Method for determining optical parameters of a subject and computer program product for carrying out the method

Abstract

Method for determining optical parameters of a subject using a video centration system, comprising the steps: - generating image data (1) of at least partial areas of a system of the subject's head and a spectacle frame arranged thereon in the position of use; and - iteratively determining the optical parameters by evaluating (2) the generated image data; wherein the evaluation (2) of the generated image data comprises computer-aided automatic image processing (BV10-BV26) of the image data and execution of a number of a plurality of predetermined manual image selection steps (BS10-BS22) that can be determined by a user of the video centering system, where the number of iteration steps performed in the iterative determination of the optical parameters depends on the number of manual image selection steps performed by the user, and wherein the iterative determination of the optical parameters is further carried out on the basis of additional statistical data which describe a dependency between two or more of the optical parameters.

Description

[0001] The present invention relates to a method for determining optical parameters of a subject and a computer program product for carrying out the method.

[0002] To determine the position of a lens in front of the eye of a wearer or subject, several optical parameters must be determined. This is done, firstly, to obtain the information needed for grinding and fitting into the frame, and secondly, to optimize the lens itself and optimally adapt it to the subsequent wearing position or usage.

[0003] In order to fully exploit the optical advantages of individual spectacle lenses, especially individually fitted progressive lenses for a spectacle wearer, it is therefore necessary to calculate and manufacture these spectacle lenses with knowledge of the wearer's wearing position and to wear them according to the wearing position used for calculation and manufacture. The wearing position depends on a variety of individual parameters, such as the subject's pupil distance, the frame lens angle, the lens tilt, and the corneal vertex distance of the spectacle-eye system. Furthermore, it is necessary that the spectacle lenses are arranged or centered in a spectacle frame according to the individual parameters used for manufacturing, so that the spectacle lenses are actually worn according to the individual parameters in the wearing position. For this purpose, so-called centering data such asThe lens length, lens height, distance between the lenses of a pair of spectacles, the decentration of a centering point, and the centering height are required. These and other optical parameters, which can be used or are necessary, in particular, to describe the wearing position, are contained in relevant standards, such as DIN EN ISO 13666, DIN EN ISO 58208, DIN EN ISO 8624, and DIN 5340, and can be found there.

[0004] In principle, the determination of individual parameters and centering data can be done manually using a variety of measuring devices, so the respective reading is immediately known. However, each manually determined parameter requires a separate test procedure, which, in turn, is highly dependent on the person performing the test and, due to its inherent nature, can be subject to significant errors, such as parallax.

[0005] In addition, so-called video centration systems can be used to determine individual parameters and centration data. These systems determine individual or all parameters by taking an image of a person wearing glasses and possibly with the aid of other aids. Such a video centration system is disclosed, for example, in document EP 1 844 363 B1. The video centration system described therein is based on a stereo camera system and fixation using a mirror image, which enables excellent results with a single measurement.

[0006] In comparison to a 2D projection-based procedure, which requires up to three images, which may require the subject to change location (e.g. take a step to the side) and possibly also to remove the frame, a stereo camera system can determine all parameters with a single image.

[0007] The result is determined from the captured image through evaluation. The evaluation involves a sequence of manual selection steps in which predetermined features are selected within the image. The user or the video centering system can be assisted by image processing. Once all predefined selection steps have been completed, the corresponding parameters are determined and displayed.

[0008] When determining individual parameters and centration, the aim is to achieve precise and rapid measurements. Accuracy is primarily defined by the measurement method. The method used by Rodenstock, based on a stereo camera system and fixation using a mirror image, delivers excellent results with a single measurement image. Other methods suffer from inherent errors due to model assumptions or the loss of information due to 2D projection. The duration of a measurement is influenced by various factors. Firstly, methods using a frame attachment are not ideal, as they require prior preparation of the frame and the correct fit of the attachment must be additionally checked throughout the measurement. Furthermore, a distinction can be made between methods with a single image and methods with multiple images. With a stereo camera system, all parameters can be determined with a single image.2D projection-based procedures require up to three images, which may require a change of location and, in some cases, removal of the frame. When evaluating the acquired images, the quality of the supporting image processing plays a particularly important role in determining how quickly the evaluation can be performed.

[0009] The document DE 10 2008 012 268 A1 discloses a method for three-dimensional display of display image data with the steps: - three-dimensional display of display image data such that - a fixation target is displayed three-dimensionally and / or - a part of the subject’s head is illuminated and / or - information data is presented three-dimensionally, - Generating image data of at least a partial area of ​​the subject’s head, - Determining the subject's parameter data using the image data.

[0010] It is an object of the present invention to provide an improved method for determining optical parameters of a subject by means of a video centering system, which allows a faster determination of the parameters.

[0011] This object is achieved by the subject matter of the independent claims. Advantageous embodiments are the subject matter of the dependent claims.

[0012] A first independent aspect for solving the problem concerns a method for determining optical parameters of a subject by means of a video centering system, comprising the steps: - generating image data of at least partial areas of a system of the subject's head and a pair of spectacle frames or spectacles arranged thereon in the position of use; - iterative determination of the optical parameters by evaluating the generated image data, whereby the evaluation of the generated image data comprises a computer-assisted automatic image processing of the image data and an execution of a number of a plurality of predetermined manual image selection steps that can be determined by a user of the video centering system, and wherein the number of iteration steps performed during the iterative determination of the optical parameters depends on the number of manual image selection steps performed by the user.

[0013] For the purposes of the present invention, a test subject is, in particular, a spectacle wearer or a patient for whom spectacles are to be manufactured or fitted. For the purposes of the present invention, a user is understood to be a person who operates the video centering system. A user can be, for example, an optician or ophthalmologist. However, it is also possible for the test subject to operate the video centering system themselves, thus making the test subject and the user the same person.

[0014] Image data is generated, in particular, by capturing digital images, preferably using a stereo camera system. The image data or digital images are preferably generated from at least two different recording directions. The images can be captured sequentially with a single camera or simultaneously with several, in particular two, cameras located at different locations.

[0015] For the purposes of the present invention, two different recording directions mean that different image data are generated from overlapping partial regions of the head, preferably from one and the same partial region of the head, in particular that image data are generated from identical partial regions of the user's head under different perspective views. Consequently, although the same partial region of the head is imaged, the image data differs. Different recording directions can also be achieved, for example, by generating the image data from at least two image recording devices or cameras, wherein the effective optical axes of the at least two image recording devices are not parallel.

[0016] Preferably, the image data or digital images are generated using a stereoscopic image recording device. In other words, the video centering system is preferably based on stereoscopic image recording. Preferably, the image data comprise or are digital stereoscopic images. In particular, the recorded images correspond to the generated image data.

[0017] Preferably, the pupils of the subject and a spectacle frame edge or a spectacle lens edge are depicted in the generated image data, wherein in the generated image data, the pupils of the subject are bordered by the spectacle frame edge or the spectacle lens edge.

[0018] For the purposes of this description, "spectacles" refers to a pair of spectacle frames with or without lenses. Thus, spectacles within the meaning of this description do not necessarily have to have lenses, but can simply be a pair of frames. For example, to carry out the method according to the invention, the test subject can wear only a pair of spectacle frames into which lenses are to be ground to correct ametropia. Alternatively, the test subject can also wear a pair of spectacle frames with corresponding lenses.

