Stereoscopic camera, wearable device comprising said camera, and stereoscopic vision procedure

Abstract

The present invention relates to a stereoscopic camera comprising: ▪ at least two optical lenses (5), hereinafter simply referred to as "lenses", ▪ image sensor means (10), hereinafter simply referred to as "sensor means", where the sensor means include ▪ at least one active area (11), at least two optical paths (20), each configured to convey the optical images from a respective lens to a respective active area (11), where said conveyed images are called "projections"; ▪ each active area (11) includes at least one region of interest (25), hereinafter simply referred to as ROI, and the sensor means (10) include at least one ROI (25) for each lens (5); characterized in that the ROI (25) of each lens (5) is movable within the respective active area.

Description

[0001] Patent Holders : Techsigno S . r . l . Unipersonale - Via Dei Boschi 2 / 13 - 33040 Pradamano (UD) - Italy - VAT No . 01604580934

[0002] Title : Stereoscopic Camera , Wearable Device Comprising Said Camera , and Stereoscopic Vision Procedure

[0003] ★ ★ ★ ★ ★

[0004] DESCRIPTION

[0005] The present invention relates to a stereoscopic camera, a wearable device comprising said camera, and a stereoscopic vision procedure .

[0006] The invention was made with particular reference to medical diagnostic use ; however, applications in any sector requiring high-precision vision, such as the j ewelry sector, are not excluded .

[0007] STATE OF THE ART

[0008] Traditional cameras generally comprise an optical lens that serves as an entry point for optical images and conveys them through an optical path to an image sensor, which is a digital electronic device that converts optical images into digital images .

[0009] Digital images can be sent to a camera viewer to be viewed .

[0010] In general , the image sensor includes a region of interest , called ROI , which is a portion of the sensor where the quality of the acquired images is superior, as it discards the portions of the optical image where distortion or aberration due to the lenses can occur. Outside this region, therefore, there is generally a loss of quality.

[0011] Stereoscopic cameras used for diagnostic purposes, such as those used by dentists, comprise two lenses and two sensors.

[0012] An example is known in patent literature from 10201800004694 .

[0013] Such cameras have a point of convergence of the optical paths at which the object to be observed, also called the target, must be placed. When it is in this position, to be correctly viewed stereoscopically, the object must also be projected into the ROI of both sensors .

[0014] In an initial phase, and periodically, the cameras require calibration to ensure that the ROIs point to the same target in the sensor's field of view. Such calibration requires the shifting of the optical lenses.

[0015] During use, the problem arises from the fact that the target modifies its distance from the camera and therefore shifts with respect to the focus point, which is the point of convergence of the optical paths. To compensate for this shift, it is necessary to change the inclination between the optical paths, which also requires adjusting the inclination of the lenses.

[0016] The changes in lens inclination necessary for both calibration and compensation are extremely precise and make it necessary to equip the camera with extremely sensitive, complex, and expensive mechanical parts. Consider that to obtain acceptable results from an optical point of view, it is necessary to use micrometric positioning systems that allow the optical lenses to be tilted to fractions of a degree .

[0017] Furthermore , to date , the calibration of the ROI s to be used as a starting reference requires the disassembly and setting of the mechanical parts .

[0018] The general purpose of the present invention i s to overcome all or part of the problems of the known technique .

[0019] A preferred purpose of the present invention i s to provide a stereoscopic camera with simpli fied mechanical construction compared to the known technique .

[0020] A preferred purpose of the present invention is to provide a stereoscopic camera that does not require complex and expensive mechanical calibration and compensation components .

[0021] A preferred purpose of the present invention i s to provide a stereoscopic camera that allows easy and practical centering of the obj ect to be captured with respect to the ROI s .

[0022] A preferred purpose of the present invention i s to provide a stereoscopic camera that allows easy and practical calibration .

[0023] A preferred purpose of the present invention i s to provide a stereoscopic camera that allows easy and practical compensation .

[0024] A preferred purpose of the present invention i s to provide a stereoscopic camera that does not require disassembly for the initial calibration of the ROI s to be used as a starting reference.

[0025] A preferred purpose of the present invention is to provide a stereoscopic camera that is easy and practical to use.

[0026] A preferred purpose of the present invention is to provide a stereoscopic camera that is easy and economical to manufacture.

[0027] GENERAL INTRODUCTION

[0028] The purposes are resolved by a stereoscopic camera, a wearable device comprising said camera, and a stereoscopic vision procedure as indicated in the attached claims.

