CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 62/421,497, filed on November 14, 2016, and U.S. Provisional Patent Application Serial No. 62/514,285, filed on June 2, 2017, and further relates to U.S. Utility

Application Serial No.: 14/939,535, filed on November 12, 2015; U.S. Utility Application Serial No. 14/863,520, filed on September 24, 2015; and U.S. Provisional Application Serial No. 62/054,479, filed on September 24, 2014, all of the foregoing applications hereby being incorporated by reference herein in their entireties.

FIELD OF THE INVENTION

[0002] The present invention relates generally to imaging devices and, more

particularly, to a surface property capture and measurement device for distinguishing specular highlights from other reflections and for gathering, storing and comparing the dimensional, topographical and tonal (hue, saturation and brightness) properties and characteristics of any surface being captured by the device.

BACKGROUND OF THE INVENTION

[0003] Cameras, specifically digital cameras, are currently the most commonly utilized image gathering devices, and can be found in many commonly owned and carried products, such as smart phones and/or tablet devices. While such cameras and other image capturing devices are generally suited for what may be regarded as ordinary performance, there is a need for a digital data gathering device, such as a digital camera to gather, that is capable of storing and comparing the dimensional, topographical and tonal (hue, saturation and brightness) properties and characteristics of any surface being imaged by the device.

[0004] In connection with the above, the measurement of samples that are not completely flat are also problematic for color measurement devices. This issue lies in how to deal with specular reflection. Specular reflection is the reflection of light that occurs at the surface of a sample, and as such, does not interact with the sample. As such, specular reflection is generally roughly the color of the incident light. It reflects from the surface as a billiard ball bounces from the bumper of a billiard table, which is to say, the angle of reflection is equal and opposite the angle of incidence.

[0005] Light which enters the sample and later exits is referred to as bulk reflection. Specular reflection views the surface at a microscopic level. A very smooth surface will tend to appear glossy, since directional light will specularly reflect in the same direction. When this happens, the human eye perceives the glossiness as a specular highlight. If the sample is a glossy magazine, many individuals will tend to orient the magazine so as to minimize the specular reflection. If the surface has a glossy surface at the microscopic level, but has texture when viewed at a larger scale, as in a blackberry or a car, the brain will discount the specular reflection when assessing the color of the object.

[0006] Conversely, a surface which is rough will tend to scatter the specularly reflected light so that the sample appears matte. An individual still viewing the specularly reflected light will no longer perceive that specularly reflected light as a specular highlight.

[0007] Numerous approaches have been taken to deal with measuring the light reflected from a sample. Some instruments have been designed to measure only the specular reflectance, while some have been designed to capture substantially all the reflected light, bulk and specular. Others instruments have been designed so as to measure predominantly the bulk reflection, while still other instruments have been designed so as to virtually eliminate specular reflection so as to measure strictly the bulk reflection.

[0008] For example, in a gloss meter, the illumination and detection angles are equal and opposite. While this arrangement will capture both specular and bulk reflection, at shallow angles, the specular reflection will predominate and these measurements may serve as a process control parameter in the assessment of gloss.

[0009] In a reflection measurement device with diffuse geometry, the sample is presented to a sample port which is a hole at one end of a sphere. The inside of the sphere is coated with a very highly reflective and matte white coating. Such a device is known as an integrating sphere. A light is trained on one portion of the inside of the sphere. The light reflects in all directions, multiple times. As a result, the sample is illuminated equally from all directions. A sensor is generally positioned opposite the sample port, offset by 8 ^° . While this may seem to be a device which only measures the light reflect at 8 ^° from azimuth, the Helmholtz reciprocity principle states that illumination and detection can be reversed without changing the results. Thus, this arrangement is equivalent to light hitting the surface at 8 ^° from azimuth and being sensed equally at all angles.

[0010] Color measurement instruments with diffuse geometry have gained acceptance in many industries, in particular for the measurement of paint. Since a substantial portion of the reflected light is measured, diffuse measurement devices are reasonably insensitive to differences in the texture of the surface to which the paint has been applied. As a result, the repeatability of the colorant formulation software is improved. [0011] As will be appreciated, however, this does not necessarily mean that the visual appearance of the final product is more tightly controlled. In particular, the diffuse measurement condition will most accurately approximate the visual appearance of a measured sample under diffuse lighting, which may or may not be appropriate for the intended conditions where the painted sample is to be viewed. In general,

measurements of a moderately glossy sample under diffuse lighting conditions will suggest a color that is less saturated and lighter than under more directed illumination.

