Method for the three-dimensional synthetic reconstruction of objects exposed to an electromagnetic and/or elastic wave

• US 8,345,960 B2
• Filed: 03/24/2009
• Issued: 01/01/2013
• Est. Priority Date: 03/25/2008
• Status: Active Grant

• Current Assignee: Sispia, Co., Thales SA
• Original Assignee: Sispia, Co., Thales SA
• Inventors: Berginc, Gérard, Berechet, Ion, Berechet, Stefan
• Primary Examiner(s): LE, BRIAN Q
• Application Number:
  US12/934,101
• Publication Number:
  US 20110019906A1
• Time in Patent Office: 1,379 Days
• Field of Search: 382/103, 382/107, 382/154, 382/276, 382/285, 348 47- 60, 345/7, 345/8, 345/9, 345/55, 345/156, 345/157, 345/158, 345/419, 345/427, 345/632, 345/633, 345/473, 345/474, 345/FOR.209, 702/152, 702/153, 463/36, 463/37, 715/757, 715/852
• US Class Current: 382/154
• CPC Class Codes: G01B 11/25 by projecting a pattern, e.g. one or more lines, moiré fringes on the object G01B11/255 takes precedence ; image analysis for depth or shape recovery G06T7/50
• CPC Class Codes: G01B 17/06 for measuring contours or curvatures
• CPC Class Codes: G06T 5/70 Denoising; Smoothing
• CPC Class Codes: G06T 7/521 from laser ranging, e.g. using interferometry; from the projection of structured light

Abstract

A method for synthetic reconstruction of objects includes: extracting criteria from a knowledge base; extracting, from sensed signals filtered by the criteria, weak signals; extracting, from the weak signals, weak signals of interest; removing noise from and amplifying the weak signals of interest and obtaining useful weak signals; identifying useful direct information, from useful weak signals filtered by the criteria and supplying optimum criteria; reconstructing, using the useful direct information, information of interest; reconstructing, using the information of interest, useful information and supplying optimum criteria; reconstructing, based on the useful information, three-dimensional information, supplying a recognition state file and supplying the optimum criteria; and updating the criteria with the optimum criteria.

Claims

1. A method for synthetic reconstruction of an object exposed to a wave, starting from sensed signals produced by this exposure, and from a knowledge base, wherein the knowledge base comprises various filtering criteria, namely direct mode search criteria, criteria for extraction of the weak signals, criteria for identification in direct mode, three-dimensional observation grids linked to the illumination or reception angle of the wave, criteria for three-dimensional observation grids, three-dimensional reconstruction criteria, rules for optimization associated with the criteria for identification in direct mode, with the three-dimensional observation grids, with the criteria for three-dimensional observation grids, with the three-dimensional reconstruction criteria, and corresponding optimum criteria, following said optimization rules, and wherein the method comprises the following steps:

extracting, from the knowledge base, direct mode search criteria,

extracting, from the knowledge base, criteria for extraction of the weak signals,

extracting, from the knowledge base, criteria for identification in direct mode and the associated rule for optimization,

extracting, from the knowledge base, three-dimensional observation grids and the associated rule for optimization,

extracting, from the knowledge base, criteria for three-dimensional observation grids and the associated rule for optimization,

extracting, from the knowledge base, three-dimensional reconstruction criteria and the associated rule for optimization,

extracting, from a set of sensed signals, filtered through the extracted direct mode search criteria, weak signals,

extracting, from the weak signals filtered through the criteria for extraction of the extracted weak signals, weak signals of interest,

removing the noise from the weak signals of interest so as to obtain useful weak signals, wherein

if the rule for optimization of the criteria for identification in direct mode is satisfied by the useful weak signals, then;

these extracted criteria for extraction in direct mode are optimum criteria for extraction in direct mode,

update the knowledge base with said optimum criteria for extraction in direct mode,

the extracted direct mode search criteria are optimum direct mode search criteria,

update the knowledge base with said optimum direct mode search criteria,

identify useful direct information, based on the useful weak signals filtered through the criteria for identification in direct mode,

otherwise, change these criteria for extraction of the weak signals and reiterate the steps for extraction of these criteria, the steps for extraction of weak signals of interest, for removing the noise from the weak signals of interest to obtain useful weak signals, and for identifying useful direct information, and the step concerning the rule for optimization of the criterion, and

if the rule for optimization of the criteria for identification in direct mode is not satisfied by the useful weak signals, then change these direct mode search criteria in the knowledge base and reiterate the steps for extraction of these criteria, the steps for extracting, from a set of sensed signals, filtered through the extracted direct mode search criteria, weak signals, for extraction of weak signals of interest, for removing the noise from the weak signals of interest to obtain useful weak signals, and for identifying useful direct information and the step concerning the rule for optimization of the criterion,

