WO2015047067A1

WO2015047067A1 - Three-dimensional image scanner

Info

Publication number: WO2015047067A1
Application number: PCT/MX2014/000009
Authority: WO
Inventors: Salvador FLORES RUIZ
Original assignee: Generadora De Desarrollos Tecnologicos Gdtec, S. De R.L. De C.V.
Priority date: 2013-09-24
Filing date: 2014-01-16
Publication date: 2015-04-02
Also published as: MX2013010928A

Abstract

The invention relates to a system relative to an electronic assembly with optical functions, which relates to applications of specialised computer programs for obtaining files, data and references for the electronic representation of figures in three dimensions, and is able to record data relating to figures in three dimensions, using an image captured by a digital camera and using the digital bands, and by means of precise calculations, the data required for recording a three-dimensional model is determined, and the use thereof is applicable in industrial branches. Compared to existing systems, the aim of this invention, inter alia, is to present a complete scan in a much shorter interval of time than other means, by means of a reduction in the amount of time required for the capture thereof by means of digital images and in the processing of data relating to the figure to be matched, rapidly. These advantages are obtained by means of an assembly that costs considerably less than other existing means, is compact and transportable, has a resolution adaptable to the application or required means, and can be intuitively operated by the user such that extensive training is not required.

Description

SCANNING OF IMAGE IN 3 DIMENSIONS

TECHNICAL FIELD

Electronic equipment with optical functions that is related to applications of specialized computer programs for obtaining files, data and references for the electronic representation of figures in three dimensions and apply their use in the industrial branches such as: Health Industry, Industrial Design , Machining, Inspection of molds and finished products, Reverse engineering, Tundish industry, Plastic industry, Automotive industry, Aeronautics industry, Cinematography, Computer games, Security and personnel control, Jewelry and goldsmiths among others.

OBJECT OF THE INVENTION

The present invention, as expressed in the enunciation of the descriptive section, refers to an invention capable of making a record of data relating to figures in three dimensions, by using an image captured by a digital camera, digital bands and precise calculations that determine the data necessary for the registration of a three-dimensional model. This invention in comparison with existing systems aims among others to present a complete scan in a much shorter time to other means, by a decrease in the time required for capture by digital images and in the processing of data relating to the figure to arrange, without the need for long static periods of the object to be registered; These advantages arise through a team of cost considerably lower than other existing means, in a compact and transportable presentation, with a resolution adaptable to the application or necessary means and with an intuitive operation for the user so that extensive training is not required. BACKGROUND

At present there are known systems for scanning figures in three dimensions, however all these are derived from traditional scanning systems, which are electronic devices that allow digitizing information, whether texts or images; These systems initially emerged in the year 1984 in black and white formats with a resolution of 200dpi, a quality that has been increased over the years in line with technological development.

These systems mostly used the technology known as CCD (charge-coupled device) which is an integrated circuit that contains a specific number of linked or coupled capacitors, in the case of scanning technologies, refers to the sensor with tiny photoelectric cells that record the image; its resolution capacity or image detail depends on the number of photoelectric cells in the CCD that are expressed in pixels, with digital cameras incorporating CCDs with capacities of up to one hundred and sixty million pixels (160 megapixels).

This technology can detect variations in the intensity of light and its frequency, under this premise the scanners worked illuminating sections of the paper through glass, the light was transmitted with greater or lesser intensity depending on the colors or tones, and reflected in a system of mirrors aligned to the lens that focused the rays towards a sensor that converted the intensity into electric current; At this point an analog, digital converter converts electrical current into zeros and ones, which form the pixels of the images. After this base technology and with the advancement of technology, various systems have been generated to not only register elements in documents but in physical figures of three dimensions, among these there are those that use laser illumination to obtain the information of the object to be scanned, in reason that the laser is a coherent and punctual source of illumination, however the capture time and high cost of the specialized equipment with elements modified by the presented invention through an original system that as a whole intertwines physical elements and mathematical calculations presents in a fraction of time a complete three-dimensional scan. It is necessary to point out that the available systems and technologies of three-dimensional active image acquisition through optical systems are generally divided into the following capture methods: i. TOF (Flight Time).

