPEG image responsive to said converted DCT coefficients being near said selected image color.

2. A method for querying by image colors using Joint Photographic Experts Group (JPEG) format for images from the internet as recited in claim 1 further includes the step of converting said selected image color to a selected coordinate system of said image.

3. A method for querying by image colors using Joint Photographic Experts Group (JPEG) format for images from the internet as recited in claim 1 wherein the step of identifying said match within the JPEG image is responsive to said converted DCT coefficients being within a predefined distance of said selected image color.

4. A method for querying by image colors using Joint Photographic Experts Group (JPEG) format for images from the internet as recited in claim 1 wherein the step of identifying said match within the JPEG image is responsive to said converted DCT coefficients being equal to said selected image color.

5. A method for querying by image colors using Joint Photographic Experts Group (JPEG) format for images from the internet as recited in claim 1 further includes the steps of identifying a selected area of an image;

comparing converted DCT coefficients with said selected area of said image; and

wherein the step of comparing said converted DCT coefficients with said selected image color is responsive to identified converted DCT coefficients being within said selected area of said image.

6. A method for querying by image colors using Joint Photographic Experts Group (JPEG) format for images from the internet as recited in claim 1 wherein said step of acquiring said plurality of DCT coefficients from said JPEG image includes the steps of acquiring a plurality of DCT coefficients of multiple DCT blocks within said JPEG image, identifying a group of DCT blocks, and computing a weighted DCT coefficient average of said group of DCT blocks and wherein said step of comparing said converted DCT coefficients with said selected image color includes the step of comparing said converted DCT coefficients for said computed weighted DCT coefficient average of said group of DCT blocks with said selected image color.

7. A method for querying by image colors using Joint Photographic Experts Group (JPEG) format for images from the internet as recited in claim 1 wherein said step of acquiring said Plurality of DCT coefficients from a JPEG image includes the steps of acquiring a plurality of DCT coefficients from a plurality of DCT blocks within said JPEG image;

and wherein said step of identifying said match within the JPEG image responsive to said converted DCT coefficients being near said selected image color further includes the steps of calculating a match quality value responsive to each identified match of said converted DCT coefficients and said selected image color; and

responsive to said calculated match quality value, calculating a degree of match.

8. A computer program product for use in a computer system comprising:

a recording medium;

means, recorded on the recording medium, for selecting an image color;

means, recorded on the recording medium, for acquiring a plurality of Discrete Cosine Transform (DCT) coefficients from a JPEG image;

means, recorded on the recording medium, for converting said acquired plurality of DCT coefficients to a selected coordinate system of said selected image color;

means, recorded on the recording medium, for comparing said converted DCT coefficients with said selected image color; and

means, recorded on the recording medium, for identifying a match within the JPEG image responsive to said converted DCT coefficients being near said selected image color.

9. A computer program product as recited in claim 8 wherein said means, recorded on the recording medium, for acquiring said plurality of DCT coefficients from said JPEG image include means, recorded on the recording medium, for acquiring a plurality of DCT coefficients from a plurality of DCT blocks within said JPEG image;

and further include means, recorded on the recording medium, for calculating a match quality value responsive to each identified match of said converted DCT coefficients and said selected image color; and

means, recorded on the recording medium, responsive to said calculated match quality value for calculating a degree of match.

10. A computer program product as recited in claim 8 wherein said means, recorded on the recording medium, for acquiring said Plurality of DCT coefficients from said JPEG image includes means, recorded on the recording medium, for acquiring a plurality of DCT coefficients of a plurality of DCT blocks within said JPEG image, for identifying a group of DCT blocks, and for computing a weighted DCT coefficient average of said group of DCT blocks and wherein said means, recorded on the recording medium, for comparing said converted DCT coefficients with said selected image color includes means, recorded on the recording medium, for comparing said converted DCT coefficients for said computed weighted DCT coefficient average of said group of DCT blocks with said selected image color.

11. A computer program product as recited in claim 8 wherein said means, recorded on the recording medium, for identifying said match within the JPEG image responsive to said converted DCT coefficients being near said selected image color include means, recorded on the recording medium, for identifying a predefined distance or for identifying a predefined range, and wherein said means, recorded on the recording medium, for identifying said match within the JPEG image is responsive to said converted DCT coefficients being within said predefined distance or within said predefined range of said selected image color.

12. A computer system having apparatus for querying by image colors using Joint Photographic Experts Group (JPEG) format for images comprising:

a processor,

a memory;

a communications adapter;

a bus connecting said processor, memory, and communications adapter;

means for selecting an image color;

means for acquiring a plurality of Discrete Cosine Transform (DCT) coefficients from a JPEG image;

means for converting said acquired plurality of DCT coefficients to a selected coordinate system of said selected image color;

means for comparing said converted DCT coefficients with said selected image color; and

means for identifying a match within the JPEG image responsive to said converted DCT coefficients being near said selected image color.