[0019] Automatic or machine image processing of the image data comprises, in particular, known pattern recognition algorithms with which specific elements or features of an image can be recognized and / or marked using software or computer support. For example, image processing comprises algorithms with which specific shapes, points, and / or the surroundings of points can be searched for. Preferably, the computer-assisted automatic image processing comprises automatic detection of pupils or pupil centers of the subject and automatic detection of one or more frame edge points and / or lens edge points, such as an upper, lower, nasal, or temporal frame edge point and / or lens edge point, of the subject's spectacles or spectacle frame.

[0020] Preferably, the evaluation of the glasses data generates evaluation data comprising 3D data or location information in three-dimensional space of predetermined points of the system of the subject's head and the glasses arranged thereon in the wearable position. The optical parameters are determined, in particular, based on the generated evaluation data or location information.

[0021] Preferably, the evaluation data generated by evaluating the image data includes location information for at least one of the following points: - Intersection points of a horizontal plane in the subject's reference system with the rims of the lens and / or the rims of the spectacle frames, whereby the subject's horizontal plane intersects both pupils of the subject and runs parallel to a predetermined zero line of sight of the subject, - points of intersection of a vertical plane in the subject's reference system with the rims of the lens and / or the rims of the frame of the spectacles, the vertical plane of the subject being perpendicular to the horizontal plane of the subject and parallel to the subject's predetermined zero line of sight and intersecting a pupil of the user; - at least one pupil center; - Limits of at least one of the user's spectacle lenses according to a dimension in the box size; - a center point of the frame of the glasses.

[0022] For the purposes of this invention, dimensioning in box dimensions is understood to mean the measurement system as described in relevant standards, for example in DIN EN ISO 8624 and / or DIN EN ISO 13666 and / or DIN 58208 and / or DIN 5340. Furthermore, with regard to the box dimensions and other conventional terms and parameters used, reference is made to the book "The Optics of the Eye and Visual Aids" by Dr. Roland Enders, 1995, Optische Fachveröffentlichung GmbH, Heidelberg, as well as the book "Optik und Technik der Brille" by Heinz Diepes and Ralf Blendowski, 2002, Verlag Optische Fachveröffentlichungen GmbH, Heidelberg. The standards and the aforementioned book constitute an integral part of the disclosure of the present application for the definitions of terms.

[0023] The boundaries according to a box dimension include, for example, frame points for one or both eyes, which are located furthest outside or inside and / or above or below. These frame points are conventionally determined using tangents to the frame or the areas of the frame associated with the respective eyes (cf. DIN 58 208; Figure 3).

[0024] The zero gaze direction within the meaning of this invention is a gaze direction straight ahead with parallel fixation lines. In other words, it is a gaze direction defined by the position of the eye relative to the subject's head, with the eyes looking at an object that is at eye level and located at an infinitely distant point. Consequently, the zero gaze direction within the meaning of this invention is determined solely by the position of the eyes relative to the subject's head. If the subject's head is in a normal upright posture, the zero gaze direction essentially corresponds to the horizontal direction in the Earth's reference system. However, the zero gaze direction can be tilted relative to the horizontal direction in the Earth's reference system, for example if the subject tilts their head forward or to the side without further movement of the eyes.Similarly, the zero gaze direction of both eyes defines a plane that is essentially parallel to the horizontal plane in the Earth's reference frame. The plane defined by the two zero gaze directions of both eyes can also be inclined relative to the horizontal plane in the Earth's reference frame, for example, if the subject tilts their head forward or to the side.

[0025] Preferably, the subject's horizontal plane corresponds to a first plane, and the subject's vertical plane corresponds to a second plane perpendicular to the first plane. For example, the horizontal plane in the subject's reference frame can be parallel to a horizontal plane in the Earth's reference frame and only pass through the center of one pupil. This is particularly the case if the subject's two eyes are positioned at different heights (in the Earth's reference frame), for example.

[0026] Advantageously, the method according to the invention uses two-dimensional image data to determine a representation of at least a portion of the system of the subject's head and the glasses arranged thereon in the wearable position. Based on this three-dimensional representation, spatial relationships in the three-dimensional space of the evaluation data can be easily determined, and the subject's optical parameters can be determined from this.

[0027] In addition to the computer-assisted automatic image processing of the image data, the evaluation of the image data further comprises executing a number or a subset of a plurality of predefined manual image selection steps that can be determined by a user of the video centering system.

[0028] For the purposes of this invention, a predefined or predetermined image selection step is understood to mean a user interaction step in which a recorded image is displayed to the user and the user selects one or more predefined elements, such as the pupil centers of the subject or the frame rim or lens points of the glasses. For example, the user can move displayed selection crosses for this purpose, in particular using arrow keys on a keyboard and / or a computer mouse. Alternatively or additionally, the user can also select the selection elements directly by clicking on them with the computer mouse. The image displayed to the user preferably already has a preselection of the element(s) to be selected based on prior automatic image processing.The user can review this automatic preselection and edit it if necessary.

[0029] The image selection steps are predefined with regard to the elements to be selected. In particular, the image selection steps can also be predefined with regard to the order in which they are to be performed, so that the individual image selection steps can only be performed by the user in a predefined or predetermined order.

[0030] According to the invention, the user can specify the number of image selection steps to be performed. The user-determinable number x of the plurality N of predefined manual image selection steps can be an integer between zero and the total number N of predefined image selection steps, ie, 0 ≤ x ≤ N, where x and N are integers.

[0031] This means that the user can, for example, specify or decide to carry out none, some, or all of the available or predefined manual image selection steps. However, it can also be provided that the user must carry out a predetermined number of image selection steps, e.g., one or two image selection steps, and only then can decide or specify whether and when to abort the iterative determination. For example, the number x of the plurality N of predefined manual image selection steps that can be specified by the user can be an integer between one and the total number N of predefined image selection steps, e.g., 1 ≤ x ≤ N. Preferably, the number x of the plurality N of predefined manual image selection steps that can be specified by the user is an integer between two and the total number N of predefined image selection steps, e.g., 2 ≤ x ≤ N.

[0032] The optical parameters are determined iteratively by evaluating the generated image data, with the number of iteration steps depending on the number of manual image selection steps performed by the user. In other words, the optical parameters are determined step by step, i.e., the determination approximates the exact solution through repeated iteration or determination steps.

[0033] After each iteration step, the determined optical parameters can be updated. Updating can include optimizing, refining, improving, and / or replacing at least one of the optical parameters to be determined. For example, in the first iteration step, initially estimated or initially assumed values ​​of optical parameters can be updated with the aid of performed evaluation steps, i.e., with the aid of one or more automatic image processing steps and / or with the aid of one or more executed image selection steps, in particular based on the evaluation data generated by the evaluation.

[0034] In principle, it is also possible for the number of iteration or determination steps for determining the optical parameters to be just one, i.e., only a single iteration or determination step is performed in total, and thus no repeated or updated determination takes place. This is particularly the case if the user does not perform any manual image selection steps, i.e., if the number of manual image selection steps performed by the user is zero, and the optical parameters are determined solely on the basis of automatic image processing. Although in this case the optical parameters may only be determined with a relatively low degree of accuracy, the optical parameters are determined without additional manual image selections by the user, and are therefore determined very quickly.