• The ToF works like a stopwatch, its function is that when a particular person crosses a ToF plane, a timer starts to work (Time-to-Digital Converter or TDC). When the particle comes out crossing a plane of the ToF on the other side of the magnet, the time counter stops, in the case of these systems a laser beam is used generally in the infrared or green spectrum, which is fired on the target To measure, this type of technology determines the distance to the object by timing the round trip time of a pulse of light. It is necessary to aim the laser using high precision servomechanisms to move mirrors that direct the beam to the different positions where it is necessary to determine the distance, in this way it is possible to acquire up to 10,000 points per second but the required precision requires very sophisticated and high equipment. cost. ii. Laser Scanning

• In this system it is usual to use an optical triangulation that takes technical advantage of the light rays travel that in known patterns and by means of optical principles with vectorial calculation the position of a point in space can be identified knowing two of its vectors: a - The one that forms the direction and angle of a beam of light emitted from a laser emitting apparatus generally of visible length, but not exclusively, and

b - The angle of the pixel detected in the sensor of the pickup device with the known optics mounted on the front thereof, which will allow to determine the distance of the third missing vector. It is possible to use points or lines for this technological model, in which the precision of mechanics is a limiting factor in its use, since mechanical variation produces incorrect results and information collection times eff the range of minutes. iii. Binary coding.

• As a matter of principle it is clear that the binary code is the system of representation of texts, or processors of computer instructions using the binary system (two-digit numerical system, or bit: the "0" (closed) and the "1" ( open), however this is not the only system that can be determined as binary, in the specific area to be treated is a well known technology which uses projection patterns by incandescent or LED projectors on LCD matrices to achieve binary coding, that is, only fully illuminated or completely dark, light structures with a pixel depth, adding and arranging the layers of the patterns can obtain a resolution dependent on the projection pattern for each pixel of the camera. This implies that an 8-bit pattern will generate 256 levels of depth per pixel, which are recorded, but this results in the technical impossibility of making it possible to build teams of good resolution and speed by the number of patterns that must be presented to achieve a correct definition. iv. Gray Code

• In the same line of the previous points, this technology turns out to be relatively similar to the one mentioned in previous points, with the key difference that instead of coding only ones and zeros, several values of gray (N) are encoded in the presented patterns by the projection team; this results in obtaining higher resolution depth and gives a lower degree of resistance to errors or atmospheric noise than the coding method previously described. Based on this, this system requires a large number of patterns to be projected, so it does not represent an advantage in time, energy or equipment over the previous method, although it does result in an improvement in the result of its resolution; Regarding this, the way to assemble the depths requires a considerable amount of mathematical calculations which results in a slow execution process in the objective of data recovery relative to the depth of the digitized figure. v. Calculation of Intensity.

The devices that use this system are based on the application of a method that is based on a variation of taking the patterns (N) to the maximum allowable the projector or the sensor or sensor of the camera; Once this has been accomplished, instead of an assembly of the patterns, a calculation of the intensity of the reflection or brightness is made, which as a result is simpler and quicker. Unfortunately, the indicated method requires a greater amount of time for these projection patterns to reach the maximum of their equipment intensity (N) - The obtained resolution is higher than the one established in the point indicated above and proportional to the time required to capture it. the points necessary for the determination of said information; however, it suffers from a susceptibility to so-called "noise" or interference from the sensors inherent in the pick-up devices as digital cameras are by the subtle variations in the illumination of the light patterns. saw. Optical Interferometry

• This method is the one that determines the object by means of analysis of the interference of wave phases (usually electromagnetic) on an object of a projected matrix, it is one of the most precise techniques and it reaches to detect 1/200 of the length of wave used. It requires high optical quality equipment and techniques of construction and interpretation of information whose cost is extremely high for its proper development and application, discarding it as an option accessible to the general public. vii. Patterns of Moiré

It is an interference pattern that is formed when two gratings of lines with a certain angle are superimposed, or when such grids have slightly different sizes, in the concrete application consists of the presentation of the diffraction of waves presented through grids that generate interference patterns. Traditionally only the information of ridges and valleys of generated patterns is used, for this reason it is unduly discarded valuable information of other intermediate values that arise through this method; however, it generates a considerable resolution of the order of 1/10 to 1/100 of the interference patterns generated. Mathematical processing is not of considerable complexity but suffers from limitations regarding the use of precise light sources and complex grids; at the same time that the optics must be of quality, since the level of precision provided by this method is high. In order to make an adequate use of the depth information provided by this method, precision actuators and controls are required that increase its cost and difficulty of access. viii. DLP (Digital Light Processing). In the DLP projectors, the image is projected by microscopic mirrors arranged in a matrix on a semiconductor chip, known as Digital Micromirror Device (DMD), each mirror represents a pixel in the projected image being that the number of mirrors corresponds with the resolution of the projected image; While these mirrors can be quickly relocated to reflect light through the lens or onto a heat sink. This technology sends light patterns starting from positioning micro mirrors in thousandths of a second, with repeatability capacity and generation of enormous contrasts of the order of 2000: 1 and with high reliability as a self-contained chip is used, eliminating the need of the presence of mechanisms of high electromechanical precision, because they are already contained in said chip. It represents the greatest technological advance for this type of devices in a medium and high range of its cost-benefit; With this technology, with a few bits of resolution in the tonality, a large range of contrast can be generated, significantly improving the resolution of the system. ix. Projection of Digital Bands.