[0029] In particular, said stereoscopic camera comprises :

[0030] • at least two optical lenses (5) , hereinafter simply referred to as "lenses";

[0031] • image sensor means (10) , hereinafter simply referred to as "sensor means", where the sensor means include at least one active area (11) ;

[0032] • at least two optical paths (20) , each configured to convey the optical images of a respective lens to a respective active area (11) , where said conveyed images are called "projections";

[0033] • each active area (11) includes at least one region of interest (25) , hereinafter simply referred to as ROI, and the sensor means (10) include at least one ROI (25) for each lens (5) , characterized in that

[0034] • the ROI (25) of each lens (5) is movable within the respective active area, preferably via software.

[0035] According to a preferred embodiment of the invention, the stereoscopic camera comprises:

[0036] • at least two optical lenses (5) , hereinafter simply referred to as "lenses";

[0037] • image sensor means (10) , hereinafter simply referred to as "sensor means", where the sensor means include at least one active area (11) ;

[0038] • at least two optical paths (20) , each configured to convey the optical images of a respective lens to a respective active area (11) , where said conveyed images are called "projections";

[0039] • each active area (11) includes at least one region of interest (25) , hereinafter simply referred to as ROI, and the sensor means (10) include at least one ROI (25) for each lens (5) ;

[0040] • the ROI (25) of each lens (5) is movable within the respective active area, via software, characterized in that the lenses (5) have optical paths converging at a target point (8) ; each lens has a field of view (7) , and each field of view (7) of each lens is projected onto a focal plane PF, following the optical path 20, on which also lies a respective active area (11) of the sensor means (10) ; said projection of the field of view has a predetermined extension on the focal plane PF greater than the extension of the active area (11) , and the active area (11) is substantially centered (that is, at the center) in said projection.

[0041] The relevant extension is therefore on the focal plane .

[0042] DEFINITIONS

[0043] FOCAL PLANE: an ideal plane on which the active area is located

[0044] ACTIVE AREA: each active area is a portion of the sensor means configured to receive at least one optical image and to convert it into a corresponding digital image. It develops on a plane hereinafter called the focal plane PF.

[0045] ROI (Region Of Interest of the image sensor means) (10) : an area on the focal plane corresponding to a digital image captured by the sensor means (10) . The ROI is therefore a region of the active area configured to acquire digital images that correspond to respective "portions" of optical images, where the optical images correspond to the projections of the field of view, that is , they are proj ected onto the active area of the sensor means by the optical lenses . The image sensor means are configured to acquire digital images only in the ROI s because their quality is advantageously superior, as portions of the optical image , where distortion or aberration due to the lenses may occur , are discarded . The ROT therefore generates digital images that correspond to " cutouts" of optical images .

[0046] FIELD OF VIEW : the portion of space that can be visible , given the position of the lens . Basically, it can be represented by its aperture angle , also called the angle of vision, and depends on constructive optical parameters such as the focal length .

[0047] PROJECTION OF THE FIELD OF VIEW : the optical image , perceived by the lens through its field of view, proj ected on the focal plane , that is , the area on the focal plane corresponding to the entire optical image seen by the optical lens proj ected onto said focal plane .

[0048] DETAILED DESCRIPTION

[0049] Further features and advantages of the present invention will be better understood from the following detailed description of its preferred embodiments , made with reference to the attached drawings and given as an indication and not as a limitation .

[0050] Figure 1 schematically shows a stereoscopic camera according to the present invention .

[0051] • Figure 2 shows the alignment between an active area of the sensor means of the camera of figure 1 and the proj ection onto it of the field of view of one of the lenses .

[0052] • Figures 3 and 4 schematically show in side and top view a wearable diagnostic device comprising a stereoscopic camera according to the present invention .

[0053] • Figure 5 schematically shows the lenses of the camera of figure 1 in a condition where a target i s at the point of intersection of the optical paths of the two lenses .

[0054] • Figure 6 schematically shows an example of how the target is seen in the two active areas 11 of the camera of figure 5 , when the camera is not calibrated .

[0055] • Figure 7 shows the shi fting of the ROI s for the calibration of the situation in figure 6 .

[0056] • Figure 8 schematically shows the lenses of the camera of figure 1 in a condition where the target is at a point far from the point of intersection of the optical paths of the two lenses .

[0057] • Figure 9 schematically shows an example of how the target is seen in the two active areas 11 of the camera of figure 7 , when the camera is not compensated .