[0012] One compromise is to blacken a portion of the inside of the integrating sphere which is at an opposite angle from the detection angle. In this way, the sample is not illuminated at an angle what would allow for measurement of glossy specular reflection. Such measurements are more closely correlated to visual appearance of moderately glossy samples.

[0013] The 45/0 geometry illuminates the sample at 45 ^° from the azimuth and detection is done at the azimuth angle. This geometry has been standardized in the print industry where samples are generally flat. It has been found that this measurement condition is a reasonable approximation to how printed material is often viewed, so it provides a measurement which correlates well with visual appearance. Note that, as stated before, a glossy catalog will generally be oriented so as to minimize the specular reflection. Matte surfaces (such as standard office paper and newsprint) show less variation in geometry, since they approximate a Lambertian distribution, hence 45/0 geometry will produce measurements that are substantially similar to other geometries, especially diffuse with specular excluded.

[0014] Further the Helmholtz reciprocity principle states that 45/0 and 0/45 geometry will produce equivalent results such that the discussion hereinafter relating to 45/0 geometry applies equally well to 0/45 geometry. [0015] While light may be coming from one direction at 45°, it has been found to be advantageous to illuminate from multiple directions, or preferably with annular illumination, where light hits the sample in a cone.

[0016] The 45/0 geometry, however, has proven to be problematic for printing presses that deliver ink that is still partially wet when delivered from the press. Such presses include cold set newspaper presses and sheet fed offset presses. If a sample is measured "hot off the press", the 45/0 reflectance will be substantially lower than after the sample has had time to dry. The reason for the change is that ink will tend to conform closer to the rough surface of the paper as it dries.

[0017] This drying process could be a matter of minutes, or in some cases several days. This is a problem where the measurements are to be used for real-time process control of the color on press. This application dictates timely measurements of the printed product, which is unfortunately the time when the color measurement is changing most rapidly.

[0018] One solution to this problem is the addition of cross polarized filters into a 45/0 geometry, in which one polarizing filter is placed between the illumination source and the sample. In this way, the sample is illuminated with polarized light. A second polarizing filter is placed between the sample and the detector. The second polarizing filter is rotated at 90° from the first so as to exclude any light which did not change polarization when reflected from the sample.

[0019] Since specular reflection does not change polarization, but bulk reflection

(generally) randomizes the polarization, this arrangement will largely eliminate all specular measurements from the measurements. As a result, measurements made with a 45/0 device with cross polarized filters of a printed sample will change little as the ink dries. [0020] As will be appreciated, the benefit of this geometry is that it makes process control much less prone to variation due to variations in sampling time. The

measurement taken directly after printing will more closely match a measurement made two days later. The disadvantage is that that the visual appearance of the printed sheet will change over time, and the measurements will not reflect this. This is one instance where the aims of process control and of meeting customer expectations can be at odds with each other.

[0021] Color measurement with a 45/0 geometry with cross polarizing filters has surprisingly been found to have one application where it is favored because it is more directly correlated with visual appearance. This is in the measurement of paintings on canvas. It has been found that standard 45/0 geometry and diffuse geometries both give measurements which are indicative of a more washed out color, which is to say, the colors are less rich because the reflectance values are higher than what a human observer perceives.

[0022] The reason for the higher reflectance is that the threads that make up the canvas are generally coated with a glossy surface. Portions of the sides of these threads will present themselves at an angle where the specular reflectance is directed to the detector. The reason for the visual appearance of a lower reflectance (that is, a richer color) is that the brain will perceive the light from the sides of the threads as specular highlights, and will discount them from the assessment of color.

[0023] The use of a digital camera as part of the sensor is well known in the art. As one example, US Patent 6,178,254 ("the '254 patent") describes a system that utilizes an imaging device as the sensor. In particular, the system of the '254 patent uses statistical analysis of images collected from the imaging device to differentiate between areas of homogenous color and areas that are presumed to be defects. Elimination of these defect areas thus provides a measurement that more accurately reflects the color of a defect-free surface.

[0024] As will be understood, the system of the '254 patent is appropriate for a process control system that is, for example, gauging the amount of a colorant, such as ink, in a manufactured product. Thus, for some applications, it may be desirable to eliminate said defects from the measurement. But in some applications, it may be preferred to include the defects in the measurement, but still exclude the specular highlights.