[0035] For example, if the user performs exactly one image selection step, ie, if the number of manual image selection steps performed by the user is one, the number of iteration steps is preferably two. If the number of manual image selection steps performed by the user is two, the number of iteration steps can be one or three, depending on the embodiment. If the number of manual image selection steps performed by the user is greater than three, the number of iteration steps is preferably greater than or equal to three, and in particular greater than or equal to five.

[0036] The method according to the invention thus advantageously allows the user a high degree of flexibility with regard to accuracy and speed by specifying the number of image selection steps they perform. In particular, the method according to the invention enables faster determination of the optical parameters while taking accuracy into account. If, for example, the user attaches importance to the most accurate determination of the optical parameters, they can carry out all of the predefined image selection steps. However, if the user focuses on determining the optical parameters as quickly as possible, or if it is sufficient that only some of the optical parameters are determined with a certain degree of accuracy, the user can accelerate the process by performing no or only some of the predefined manual image selection steps.

[0037] By specifying the number of image selection steps performed, the user can advantageously influence the accuracy and speed of the method according to the invention or the determination of the optical parameters. This is because the accuracy of the method according to the invention or of the determined optical parameters depends on the number of image selection steps performed by the user. In particular, the accuracy of at least one of the optical parameters increases with an increasing number of image selection steps performed. In other words, the accuracy of the method is successively increased with an increasing number of image selection steps performed. With the method according to the invention, the user is thus able to select an optimal ratio of speed and accuracy for the respective application. This is, for example,This is advantageous when it is not necessary for an application to determine the optical parameters with the highest possible accuracy. Or when the user only wants to determine those optical parameters that can already be output with sufficient accuracy after automatic image processing and / or a few manual image selection steps.

[0038] No additional time is required to achieve the full accuracy provided by the measuring device or video centering system. The time invested in evaluation thus achieves optimal accuracy and quality of the determined optical parameters.

[0039] The method for determining optical parameters of a subject using a video centration system may in particular comprise the following steps: - generating image data of at least partial areas of a system of the subject's head and of glasses arranged thereon in the position of use; - iterative determination of the optical parameters by evaluating the generated image data, whereby the evaluation of the generated image data comprises a computer-assisted automatic image processing of the image data and an execution of a number of a plurality of predetermined manual image selection steps that can be determined by a user of the video centering system, and wherein the accuracy and / or quality of the determined optical parameters depends on the number of manual image selection steps performed by the user.

[0040] Preferably, after each image selection step carried out by the user, the optical parameters are determined again, updated, refined and / or optimized, in particular on the basis of the evaluation result available after the last image selection step carried out or the evaluation data available after the last image selection step carried out.

[0041] Preferably, the method further comprises providing the determined optical parameters. The term "providing" encompasses, for example, displaying, outputting, and / or making the determined optical parameters accessible, in particular with the aid of an interface, e.g., for consulting programs, ordering software, or storage in a database. In other words, the data can be provided in the form of a display and / or making them accessible using an interface.

[0042] In a preferred embodiment, the optical parameters determined by the method according to the invention comprise both individual parameters and centering data.

[0043] Individual parameters within the meaning of this invention are, for example: - the monocular pupillary distance (PD), i.e. the distance between the center of the frame and the center of the pupil when the eye is in primary position; - the corneal vertex distance (CVD), ie the distance between the back surface of the lens and the apex of the cornea, measured in the direction of view perpendicular to the frame plane; - the anterior tilt (VN), ie the angle in the vertical plane between the optical axis of the lens and the fixation line of the eye in primary position; - the frame lens angle (FSW), ie the angle between the frame plane and the right or left lens plane; - the individual head posture, i.e. the head tilt and head rotation.

[0044] Centering data within the meaning of this invention are, for example: - the lens length (SL), ie the distance between the vertical sides of a rectangle circumscribing the frame rim; - the lens height (SH), ie the distance between the horizontal sides of the rectangle circumscribing the frame rim; - the distance between the lenses (AzG); - the decentration of the centering point, horizontal (u), ie the horizontal distance of the centering point from the geometric center of the disc; - the decentration of the centering point, vertical (v), ie the vertical distance of the centering point from the geometric center of the disc; - Centering height or grinding height (y), ie the distance from the reference point to the lower edge of the frame in vertical direction.

[0045] In a further preferred embodiment, the number of iteration steps is greater than or equal to three if the number of manual image selection steps performed by the user is greater than three.

[0046] In a further preferred embodiment, the method further comprises providing initial or initial optical parameters, wherein the optical parameters of the test subject are determined on the basis of the provided initial optical parameters and additional evaluation data which are generated by the evaluation. The additional evaluation data preferably comprise, as already described above, 3D data or location information in three-dimensional space of predetermined points of the system of the test subject's head and the glasses arranged thereon in the position of use. The initial optical parameters which are provided before the start of the evaluation preferably comprise estimated or assumed values, in particular standard values, for at least some or all of the optical parameters to be determined. For example, the initial optical parameters orThe standard values ​​are derived from mean values ​​of previous measurements or from empirical values. Preferably, the initial optical parameters or the standard values ​​are updated, improved, or replaced by the evaluation of the method according to the invention, in particular with the aid of the evaluation data generated by the evaluation.

[0047] The default values ​​are based, for example, on the values ​​of non-individualized products or correspond to statistical averages obtained in advance. Reasonable assumptions are particularly relevant for HSA, VN, and FSW. For PD, SL, and SH, the determination of the statistical averages can consider the following criteria, for example, to achieve a better agreement with the final determined value: - the optician where the measurement takes place; - the geographical region in which the measurement takes place; - the date on which the measurement takes place; - Age, gender, name of the subject or customer for whom the measurement is being carried out; and / or - Data from previous measurements for this customer.

[0048] In addition, additional auxiliary parameters derived from source data from a previous measurement, such as the SL / SH ratio or the ratio of interpupillary distance to the insertion height, can be provided or used. Such auxiliary parameters advantageously make it possible to provide additional initial optical parameters based on existing standard values. Alternatively or additionally, these auxiliary parameters can also be used in the evaluation of the image data. For example, the auxiliary parameter or the SL / SH ratio can be used to approximate the SH if the SL has already been approximately determined.

[0049] The initial optical parameters or standard values ​​can be taken into account as follows: Due to fashion trends or fashionable ideals, certain frame shapes are popular during a certain fashion period, which may be approximately one year, for example. Thus, the mean values ​​of the AzG, SL, or SH parameters can also change after this fashion period. Since this trend is generally only geographically limited, a change in the parameters can only be observed locally (continent, country, city). An average for these parameters is therefore preferably calculated taking into account all images taken and evaluated in the local area that are no older than, for example, one year.

[0050] With regard to the pupil distance, for example, the gender, as well as the age and geographical information about the location at which the measurement or the method according to the invention, ie the determination of the optical parameters, is carried out, could be taken into account or used.

[0051] To provide the initial optical data, predetermined filters can be applied to measurements already performed, i.e., to previous measurement results. A meaningful determination and application of appropriate filters to measurements already performed is a separate task of statistical data analysis. The filters can be dynamic, i.e., requiring a recalculation for a single measurement, or they can be based on a static model. In this context, static means that a filter with the same data at different locations and times will arrive at the same result. Dynamic means that the filter takes location and / or time into account. For example, a dynamic filter, as described above, can only consider data that was created within one year retroactively from the time of measurement, while older data is ignored. In the static case, a recalculation is necessary if the data basis changes, e.g.,when new data is added. In the dynamic case, a recalculation is necessary for each measurement to account for the dynamically changing data basis.