• Through this method a useful and considerable improvement is obtained through the use of this technology that takes advantage of the projection of digitally generated bands and taking advantage of recent advances in digital image projectors. This system is based on the generation of the so-called "light bands" and the analysis of the responses to the phases of the interference patterns formed. Being viable the use of a variety of said bands projected with 90 or 120 degrees of lag; keeping the advantages as in the case of the 90 degree shift between bands where only four patterns are required to capture the information, or in the case of higher resolution of 120 degrees between bands where only 3 patterns are required for the same purpose. These elements are presented as undeniable advantages, with respect to their cost benefit, however, in turn present some drawbacks such as the requirement of a large number of mathematical calculations to obtain the information of the depth from the phase and the need to a stable source of light. In other words, the more continuity in the presented pattern, the more accurate the depth image will be, up to the capture limit of the camera's sensor.

However, this system presents a great development recently due to its enormous potential since high precision positioning mechanisms are not required. The present invention seeks a greater use by the creative application of systems for the versatility indicated in a much shorter period of time with the sum of data of different interlaced positions. BRIEF DESCRIPTION OF THE FIGURES

Figure 1 is a front view of the internal elements of the invention, observing the position of camera in upper inclined element (1), the angular support (2) thereof in exact angle, the straight support (3) for its fixture and projector apparatus of lighting standards (4) guided.

Figure 2 is a rear view of the internal elements of the invention, observing the position of the camera in the inclined upper element (1), the angular support (2) thereof at an exact angle, observing how its thickness is less than having a shape triangular, the straight support (3) for its support and the projector apparatus of lighting standards (4) attached to the indicated support.

Figure 3 is a side view of the internal elements of the invention, observing the position of camera in upper inclined element (1), the angular support (2) thereof in exact angle in triangular form, attached to the straight support ( 3) for its support and the projector apparatus of guided lighting standards (4).

Figure 4 is a front perspective view of the internal elements of the invention, observing the position of photographic camera in inclined upper element (1), the angular support (2) thereof in an exact angle in triangular shape, the straight support (3) for its support and the projector apparatus of guided lighting standards (4).

Figure 5 is a front view of the so-called housing (5) that covers the interior elements of the invention, its upper part is observed the sliding curtain to cover the camera (7) and in its lower part the lighting exit orifice ( 6).

Figure 6 is a side view of the housing (5) that covers the interior elements of the invention, its upper part is observed plastic tab of the sliding curtain to cover the camera (7). Figure 7 is a rear view of the so-called housing (5) covering the interior elements of the invention, its upper part is observed the handle for transport (8). Figure 8 is a front perspective view of the so-called housing (5) that covers the interior elements of the invention, its upper part is observed the sliding curtain to cover the camera (7) and in its lower part the exit orifice of lighting (6).

Figure 9 is a front perspective view with transparency of the internal elements of the invention, observing the position of photographic camera in inclined upper element (1), the angular support (2) thereof in an exact angle in triangular shape, the straight support (3) for its support and the projector apparatus of lighting patterns (4) guided; while in its external form the so-called housing (5) that covers the interior elements of the invention is observed, its upper part is observed the sliding Curtain to cover the camera (7) and in its lower part the outlet of lighting (6) with the handle for transport on the back.

