TECHNICAL FIELD

The present invention relates to the technical field of control methods for generating images on displays of various nature.

In particular, the present invention is advantageously used in generating the interlacing mapping which can be implemented in an auto-stereoscopic screen, which is a screen provided for displaying three-dimensional images.

STATE OF THE ART

As is known, the neurophysiological capacity of the "stereoscopic" or three-dimensional vision in human beings results from the particular physiological features of the optical system and of how the nervous system reads and processes the visual signals perceived by each of the two eyes human beings normally have: on the other hand, it is known that devices for displaying and "artificially" generating images historically created in human history (technological but also artistic) are mainly limited to depicting two-dimensional images, in a static or "dynamic" form (i.e., in the form of a flow of sequential images which thus reproduce scenes dynamically evolving over time) because of the difficulty of replicating the generation and the perception, by a human being, of a sufficiently accurate and realistic three-dimensional image. However, it is also known that there are different technologies suitable for artificially recreating an image perceivable as "three- dimensional" by human beings: for example, the so-called stereoscopic glasses, which are to be used in combination with particular (static or "dynamic") images referred to as "anaglyph" and actually consisting of two overlapping images taken with angles suitably different from each other are known: the structure of said stereoscopic glasses, functionally coupled with the pair of partial images forming an anaglyph and suitably interfaced with the eyes of a human being, makes it possible that each eye sees only the image relative to a view angle, then the two different images separately reach the brain, which neurologically processes them in a three- dimensional object (N.B.: in other words, the stereoscopic glasses make the three-dimensional vision possible by a suitable use of chromatically different lenses worn by a user/observer looking at an image specifically decomposed according to the above-mentioned "anaglyph" mode).

The stereoscopic glasses have remarkable operation and application limits, often involving inconvenience for the users and being susceptible of generating a quality of the image which can be affected by chromatic aberrations and/or form distortions or other vision/perception faults (blurs and so on), obviously besides the fact that they need to be "optically pointed" towards anaglyph images.

In order to solve the drawbacks of this three-dimensional displaying technology at least partially, the so-called auto-stereoscopic screens, being functionally able to generate an image perceived as three-dimensional by the human eye without the need to use further devices, have been developed.

Operatively, the image is decomposed in a plurality of distinct views cooperatively defining a resulting stereoscopic image.

In other words, each view represents a different angle of a same image and when the various views are projected towards the human eye in the same moment and spatially separated, the latter interprets the received information reconstructing a stereoscopic image.

In this context, each pixel composing the screen, in particular each sub-pixel, is controlled so as to display a respective view, which is then suitably addressed by a so-called "parallax barrier" towards the user. The parallax barrier performs an optical decomposition of the image by projecting the various views generated by the sub-pixels in different angular directions, using the optical principle of parallax.

Such decomposition is generated by a series of parallel slots placed side by side or by a suitable lenticular structure without the need to use secondary optical devices, as the support is provided with a system providing for addressing to each eye the image intended for it according to modes such that it can reconstruct the desired resulting stereoscopic image.

Thus, in the modern displaying technologies, the parallax barriers are made based on LED (light emitting diode) matrixes, such that the image generated by the selective lighting of the pixels constituting such LED matrixes is decomposed and suitably perceived by the user/observer.

The association between the pixels and the barrier can be considered as a layering or overlapping of substantially planar elements ordered along an ideal axis (which can be referred to as an ideal "vision axis") originating from a first layer consisting of the LED matrix defining the pixels to pass through the optical barrier towards the point where the eyes of the user/observer are: along this axis, the LED matrix and the optical barrier are usually in a relation of mutual adjacency (or otherwise in a relation of mutual vicinity/proximity), while the position of the user/observer can be at a remarkably longer distance, as a function of the various fields of use of the screen comprising such matrix and such optical barrier mutually associated.

