Patent Description:
In a standard portable spectrophotometer, the incident light is generally, but not always, set at an angle of forty-five (<NUM>) degrees from normal. The resulting spectral reflectances that can be gathered are generally in the same plane as the incident light and are on either side of the specular angle (the equal and opposite angle to the incident light) as well as nearer to the incident light source itself.

New portable spectrophotometric devices offer a vast multitude of angular color response (spectral reflectance) data. Besides the addition of several new angles, including azimuthal, or out-of-plane angles, many instruments also offer additional light sources with different geometries. By way of example, the incident light source of a second illuminator may be located at fifteen (<NUM>) degrees from normal. The plurality of combinations of incident light and angular response can provide both too little information and too much information regarding the target coating,.

Thus, there is a need for systems and methods that can be used to evaluate all of the data, including specific combinations of data, obtained from a spectrophotometer by using multi-dimensional geometrical evaluation and calculations. <CIT> discloses a system for displaying one or more images to select one or more matching formulas to match color and appearance of an article, said system comprising:.

<CIT> discloses methods and device for measuring an appearance property of a surface using a spatially under-sampled bidirectional reflectance distribution function.

In a first aspect, embodiments of the invention provide a computer implemented method. The method includes generating, using a processor, a multi-dimensional geometric object from a plurality of data obtained from a spectrophotometric measurement of a target coating, wherein generating a multi-dimensional geometric object includes generating the object based on at least one of a point of measurement on the target coating, an incident light angle, a reflected light angle, and a spectral reflectance value or assigned value for a light source at a particular wavelength; calculating, using the processor, at least one value of a geometric property of the multi-dimensional geometric object, wherein perimeter, area of a face/plane, total surface area or volume of the multi-dimensional geometric object is calculated; correlating, using the processor, the at least one calculated value with a plurality of known values corresponding to multi-dimensional geometric objects calculated for an empirical dataset to identify at least one pigment effect in the target coating; and outputting, using the processor, the at least one pigment effect.

In another aspect, embodiments of the invention are directed to a system. The system includes a database, and a processor in communication with the database. The processor is programmed to generate a multi-dimensional geometric object from a plurality of data obtained from a spectrophotometric measurement of a target coating, wherein generating a multi-dimensional geometric object includes generating the object based on at least one of a point of measurement on the target coating, an incident light angle, a reflected light angle, and a spectral reflectance value or assigned value for a light source at a particular wavelength; calculate at least one value of a geometric property of the multi-dimensional geometric object, wherein a perimeter, area of a face/plane, total surface area or volume of the multi-dimensional geometric object is calculated; correlate the at least one calculated value with a plurality of known values corresponding to multi-dimensional geometric objects calculated for an empirical dataset to identify at least one pigment effect in the target coating; and output the at least one pigment effect.

Embodiments of the invention provide an apparatus. The apparatus includes means for generating a multi-dimensional object from a plurality of data obtained from a spectrophotometric measurement of a target coating, and means for calculating at least one geometric property of the multi-dimensional object. The apparatus also includes means for correlating the at least one value with a plurality of known values to identify at least one pigment effect in the target coating, and means for outputting the at least one pigment effect.

In a further aspect, embodiments of the invention provide a non-transitory computer readable medium including software for causing a processor to:
generate a multi-dimensional geometric object from a plurality of data obtained from a spectrophotometric measurement of a target coating, wherein generating a multi-dimensional geometric object includes generating the object based on at least one of a point of measurement on the target coating, an incident light angle, a reflected light angle, and a spectral reflectance value or assigned value for a light source at a particular wavelength; calculate at least one value of a geometric property of the multi- dimensional geometric object, wherein a perimeter, area of a face/plane, total surface area or volume of the multi-dimensional geometric object is calculated; correlate the at least one calculated value with a plurality of known values corresponding to multi-dimensional geometric objects calculated for an empirical dataset to identify at least one pigment effect in the target coating; and output the at least one pigment effect.

In various embodiments, the present invention generally relates to systems and methods for identifying physical property attributes of cured complex coating (e.g., paint) mixtures using multi-dimensional geometrical data that is calculated based on the spectral reflectance and colorimetric response from a spectrophotometer. Although the description herein is directed to two- and three-dimensional objects, it can be understood that objects of any dimension (e.g., four-dimensional) are contemplated by embodiments of the present invention.

While the description herein generally refers to paint, it should be understood that the devices, systems and methods apply to other types of coatings, including stain and industrial coatings. The described embodiments of the invention should not be considered as limiting. A method consistent with the present invention may be practiced in a variety of fields such as the matching and/or coordination of apparel and fashion products.

Embodiments of the invention may be used with or incorporated in a computer system that may be a standalone unit or include one or more remote terminals or devices in communication with a central computer via a network such as, for example, the Internet or an intranet. As such, the computer or "processor" and related components described herein may be a portion of a local computer system or a remote computer or an on-line system or combinations thereof. The database and software described herein may be stored in computer internal memory or in a non-transitory computer readable medium.