Figure 10 is a front perspective view of the so-called housing (5) covering the interior elements of the invention, its upper part is observed the sliding curtain to cover the camera (7) and in its lower part the exit orifice of lighting (6); likewise, the data cables (9) or other transfer medium that receives the images from the camera and the data cable (10) that sends instructions to the projector of illumination patterns (4) that exit through its exit orifice, are observed. lighting (6), from the computer running the SISAD3D program, which sends instructions on necessary lighting patterns and receives images, which in turn generates images in 3 dimensions through the algorithms of its programming in direct and constant relation with its elements physical DETAILED DESCRIPTION The 3-dimensional image scanner with use of the "SISAD3D" program (11) to which the invention refers is initially implemented by a unique photographic system (1) of digital technology and high definition, whose composition or technical elements they are habitual in similar technologies without a direct appropriation of the same one; which is subject to an angular support (2) which keeps the function of keeping said instrument held in a precise manner and at a specific angle with respect to the straight support (3).

The straight support (3) is the element of the invention that maintains the inner integrity of the invention, predetermining the distance between its parts and maintaining its unit, in its upper part is the angular support (2) which maintains the camera photographic in proper position and Angle as indicated; while in its lower part the so-called lighting pattern projector (4) is held, which is an instrument that under precise indications of the computer or computer program (11) emits light in intensity or continuity that is required for the execution of the system.

The straight support (3) maintains the appropriate distance between the photographic camera (1) and the illumination pattern projector (4) for an adequate functioning of the system, differentiating itself from existing systems by coexisting in a single attached attachment and not separately; additionally it only depends on a projector (4) and a single camera (1) joined without a multitude of them. Each of these elements, the camera (1), the angular support (2), the straight support (3) and the lighting pattern projector (4) are protected by a plastic cover that has been called housing (5), which keeps the function of facilitating the use of the invention and its manipulation, in its upper front part there is a sliding curtain (7) that protects and covers the camera (1), in its lower part it is observe an illumination exit hole (6) emitted by the lighting pattern projector (4).

In its upper rear part at the height of the sliding curtain (7) there is a handle for transport (8) that precisely facilitates the manipulation of the invention and its mobility; all of the above as elements of the housing (5) that stores the protection, transport and manipulation function allowing the entry of images to the camera (1) through the sliding curtain (7) and the output of light patterns of the projector (4) through the illumination exit hole (6).

Finally, the camera (1) is linked by a data cable (9) or other means of transfer to the computer (11) running the computer program "SISAD3D" which receives the relative images which analyzes through its algorithms specific also the lighting pattern projector is connected in the same way by a data cable (10) or other means of transfer to the computer (11) running the computer program "SISAD3D" which coordinates and sends the orders to the pattern project of light for capturing images of the camera (1) to which the corresponding algorithm will be applied for the determination by said program, through its physical and software elements, of a three-dimensional figure based on the leftovers emitted by the object to be scanned, in direct coordination between the capture of images and the light emitted.

Claims

Having described my invention, as above, I consider as a novelty and claim of my property contained in the following claims.

1 - The 3-dimensional image scanner is a system that combines in a novel way its physical elements such as photographic camera, angular support, straight support, projector of lighting patterns protected by a housing, which facilitates the capture of images and the emission of light patterns, their transport and their connection to the computer with the computer program element "SISAD3D", in this conjunction a 3-dimensional image is generated based on the light patterns at a considerable speed and much less than the existing in the market.

2 - The first element of its protection arises in its relation with the electronic system that will be executed in a personal computer, namely the program "SISAD3D" (11) so its relation with a computer is necessary; for what initially must be counted on a computer ignited and enabled with the indicated program; Once this is done, the connection must be made by means of the indicated data cables (9) or other means of transfer and (10) for the continuous communication and reception of information between the electronic system and its physical elements for gathering information and issuing information. light.

3 - After checking the proper connection between the physical elements of the invention with the computer, the "SISAD 3D" software must be executed, which will immediately recognize the connected elements, which must be switched on for recognition; because they will be the ones who will follow the specific instructions of the program already protected as an element of intellectual property. Once this connection has been verified, the information corresponding to the object that is proposed must be established in order to obtain an image in 3 dimensions, determining the individual data of the same in the indicated software.

4 - After this the physical elements of the invention are directed towards the objective to take the corresponding measurements or images, determining by the obtained images the existing lighting conditions to determine the additions of the project of lighting patterns (4) as well as the distance corresponding between the system and its objective for an adequate measurement and application of corresponding calculations.

5 - For the development of this technology, the best qualities of two methodologies were chosen: Digital light processing for the projection of digital bands with phase shift algorithms; said algorithms are used in optical metrology due to the following advantages and characteristics:

to. Resolution point by point, that is, capture a distance for each pixei of the camera.

