Comparing projectile shells
AssigneeMinisterie de L'Interieur - Direction de la Police Judicaire Sous-Direction de la Police Technique et Scientifique Service Central des Laboratoires
InventorsFranck Demoly, Denis Perraud
Life of this patent
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Abstract
Digital data, each piece of data corresponding to a different criterion associated with an impression on a projectile, is stored in a database. A number of images of a target projectile are processed to extract the data, where each datum corresponds to one of a different criterion. The different criteria include such features as shape, position, texture, and striation, center and shape of the percussion zone, caliber of the projectile, impressions of the stop, ejector, loading indicator, and feed mechanism et alia. The data from the target projectile is then compared to the data from the reference projectile for a possible match.
Claims21
Process for comparing projectile shells characterized in that the process comprises:
- a step of constituting and storing information concerning different existing projectiles in a memory of a database, containing, for each referenced projectile, a large amount of digital data, each piece of data corresponding to a different criterion associated with an impression on the projectile;
- a step of taking a determined number of images of a target projectile and processing these images by a data processing system to extract the digital data, each datum corresponding to one of the criteria of the database;
- a step of processing and extracting the digital data comprising a step of selection on a display means by interactive means from an image zone displayed on the display means and including the impression corresponding to a criterion, conversion of the selected zone of the image into a digitized representation of the image, then processing the digitized representation to extract the parameters that correspond to a given criterion;
- a step of comparing each of the pieces of data of a target projectile with the data from each referenced projectile for the same criteria.
Device characterized in that it comprises a presentation table of the specimen projectile provided with glancing illumination parallel to the support of the projectile, a support that carries a digital-type camera with a wide field in a direction perpendicular to the support plane of the camera having a resolution of 1280.times.1024 pixels;
- a device for analyzing digital data representing the acquired image and making it possible to extract, for a given specimen, the digital value representing each criterion associated with a type of impression different from a scratch,
- interactive means making it possible for the user to complete the other criteria constituting the data from the database such as data relating to caliber, defects;
- means for storing these data on a transportable or transferable physical carrier.
Dependencies are inferred from the claim text.