[0052] Further previously known information, such as the exact name of the spectacle frame selected or worn by the test subject in conjunction with a frame catalog, ie a digitally available description of the frame shape, can also be used to provide the initial optical parameters.

[0053] In a further preferred embodiment, image data are generated by recording a first image of at least partial areas of the system of the subject's head and of glasses arranged thereon in the use position in a first recording direction and recording a second image of at least partial areas of the system in a second recording direction, wherein the first and the second recording direction differ from one another.

[0054] In a further preferred embodiment, the evaluation of the image data begins with determining the positions of the test subject's pupils in the first image. In particular, a first evaluation step can comprise determining the position of a first pupil of the test subject in the first image and determining the position of a second pupil of the test subject in the first image. Immediately thereafter, i.e. in a second evaluation step which immediately follows the first evaluation step, the position of the test subject's first pupil in the second image and the position of the test subject's second pupil in the second image can be determined. Both the first evaluation step and the second evaluation step thus each comprise two evaluation sub-steps, namely determining the position of the first pupil and determining the position of the second pupil.The determination of positions of the pupils in the first and second images can each be carried out on the basis of automatic image processing and / or at least one image selection step carried out by the user.

[0055] In this way, an optimal evaluation sequence is achieved with regard to the iterative or updated determination of the optical parameters. In particular, by initially determining the pupil positions in both recordings or images, the accuracy of the iteratively determined or provided parameters can be quickly and effectively increased, since 3D coordinates are obtained at an early stage. By determining the pupil positions in both recordings, for example, a total pupil distance can already be determined, which can then be provided in an updated form. In particular, an initial standard value for the total pupil distance can be updated or replaced. With a stereo camera system, there are no further dependencies for the total pupil distance, so that full measurement accuracy is already achieved here. In 2D projection methods, an additional head rotation to be determined could, for example,can still be considered as a correction value. An updated monopupillary distance can also be determined or provided by halving the total pupil distance. In addition, an HSA value can be updated based on the model.

[0056] In a further preferred embodiment, a first image selection step that can be carried out or is performed by the user comprises a manual selection of positions of the pupils or pupil centers of the subject in the first image. Furthermore, a second image selection step that can be carried out or is performed by the user immediately after the first image selection step comprises a manual selection of positions of the pupils or pupil centers of the subject in the second image. In particular, the first image selection step comprises a first image selection sub-step, namely a manual selection of the position of the first pupil or pupil center in the first image, and a second image selection sub-step, namely a manual selection of the position of the second pupil or pupil center in the first image.Accordingly, the second image selection step also comprises in particular a first image selection sub-step, namely a manual selection of the position of the first pupil or pupil center in the second image, and a second image selection sub-step, namely a manual selection of the position of the second pupil or pupil center in the second image.

[0057] In a further preferred embodiment, a third image selection step, which can be carried out or is carried out by the user immediately after the second image selection step, comprises a manual selection of, preferably temporal or particularly preferably nasal, frame edge points of the spectacles worn by the subject in the first image. Furthermore, a fourth image selection step, which can be carried out or is carried out by the user immediately after the third image selection step, comprises a manual selection of, preferably temporal or particularly preferably nasal, frame edge points of the spectacles worn by the subject in the second image.

[0058] In other words, after the pupils, which can be referred to as the first selection elements, preferably the temporal, or particularly preferably the nasal, frame edge points are selected as the second selection element. From this, a further improved estimate of the mono-PD can be derived and provided. Such an iterative determination can be continued accordingly for the remaining optical parameters. The optical parameters that have not yet been finally determined can be provided again in an updated form with each additional known measurement point, i.e., with each additional image selection step and / or automatic image processing step performed, or with each additional iteration step performed.

[0059] In a further preferred embodiment, one or more image selection steps that can be carried out or are carried out by the user immediately after the fourth image selection step comprise a manual selection of further, in particular temporal, nasal, lower and / or upper, frame edge points of the spectacles worn by the subject in the first and / or second image.

[0060] In a further preferred embodiment, further image selection steps that can be executed or are executed by the user in the specified order include: a manual selection of a frame horizontal of the glasses worn by the subject in the first image, manually selecting at least one nasal-lower box measurement of the glasses worn by the subject in the first image, and / or manually selecting at least one temporal-upper box measurement of the glasses worn by the subject in the first image.

[0061] Preferably, two nasal-inferior box measurements should be selected, one for the left and one for the right lens. Similarly, two temporal-superior box measurements should be selected, one for the left and one for the right lens.

[0062] In a further preferred embodiment, a corresponding automatic image processing step is performed immediately before each executable manual image selection step. In particular, automatic image processing associated with an image selection step can preselect the image elements to be selected in the respective image selection step. The user then only needs to check the automatic preselection and correct it if necessary. This thus facilitates user interaction. Preferably, all data evaluated up to that point are incorporated into the determination of the optical parameters immediately before a selection step.

[0063] According to the invention, the iterative determination of the optical parameters is further carried out on the basis of additional statistical data, in particular on the basis of the aforementioned auxiliary parameters, which describe a dependency between two or more of the optical parameters. For example, the statistical data can describe a dependency between SL and SH. This is helpful, for example, if the SL has already been largely determined after determining the temporal and nasal frame edge points, but only the original standard values ​​or mean values ​​are available for the SH. In this way, the accuracy of other optical parameters can be quickly increased without the need for an additional manual image selection step. In particular, the quality of the automatic preselection can be improved, further reducing the corrections to be made by the user.

[0064] In a further preferred embodiment, the determined optical parameters or the updated optical parameters of the subject are provided, ie output or displayed, with an indication of the expected accuracy or quality of the determined optical parameters.

[0065] This can be done in a display, for example, in the form of color coding, where red corresponds to poor accuracy or quality, yellow to medium accuracy or quality, and green to good accuracy or quality. Alternatively, the accuracy or quality of the parameters can be indicated for each specific optical parameter using contrast (e.g. white on white = poor quality, gray on white to black on white = good quality) or other quality categorizations, such as the Rodenstock categorization "Superior / Excellence / Perfection" or "Gold / Silver / Bronze". When provided in an interface to consulting programs or ordering software, an additional value for the parameter can provide information about its quality, for example a value between 0% and 100%. However, labeling can also occur without being explicitly specified, for example by being described in the manual and the user orOperator through whose reading has acquired the knowledge that an evaluation only reaches maximum accuracy after it has been fully carried out and that if the evaluation is aborted prematurely, values ​​are uncertain within certain limits.

[0066] In a further preferred embodiment, the determined optical parameters are displayed after each iteration step, in particular after each automatic image processing step and / or after each image selection step, optionally with an indication of the accuracy or quality. For example, the determined optical parameters can be displayed on a computer screen. Based on the displayed current results of the optical parameters, the user can more easily decide whether further manual image selection steps are necessary to further increase the accuracy of the parameters, or whether the accuracy is already sufficient and the determination process can therefore be aborted prematurely.

[0067] A further independent aspect for solving the problem relates to a computer program product comprising program parts which, when loaded into a computer, are designed to carry out a method according to the invention.

[0068] The above or below statements regarding the embodiments of the first aspect also apply to the above-mentioned further independent aspect and in particular to preferred embodiments thereof.