They are not very sensitive to the reflection of surfaces and therefore can operate in a wide range of textures and surfaces.

They are not so sensitive to environmental lighting that the phase difference is measured and not the absolute phase. 6 - Based on the above, a variety of phase shift algorithms have been developed previously, including three, four and up to five images or phases per acquisition. In order to streamline the process and reduce the possibility of movement during capture, a three-phase algorithm is selected that is faster in its acquisition. So a phase shift of 2/3 is selected which is symmetrical between phase and makes the system very resistant to non-linearity errors, this reduces the effect of the parameters of the emitters of the projector and the pickup of the sensor of the camera, intrinsically in the design.

7 - The integration of digital band projection with phase shift algorithms represents an opportunity for technological research and development and allows its optimization in cost, its improvement in the calibration processes and the tuning of the system that performs the functions mentioned with technology of more affordable level in price and availability. This technology is fulfilled in the elements of the invention in a novel and unique system of using simple physical elements but not previously generated. Its direct way of solving its objectives can generate the erroneous perception of existing elements, but the creation of novel elements such as its supports, projectors and angles; as the application of a previously existing software system generates a novelty never seen in the area, which previously depended on a multitude of elements and large periods for the emission of images.

8. The elements of the invention are constituted in several physical and electronic elements in novel presentations in a conjunction and relationship that had not been obviated by any technician or entity. Its parts are named in: Parts of the system:

• Information acquisition system (Camera) (1)

• Pattern projection system (Projector) (4)

• Support structure for the camera and projector (2) (3). The structure maintains a variable degree of inclination (2) between the camera and the projector. This angle depends directly on the distance at which the object to be scanned is located.

• Object to scan

• Software for calculation, information management and graphic user interface (11)

Process i. The Software (11) projects lighting patterns (4) on the object to be scanned. The patterns depend on the object, ambient lighting and the distance to which the lens is located. ii. The software (11) coordinates the different photographic images (1) of the object to be scanned between each of the different projected patterns (4). iii. The software (11) uses the information acquired in each photographic shot to manipulate it with the previously designed algorithms and obtain as a result a set of data that will represent the object three-dimensionally through the use of triangular stitch meshes. 9 - In the technological model, three images are used for which their intensity is defined by the following equations:

Ji (x ₅ y) = J '(x _s y) + i "(x, y) cos [<¿> (x, y) - 2π / 3], (1) J ₂ (x, y) = i '(x, y) + l "(x _f y) cos [<j> (x, y)], (2) J ₃ (x, y) = f (x, y) + f (x, y) cos [^ (x, y) + 2π / 3], (3)

These formulas denote the projection of a mono band or multiband pattern with characteristics in its sinusoidal intensity, going through the total white and black. Where:

í '(*, y)

It is the intensity averaged. f ^* ( ₅ ) It is the intensity of the modulation.

It is the phase, which is the unknown to solve by the following substitution.

<(x, y) = tan -i Λ / 3 (/ Ι - J ₃ )

(4)

2l ₂ - - h

The above formula provides a working range of + Pi to -Pi, that is, the presentation of three unique patterns with a single band, avoids the need to use phase unfolding functions.

10 - For the intensity of the texture is required.

/ f (x _s y) = / '(x ₅ y) + i "(x _s y)

(+ H + h) + y¾Ji - hf + _(2/2 - / - hf

(5) For the choice of the lighting and capture system it is taken into account that the model to be developed provides a depth vector for each of the camera's pixels, under the following important assumptions: »There is sufficient depth of gray scales in The proyector.

• The camera's sensor has enough depth to capture the gray reflected on the object.

• The object is illuminated by the projection of the band or bands.

11.- In addition, an optical defocusing of the projector's objective is proposed, this will cause optical interference to generate intermediate shades of gray, achieving a greater tonal richness than that allowed by the design of the projector itself. Once the object is focused, the program is executed which, by using the indicated algorithms and relative formulas, generates a 3-dimensional image in a period of time of a few minutes, making it possible to capture multiple angles of the object for presentation and precision. .

12.- The invention after using the indicated elements and in a much shorter time than any existing system generates a three-dimensional CAD file. (Computer Aid Design) being usable for a variety of objectives, from medical, artistic, design, industrial, educational and others. Being that its celerity and mobility arise from the novel conjunction of its elements in a result that had not previously been determined or used in a similar format, being that its own fusion of elements generates an undeniable novelty, such as its direct industrial application.