[0025] In still further applications, such as monitoring whether a manufactured product meets customer expectations for color appearance, it may be preferred to distinguish between anomalous regions based on both a) distinguishing between specular highlight and manufacturing defect, and b) whether the anomalous region is large enough to be perceptible.

[0026] The system of the '254 patent, however, lacks any means for distinguishing between defects and specular highlights, and also lacks a means for distinguishing between anomalous regions that are perceptible and those which are not.

[0027] US Patent 8,441,642 ("the '642 patent") describes a color measuring device which deals with specular reflections by collecting images that have been illuminated from three different directions. The images are compared to determine pixels that are "gloss or shadow image points". These pixels are "recognizable due to the fact that the three measurement values of the image point captured from different directions of

illumination (but in the same spectral range) differ significantly." These gloss or shadow points may be excluded from measurement. If the spatial resolution of the imaging device is finer than that of the human eye, points may be eliminated where the human visual system is incapable of distinguishing a specular reflection. [0028] A further flat correction step may also be applied. The aim of this flat correction is to compute a compensation for the inclination of the measurement points caused by the texture and the resultant distortion to the measurement value compared with non- inclined, plane parallel measurement points. Also compensated are the effects of interference caused by different vertical positions of the individual image pixels from the measurement plane. Thus, the approach of the '642 patent deals with specular reflection in a manner which will presumably agree with measurements taken with a measurement device with 45/0 geometry with cross polarization. Thus, similar limitations apply.

[0029] Neither the '254 nor the '642 patents recognize that need for a measurement system that selectively excludes anomalous regions from a color measurement based on a determination of whether the anomaly is perceptible.

[0030] In summary, the diffuse with specular included geometry and the 45/0 geometry with cross polarizers both deliver consistent measurements irrespective of the

smoothness of the surface, one by endeavoring to capture all of the specular reflection, and the other by endeavoring to eliminate all of the specular reflection. This

consistency, however, comes by sacrificing some of the correlation to visual appearance.

[0031] What is needed is a color measurement device which can exclude specular reflectance from a color measurement when it is perceived as being a specular highlight, and include it otherwise.

SUMMARY OF THE INVENTION

[0032] It is an object of the invention to provide a surface property capture and measurement device. [0033] It is another object of the present invention to provide a surface property capture and measurement device that enables a digital data gathering device to gather accurate and consistent dimensional, topographical and tonal properties and characteristics by precisely controlling the primary factors needed to capture consistent data.

[0034] In an embodiment, a surface measurement device is provided. The device includes multiple light sources, an imaging device, and a computer. The light sources are positioned so as to illuminate a sample from different directions. The imaging device is positioned preferably directly above and pointed toward the sample. Images are captured with the sample illuminated from different directions. Those images are analyzed in a first pass to characterize pixels as either a) having a large portion of specular reflection, b) being part of a shadow, or c) being part of the sample that is oriented perpendicular to the imaging device. As a result of said characterization, certain of the pixels are either included or excluded from a subsequent color

measurement.

[0035] In an embodiment, an apparatus for a digital data gathering device is provided. The apparatus includes a housing having a first end and a first aperture formed in said first end, and a second end and a second aperture formed in the second end, an illumination source in communication with an interior of the housing, and at least one opening in the housing permitting ingress of ambient light into the housing to illuminate the second aperture when the second end of the apparatus is placed in touching contact with a surface.

[0036] In another embodiment, a method for calibrating and evaluating light entering through a lens of a digital data gathering device is provided. The method includes the steps of attaching a shroud to the digital data gathering device, the shroud having a first end and a first aperture formed in the first end, and a second end and a second aperture formed in the second end, positioning the second end of the shroud in touching contact with a surface, thereby preventing ambient light from entering an interior of the shroud through the second aperture, aligning the second aperture with a target area of the surface under ambient light entering through an opening in the shroud, illuminating the second aperture and the target area of the surface with light from an illumination source positioned within the shroud, and performing an exposure operation of the digital data gathering device, the exposure operation causing the digital data gathering device to gather digital data pertaining to the target area of the surface.

[0037] In yet another embodiment, an apparatus for a digital data gathering device includes a shroud having a first end and a first aperture formed in the first end, and a second end opposite from the first end, the first end being configured for selective attachment to the digital data gathering device, a surface property reference disk positioned at the second end and having a second aperture in general alignment with the first aperture and the lens of the digital data gathering device, the surface property reference disk further including an array of reference indicia on an inner surface of the surface property reference disk, an illumination source in communication with an interior of the shroud and being configured to illuminate the second aperture when, at least one opening in the shroud permitting ingress of ambient light into the interior of the shroud to illuminate the second aperture when the second end of the apparatus is placed in touching contact with a surface.