[0069] In the following, individual embodiments for achieving the object are described by way of example with reference to the figures. In some cases, the individual embodiments described have features that are not absolutely necessary to carry out the claimed subject matter, but which provide desired properties in certain applications. Thus, embodiments that do not have all the features of the embodiments described below are to be regarded as falling within the scope of the described technical teaching. Furthermore, to avoid unnecessary repetition, certain features are only mentioned in relation to individual embodiments described below. It is pointed out that the individual embodiments should therefore not only be considered in isolation but also in conjunction with one another.Based on this overview, those skilled in the art will recognize that individual embodiments may also be modified by incorporating one or more features of other embodiments. It is noted that a systematic combination of the individual embodiments with one or more features described with reference to other embodiments may be desirable and useful, and should therefore be considered and considered to be encompassed by the description. Short description of the drawings Fig. 1 shows a schematic flow diagram for determining optical parameters according to a conventional procedure; Fig. 2 shows a schematic flow diagram for determining optical parameters according to a preferred embodiment of the present invention; Fig.3 shows a schematic diagram of the evaluation sequence in the determination of optical parameters according to a preferred embodiment of the present invention; Fig. 4 shows exemplary values ​​of optical parameters which were determined after different evaluation steps of the method according to the invention. Detailed description of the drawings

[0070] The position information chosen in this description, such as top, bottom, side, etc., refers to the figure directly described and shown and, if the position changes, must be transferred accordingly to the new position.

[0071] The following description of the method according to the invention refers, by way of example, to a video centering system suitable for recording stereoscopic images using a first camera and a second camera, ie, to a video centering system with a stereo camera system. It is understood, however, that the method according to the invention can also be applied to other video centering systems, e.g., systems with only one camera, with which all optical parameters can be determined.

[0072] Where this description refers to a “frame rim”, this term should be replaced by the term “lens rim” in the case of rimless frames.

[0073] In the Fig. 1 and Fig.2, “K1” means a first camera view and “K2” means a second camera view. In particular, “K1” means a first camera image or a first image taken with the first camera, and “K2” means a second camera image or a second image taken with the second camera. The upper boxes each refer to a user interaction or an image selection step and are therefore each marked with the numbered reference symbol “BS”. The abbreviation “Pupils K1” of the image selection step BS1 or BS10 means that in this step the user can select or selects the pupils of the subject shown in the first camera view K1. Accordingly, for example, the abbreviation “Frame Edge K2” of the image selection step BS4 or BS16 means that in this step the user can select or selects predetermined points on the frame edge or lens edge of the subject’s glasses shown in the second camera view K2.The middle boxes each refer to automatic image processing and are therefore marked with the numbered reference symbols "BV." The . Fig. The abbreviation "Image Processing Frame Edge ++" used in Figure 2 means that one or more predetermined points or elements of the frame or lens edge, e.g., upper, lower, nasal, or temporal frame edge points or lens edge points, or even a frame horizontal or box dimension, are automatically detected. The lower boxes refer to the specific optical parameters.

[0074] The Fig.Figure 1 shows a schematic flow diagram for determining optical parameters according to a conventional procedure. The starting point is a measurement recording 1, in which image data is generated by capturing a first image with a first camera K1 and a second image with a second camera K2. The first and second cameras are located at different locations, so that images of the subject's head are captured from different perspectives, e.g., from the front with the first camera K1 and from below with the second camera K2.

[0075] After measurement recording 1, the generated image data or the recorded images are evaluated. For this purpose, the test subject's pupils are first detected in both the first and second images by means of computer-assisted automatic image processing BV1 using corresponding image or pattern recognition algorithms. This is followed by user interaction or an image selection step BS1 to be carried out by the user, in which the user selects the test subject's pupils in the first image recorded with the first camera K1. After that, the frame rim or the lens rim of the glasses worn by the test subject is detected in both the first and second images by means of further computer-assisted automatic image processing BV2 using corresponding image or pattern recognition algorithms. This is followed by further user interaction ora further image selection step BS2 to be performed by the user, in which the user selects or chooses predefined frame or lens edge points of the glasses worn by the subject in the first image recorded with the first camera K1. Finally, the interactive image selection steps BS3 and BS4 to be performed by the user follow, which correspond to the image selection steps BS1 and BS2 with the difference that the image selection steps BS3 and BS4 are based on the second camera image K2. With the image selection step BS3, the user selects the subject's pupils in the second camera image K2, while in the subsequent image selection step BS4 the user selects predefined frame edge points or lens edge points of the glasses worn by the subject in the second camera image K2.Once the user has completed the image selection steps BS1 to BS4, the individual parameters PD, HSA, VN, FSW, head rotation and head inclination can be determined from the resulting evaluation data.

[0076] To also determine centration data, the user must perform further user interactions or image selection steps based on the first camera image K1. Specifically, the user must select the frame horizontal dimension in the first camera image K1 using image selection step BS5 and the lower nasal box dimension in the first camera image K1 using image selection step BS6 so that the centration data AzG and y can be determined. To also determine the centration data SL, SH, u, and v, the user must further perform image selection step BS7, in which they select the upper temporal box dimension in the first camera image K1.

[0077] In the Fig.In the conventional method illustrated in Figure 1, the user must therefore perform all image selection steps BS1 to BS7 to determine the optical parameters, ie, the individual parameters and the centering data. Consequently, with the conventional method, the user has no influence on the speed of the method, apart from the time required for the individual image selection steps.

[0078] The Fig. Figure 2 shows a schematic flow diagram for determining optical parameters according to a preferred embodiment of the present invention. As with the conventional method of Fig.1, the starting point of the method is a measurement recording 1, in which image data is generated by capturing a first image B1, e.g., with a first camera, and a second image B2, e.g., with a second camera. Similar to the conventional method, a number of user interaction steps or image selection steps BS10 to BS22 are also specified for determining the optical parameters.

[0079] In contrast to the conventional method, however, in the method according to the invention all the Fig.The image selection steps shown in Figure 2 are optional, meaning the user of the video centering system can decide for themselves whether and how many of the predefined, possible image selection steps to perform. In other words, they can specify the number of image selection steps performed. By adjusting the number of image selection steps performed, the user can influence, in particular, the number of iteration steps performed and / or the accuracy or quality of the determined optical parameters, and thus also the speed of parameter determination.

[0080] Unlike in the Fig. 1 are in the Fig. 2 Therefore, the individual optical parameters are indicated by numbers in square brackets. These numbers refer to the accuracy or quality of the respective optical parameters. The following means: [1] a zeroth estimation, ie a fully automated determination or the use of initial optical parameters as a basis, [2] a first estimate, [3] a second estimate, and [4] the final result.

[0081] The accuracy or quality is therefore lowest for the specific optical parameters marked with [1] and highest for the specific optical parameters marked with [4]. Furthermore, the accuracy or quality of the specific optical parameters marked with [2] is lower than the accuracy or quality of the specific optical parameters marked with [3].

[0082] For example, it is possible that the user does not perform any of the possible image selection steps. In this case, only computer-assisted automatic image processing of the generated image data or the captured images is performed. In a first image processing step BV10, the subject's pupils are automatically detected in both the first and second captured images. In a second image processing step BV12, the frame rim or specified points or elements of the frame rim of the glasses worn by the subject are detected in both the first and second captured images using appropriate image or pattern recognition algorithms.

[0083] Based on the image processing steps BV10 and BV12, all optical parameters can already be determined and output fully automatically. This determination, which is based on only one determination or iteration step, thus represents a zeroth estimate for all optical parameters and corresponds to the lowest accuracy.