In this context, it is apparent that, in order to produce a well- defined image in a certain space direction due to the principle of parallax, determining the correct interlacing mapping between the views to be projected and the single sub-pixels is critically important. In other words, it is essential to define in an accurate, quick, and efficient manner which view is to be univocally associated with which sub-pixel.

Indeed, in a case of incorrect mapping between views and sub-pixels, the screen would project image "portions" incorrectly related to each other and the single eye of the observer would no longer perceive a coherent image, losing accordingly the stereoscopic effect or, in the most serious cases, making the information content of the image totally incomprehensible.

Such aspect is still more significant in the case in which it is desirable to employ the auto-stereoscopic screens in fields with high efficiency and quality requirements, such as for example in real-time imaging required during surgeries via endoscopic probes, remotely or otherwise if a team of specialized professionals needs to display the surgery area, usually sub-cutaneous and/or involving complex and crucially important organs or apparatuses, to guide robotic surgical instruments or otherwise to direct instruments inside a human body without having a direct vision thereof: in such fields, the incorrect perception of a three-dimensional structure of an object (which can be an organ of the patient!) could generate even very serious surgical errors or lengthen the surgery time in an extremely inconvenient manner, and also generate an additional load of neuro-muscular fatigue for the professionals intervening on the patient.

Thus, there is a strong need to develop innovative control modes of the screens through which generate an accurate interlacing mapping by which it is possible to control the operation of the single sub- pixels anytime to generate the correct view and thus to allow thereby a high-quality resulting stereoscopic image to be projected.

OBJECT OF THE INVENTION

In this context, the technical task at the basis of the present invention is to provide a method for generating an interlacing mapping overcoming at least part of the above-mentioned drawbacks of the known art.

In particular, an object of the present invention is to provide a method for generating an interlacing mapping simply and efficiently executable on any screen to determine a clear and reliable association between the various views composing the stereoscopic image to be displayed and the sub-pixels composing the screen which has to project such image.

The stated technical task and the specified objects are substantially reached by a method for generating an interlacing mapping, comprising the technical features explained in one or more of the attached claims.

In detail, the method for generating an interlacing mapping is computer-executable.

Such a method is advantageously employed for generating the interlacing mapping in an auto-stereoscopic screen.

In particular, the auto-stereoscopic screen can be of the type comprising a plurality of sub-pixels defining a generation matrix and suitable for generating respective distinct views cooperatively defining a resulting stereoscopic image.

The auto-stereoscopic screen can further comprise an optical barrier associated with the generation matrix and suitable for angularly separating such views.

The method is operatively executed acquiring a first identification data of a geometric conformation and of a spatial arrangement of the plurality of sub-pixels.

A second identification data of the optical barrier is also acquired. In particular, such second data identifies an optical behaviour of the barrier.

A simulated matrix representing the generation matrix as a function of the first data and a simulated barrier overlapped to the simulated matrix as a function of the second data are generated. In particular, the simulated barrier is configured to reproduce the optical behaviour of the optical barrier.

A continuous sequence of adjacent measurement strips in which each measurement strip has the same sub-pixels spatial distribution is individuated on the simulated matrix.

A plurality of simulated optical sensors corresponding to the elements of the simulated matrix are generated, totally covering a measurement strip.

The emission of a plurality of light beams on the measurement strip is simulated.

The light beams are divergent from respective emission points representing the possible positions of an eye of an observer relative to the auto-stereoscopic screen.

Each emission point identifies a same view.

Each light beam comprises a respective plurality of optical rays distinct and angularly spaced so as to totally cover the measurement strip.

Each light beam identifies a respective view univocally associated with such light beam.

Consequently, all the optical rays pertaining to the same light beam represent the same view, while optical rays pertaining to different light beams will represent different views.

Each optical ray is independently acquired on the plurality of optical sensors generating a measurement signal identifying a position thereof on the measurement strip.

A correlation between distribution of the optical rays on the simulated matrix and sub-pixels of the matrix itself is determined. The interlacing mapping comprising instructions configured to control each sub-pixel to generate the view associated with the corresponding optical ray is generated.