[0058] • Figure 10 shows the shi fting of the ROI s for the compensation of the situation in figure 9 . With reference to figure 1 , a stereoscopic camera according to the present invention is schematically shown, indicated as a whole with reference number 1 .

[0059] Camera 1 comprises at least two optical lenses 5 , hereinafter simply referred to as " lenses" , and image sensor means 10 , hereinafter s imply referred to as " sensor means" . The sensor means include at least one active area 11 , and each lens 5 proj ects its optical images onto a respective active area 11 . Each active area is configured to receive an optical image and to convert it into a digital image . For example , the sensor means are of CCD or CMOS type .

[0060] Preferably, the camera also includes display means 15 , operatively connected to the sensor means 10 to receive and display the digital images generated by the latter . The display means , for example , comprise a single display for both eyes of a user, or a pair of displays , one for each eye .

[0061] Camera 1 includes an optical path 20 for each lens 5 , configured to convey the optical images that enter the sensor means 10 through the respective lens 5 .

[0062] Preferably, the lenses 5 have optical paths converging at a target point 8 .

[0063] Each lens has a field of view 7 , of predetermined extension ( that is , of predetermined angle ) . Each field of view 7 of each lens is proj ected onto a focal plane PF on which also lies a respective active area 11 of the sensor means 10 , following the optical path 20 .

[0064] The extension of said proj ection is greater than the extension of the active area 11 , and the active area 11 is substantially centered (that is, at the center) in said projection.

[0065] Preferably, the extension of the projection of the field of view 7 is at least double the extension of the active area.

[0066] The centering between the projection of the field of view 7 and the active area 11, and their difference in extension, make it possible to discard the areas of the optical image which are of low quality due to distortions or aberrations.

[0067] The centering, for example, is between the projection of an optical axis AF of the field of view 7 and a predetermined vicinity 9 of the center of the active area 11. Such tolerance is possible thanks to the significant difference in extension between the field of view 7 and the active area 11. This advantageously simplifies construction and reduces costs.

[0068] For each lens, a Cartesian coordinate system XYZ is conventionally defined, where the X and Y directions are on the focal plane PF and the Z direction is parallel to the optical axis AF, preferably coincident. Being Cartesian coordinates, the directions are understood to be orthogonal to each other. For example, the Cartesian coordinates have their origin at a central point of the active area 11.

[0069] Each active area 11 includes at least one region of interest 25, hereinafter simply referred to as ROI, and the sensor means include at least one ROI for each lens 5. Each ROI captures a portion of the optical image, which is transmitted to the display means 15. The at least one ROT for each lens is generally movable , via software - preferably digitally, within the respective active area 11 .

[0070] This allows easy calibration performed via software , preferably digitally, and / or easy compensation performed via software , preferably digital ly, of the camera, to center one or more ROI s in the proj ection on the focal plane of target 50 .

[0071] In particular, the camera is configured for calibration when it is able to shi ft the ROI according to the X and Y coordinates at least to center it on the proj ection of target 50 when the latter is at target point 8 but its proj ection is displaced from an " initial reference position" of the ROI of at least one lens . The initial reference position is preferably a central position with respect to the active area 11 . The position reached by the ROI following calibration is called the " calibrated reference position" .

[0072] In addition, the camera is configured for compensation i f it is also able to shi ft the respective ROI s according to the X and Y coordinates at least to center them on the proj ection of target 50 when the latter is displaced in the Z direction with respect to target point 8 , and consequently its proj ection in at least one active area 11 is displaced from the respective ROI when it is in the " calibrated reference position" .

[0073] For this purpose , in general , camera 1 includes identi fication means 30 configured to identi fy, for each lens 5 , the position of the proj ection of a predetermined target 50 within the respective active areas 11, for example by determining the X and Y coordinates, for example of the centroid. For example, said position includes the distance in X and Y coordinates from the ROI in the calibrated reference position.

[0074] Camera 1 also includes shifting means 35, configured to shift via software, preferably digitally, each ROI 25 in the respective active area 11. The shifting means 35 are preferably configured to shift each ROI 25 independently of the others.

[0075] With reference to figures 5, 6, and 7, we will illustrate below how the general characteristics described can be exploited for camera calibration.

[0076] As mentioned above, the need for calibration exists at least when target 50 is in the Z direction at target point 8, but at least one lens 5 projects it in the respective active area 11 not centered with respect to the ROI 25 when it is in the "reference position" at the center of active area 11.