[0084] The determination can be carried out in particular without a model, i.e. without any prior assumptions. However, initial optical parameters, i.e. estimated values ​​or standard values ​​for the optical parameters to be determined, are preferably provided as a starting point. For example, the following standard values ​​can be used: VN = 7°, HSA = 13 mm, FSW = 5°, PD = 64 mm. Before any user interaction takes place, these model assumptions or standard values ​​can be improved by automated image processing. For example, pupil detection can already determine a suggestion as to where the pupils are located. On this basis, the overall PD can be provided in an optimized form. This also applies to the other selection elements of the frame edge and the parameters derived from them. The initial optical parameters can therefore be adjusted or improved by automatic image processing. For example,the initial optical parameters HSA and PD are adjusted based on the detected pupils.

[0085] After the image processing step BV10, the user can perform an optional image selection step BS10 by selecting the subject's pupils in the first camera image K1. Following this user interaction, the further image processing steps BV14 regarding the pupils and BV16 regarding the frame rim can be performed, so that finally, based on the evaluation data generated thereby, all output or displayed optical parameters are updated in a second determination step or iteration step. The user can abort the determination process at this point if the accuracy of the determined optical parameters is already sufficient, or execute the next predefined or possible image selection step BS12.

[0086] If the user carries out the image selection step BS12 by selecting the subject's pupils in the second camera image K2, the image processing step BV18 ​​is then carried out with regard to the frame rim. Using the evaluation data thus generated, all of the determined optical parameters can then be updated. In addition, the total pupil distance can be output or displayed with increased accuracy, i.e., as a first estimate, while, for example, head inclination and head rotation are still based on a lower accuracy, namely the zeroth estimate. The user can abort the determination process at this point, provided the accuracy of the optical parameters determined up to that point is already sufficient, or carry out the next predetermined or possible image selection step BS14.

[0087] If the user carries out the image selection step BS14 by selecting one or more predefined frame edge points, e.g., nasal frame edge points, of the subject's glasses in the first camera image K1, a further image processing step BV20 is then carried out with regard to the frame edge. Using the evaluation data generated in this way, all of the determined optical parameters can then be updated. In addition, following the steps carried out so far, the monopupillary distance and the value for AzG, for example, can be output or displayed with increased accuracy, namely as a first estimate. The user can abort the determination process at this point, provided the accuracy of the optical parameters determined up to that point is already sufficient, or carry out the next predefined or possible image selection step BS16.

[0088] If the user executes the image selection step BS16 by selecting the frame edge point selected in the previous image selection step BS14 in the second camera image K2, a further image processing step BV22 is subsequently performed with regard to the frame edge. The user can abort the determination process at this point, provided the accuracy of the optical parameters determined up to that point is already sufficient, or execute the next predefined or possible image selection step. In particular, further image selection steps and image processing steps can be executed at this point, which proceed analogously to BS14, BV20, BS16, and BV22, but relate to further predefined frame edge points, in particular to temporal, lower, and / or upper frame edge points.Preferably, these further steps are carried out for each additional specified frame edge point alternately between camera view 1 and camera view 2.

[0089] For example, if the user has selected the nasal, upper, and lower frame edge points in the image selection steps BS14 and BS16, all specific optical parameters can now be updated using the resulting evaluation data. In particular, after the steps performed so far, the forward tilt, the HSA, the head tilt, and the head rotation can be output or displayed with increased accuracy, namely as a first estimate. However, the frame lens angle, the lens height SH, the grinding height y, and the value for v are still based on a lower accuracy, namely the zeroth estimate.

[0090] If the user carries out the further predefined image selection step BS18 by selecting the frame horizontal of the test subject's glasses in the first camera image K1, a further image processing step BV24 is then carried out with regard to the frame edge. Using the evaluation data generated in this way, all of the determined optical parameters can now be updated. In particular, after the steps carried out so far, for example, the total pupil distance can be output or displayed with even greater accuracy, namely in a second estimate, and the head inclination can be output or displayed with the highest accuracy, i.e. as the final value. The user can abort the determination process at this point, provided the accuracy of the optical parameters determined up to that point is already sufficient, or carry out the next predefined or possible image selection step BS20.

[0091] If the user carries out the further predefined image selection step BS20 by selecting the lower nasal box measurement of the test subject’s glasses in the first camera image K1, a further image processing step BV26 is then carried out with regard to the frame rim. Using the evaluation data generated in this way, all of the determined optical parameters can now be updated. In particular, after the steps carried out so far, for example, the monopupillary distance, the HSA, the forward inclination and the frame lens angle can be output or displayed with even greater accuracy, namely in a second estimate, and the grinding height y and the value for AzG can be output or displayed with the highest accuracy, i.e. as the final value. The user can abort the determination process at this point, provided the accuracy of the optical parameters determined up to that point is already sufficient, or they can select the next predefined orpossible image selection step BS22.

[0092] If the user carries out the further predefined image selection step BS22 by selecting the upper temporal box dimension of the subject's glasses in the first camera image K1, all optical parameters can consequently be output or displayed with the highest accuracy, ie as final values.

[0093] The image processing steps BV12 and BV16 and the associated determination steps or iteration steps are optional, i.e., in one possible embodiment of the method according to the invention, it can be specified that the user must perform at least the image selection steps BS10 and BS12. In this case, the determination step following the image processing step BV18 ​​is not the third, but the first determination step or iteration step of the determination method.

[0094] In order to quickly increase the accuracy of the provided parameters, it has been found within the scope of the present invention that it is advantageous to change the evaluation sequence compared to the conventional method, so that 3D data can advantageously be obtained at an early stage. In particular, the pupil positions in both images are first determined. From this, an overall PD can be determined, which can then be provided in an updated form. In a stereo camera system, no further dependencies exist, so that full measurement accuracy is already achieved here. In 2D projection methods, an additionally determined head rotation could also be taken into account, for example as a correction value. An updated mono PD can also be provided from the overall PD by halving it. In addition, an HSA value can already be updated.

[0095] The second selection element is the temporal or, preferably, the nasal frame edge points. From this, a further estimate of the mono-PD can be made and provided. This determination can be continued for the other values. The values ​​not yet finally determined can be updated with each additional known measurement point.

[0096] This updated provision can again include statistical data that describe a dependency between the parameters, for example between SL and SH, if the SL has already been largely determined after determining the temporal and nasal frame edge points, but only the original mean values ​​are available for the SH.

[0097] The provision of the specific optical parameters is preferably carried out with a label indicating the expected accuracy or quality of the information.

[0098] The Fig. Figure 3 shows a schematic diagram of the evaluation sequence in the determination of optical parameters according to a preferred embodiment of the present invention. For this purpose, a total of seven different image selection steps A to G are outlined by way of example, with the points or elements to be selected by the user, which can be carried out by the user after an initial machine image preprocessing. Furthermore, the third column indicates in which camera view or images the respective image selection steps are carried out. In the example shown here, the image selection steps A to D are carried out alternately in the first camera image and the second camera image. The image selection steps E to G, on the other hand, are only carried out in the first camera image. Furthermore, the right-hand column shows the Fig.3 shows the accuracy with which some of the optical parameters can be determined after the respective image selection steps. Similar to the Fig. 2, the accuracy of the optical parameters is also indicated here by a number from 1 to 4 after each optical parameter, where 1 represents the lowest accuracy and 4 the highest. After machine image processing, all optical parameters can be determined or provided with the lowest accuracy, i.e., with a zero-degree estimate. In subsequent steps, the accuracy of at least some of the optical parameters can be successively increased until, at the end, i.e., after the image selection step G has been executed, all parameters are determined with the highest accuracy.