Advantageously, the above-described method allows to simply generate the interlacing mapping innovatively evaluating the propagation of light beams associated with distinct views as a function of the possible positions of the eye of the observer, verifying which sub- pixels they fall on and thus which sub-pixels need to show such view. BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the present invention will be clearer by the indicative, and therefore not limitative, description of a preferred but not exclusive embodiment of a method for generating an interlacing mapping, as illustrated in the attached drawings in which:

- figure 1 shows an exploded schematic view of an auto-stereoscopic screen;

- figures 2A-2H summarily show some possible sub-pixels spatial distributions alternative to that schematically represented in figure 1;

- figure 3 schematically shows a possible configuration of execution of the method according to the present invention;

- figure 4 is a representation in view of figure 3.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

The method object of the present invention allows to generate and determine in a particularly simple and accurate manner the interlacing mapping for an auto-stereoscopic screen.

Such a method can be advantageously executed by a computer so as to optimize the execution time.

With reference to figure 1, an auto-stereoscopic screen is generally referred to as number 1 and basically comprises a generation matrix 2 suitable for defining at least one image by a number of pixels 3 formed in turn by respective sub-pixels which can be arranged according to a large variety of geometries and spatial distributions. In the example illustrated in figure 1, the sub-pixels are mutually juxtaposed in the generation matrix 2 according to a number of "n" rows and "m" columns mutually transversal and for example perpendicular, as well as reciprocally arranged along respective parallel horizontal axes H or vertical axes V.

On the other hand, in figure 2, further possible sub-pixels spatial distributions are presented still by way of example.

Such sub-pixels are suitable and configured to generate respective distinct views cooperatively defining a resulting stereoscopic image.

In other words, the resulting stereoscopic image to be presented to the observer 0 results from the overlapping of multiple distinct views and, simultaneously displaying such views on the various sub- pixels defining the generation matrix 2, an interlaced image perceivable as three-dimensional by the human visual system (that is the resulting stereoscopic image) when viewed through a suitable optical barrier 4 is generated.

Thus, the auto-stereoscopic screen 1 further comprises the optical barrier 4, which is associated with the generation matrix 2 and is suitable for receiving and decomposing the interlaced image by addressing and orienting the single views to allow the three- dimensional effect to be perceived by the observer 0.

Therefore, the optical barrier 4 is associated with the generation matrix 2 and angularly separates the interlaced image in the various views composing it and being generated by the sub-pixels so as to correctly orient them to allow the resulting stereoscopic image to be actually perceived by the observer.

Advantageously, the generation matrix 2 and the optical barrier 4 are aligned along a visual axis illustrated as A in the attached figures: in order to use the screen 1, a user/observer who can be at a predetermined screen distance can be positioned along such axis A.

In order to determine which specific views are to be displayed via the distinct sub-pixels in order to correctly display the resulting stereoscopic image, an interlacing mapping operatively defining the rules of association between views and sub-pixels is applied.

In other words, the interlacing mapping defines the maps as a function of which it is determined the activation mode of each sub- pixel that allows to display the correct view so as to generate the desired resulting stereoscopic image.

Thus, the present method allows to generate in a particularly simple and efficient manner such set of instructions.

Operatively, the method is executed acquiring a first identification data of a geometric conformation and of a spatial arrangement of the plurality of sub-pixels.

In other words, the shape and position of the sub-pixels composing the generation matrix 2 are identified.

Such operation can be advantageously executed by an optical inspection of an auto-stereoscopic screen 1 or acquiring such information from a suitable file or document containing the specifications of the screen.

A simulated matrix 5 representing the generation matrix 2 is thus generated as a function of such first data.

In particular, the computer generates a simulated environment in which a simulated matrix 5 accurately replicating the features of the generation matrix 2 is introduced/generated.

