Image defect display system

• US 20030053713A1
• Filed: 09/19/2001
• Published: 03/20/2003
• Est. Priority Date: 09/19/2001
• Status: Active Grant

• Current Assignee: Amy H. Muntz, Philip B. Romanik
• Original Assignee: Amy H. Muntz, Philip B. Romanik
• Inventors: Muntz, Amy H., Romanik, Philip B.
• Granted Patent: US 6,990,255 B2
• Time in Patent Office: Days
• US Class Current: 382/284
• CPC Class Codes: G06T 5/50 using two or more images, e.g. averaging or subtraction
• CPC Class Codes: G06T 7/0004 Industrial image inspection

Abstract

A system for taking a sequence of images and converting them to a single composite image that contains the combined visual information of the defects found in the source images. The source images are aligned and manipulated, if necessary, such that they can be superimposed together. Optional image processing steps are applied to further enhance the defects. Both the number of input images and the algorithm used to combine these images can be adjusted to allow an observer to see a persistent display of the defects found in the images. Status, diagnostic and defect information, consisting of graphics and textual messages, are then applied to the composite image for display.

Claims

1. A method for computing a digital image to visually highlight and persist the location of defects, comprising:

a. accepting a number of digital images from an image analysis system or image database,

b. performing alignment and normalization on said images, as required, to register the images with respect to each other,

c. computing a composite image from said images to enhance any defects found in the input images, as well as cause the visual persistence of these defects in the composite image,

d. formatting said composite image with additional annotations for display.

2. A method according to claim 1, wherein the step of accepting digital images is not limited to looking at every image available, but only those images which meet some criteria.

3. A method according to claim 1, wherein the step of performing alignment and normalization comprises:

a. performing zero or more image processing steps to help highlight defects in the image.

b. translating each image, if necessary, to align the objects,

c. performing a six degree-of-freedom alignment if a translation only alignment is not sufficient to allow the sequence of images to be aligned,

d. normalizing each image to compensate for variations in brightness, contrast and color,

e. optionally reducing the pixel depth of each aligned image,

f. storing the transformed images in a queue to enhance performance,

g. combining the aligned images into a single composite image.

4. A method according to claim 3, wherein the step of applying image processing comprises:

a. applying zero or more sequential steps of image processing to an image,

b. selecting an image processing algorithm for tuning the system to detect certain kinds of defects,

c. changing the image processing steps or parameters in realtime until the desired amount of image processing has been achieved.

5. A method according to claim 3, wherein the step of computing the composite image comprises:

a. applying an arbitrary algorithm, pixel-by-pixel, on the aligned images, to produce a single output image,

b. optionally including information from previously computed composite images,

c. constructing the composite image such that the information from the aligned images is either overlaid or offset from each other.

6. A method according to claim 1, wherein the step of formatting the composite image comprises:

a. modifying the composite image with a template image, supplied by the analysis equipment or computed locally, to highlight differences between the composite image and template image,

b. annotating the composite image with graphics or textual results obtained from the image analysis equipment.

7. A method according to claim 6, wherein the step of annotating the composite image is done such that the graphics are altered with the same transformations as applied to align the images, and any textual information is combined from all input images and displayed.

8. A system for computing a digital image to visually highlight and persist the location of defects, comprising:

a. a processor receiving a number of digital images each having optional defect or status information,

b. a processor performing alignment and normalization on said images to register the images with respect to each other,

c. a processor computing a composite image from said images to enhance any defects found in the input images, as well as cause the visual persistence of defects in the composite image,

d. a processor formatting said composite image with additional annotations for display.

9. A system according to claim 8, wherein the processor prepares each image by first applying zero or more image processing steps to help highlight defects followed by alignment and normalization steps.

10. A system according to claim 8, wherein the processor computes a composite image by combining information from each input image, pixel-by-pixel, such that the composite image will visually show defects from one or more of the input images.

11. A system according to claim 8, wherein the processor computes a displayable image by finding the difference between a template image, if any, and the composite image and by combining this image with any available defect or status information, in both graphical and textual form.