Defective object inspection and separation system using image analysis and curvature transformation

A method performed by an image processor for grading defective objects, the method comprising the steps of:

• acquiring an image of a plurality of objects;
• performing a curvature transform on the image to correct the image for differences in gradation caused by differences in light reflectance of the objects;
• locating, within the corrected image, defect segments based on differences in gradation caused by differences in light reflectance of the defect segments;
• separating the defect segments from normal surfaces of the objects using thresholding on the corrected image;
• and
• assigning grades to the objects corresponding to the defect segments based on characteristics of the defect segments.

An image processor comprising:

• means for receiving an image of a plurality of objects;
• means for transforming the image into a corrected image, correcting for differences in gradation caused by differences in light reflectance of the objects;
• means for locating, within the corrected image, defect segments based on differences in gradation caused by differences in light reflectance of the defect segments;
• and
• means for grading the objects having the defect segments based on characteristics of the defect segments.

A method performed by an image processor for detecting defective objects, the method comprising the steps of:

• acquiring an image of an object;
• performing a curvature transform on the image to correct the image for differences in gradation caused by differences in light reflectance of the object;
• and
• detecting a defect in the object using the corrected image.

A method performed by an image processor for identifying a defect in an object, the method comprising the steps of:

• receiving an image of the object;
• performing a curvature transform to correct the image to compensate for curvature of the object;
• and
• locating, within the corrected image, the defect in the object.

A method performed by an image processor for identifying a defect in an object, the method comprising the steps of:

• receiving a pixel image of the object;
• identifying a contour of the object from the pixel image;
• performing a curvature transform to correct the pixel image to compensate for the contour of the object;
• and
• locating the defect within the corrected pixel image.

A method performed by an image processor for identifying a defect in an object using a pixel image of the object, the method comprising the steps of:

• identifying a contour of the object from the pixel image;
• performing a curvature transform to correct the pixel image to compensate for the contour of the object;
• segmenting at least one pixel of the corrected pixel image, which pixel corresponds to the defect;
• and
• applying a threshold to the pixel that corresponds to the defect to thereby identify the defect.

A method performed by an image processor for preserving a defect identified in an image including an object, the image being stored in a memory, the method comprising the steps of:

• generating a binary image of the image stored in the memory, the binary image having a first value assigned to background and defect pixels of the image and a second value assigned to object pixels of the image;
• creating a dilated image of the object, the dilated image having the second value assigned to the background pixels and the first value assigned to the object and defect pixels, and storing the dilated image in the memory;
• and
• combining the binary image with the dilated image to differentiate the defect in the image.

A defect preservation apparatus for detecting potential defect data in video data, comprising:

• means for receiving the video data;
• means for generating binary image data from the received video data, said binary image data having a first value assigned to background and defect portions of the video data and a second value assigned to object portions of the video data;
• means for performing a multiple-pass dilation function on the video data, using a plurality of masks, to generate a dilated image in which said second value is assigned to the background portions and said first value is assigned to the object and defect portions;
• and
• means for combining the binary image with the dilated image to detect the potential defect data.

An article of manufacture comprising a computer usable medium having computer readable program code means embodied therein for detecting defective objects, the computer readable program code means in the article of manufacture comprising:

• computer readable program code means for causing a computer to acquire an image of an object;
• computer readable program code means for causing the computer to perform a curvature transform on the image to correct the image for differences in gradation caused by differences in light reflectance of the object;
• and
• computer readable program code means for causing the computer to detect a defect in the object using the corrected image.

An article of manufacture comprising a computer usable medium having computer readable program code means embodied therein for identifying a defect in an object using a pixel image of the object, the computer readable program code means in the article of manufacture comprising:

• computer readable program code means for causing a computer to identify a contour of the object from the pixel image;
• computer readable program code means for causing the computer to perform a curvature transform to correct the pixel image to compensate for the contour of the object;
• computer readable program code means for causing the computer to segment at least one pixel of the corrected pixel image, which pixel corresponds to the defect;
• and
• computer readable program code means for causing the computer to apply a threshold to the pixel that corresponds to the defect to thereby identify the defect.

A method for identifying a defect in an object of a plurality of objects using an image processing system that acquires an image of the object, the acquired image including an object image and a background image, the method comprising the steps of:

• separating the object image from the background image in the acquired image;
• creating a series of rings of the object image to create a contour image, each of the rings relating to a different intensity level of the object due to the object's varying reflectance levels;
• converting the contour image to a binary image;
• forming an inverse image of the binary image;
• and
• identifying the defect in the object by adding the inverse image to the contour image.

A method for determining the contour of an object using an image processing system that acquires an image of the object, the acquired image including an object image and a background image, the method comprising the steps of:

• separating the object image from the background image in the acquired image;
• creating a series of rings of the object image, each of the rings relating to a different intensity level of the object due to the object's varying reflectance levels;
• converting the rings to a binary image;
• forming an inverse image of the binary image;
• and
• combining the inverse image with the binary image to determine the contour of the object.