Systems and methods for locating a pattern in an image

• US 6,477,275 B1
• Filed: 06/16/1999
• Issued: 11/05/2002
• Est. Priority Date: 06/16/1999
• Status: Expired due to Term

• Current Assignee: Teledyne Digital Imaging US, Inc (Teledyne Technologies Incorporated)
• Original Assignee: Coreco Imaging, Inc. (Teledyne Technologies Incorporated)
• Inventors: Melikian, Simon H., Israni, Rohit G.
• Primary Examiner(s): Boudreau, Leo
• Assistant Examiner(s): Mariam, Daniel G.
• Application Number:
  US09/333,701
• Time in Patent Office: 1,238 Days
• Field of Search: 382/103, 382/112, 382/115, 382/119, 382/124, 382/141, 382/145, 382/147, 382/149, 382/159, 382/170, 382/173, 382/181, 382/209, 382/217, 382/219, 382/224, 382/225, 382/278, 382/309, 382/218, 235/380, 348/86, 348/91, 348/92, 348/125, 348/129, 348/130, 348/169, 902/25, 902/26, 902/28
• US Class Current: 382/217
• CPC Class Codes: G06T 2207/30152 Solder
• CPC Class Codes: G06T 7/001 using an image reference approach
• CPC Class Codes: G06T 7/74 involving reference images or patches
• CPC Class Codes: G06V 10/7515 Shifting the patterns to accommodate for positional errors

Abstract

In one aspect the invention provides processes for locating a pattern within an image that can comprise the acts of providing a template representative of the pattern to be located within an image. The image can be subdivided into a plurality of sub-images, each being representative of a portion of the image. The process can then compare each of the sub-images to the template to generate a plurality of score signals representative of a location of the pattern, and can then process the score signals to determine a location for the pattern. In one practice, the step of processing the score signals can include a step of identifying at least one sub-image that includes a degraded image. As described above, a degraded image can include an image that has had a portion obscured by shadows or debris. Additionally, an image can be degraded at spots of high-reflection that create glare and wash-out portions of the image.

Claims

1. A process for locating a pattern within an image, comprising:

providing a template representative of said pattern,

subdividing said image into sub-images representative of a portion of said image,

comparing each of said sub-images to said template to generate score signals representative of a location of said pattern determined as a function of a respective sub-image,

fitting a plurality of signal intensity values to a surface for determining score signals, and

processing said score signals to generate a location signal representative of a sub-pixel location signal to determine a location of said pattern.

2. A system for locating a pattern within an image, comprising:

a data memory having storage for a template representative of said pattern,

a pattern recognition mechanism for determining a location of said pattern within one pixel;

an image processor for dividing said image into sub-images representative of a portion of said image,

a comparator for comparing said sub-images to said template to generate score signals being representative of a location of said pattern,

a locator for processing said score signals to determine a location for said pattern, and

a processor for fitting a plurality of signal intensity values to a surface, for determining a sub-pixel location signal.

3. A process for determining the location of an object, comprising

providing a template representative of said object,

obtaining an image which contains at least a portion of said object,

subdividing said image into sub-images representative of a portion of said image,

comparing said sub-images to said template to generate score signals representative of an expected location of said object,

fitting a plurality of signal intensity values to a surface for determining said score signals, and

processing said score signals to determine the location of said object and to generate a location signal representative of a sub-pixel location signal.