In various embodiments, multi-dimensional geometric methodology has various purposes. In order to use all available angles within a given system, multi-dimensional geometries may be used to create an alternate bi-directional reflectance distribution function ("BRDF")-type analysis. This type of analysis does not exclude any angles, but instead uses all angles to create a hemispherical "map" or "fingerprint" of a particular texture or pigment type, whether gonioapparent or not. The appropriate "map" shape and features, such as side length, internal angles, etc., may be used as a comparison tool to identify, thus fingerprint, specific pigments or generic pigment types. Also, multi-dimensional geometries may be used to evaluate only specific combinations of angles in order to achieve purposeful manipulations. In various embodiments, this includes the specific exclusion of specific singular angles or combinations of angles. Such a methodology may be used when a particular texture or effect is being sought after as being included or not included in a target coating. Also, multi-dimensional geometries may be used to accommodate and correct the potential assumption that received spectral reflectance values are incorrect in some way. Exemplary reasons for irregularity or abnormality of spectral reflectance data, even if minor in nature, include incident light angle location, incident light fluctuation, aperture size, target coating surface non-uniformity, etc..

<FIG> illustrates a process for analyzing a target surface coated with a target coating according to various embodiments of the invention. At step <NUM>, data relating to readings of the target surface are obtained from a spectrophotometer. At step <NUM>, the manner in which the angles and light sources converge to create multi-dimensional objects is determined. The objects may be created using the physical angular layout of the spectrophotometer. By way of example, for a two-dimensional object two angular reflectances may be joined with a straight line on top with both reflectances converging on the point of measurement to create a triangle. Also, by way of example, for a three-dimensional object a tetrahedron may be constructed by considering the point of measurement on the target coating to be the apex of an inverted tetrahedron, where the apex lies with the coordinates (<NUM>, <NUM>, <NUM>). In both the two- and three-dimensional examples, the location of the other vertices of the object become coordinates that are functions of: (<NUM>) a version of the angle reflected light, which may be dependent upon the incident light angle; (<NUM>) an indication of in-plane or out-of-plane and the location within that plane to indicate the flare or tilt of the multi-dimensional shape; and (<NUM>) the spectral reflectance value or assigned value for the light source at a particular wavelength. While triangular and tetrahedral examples are given herein, it can be understood that any multi-dimensional object may be created because the values of the vertices and/or sides, whether straight or arced, can be mathematically calculated. When using spectral reflectance data, in various embodiments all wavelengths may be considered individually for initial analysis, and then integrated together either in part or as a whole. In various embodiments, multi-dimensional vertices or sides may be created using a variety of colorimetric information, rather than spectral reflectance data, thus eliminating the need to complete the analysis for multiple wavelengths.

<FIG> and <FIG> illustrate examples of multi-dimensional objects that may be created using the physical layout of a spectrophotometer.

In various embodiments one of the sides of the multi-dimensional shape may be inclusive of the incident light itself. In the case where the incident light is used as one side of the multi-dimensional shape, the coordinates may be determined as explained herein, with the exception of the spectral reflectance or colorimetric data. Because the illuminator is assumed to be calibrated properly, the correct assumption in place of spectral reflectance is <NUM>, or <NUM>%, as the input incident light. In the case where the incident light is not used as one side of the multi-dimensional shape, the incident light angle, either from normal or from parallel, may be used within the coordinate definitions of other angular data. This may be useful when working with data from multiple incident light angles or when including a comparison of the data received from the same physical receptor on the instrument, however the incident light came from multiple angles.

Once the multi-dimensional object has been determined, it can be used to calculate values for the newly created multi-dimensional object at step <NUM>. By way of example, in various embodiments perimeter, area of a face/plane, total surface area, or volume may be calculated, among other geometric properties. All calculations may take the standard form used in multi-dimensional geometric calculus, substituting in the various values determined for the vertices and sides, as discussed hereinabove, and iterating for multiple wavelengths as desired. In various embodiments, the calculations may be completed for some or all combinations and permutations of incident light angle data and/or two or more pieces of spectral reflectance data/colorimetric data. This allows for the comparison of individual angular data pieces as pairs, triples, quadruples, etc., as well as comparisons and specific combination comparisons.

When using spectral reflectance data, the calculation occurs individually for each wavelength. In various embodiments, statistics, such as mean, median, and sum may be used to create a singular value out of multiple wavelength calculated multi-dimensional geometric values. In various embodiments, individual wavelengths may be compared between multi-dimensional geometric analyses. In such a situation the focus may be on the wavelength or wavelengths of maximum reflectance, and possibly secondary maximum reflectance, where a majority of color and/or texture would be visibly perceived within the visible spectrum. An analysis of shifting maximum reflectances by wavelength may also be completed using multi-dimensional geometric analysis.

