Abstract: A method includes capturing a first image of a surface illuminated from a first direction along an axis by a first light at a first elevation angle with other lights of the illumination system off, and capturing a second image of the surface illuminated from a second direction along the axis by a second light at a second elevation angle with the other lights off, the second direction being opposite the first direction, the second elevation angle being substantially identical to the first elevation angle. The images are processed by taking a derivative of a reflected light intensity at each of a plurality of pixel locations in the images, respectively. The respective derivatives are employed to identify a set of invalid pixels where a photometric stereo condition is not satisfied. A photometric stereo reconstruction is generated based on a set of images and the identified set of invalid pixels.

Abstract: There is described herein a method and system for detecting, in a segmented image, the presence and position of objects with a dimension greater than or equal to a minimum dimension. The objects exhibit a property whereby a distance map of the object at a first scale and a distance map of the object at a second scale greater than the first scale differ by a constant value over a domain of the distance map of the object at the first scale. A distance map of a model object is compared to a distance map of a target object using a similarity score that is invariant to an offset.

Abstract: A method for recognizing an occurrence of an object in an image is provided where the appearance of the object may vary from one occurrence to another. The method includes defining a model set for object recognition, the model set including at least one model, acquiring a target image, processing the target image according to a set of morphological operations to obtain a set of morphologically-processed target images, performing object recognition on the set of morphologically-processed target images for the defined model set, and selecting at least one candidate occurrence of a model of the defined model set in the target image based on the object recognition performed on the set of morphologically-processed target images.

Abstract: A method for detecting a position of a sheet of light is described. A second derivative filter is applied to an intensity profile of a line of pixels. An ingress pixel position associated with an ingress zero-crossing second derivative value is determined. The ingress pixel position is between a first pixel position with a first minimum intensity value of the intensity profile and a second pixel position with a first maximum intensity value of the intensity profile. An egress pixel position associated with an egress zero-crossing second derivative value is determined. The egress pixel position is between a third pixel position with a second maximum intensity value of the intensity profile and a fourth pixel position with a second minimum intensity value of the intensity profile. A midpoint pixel position between the ingress pixel position and the egress pixel position is output as the position of the sheet of light.

Abstract: In a method and system for detecting a position of a sheet of light in an image, two parameters are used, namely the width of the widest peak to be detected and the intensity difference of the least-contrasted peak to be detected. From these two parameters, a size S, a distance D, and a threshold T are determined. A region of interest (ROI) is determined based on the intensity profile associated with a line of pixels of the image, distance D and threshold T. A derivative filter of size S is applied to the intensity profile to produce a slope of the intensity profile. In the determined ROI, one or more zero-crossings in the slope of the intensity profile are detected. From the detected zero-crossings, a zero-crossing is selected and the position of the selected zero-crossing is returned as the detected position of the sheet of light for the line of pixels.

Abstract: A method for the detection of an irregularity in an object based on an image of the object that includes the steps of binarizing the image at a plurality of binarization thresholds to obtain a plurality of binarized images, extracting information from each of the binarized images, estimating the regular object resulting from the binarization at the respective binarization threshold of an image of a version of the object in which the irregularity is absent, combining the information extracted from each of the binarized images, and detecting the irregularity based on the combined information. A method for the detection of a defect in a solder element based on an X-ray image of the solder element.