[0099] In image selection step A, the subject's right pupil 11 and left pupil 12 are selected in both camera images. In image selection step B, the right nasal frame edge point 13 and the left nasal frame edge point 14 of the subject's glasses are selected in both camera images. In image selection step C, the right upper frame edge point 15, the left upper frame edge point 16, the left lower frame edge point 17, and the right lower frame edge point 18 of the subject's glasses are selected in both camera images. In image selection step D, the right temporal frame edge point 19 and the left temporal frame edge point 20 of the subject's glasses are selected in both camera images. In image selection step E, the frame horizontal line 21 is selected in the first camera image.In image selection step F, the nasal lower box dimension 22 of the right lens and the nasal lower box dimension 23 of the left lens are selected in the first camera image. In image selection step G, the temporal upper box dimension 24 of the right lens and the temporal upper box dimension 25 of the left lens are selected in the first camera image.

[0100] In principle, after each image selection step, all optical parameters not yet finally determined can be re-determined or updated using the additional information obtained. It is also possible that the image selection steps B, C, and D can be performed in a different order than those specified in the Fig. 3 shown sequence.

[0101] Table 1 below shows another example sequence of image selection steps. The first column lists the number of the step, the second column the selection element to be selected, the third column the dependencies on already selected elements, and the fourth column the corresponding 3D point to be calculated. The numbers 1 and 2 refer to the camera view, i.e., whether the selection step is performed in the first or second image. The designations "left" and "right" refer to the left and right pupils, or to the left and right spectacle lenses, respectively. Table 1: Step Selection element Dependencies Associated 3D point 1 Pupil left 1 - Pupil left 2 Pupil left 2 - Pupil left 3 Pupil right 1 - Pupil right 4 Pupil right 2 - Pupil right 5 nasal left socket 1 Pupil left 1 nasal left socket 6 nasal left socket 2 Left pupil 2, nasal left version 1 nasal left socket 7 Left temporal version 1 Pupil left 1 Temporal left frame 8 Temporal left version 2 Pupil left 2 frametemporal left 1 Temporal left frame 9 Version top left 1 Pupil left 1 Top left version 10 Top left version 2 Pupil left 2Frame top left 1 Top left version 11 Frame bottom left 1 Pupil left 1 Frame bottom left 12 Frame bottom left 2 Pupil left 2Frame bottom left 1 Frame bottom left 13 Nasal right socket 1 Pupil right 1 nasal right socket 14 Nasal right socket 2 Pupil right 2Nasal right frame 1 nasal right socket 15 Temporal right version 1 Pupil right 1 Version temp. right 16 Temporal right version 2 Pupil right 2Frame temporal right 1 Version temp. right 17 Version top right 1 Pupil right 1 Version top right 18 Version top right 2 Pupil right 2Frame top right 1 Version top right 19 Frame bottom right 1 Pupil right 1 Frame bottom right 20 Version bottom right 2 Pupil right 2Frame bottom right 1 Frame bottom right 21 Frame horizontal 1 22 Box temporal / bottom left 1 Version all 23 Box nasal / top left 1 Version all 24 Frame shape left 1 Version all 25 Frame shape right 1 Version all

[0102] As shown in Table 1, the pupils are first selected and evaluated. After step 4, the total pupillary distance can thus already be determined. Next, the nasal frame edge points are selected and evaluated. This advantageously enables a rapid, approximate determination of the monocular pupillary distance. After the eighth step, the frame disc angle to the PD plane can be approximately determined. After the twelfth step, the left forward tilt can be determined, while the left disc length, the left disc height, and the monocular pupillary distance can be estimated with increased accuracy. After the twentieth step, the right forward tilt, the frame disc angle, and the monocular pupillary distance can be approximately determined. After step 23, the right disc length and the left disc height can be determined.

[0103] Table 2 below shows an alternative example sequence of image selection steps. The representation and labels correspond to those in Table 1. Table 2: Step Selection element Dependencies Associated 3D point 1 Pupil left 1 - Pupil left 2 Pupil left 2 - Pupil left 3 Pupil right 1 - Pupil right 4 Pupil right 2 - Pupil right 5 nasal left socket 1 Pupil left 1 nasal left socket 6 nasal left socket 2 Left pupil 2, nasal left version 1 nasal left socket 7 Nasal right socket 1 Pupil right 1 nasal right socket 8 Nasal right socket 2 Pupil right 2Nasal right frame 1 nasal right socket 9 Left temporal version 1 Pupil left 1 Temporal left frame 10 Temporal left version 2 Left pupil 2, temporal left version 1 Temporal left frame 11 Temporal right version 1 Pupil right 1 Version temp. right 12 Temporal right version 2 Pupil right 2Frame temporal right 1 Version temp. right 13 Version top left 1 Pupil left 1 Top left version 14 Top left version 2 Pupil left 2Frame top left 1 Top left version 15 Version top right 1 Pupil right 1 Version top right 16 Version top right 2 Pupil right 2 Version top right Version top right 1 17 Frame bottom left 1 Pupil left 1 Frame bottom left 18 Frame bottom left 2 Pupil left 2Frame bottom left 1 Frame bottom left 19 Frame bottom right 1 Pupil right 1 Frame bottom right 20 Version bottom right 2 Pupil right 2Frame bottom right 1 Frame bottom right 21 Frame horizontal 1 22 Box temporal / bottom left 1 Version all 23 Box nasal / top left 1 Version all 24 Frame shape left 1 Version all 25 Frame shape right 1 Version all

[0104] As shown in Table 2, the pupils are selected and evaluated first. After step 4, the total pupillary distance can thus already be determined. Next, as in Table 1, nasal frame edge points are selected and evaluated. This advantageously allows for a rapid, approximate determination of the monocular pupillary distance. The eighth step evaluates the temporal frame edge points in order to use an approximately determined FSW to further estimate the monocular pupillary distance. After the eighteenth step, the forward tilt to the left can be determined.

[0105] Two advantages of the sequence according to Table 1 compared to the sequence according to Table 2 are, for example, transferable estimates on the right side and a more varied evaluation with a recognizable intermediate status when the left or right side has been completely selected.