BRIEF DESCRIPTION OF THE DRAWING [0038] The present invention will be better understood from reading the following description of non-limiting embodiments, with reference to the attached drawings, wherein below:

[0039] Figure 1 illustrates a simplified schematic illustration of a surface property capture and measurement device, in accordance with one embodiment of the present invention.

[0040] Figure 2 illustrates a rear view of the surface property capture and measurement device of Figure 1, in accordance with one embodiment of the present invention.

[0041] Figure 3 illustrates a computerized system for use with the surface property capture and measurement device, in accordance with one embodiment of the present invention.

[0042] Figure 4 is a perspective view of an apparatus for a digital data gathering device, according to an embodiment of the present invention.

[0043] Figure 5 is another perspective view of the apparatus of Figure 4.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0044] Referring now to Figure 1, a surface property capture and measurement device in the form of a smart phone 60 in accordance with an embodiment of the present invention is shown. The smart phone 60 may include one or more ambient light sensors 62 (best seen in Figure 2) which are operative to provide measurements of one or more properties of the ambient light in the surrounding environment, e.g., articular wavelength, intensity, and/or other properties which may affect data gathered by a camera 64 integrated into the phone 60. As used herein, the term "surrounding environment" refers to the physical environment to which the field of view 66 of the camera 64 is exposed. The one or more ambient light sensors 62 may be integrated into the phone 60. As will be appreciated, however, in embodiments, the ambient light sensors 62 may be disposed in a separate case, e.g., a cell phone protective case, that fits over the phone 60.

[0045] As will be understood, integrated software within the phone 60 may then compensate data gathered by the camera 64 based at least in part on the one or more properties of the ambient light as measured by the ambient light sensors 62. Thus, such embodiments of the present invention provide for the ability to harmonize uniform light evaluation results between a plurality of separate digital data gathering devices without the need for a light-tight environment and/or a light shroud, e.g., a cone attached to the phone 60, and/or case that surrounds the sensors 62 so as to reduce and/or completely block out ambient light from the field of view of the sensors 62.

[0046] In embodiments, the phone 60 may further include one or more light sources 67, e.g., LED flash devices, which may be utilized to flood the field of view 66 with light so as to saturate the ambient light received by the camera 64. In other words, the light source 67 may push an amount of light towards an object imaged by the camera 64 so that the pushed light reflects off the object such that the amount of reflected light, pushed from the light source 67 and received by the camera 64, allows the integrated software within the phone 60 to compensate data gathered by the camera 64 as discussed herein. In some embodiments, the light source 67 may generate a ring of reflected light from an object imaged by the camera 64. As will appreciated,

embodiments of the invention that include the light source 67 may not require the use of a light shroud to adequately compensate the data gathered by the camera 64, as discussed hereinafter. In some embodiments having the light source 67, however, a light shroud may still be required, but at a reduced size, as discussed hereinafter. [0047] Further, the integrated software within the phone 60 may employ a model that accounts for the physical properties, e.g., texture, reflection, transparency, and/or translucency, of an object 68 imaged by the camera 64. For example, the integrated software may be able to determine the physical properties of the imaged object 68 via analyzing the data gathered from the object 68 via the camera 64. Additionally, the phone 60 may provide for a command line and/or graphical user interface ("GUI") through which a user of the phone 60 may provide data concerning the physical properties of the imaged object 68 to the integrated software.

[0048] As further shown in Figures 1 and 2, the phone 60 may also include a distance sensor 70 operative to measure a distance 72 between the camera 64 and the object 68 to be imaged. The distance sensor 70 may determine/measure the distance 72 based at least in part on one of electromagnetic rays, e.g., x-rays, lasers, radar; sound waves; an autofocus feature of the camera 64; and/or by physical means, e.g., an extended probe/stick. In certain aspects of the invention, the phone 60 may generate/provide an indication to a user of the phone 60 that the camera 64 is at least one of too far from the object 68, within an acceptable range of the object 68, and/or too close to the object 68 with respect to the ability of the ambient light sensors 62 to provide data sufficient to allow the integrated software to accurately compensate data gathered by the camera 64 for the ambient light in the surrounding environment.