if the rule for optimization of the three-dimensional observation grids is satisfied by the useful direct information, then;

these extracted three-dimensional observation grids are optimum three-dimensional observation grids,

update in the knowledge base, the three-dimensional observation grids with these optimum three-dimensional observation grids,

reconstruct, based on the useful direct information filtered through the extracted three-dimensional observation grids, three-dimensional information of interest,

otherwise, change these three-dimensional observation grids in the knowledge base, and reiterate the step for extraction of grids and the step concerning the rule for optimization of these new grids;

if the rule for optimization of the criteria for three-dimensional observation grids is satisfied by the three-dimensional information of interest, then;

these extracted criteria for three-dimensional observation grids are optimum criteria for three-dimensional observation grids,

update, in the knowledge base, the criteria for three-dimensional observation grids with these optimum criteria for three-dimensional observation grids,

reconstruct, based on the three-dimensional information of interest, filtered through the extracted criteria for three-dimensional grids, useful three-dimensional information,

otherwise, change these criteria for three-dimensional observation grids in the knowledge base, and reiterate the step for extraction of the grid criteria and the step concerning the rule for optimization of these new criteria,

if the rule for optimization of the three-dimensional reconstruction criteria is satisfied by the useful three-dimensional information, then;

these extracted three-dimensional reconstruction criteria are optimum three-dimensional reconstruction criteria,

update, in the knowledge base, the three-dimensional reconstruction criteria with these optimum three-dimensional reconstruction criteria,

reconstruct, based on the useful three-dimensional information, filtered through the extracted three-dimensional reconstruction criteria, three-dimensional information for the object and determine a recognition state file,

otherwise, change these three-dimensional reconstruction criteria in the knowledge base and reiterate the step for extraction of the criteria for reconstruction and the step concerning the rule for optimization of these new criteria.

2. The method as claimed in claim 1, wherein the step for removing the noise from the weak signals of interest to obtain useful weak signals also comprises a step for amplification of the noise-free signals.

3. The method as claimed in claim 1, wherein the object is exposed to an electromagnetic wave.

4. The method as claimed in claim 3, wherein the object is exposed to a laser beam whose wavelength is that in a range going from the visible to the infrared, or to microwaves.

5. The method as claimed in claim 1, wherein the object is exposed to an elastic wave.

6. The method as claimed claim 5, wherein the object is exposed to an elastic wave in the range of ultrasounds or of sounds or of infrasounds.

7. The method as claimed in claim 1, wherein the direct mode search criteria are criteria coming from amplitude correlations and/or from scattered intensity correlations and/or from time sequences and/or from probability densities and/or from spectral signatures and/or from time correlations.

8. The method as claimed in claim 1, wherein the criteria for extraction of the weak signals are criteria coming from a threshold and/or from a range and/or from a domain of evaluation of the direct mode search criterion.

9. The method as claimed in claim 1, wherein the three-dimensional observation grids are grids linked to the angle of the illumination laser beam and/or to the angle of the reception laser beam or to the angle of the excitation ultrasound beam and/or to the ultrasound reception angle.

10. The method as claimed in claim 1, wherein the criteria for three-dimensional observation grids are values of the illumination laser angle and/or of the reception laser angle and/or of the pitch of the illumination laser angle and/or of the pitch of the reception laser angle or values of the ultrasound excitation angle and/or of the ultrasound reception angle and/or of the pitch of the ultrasound excitation angle and/or of the pitch of the ultrasound reception angle.

11. The method as claimed in claim 1, wherein the three-dimensional reconstruction criteria are parameters of shape and/or of the typology of facets and/or of the number of facets and/or of the facet size of the object and/or of the behavior of the object supplied by a reference database and/or knowledge base.

12. The method as claimed in claim 1, wherein the useful direct information comprises a data subset of the backscattered and/or scattered energy type corresponding to the object extracted from the useful weak signals.

13. The method as claimed in claim 1, wherein the useful three-dimensional information is the three-dimensional reconstruction improved by the elimination of artifacts.

14. The method as claimed in claim 1, wherein the three-dimensional information on the object is the optimal three-dimensional reconstruction of the object.

15. The method as claimed in claim 1, wherein the recognition state file comprises information of the type:

“

object not reconstituted”

or “

need to enhance the knowledge base”

or “

delayed operation”

or “

unavailability of the hardware”

.

16. The method as claimed in claim 1, wherein the rules for optimization are of the type search for the maximum value of a parameter, or for a threshold comparison, or for a number of coincidences, or for a time window, or for a spectral signature, or for a time-frequency spot.

17. The method as claimed in claim 1, wherein the weak signals are signals for which the signal/noise ratio is low and/or the amplitude or the intensity is low and/or the information contained is fragmented and/or the information contained is composed of micro-events in coincidence or in occurrence.