Thus, such simulated matrix 5 is defined by a plurality of pixels, formed in turn by respective sub-pixels, having the same geometric shape and distribution of the sub-pixels of the generation matrix 2.

A subsequent step of the above-described method involves acquiring a second data identifying instead the optical barrier 4.

In particular, such second data identifies and generally represents the structure of the optical barrier 4, its conformation and its geometry. Therefore, such second data allows also to identify and to define the optical behaviour of the optical barrier 4, that is, how the latter interacts with and affects eventual optical signals passing through it.

In other words, the second data allows to identify how the optical barrier 4 processes the views which are generated by the sub-pixels and how it projects them towards the observer 0.

Thus, a simulated barrier 6 is generated as a function of such second data, still by the computer and inside the above-mentioned simulated environment.

In particular, such simulated barrier 6 is overlapped to the simulated matrix 5 and faithfully reproduces the optical behaviour of the optical barrier 4.

Therefore, it appears that inside the simulated environment, an overall simulation of the auto-stereoscopic screen 1 is generated, so as to replicate both its means by which the single views are generated (the simulated matrix 5) and its means that allow to direct and to orient such views in order to accurately generate the desired resulting stereoscopic image (the simulated barrier 6).

At this point, by using the information contained in the first data, a continuous sequence of adjacent measurement strips S in which each measurement strip S has the same sub-pixels spatial distribution is located on the simulated matrix 5.

Thus, the information related to the sub-pixels spatial distribution is used to identify a plurality of subsequent strips, all defined by the same pattern.

Therefore, the entire simulated matrix 5 is completely divided in multiple adjacent strips having the same identical sub-pixels spatial distribution.

Thus, in more detail, such strips will have the same width of the simulated matrix 5 and a height equal to the overall height of the simulated matrix divided by the number of located measurement strips. It is observed that the above mentioned procedure can be applied, even if with a distinction, both to the case in which the sub-pixels defining the simulated matrix 5 have a specific well-defined shape and distribution and to the case in which such sub-pixels do not have a specific pattern locatable and/or divisible in adjacent strips.

Indeed, if the generation matrix 2 (thus the simulated matrix 5 replicating its features) is formed and defined by a plurality of sub-pixels (or equal/corresponding displaying elements) having an irregular not repeated shape, which cannot be geometrically defined, or if their distribution is not located/analysed in order to determine its pattern, then the locating step of the strips will be executed locating a single measurement strip S which height and width will correspond to the overall height and width of the simulated matrix 5, respectively.

In other words, if the sub-pixels do not have a geometric shape/distribution divisible in a plurality of strips with the same pattern, merely a single strip coincident with the entire simulated matrix 5 will be located.

Advantageously, the above-described step allows to locate the minimum base unit defining a horizontal sector of the generation matrix 2 which is repeated on the entire auto-stereoscopic screen. Thus, since all the measurement strips adjacent to the one selected are identical from the point of view of the generation features of the images, it is possible to generate an interlacing mapping only for the selected measurement strip S and such mapping will result already optimal also for all the other strips and thus usable also to control the operation of the sub-pixels thereof.

Therefore, advantageously, executing the above-described method allows to generate an interlacing mapping in a particularly simple, quick, and efficient manner by selecting and analysing only a narrow portion of the generation matrix 2, which however represents the overall behaviour of the entire generation matrix 2.

Thus, a plurality of simulated optical sensors overlapped to the simulated matrix 5 so as to totally cover a measurement strip S, in particular only one measurement strip S, are generated still inside the simulated environment.

Therefore, the simulated optical sensors are disposed totally covering the set of sub-pixels representing the sub-unit which, if repeated a predetermined number of times, composes the entire simulated matrix 5.

On the other hand, if the measurement strip coincides with the entire simulated matrix 5, then the simulated optical sensors will be correspondingly overlapped to the entire simulated matrix 5.

Preferably, each simulated optical sensor is overlapped to a single respective sub-pixel.

