Abstract: There are described methods and system for determining a similarity or distance measure between a first ballistic specimen and a second ballistic specimen. The method comprises acquiring topographic data from the first ballistic specimen and the second ballistic specimen of at least one region of interest; computing from the topographic data at least one similarity score s for the first ballistic specimen and the second ballistic specimen; determining a non-match probability measure of the similarity score for at least one parameter characterizing a macroscopic and/or microscopic feature of the topographic data, the non-match probability measure associating the first ballistic specimen and the second ballistic specimen to a different source; and correcting the similarity score by determining a corrected similarity score that yields a same value of the non-match probability measure as the similarity score for a reference value of the at least one parameter.

Abstract: There is provided a method for analyzing at least one object under a first microscope and a second microscope concurrently by linking the two microscopes together. Movement of one microscope will result in movement of the other. This is done by computing a transformation to link a first coordinate system and a second coordinate system and generating guidance data when one of the two microscopes is displaced, the guidance data corresponding to a set of operations to be applied to the other microscope to follow movement of the microscope that is displaced.

Abstract: There is provided a method for generating a 3D representation of an object, comprising: acquiring 3D topographic data representative of at least one portion of the object having a macroscopic form and microscopic features; separating the 3D topographic data into microscopic data representative of the microscopic features and macroscopic data representative of the macroscopic form; independently scaling one of the microscopic data and the macroscopic data in order to enhance the microscopic features with respect to the macroscopic form, thereby obtaining scaled topographic data; and generating a 3D image using the scaled topographic data, thereby obtaining a modified representation having enhanced microscopic features for the at least one portion of the object.

Abstract: There is described a method for positioning an object on an optical sensor system for acquiring a surface thereof, the sensor system having a set of motors for rotating the object around a motor axis perpendicular to an optical axis of the sensor system and for translating the object in X, Y and Z directions, the method comprising: (a) acquiring a relief map of an area in a field of view of the sensor system; (b) computing a normal representative of a topography of the relief map of the area; (c) determining an angle difference between the normal and the optical axis of the sensor system; (d) comparing the angle difference to a threshold angle to determine if the surface of the area is perpendicular to the sensor axis; (e) if the angle difference is greater than a threshold angle, rotating the object to obtain a new difference angle less than the threshold angle; and (f) translating the object to reposition the area in the field of view after the rotating has displaced the area.

Abstract: There is provided a method for analyzing at least one object under a first microscope and a second microscope concurrently by linking the two microscopes together. Movement of one microscope will result in movement of the other. This is done by computing a transformation to link a first coordinate system and a second coordinate system and generating guidance data when one of the two microscopes is displaced, the guidance data corresponding to a set of operations to be applied to the other microscope to follow movement of the microscope that is displaced.

Abstract: There is provided a method for generating a 3D representation of an object, comprising: acquiring 3D topographic data representative of at least one portion of the object having a macroscopic form and microscopic features; separating the 3D topographic data into microscopic data representative of the microscopic features and macroscopic data representative of the macroscopic form; independently scaling one of the microscopic data and the macroscopic data in order to enhance the microscopic features with respect to the macroscopic form, thereby obtaining scaled topographic data; and generating a 3D image using the scaled topographic data, thereby obtaining a modified representation having enhanced microscopic features for the at least one portion of the object.

Abstract: A method and an apparatus to obtain a surface mapping of a ballistic piece of evidence (BPOE) under examination, such as a bullet or a spent cartridge case, that can be used thereafter as a 3D signature for identifying purpose during ballistic test comparison. The method comprises providing a measurement unit adapted to acquire a relief map of the surface of the BPOE and acquiring with the measurement unit the relief map of the surface to thereby obtain the mapping of the surface of the BPOE. Preferably, the measurement unit of the present invention comprises a confocal sensor such as confocal microscope. Also, the present invention includes acquiring the relief map of the bullet surface or of the cartridge case surface by acquiring and assembling a mosaic of regional reliefs that are partly overlapping with their surroundings regional reliefs.

Abstract: There is described a method for positioning an object on an optical sensor system for acquiring a surface thereof, the sensor system having a set of motors for rotating the object around a motor axis perpendicular to an optical axis of the sensor system and for translating the object in X, Y and Z directions, the method comprising: (a) acquiring a relief map of an area in a field of view of the sensor system; (b) computing a normal representative of a topography of the relief map of the area; (c) determining an angle difference between the normal and the optical axis of the sensor system; (d) comparing the angle difference to a threshold angle to determine if the surface of the area is perpendicular to the sensor axis; (e) if the angle difference is greater than a threshold angle, rotating the object to obtain a new difference angle less than the threshold angle; and (f) translating the object to reposition the area in the field of view after the rotating has displaced the area.

Abstract: A method and an apparatus to obtain a surface mapping of a ballistic piece of evidence (BPOE) under examination, such as a bullet or a spent cartridge case, that can be used thereafter as a 3D signature for identifying purpose during ballistic test comparison. The method comprises providing a measurement unit adapted to acquire a relief map of the surface of the BPOE and acquiring with the measurement unit the relief map of the surface to thereby obtain the mapping of the surface of the BPOE. Preferably, the measurement unit of the present invention comprises a confocal sensor such as confocal microscope. Also, the present invention includes acquiring the relief map of the bullet surface or of the cartridge case surface by acquiring and assembling a mosaic of regional reliefs that are partly overlapping with their surroundings regional reliefs.