[0077] Figure 6 schematically represents on the right and left the active areas 11 related respectively to the right and left optical lenses and the respective projections of target 50. The latter has been represented in the form of an extended target with three dots, the center one colored for easier identification in the X and

[0078] Y coordinates. In figure 6, the ROIs 25 related to both lenses 5 are in the initial reference position at the center of the respective active area 11.

[0079] The example shows the case where the left lens correctly projects the center of target 50 (middle dot) into the ROI 25, which is in the initial reference position. Conversely, the left lens projects the target outside the ROI when the latter is in the initial reference position, in particular it projects it higher and more to the right.

[0080] To calibrate this situation, the ROI 25 related to the right lens is shifted, preferably digitally, in the X and Y coordinates to center itself on the projection of target 50.

[0081] To identify the positions of the target for calibration purposes, the identification means 30 include, for example, visual reference means, such as a grid, visible on the display means 15 in superposition with the projection of the target, and the shifting means 35 include commands, via software - for example digital, operable by a user, to shift via software - for example digitally, the ROI on the projection of the target based on the visual reference means.

[0082] In addition or alternatively, the identification means 30 can be of a software type including a memory portion 32 in which a software that executes an identification algorithm is saved, and the shifting means 35 preferably include a memory portion 37 in which a software that executes a shifting algorithm is saved. In this case, the shifting means 35 are configured to be coordinated with the identification means 30, so as to shift the ROI 25 according to the position of target 50 identified by the identification means. For example, camera 1 includes processing means 38 configured to process shifting instructions for the shifting means 35 based on the position detected by the identification means.

[0083] In this way, it is possible to calibrate the camera without performing mechanical calibrations and without disassembling it. Consequently, the hardware construction of the camera is simpler and less expensive.

[0084] With reference to figures 8, 9, and 10, we will illustrate below how the general characteristics described can be exploited for camera compensation.

[0085] As mentioned above, the need for compensation exists when target 50 is distanced in the Z direction from the target point 8. The example of figure 8 depicts the situation where target 50 is between the lenses 5 and the target point 8. Let's suppose that in this case target 50 is initially seen by the camera as shown in figure 9, which schematically represents on the right and left the active areas 11 related respectively to the right and left optical lenses.

[0086] In figure 9, the ROIs 25 are both in the calibrated reference position at the center of the respective active area 11. In this reference position, at least one of the lenses has the projection of the target not centered with respect to the ROI . In figure 9 , a case is presented as an example where the left lens proj ects the left portion of the target into its ROI , and the right lens proj ects the right portion of the target into its ROI .

[0087] To standardi ze the view of the two lenses , the ROI s are shi fted, via software - preferably digitally, in such a way as to center them on the central portion of the proj ections of target 50 , as shown by way of example in figure 10 .

[0088] To do this , it is possible to use the same identi fication and shi fting means mentioned for calibration .

[0089] In addition or alternatively, the identi fication means 30 can be configured to identi fy the position o f target 50 in the respective Z directions with respect to target point 8 .

[0090] The processing means 38 in this case are preferably configured to associate relative compensation shi fts of the ROI in the XY coordinates to relative positions of the target in said Z direction .

[0091] In this way, it is possible to e camera 1 while keeping target 50 displayed on the display means 15 with a good image quality .

[0092] Since the camera is stereoscopic, the identi fication means 30 are generally configured to identi fy the same target 50 for each lens 5 . In case of compensation function, they can also be configured to follow said target .

[0093] In use , the stereoscopic camera identi fies a common target 50 for the two lenses through the identification means 30.

[0094] Camera 1 positions one ROI for each lens in correspondence with the projection of said target in the active area 11 of the respective lens. This is done both in case of calibration and in case of compensation.

[0095] In particular, when camera 1 detects that said projection is not centered with respect to a ROI 25 when the latter is in a reference position (for example, an initial reference position for calibration, and a calibrated reference position for compensation) , it shifts, via software - preferably digitally, said ROI to center it with respect to the projection of the target.

[0096] The identification means 30 identify such lack of centering and transmit it to the processing means 38, which process the related shifting instructions for the shifting means 35.

[0097] In case of compensation, the identification means 30 can also be equipped with a locking function to remain "locked" on target 50 and follow it.