In this way, it is possible to generate a univocal association between single sub-pixels and optical sensors, thereby allowing to achieve, according to the procedures explained below, a particularly precise and accurate interlacing mapping.

Still more preferably, in order to further optimize such aspect, each simulated optical sensor has also the same geometric conformation of the sub-pixel it is coupled to.

In other words, each optical sensor has the same shape of the specific sub-pixel it is associated with within the measurement strip S.

Thus, the emission of a plurality of light beams 7 on the measurement strip S to which the optical sensors have been overlapped is simulated.

In particular, the light beams 7 are divergent from respective emission points E representing/simulating the possible positions the observer 0, in particular the eyes of the observer 0, can assume relative to the screen 1. Therefore, the distance of the emission points E from the simulated matrix 2, which is preferably within a distance between 0.3 meters and 3 meters, replicates in the simulated environment the position the observer 0 can assume in the real environment relative to the auto-stereoscopic screen 1.

Furthermore, the emission points E are spaced from each other and preferably the distance between two adjacent emission points E (that is between an emission point E and the emission point (s) closer thereto among all the other emission points E) is preferably between 5 mm e 80 mm.

Preferably, the emission points E of the plurality of light beams 7 are aligned along a direction coplanar and parallel to the selected measurement strip S.

Each light beam 7 comprises in turn a respective plurality of optical rays 7a distinct and angularly spaced along the measurement strip S.

In other words, each light beam 7 is composed of a plurality of distinct optical rays 7a diverging starting from the respective emission point E and being projected on the measurement strip S. Furthermore, each optical ray pertaining to a same light beam 7 is associated with and identifies a same view.

Therefore, generally, each light beam 7 is univocally associated with a specific and different view selected among those cooperating to compose the resulting stereoscopic image.

Thus, the optical rays 7a are independently and autonomously acquired on the plurality of optical sensors, generating a measurement signal identifying a position of each ray on the measurement strip S.

Therefore, the optical rays 7a are projected on the measurement strip S where the optical sensors receive them generating a signal identifying the position of the point in which the interaction between a determined optical ray 7a and one of the optical sensors occurred. This operation is virtually performed in the simulation environment.

Obviously, such position is affected by the simulated barrier 6, since it is interposed between the emission points E and the measurement strip S.

Therefore, the optical rays 7a emitted by the respective emission points E are projected towards the measurement strip S, pass through the simulated barrier 6 (being deflected by the latter), and then reach the optical sensors.

In order to allow to identify without interferences the position of the optical rays 7a pertaining to the single light beams 7, the simulation of the emission of the plurality of light beams 7 is executed by simulating a sequential emission of the plurality of light beams 7 so as to emit a single light beam 7 at a time.

Such procedure assures in a particularly simple manner that a single light beam 7 is projected at any time ensuring that the generated measurement signal correctly and univocally identifies the position of the optical rays 7a pertaining to the various light beams 7.

Alternatively, the simulation of the emission of the plurality of light beams 7 can be executed by simulating the simultaneous emission of a plurality of light beams 7 having different respective wavelengths.

In this context, all the light beams 7 are simultaneously projected and the optical rays 7a pertaining to the various beams are distinguishable by virtue of their different wavelength, thus allowing thereby to generate the measurement signal in a single operation.

Once the measurement signal has been generated, a univocal correspondence between the various detected optical rays 7a and the sub-pixels is determined. In other words, the specific sub-pixels which are positioned at the point in which the various optical rays 7a reach the measurement strip S are identified.

Thus, a univocal association between optical rays 7a and sub-pixels is made and, since each optical ray 7a identifies/represents a specific view, a specific interlacing mapping can be defined.

Thus, operatively, the interlacing mapping accurately configured to control each sub-pixel of the generation matrix 2 is generated in the simulated environment, such that the view associated with the corresponding optical ray 7a is generated.