[0049] Further still, in embodiments, the camera 64, in conjunction with a processor of the phone 60, may be operative to detect and correct for surface glare arising from the object 68. For example, the object 68 may have specular highlights, which while not necessarily readily visible to a human eye, may be captured by the camera 64 so as to affect the camera's 64 ability to obtain accurate data regarding one or more optical properties of the object 68. Accordingly, and as will be discussed in greater detail below, a processor within the phone 60 may be operative to detect specular highlights in an image captured by the camera 64, remove data corresponding to the specular highlights from the image, and replace the removed data. In embodiments, the processor may replace the removed data with interpolated color data from the non- removed data within the same image.

[0050] With reference to Figure 3, a computerized system 100 in accordance with an embodiment of the present invention is shown. The system 100 includes one or more digital data gathering devices 102, 104, 106 in accordance with one or more of the embodiments disclosed above. Users of the digital data gathering devices 102, 104, 106 may each gather data (i.e., accurate digital data of a feature, characteristic, and/or condition) of a respective object 108, 110, 112. The data is then transmitted from the devices 102, 104, 106 over the Internet 114 via one or more connection points 116 and/or routers and received by a verification server 118, which stores the information in a corresponding database. The verification server 118 may be queried by users of the digital data gather devices 102, 104, 106 to verify the properties of the objects 108, 110, 112. As will be appreciated, the verification server 118 may be operated by a trusted consumer goods certification entity, e.g., the operator of the verification server may be a central verification and/or accreditation agency.

[0051] For example, a manufacturer of an object 108 may assert that object 108 possesses certain properties/qualities, e.g., that it has a specific true color. The manufacturer may then transmit data concerning the properties of object 108 via device 102 to the verification server 118. The verification server 118 may then pair the data received from device 102 to prerecorded values, i.e., the verification server 118 will match the data concerning object 108 to previously certified/recorded values. A consumer considering whether to purchase an object 112 from a third party vendor 120, who has asserted that the object 112 is object 108, or an exact copy of thereof, may query the verification server 118 by transmitting data concerning the properties of object 112 via device 106 to the verification server 118.

[0052] The verification server 118 then compares the data corresponding to object 112 to the data corresponding to object 108, and responds to the consumer's query by verifying that object 112 is indeed the same or not the same as the object 108, and/or whether objects 112 and/or 108 in fact have the qualities asserted by the manufacturer. In other words, the verification server 118 enables consumers to verify that a particular good offered for sale by a manufacturer and/or third party vendor 120 does in fact possess the qualities/properties, e.g., color, as asserted by the manufacturer and/or third party vendor 120. Thus, embodiments of the present invention provide a system 100 and method for assuring consumers that they are indeed purchasing conforming goods.

[0053] Accordingly, in embodiments, a large library, i.e., a collection of data regarding the optical properties of a plurality of objects, e.g., consumer goods, may be stored within the verification server 118. Accordingly, vendors of the manufactured goods may be able to advertise that their products conform to a given set of optical properties, and consumers may be able to locate manufactured goods matching desired optical properties. For example, a first vendor may manufacture paint for use in a consumer's home. The first vendor may paint a test wall with the manufactured paint, and then obtain one or more optical properties A, B, and C of the paint on the test wall via a device, as discussed above in accordance with embodiments of the present invention. The first vendor may then submit the obtained optical properties to the verification server 116, which in turn may return a code to the first vendor that corresponds to the obtained optical properties A, B, and C. The first vendor may then label the

manufactured paint with the code and/or the obtained optical properties. A consumer, having previously painted a wall in their home with paint manufactured by a different vendor but having optical properties A, B, and C on the wall of their home, may need to touch up the wall. Accordingly, if the consumer knows the code and/or optical properties, e.g., they wrote them down and/or have an empty can of paint with the code and/or properties listed, they can search the Internet for paints having optical properties A, B, and C. In the event that the consumer does not know the code and/or optical properties of the paint on the wall of their home, they may use a device to obtain them, as disused above, and then query the verification server 118 in order to obtain the code corresponding to the optical properties A, B, and C.

[0054] As the first vendor has labeled their manufactured paint with the code and/or as having optical properties A, B, and C, the consumer is likely to discover the

manufactured paint via the Internet, or other searchable computer database, to include the verification server 118 itself. In other words, in embodiments, the verification server 118 may contain a listing of goods that have optical properties matching those received from the consumer, and/or a list of vendors selling such conforming goods.