[0098] Advantageously, it is not necessary to shift the lenses with respect to the captured scene to center the projections of the target and the ROIs, as the shift of the ROIs is in fact a software shift of the captured scene, where the portion of captured scene is the one where the projection of the target is located. This makes the camera simpler and more economical to manufacture. Furthermore, it is not necessary to disassemble the camera to calibrate the mechanical parts of the two lenses with each other, as the calibration between the ROI s associated with the lenses can be done via software by aiming at a common target .

[0099] In the embodiment illustrated in figure 1 , the sensor means 10 include an active area 11 for each lens 5 , where each includes a ROI 25 . However, other forms of implementation are not excluded in which the same active area 11 has more than one ROI , each associated with di f ferent lenses 5 . In the latter case , camera 1 can advantageously include only one active area 11 , further simpli fying the construction .

[0100] With reference to figures 3 and 4 a wearable device 60 is represented, comprising :

[0101] • support means 65 wearable on the head of a user, for example in the form of a helmet or an element encircling the circumference of the skull ;

[0102] • a stereoscopic camera 1 according to the present invention, supported by said support means 65 .

[0103] Said camera 1 is preferably constructed according to the scheme of figures 1 and 2 , and figures 3 and 4 show a preferred form of implementation . Other forms of implementation are also possible .

[0104] In figures 3 and 4 , camera 1 includes the lenses 5 positioned in a frontal part , and the sensor means 10 positioned in a rear part . This example represents the possible , but not mandatory, case in which the optical paths 20 have respective portions internal to the camera that are non rectilinear . Said internal portions of optical paths , for example , include at least one deviation point 70 of the optical images , and preferably a plurality of them, for example made by respective prism means .

[0105] As visible in figure 4 , the camera includes two lenses 5 and two related active areas 11 . Forms of implementation with a single active area on which the fields of view 7 of each lens are proj ected, with two respective ROI s 25 , are not excluded .

[0106] Forms of implementation with a di f ferent arrangement of the camera 1 parts with respect to the support means 60 are also not excluded, for example forms of implementation where both the lenses and the sensor means are in the frontal part .

[0107] According to some preferred forms o f implementation, in general , the optical path 20 between each lens 5 and the relative active area 11 may include optical magni fication means 70 , for example mechanically adj ustable . Such optical magni fication means are preferably placed in correspondence with a central area of the support means , as in the example of figures 3 and 4 . In thi s way, it is possible to obtain a good balance of the weights of the wearable device .

[0108] We observe that for the purposes of the present invention, the parts of the camera must be functionally connected to each other and form a system, but it is not excluded that they are physically repositioned, for example supported in different areas of a support, as in the example of the helmet. For example, the detection means, the processing means, and the shifting means, being software means, can also be arranged remotely from any main body of the camera, for example comprising the lenses.

[0109] GENERAL INTERPRETATION OF TERMS

[0110] In understanding the scope of the present invention, the term "comprising" and its derivatives, as used herein, are intended as open-ended terms that specify the presence of the stated features, elements, components, groups, integers and / or steps, but do not exclude the presence of other unstated features, elements, components, groups, integers and / or steps. The above applies also to words having similar meanings such as the terms "comprising", "having" and their derivatives. Furthermore, the terms "part", "section", "portion", "member" or "element" when used in the singular can have the dual meaning of a single part or a plurality of parts. As used herein to describe the above embodiment ( s ) , the following directional terms "forward", "backward", "above", "downward", "vertical", "horizontal", "below" and "transverse" as well as any other similar directional terms refer to the embodiment as it is oriented in the operating position. Finally, terms of degree such as "substantially", "about" and "approximately" as used herein mean a reasonable amount of deviation of the modi fied term such that the end result is not signi ficantly changed .

[0111] While only selected embodiments have been chosen to illustrate the present invention, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made without departing from the scope of the invention as defined in the appended claims . For example , the si ze , shape , location or orientation of the various components may be changed as needed and / or desired . Components that are shown directly connected or contacting each other may have intermediate structures disposed between them . The functions of one element may be performed by two , and vice versa . The structures and functions of one embodiment may be adopted in another embodiment . It is not necessary for all advantages to be present in a particular embodiment at the same time . Every feature which is unique from the prior art , alone or in combination with other features , also should be considered a separate description of further inventions by the applicant , including the structural and / or functional concepts embodied by such features . Thus , the foregoing descriptions of the embodiments according to the present invention are provided for illustration only, and not for the purpose of limiting the invention as defined by the appended claims and their equivalents .