[0106] According to a further preferred example, the user selection can proceed as shown in the following Table 3. The names of the selection elements in Table 3 correspond to those in Tables 1 and 2. As shown in Table 3, in at least one of several presentation or display steps, a computer-based suggestion of one or more selection elements is presented or displayed simultaneously on a screen. In other words, the simultaneous presentation of certain selection elements on the screen takes place in a respective associated presentation step. Preferably, in a first presentation step, a computer-based suggestion for the left and right pupils is presented in the first camera view. Subsequently, in a second presentation step, a computer-based suggestion for the left and right pupils is presented in the second camera view.In a subsequent third display step, a computer-based suggestion of the selection elements of the spectacle frame specified in Table 3 is displayed in the first camera view. In a fourth display step, a computer-based suggestion of the selection elements of the spectacle frame specified in Table 3 is displayed in the second camera view. In a fifth display step, a computer-based suggestion of the upper frame horizontal is displayed in the first camera view. In a sixth display step, a computer-based suggestion of the box dimensions specified in Table 3 is displayed in the first camera view. In a seventh display step, a computer-based suggestion of the left and right frame shapes is displayed in the first camera view.At each display step, the user can manually select the respective selection elements, preferably in any order or alternatively in a predefined order. The suggested selection elements can serve as a guide. Once all selection elements of a display step have been selected by the user, the display proceeds to the next display step. Table 3: Display step Selection element 1 Pupil left 1 Pupil right 1 2 Pupil left 2 Pupil right 2 3 Version top left 1 Frame bottom left 1 Left temporal version 1 nasal left socket 1 Version top right 1 Frame bottom right 1 Temporal right version 1 Nasal right socket 1 4 Top left version 2 Frame bottom left 2 Temporal left version 2 nasal left socket 2 Version top right 2 Version bottom right 2 Temporal right version 2 Nasal right socket 2 5 Frame horizontal 1 6 Box temporal / bottom left 1 Box nasal / top left 1 Box temporal / bottom right 1 Box nasal / top right 1 7 Frame shape left 1 Frame shape right 1

[0107] The Fig.4 shows exemplary values ​​of optical parameters that were determined after different evaluation steps of the method according to the invention. The first column shows initial optical parameters as a starting point without evaluation. Since these are only estimated values, these values ​​can be shown, for example, on a display for the user in red. After determining the total pupil distance, the values ​​for PD, SL, SH and AzG can be updated or their accuracy can be improved. The updated values ​​can therefore be shown, for example, in orange. After additionally determining the nasal frame edge points at pupil level, the values ​​for PD, HSA and AzG can be updated or improved. The values ​​for HSA can therefore be shown, for example, in orange. Since the highest accuracy has already been achieved for the parameters PD and AzG, the corresponding values ​​can, for example,displayed in "green". After additional determination of the temporal frame edge points at pupil level, the values ​​for HSA, FSW, SL, SH, u and v can be updated or improved. Since the highest accuracy for the parameters PD, FSW, SL and AzG has already been achieved at this point, the corresponding values ​​can be displayed in "green", for example. The determination of the optical parameters can be continued in this way until finally all parameters have been determined with the highest accuracy and are thus displayed in "green". List of reference symbols 1 measurement recording 11 right pupil 12 left pupil 13 nasal frame edge point of the right lens 14 nasal frame edge point of the left lens 15 upper frame edge point of the right lens 16 upper frame edge point of the left lens 17 lower frame edge point of the right lens 18 lower frame edge point of the left lens 19 temporal frame edge point of the right lens 20 temporal frame edge point of the left lens 21 frame horizontal 22 nasal lower box measurement of the right lens 23 nasal lower box measurement of the left lens 24 temporal upper box measurement of the right lens 25 temporal upper box measurement of the left lens BV1 image processing pupil detection BV2 image processing frame edge detection BV10 image processing pupils BV12 image processing frame edge++ BV14 Image processing pupils BV16 image processing frame edge++ BV18 image processing frame edge++ BV20 image processing frame edge++ BV22 image processing frame edge++ BV24 image processing frame edge++ BV26 image processing frame edge++ BS1 Image selection of the pupils in camera image 1 BS2 Image selection frame edge in camera image 1 BS3 Image selection of the pupils in camera image 2 BS4 Image selection frame edge in camera image 2 BS5 Image selection frame horizontal in camera image 1 BS6 Image selection of the nasal lower box dimension in camera image 1 BS7 Image selection of the temporal upper box dimension in camera image 1 BS10 Image selection of the pupils in camera image 1 BS12 Image selection of the pupils in camera image 2 BS14 Image selection frame edge in camera image 1 BS16 Image selection frame edge in camera image 2 BS18 Image selection frame horizontal in camera image 1 BS20 Image selection of the nasal lower box dimension in camera image 1 BS22 Image selection of the temporal upper box dimension in camera image 1

Claims

[1] Method for determining optical parameters of a subject by means of a video centration system, comprising the steps: - generating image data (1) of at least partial areas of a system of the subject's head and a spectacle frame arranged thereon in the position of use; and - iteratively determining the optical parameters by evaluating (2) the generated image data; wherein the evaluation (2) of the generated image data comprises computer-aided automatic image processing (BV10-BV26) of the image data and execution of a number of a plurality of predetermined manual image selection steps (BS10-BS22) that can be determined by a user of the video centering system, where the number of iteration steps performed in the iterative determination of the optical parameters depends on the number of manual image selection steps performed by the user, and wherein the iterative determination of the optical parameters is further carried out on the basis of additional statistical data which describe a dependency between two or more of the optical parameters. [2] The method of claim 1, wherein the determined optical parameters comprise both individual parameters and centering data. [3] The method of claim 1 or 2, wherein the number of iteration steps is greater than or equal to three if the number of manual image selection steps performed by the user is greater than three. [4] Method according to one of the preceding claims, wherein the method further comprises providing initial optical parameters and wherein the determination of the optical parameters of the subject is carried out on the basis of the provided initial optical parameters and additional evaluation data which are generated by the evaluation (2). [5] Method according to one of the preceding claims, wherein the generation of image data (1) is carried out by recording a first image of at least partial areas of the system under a first recording direction and recording a second image of at least partial areas of the system under a second recording direction, wherein the first and the second recording direction differ from one another. [6] Method according to claim 5, wherein the evaluation (2) of the image data begins with a determination of positions of the pupils (11, 12) of the subject in the first image and is immediately followed by a determination of positions of the pupils of the subject in the second image. [7] Method according to claim 5 or 6, wherein a first image selection step (BS10) executable by the user comprises a manual selection of positions of the pupils (11, 12) of the subject in the first image, and wherein a second image selection step (BS12) executable by the user immediately after the first image selection step (BS10) comprises a manual selection of positions of the pupils (11, 12) of the subject in the second image. [8] Method according to claim 7, wherein a third image selection step (BS14) which can be carried out by the user immediately after the second image selection step (BS12) comprises a manual selection of frame edge points of the spectacle frame worn by the subject in the first image, and wherein a fourth image selection step (BS16) which can be carried out by the user immediately after the third image selection step (BS14) comprises a manual selection of frame edge points of the spectacle frame worn by the subject in the second image. [9] Method according to claim 8, wherein one or more image selection steps executable by the user immediately after the fourth image selection step (BS16) comprise a manual selection of further frame edge points of the spectacle frame worn by the subject in the first and / or second image. [10] Method according to claim 9, wherein further image selection steps (BS18-BS22) executable by the user in the specified order comprise: manually selecting a frame horizontal (21) of the spectacle frame worn by the subject in the first image, manually selecting at least one nasal-lower box measurement (22, 23) of the spectacle frame worn by the subject in the first image, and manually selecting at least one temporal-upper box measurement (24, 25) of the spectacle frame worn by the subject in the first image. [11] Method according to one of the preceding claims, wherein immediately before each executable manual image selection step, an associated automatic image processing is carried out. [12] Method according to one of the preceding claims, wherein the determined optical parameters of the subject are provided with an indication of the expected accuracy of the determined optical parameters. [13] Method according to one of the preceding claims, wherein the determined optical parameters are displayed after each performed iteration step. [14] Computer program product comprising program parts which, when loaded into a computer, are designed to carry out a method according to one of the preceding claims.

Images