In other words, executing the above-described method results in the generation of a mapping containing instructions so that each sub- pixel of the auto-stereoscopic screen 1 is controlled such that the specific view which is associated with the optical ray 7a which in the simulated environment fell on the same/corresponding sub-pixel in the simulated matrix 5 is generated/displayed.

Furthermore, all the sub-pixels placed in a corresponding position in the adjacent measurement strips are similarly controlled by the same set of instructions.

That is, all the sub-pixels of all the measurement strips are controlled such that the sub-pixels occupying the same absolute position within the respective strip receive the same instructions, that is, they are controlled so as to display the same view. Advantageously, the present invention reaches the proposed purposes by overcoming the drawbacks occurred in the known art, providing the user with a method for generating an interlacing mapping applicable to any screen and being able to generate a precise and accurate mapping in a particularly simple and efficient manner.

Another object of the present invention is a computer program comprising a plurality of instructions configured to cause, promote, generate the execution of a method for generating the interlacing mapping according to the above-described procedural modes and steps. Another object of the present invention is a method for generating an interlacing mapping in an auto-stereoscopic screen executed in a manner equal and corresponding to the above mentioned, but in a real environment, that is, not via a computer simulation.

In particular, the method is executed by providing an auto- stereoscopic screen 1 comprising a plurality of sub-pixels defining a generation matrix 2 (which are suitable for generating respective distinct views cooperatively defining a resulting stereoscopic image) and an optical barrier 4 associated with the generation matrix 2.

Once the geometric conformation and the spatial arrangement of the plurality of sub-pixels have been identified, a continuous sequence of adjacent measurement strips S in which each measurement strip S has the same sub-pixels spatial distribution is located on the generation matrix 2.

As discussed above, if a regular/repetitive pattern for the sub- pixels spatial distribution cannot be identified, a single measurement strip S coincident with the entire generation matrix 2 will be actually identified.

Thus, a plurality of optical sensors is applied over the measurement strip S totally covering such measurement strip S, which is entirely covering the set of sub-pixels representing the sub-unit that, if repeated a predetermined number of times, composes the entire generation matrix 2.

In this context, which is executing the method in a real and not simulated environment, the optical sensors are actually interposed between the generation matrix 2 and the optical barrier 4 and therefore, their introduction can require the temporary decoupling of the latter two elements.

It is observed that the optical sensors are equal/corresponding to the simulated optical sensors, that is, they can have the same operation features and modes of the simulated optical sensors, for example being characterized by a shape/conformation which replicates the one of the sub-pixels they are coupled to and/or be coupled each autonomously and independently with a respective sub-pixel.

Once the optical sensors have been correctly positioned and the optical barrier 4 has been reapplied to the generation matrix 2, it is possible to provide a plurality of light sources each configured to emit a respective light beam 7 which is univocally associated with a respective one of the views to be displayed on the generation matrix 2.

In particular, each light source is positioned at a respective reference point which, in a manner equal and corresponding to the emission points E of the simulated environment, represents possible positions of an eye of an observer 0 relative to the auto- stereoscopic screen 1.

Similarly, each light beam 7 comprises a respective plurality of optical rays 7a distinct and angularly spaced along the measurement strip S.

Therefore, even the light sources implemented in this context can operate according to the same modes discussed and deepened above, especially in relation to their positioning and to the generation and emission modes of the respective light beams (i.e., simultaneous generation of all the light beams 7 at different wavelengths or sequential generation of the single light beams 7).

Thus, each optical ray 7a is independently detected/measured by the optical sensors generating a measurement signal identifying a position of each ray on the measurement strip S (thus on the generation matrix 2).

The measurement signal thus acquired is processed according to the same modes applied in the simulated environment so as to determine the desired univocal correspondence between optical rays 7a (and thus views) and sub-pixels. In this way, it is possible to determine the mapping which can be used to control the operation of the generation matrix 2 so as to display the views that allow to achieve the interlaced image via the sub-pixels thereof. Such interlaced image viewed by the observer 0 through the optical barrier allows him/her to perceive the resulting stereoscopic image.