Claims

CLAIMS1. Stereoscopic camera comprising:• at least two optical lenses (5) , hereinafter simply referred to as "lenses",• image sensor means (10) , hereinafter simply referred to as "sensor means", where the sensor means include at least one active area (11) ;• at least two optical paths (20) , each configured to convey the optical images of a respective lens to a respective active area (11) , where said conveyed images are called "projections";• each active area (11) includes at least one region of interest (25) , hereinafter simply referred to as ROI, and the sensor means (10) include at least one ROI (25) for each lens (5) ; characterized in that• the ROI (25) of each lens (5) is movable within the respective active area.

2. Camera according to claim 1, characterized in that the ROI of each lens is movable independently of the ROIs of the other lenses.

3. Camera according to any one of claims 1 or 2, characterized in that it comprises:• identification means (30) configured to identify,in the projection of each lens (5) , the position of a predetermined target (50) ;• shifting means (35) configured to shift via software each ROI (25) in the respective active area (11) to center it on said target (50) .

4. Camera according to claim 3, characterized in that the shifting means (35) are digital.

5. Camera according to claims 3 or 4, characterized in that the identification means include a memory portion (32) in which software that executes an identification algorithm is saved.

6. Camera according to any one of claims 3 to 5, characterized in that the shifting means (35) include a memory portion (37) in which software that executes a shifting algorithm is saved.

7. Camera according to any one of claims 3 to 6, characterized in that it includes at least one of the following options:A) the camera includes viewing means (15) and the identification means (30) include visual reference means visible to a user on the viewing means (15) superimposed on the projection of the target, the shifting means (35) including software commands operable by a user to shift the respective ROIs onto the respective projections of the target based on the grid;B) the identification means (30) and the shifting means (35) are coordinated with each other to automatically shift the ROIs within the respective active areas so as to center them on the respective projections of the targets (50) ;C) the optical paths converge at a target point (8) and the identification means are configured to detect any distance of a target (50) from the target point (8) in the direction (Z) of the respective optical paths, in which case the camera includes processing means (38) configured to process instructions for the shifting means, where said instructions are configured to compensate for said distance by shifting the respective ROI in the active area (11) .

8. Camera according to any one of claims 3 to 7, characterized in that the identification means are configured to identify for each lens the position of the target (50) in the projection with respect to a respective initial reference position of the ROI;• the shifting means are configured to shift the ROI to a respective calibrated reference position, in which it is centered on the projection of the target ( 50 ) .

9. Camera according to claim 6, characterized in that:• the optical paths converge at a target point (8) and the identification means are configured to detect for each lens (5) any distance of a target(50) from the target point (8) in the direction (Z) of the respective optical path (20) ;• the shifting means (35) are configured to compensate for said possible distance by shifting the ROI in the active area from a calibrated reference position to a position centered on the projection of the target (50) .

10. Camera according to any one of the preceding claims, characterized in that the identification means (30) of each lens (5) are configured to identify the same target (50) .

11. Camera according to any one of the preceding claims, characterized in that:• each lens (5) has a field of view (7) , which is projected onto a focal plane PF on which also lies a respective active area (11) ;• the extension of said projection of each field of view (7) is greater than the extension of the respective active area (11) , which is substantially centered on said projection of the field of view.

12. Camera according to claim 11, characterized in that the extension of the projection of the field of view (7) is at least double the extension of the active area.

13. Wearable vision device, comprising:• support means (65) wearable on the head of auser;• a stereoscopic camera (1) according to any one of the preceding claims supported by said support means (65) .

14. Stereoscopic vision procedure, characterized by the following steps:• arranging a camera according to any one of claims 1 to 12;• arranging a target (50) outside the camera and positioning it in the field of view (7) of each lens ;• shifting the ROIs with respect to the respective active areas, in order to center those that are not centered on the respective projection of the target.

15. Procedure according to claim 14, characterized in that it calibrates the camera as follows:• positioning a target at a target point where the optical paths converge;• when the target (8) is at the target point, and the ROIs of the lenses are in the respective initial reference positions, identifying the lenses with the ROI not centered on the projection of the lens;• shifting the ROI of the non-centered lenses to a calibrated reference position in which it is centered with said position.

16. Procedure according to claim 15 characterized in that it compensates camera 1 as follows:• when the ROIs are in the respective calibrated reference positions, shifting the target (50) away from the target point (8) in the direction (Z) of at least one optical path and compensating for said shift by shifting the respective ROI in the respective active area from the calibrated reference position to a position centered on the projection of the target.

Images