In the case of a desire to use a data point that is not physically available to be measured, simple geometric laws may be invoked to interpolate the proper values as a new vertex or side. For example, the Law of Cosines may be employed for a triangular two-dimensional plane. The calculated values, vertices, and side lengths yield data with which to create the foundation of the texture analysis, though at the risk that may be created by any form of interpolation (or extrapolation).

The calculated multi-dimensional values from the colorimetric or spectral reflectance data may be correlated, for example empirically, to known characteristics at step <NUM> to identify textures, primary flake types, or other appearance information in the target coating mixture. In various embodiments, to employ an empirical method the multi-dimensional geometric data points (perimeter, area, etc.) are calculated for an empirical dataset and all desired combinations of angles that are representative of the expected mixtures and colors that will need to be handled in typical situations. The empirical data set may be used at step <NUM> to create a predictive correlation: y = f(x), where y represents the desired characteristic for identification or a qualitative question regarding the target coating, and f(x) is some function of x's, where x is one or more variables using the multi-dimensional geometric calculated values from a specific set or multiple sets of angular considerations. In various embodiments, it may be desirable to limit the angular comparison sets to those that are most feature-defining for the particular characteristic of the target coating that is being identified. The resulting function may be linear or non-linear as defined by the empirical data set.

<FIG> is an example of the use of a three-dimensional volume calculation in a specific combination of angles to predict whether a target coating will contain a gonioapparent effect that is in question. In this case, a volume calculation with a value higher than approximately <NUM> may indicate the high likelihood of containing a gonioapparent effect pigment. <FIG> illustrate examples of the use of two-dimensional internal polygonal angle calculations at two different physical angular locations (x and y). <FIG> illustrates examples within the empirical set that are gonioapparent but do not contain any aluminum pigments and <FIG> illustrates examples within the empirical set that are gonioapparent and contain aluminum pigments. Though both correlations are linear, the difference in y-intercept values between the two correlations illuminates the usage, or lack thereof, of an aluminum pigment.

Once an empirical correlation has been determined, it can be used to derive the predicted value, and thus composition, of the target coating. This may be achieved by using the target coating's values for the x's (multi-dimensional perimeter, area, etc.) and calculating the answer for y (the texture effect). The features of the target coating are output at step <NUM>. While examples have been given herein for the content of a gonioapparent pigment and/or aluminum pigment, embodiments of the systems and methods may be as specific as which gonioapparent pigment at which size flake of that pigment by iteratively choosing the most important combinations of angles for the multi-dimensional geometric calculations. In various embodiments, the empirical correlations may be improved by including other non-multi-dimensional information, such as for example singular angle colorimetric data.

The quality of the overall "map" or "fingerprint" and the quality of the empirical correlation may be dependent upon the quality of the input data. The quality of the input data may be dependent upon the quality of the instrumentation and the quality of the data set used to create a set of knowns for the overall map or the empirical correlation. While any quality of data from an instrument or empirical data set will result in an answer, the result may be improved with the use of a high quality instrument and a widely varied, high quality empirical data set.

The entire set of calculations described herein may be used to facilitate the choice of specific angle combinations and to accommodate the volume of calculations required to derive and then use an empirical correlation using multi-dimensional data.

<FIG> illustrates an embodiment of a system <NUM> which may be used to identify physical property attributes of a coating mixture of a target sample. A user <NUM> may utilize a user interface <NUM>, such as a graphical user interface, to operate a spectrophotometer <NUM> to measure the properties of a target sample <NUM>. The data from the spectrophotometer <NUM> may be transferred to a computer <NUM>, such as a personal computer, a mobile device, or any type of processor. The computer <NUM> may be in communication, via a network <NUM>, with a server <NUM>. The network <NUM> may be any type of network, such as the Internet, a local area network, an intranet, or a wireless network. The server <NUM> is in communication with a database <NUM> that may store the data and information that is used and generated by the methods of embodiments of the present invention. Various steps of the methods of embodiments of the present invention may be performed by the computer <NUM> and/or the server <NUM>.

In another aspect, the invention may be implemented as a non-transitory computer readable medium containing software for causing a computer or computer system to perform the method described above. The software can include various modules that are used to enable a processor and a user interface to perform the methods described herein.

Claim 1:
A computer implemented method, comprising:
generating, using a processor (<NUM>), a multi-dimensional geometric object from a plurality of data obtained from a spectrophotometric measurement of a target coating (<NUM>), wherein generating a multi-dimensional geometric object includes generating the object based on at least one of a point of measurement on the target coating (<NUM>), an incident light angle, a reflected light angle, and a spectral reflectance value or assigned value for a light source at a particular wavelength;
calculating, using the processor (<NUM>), at least one value of a geometric property of the multi-dimensional geometric object, wherein perimeter, area of a face/plane, total surface area or volume of the multi-dimensional geometric object is calculated;
correlating, using the processor (<NUM>), the at least one calculated value with a plurality of known values corresponding to multi-dimensional geometric objects calculated for an empirical dataset to identify at least one pigment effect in the target coating (<NUM>); and
outputting, using the processor (<NUM>), the at least one pigment effect.