[0055] While the determination of accurate digital data gathering has been discussed in connection with Figures 1-3, Applicants have further discovered that more accurate digital characteristic data can also be obtained by a careful analysis and compensation for glare, or spectral discontinuities, that may be present when collecting digital characteristic data of an item, as will be discussed in greater detail below.

[0056] Embodiment #1: XYZ camera with three white LEDs

[0057] In a first embodiment, the imaging device is a three-channel device wherein the three channels have a spectral response that is substantially close to the CIE tristimulus function, i.e. XYZ. The spectral response may alternately be designed so as to

approximate the actual spectral response of the human eye, also known as LMS. [0058] The light source may be, for example, a set of three white LEDs. They are preferably arranged in a ring around the measurement area of the sample so that light from all three impinges a flat sample surface at 45 ^° . The white LEDs may be arranged 120 ^° apart around the ring.

[0059] Alternately, there may be two, or more light sources. They may be of any other type of light source, e.g. incandescent, fluorescent, Xenon flash, or other gas emission light source. The spectral response of the channels may be modified so as to take into account the spectral emission of the light source.

[0060] Embodiment #2: B/W camera with bandpass filters and three white LEDs

[0061] In a second embodiment, the imaging device may be a black and white camera. A multiplicity of broad-spectrum light sources is filtered so as to selectively illuminate the sample with narrow bands of the visible spectrum. Said filters may, for example, be interference filters which illuminate the sample with light in the ranges 400 nm to 420 nm, 420 nm to 440 nm, etc., up to 680 nm to 700 nm.

[0062] Embodiment #3: RGB camera with multiplicity of LED colors

[0063] In a third embodiment, the imaging device is a multi-channel RGB camera of the Bayer design or with a color separation prism. The light sources are LEDs at a variety of emission colors, such as deep red, orange-red, amber, green, cyan, blue, and violet. There may be three LEDs of each color, arranged in groups, wherein each group contains one of each of the colors, and wherein the groups are arranged so as to be separated by 120 ^° around a ring.

[0064] Each of the LEDs in each of the groups is used to illuminate the sample area and an image is collected. Thus, if there are three groups of seven LEDs, there will be a total of 21 images collected. [0065] Embodiment #4: multiple cameras and one light source

[0066] The arrangement may be set up so as to be 0/45, which is to say, there is one light source at 0 ^° (perpendicular to the sample surface) and there are a set of cameras arranged in a ring around the measurement area. This is a salubrious arrangement in that a single filter wheel can be positioned between the light source and the sample. This arrangement will likely require a geometric correction of the pixels in the images so that corresponding positions in the images align with each other.

[0067] Embodiment #5: three light sources at 120 ^° with additional LEDs not in groups

[0068] Specular reflection is largely wavelength independent. Thus, a single set of light sources arranged in a ring (e.g. three white LEDs arranged 120 ^° apart) may be adequate to characterize the pixels as being specular highlight. Note that any pixel which is characterized as being flat (parallel to the sample surface) will likely not be subject to variance as the direction of illumination changes.

[0069] Thus, white LEDs are positioned around the ring at 0 ^° , 120 ^° , and 240 ^° . The rest of the available positions are occupied by LEDs of various colors, without the restriction of being triplicated around the ring. Some of the LEDs may have narrowband filters so as to provide greater selectivity of the spectral illumination.

[0070] Embodiment #6: combined polarized and non-polarized imaging

[0071] It has been identified that specular cross-polarized filters can be used to eliminate substantially all of the specular reflection, without regard to whether the specular reflection would be perceived as a specular highlight.

[0072] In this embodiment, an imaging device is used to capture both cross-polarized and nonpolarized images. Algorithms are then used to compare the resulting images and determine the amount of specular reflection at each pixel in the images. If sufficient adjacent pixels with sufficient amounts of specular reflection are found, then the grouping is characterized as being a specular highlight.

[0073] In one implementation of this embodiment, the imaging device is at 0 ^° , perpendicular to the sample surface. A first polarized filter is between the imaging device and the sample. The light sources are arranged in a ring, with a subset of the light sources including a second set of polarizing filters between the illumination source and the sample. The second set of polarizing filters is oriented with polarization direction perpendicular to the polarization orientation of the first polarizing filter. A subset of the images is collected with only the illuminations sources which include polarizing filters and another subset of the images are collected without the

illumination sources which do not include polarizing filters.

[0074] With respect to the software, the imaging subsystem provides a collection of images wherein the individual pixels contain varying amount of specular reflection. A region of interest is established within the images. The pixels within the region of interest are analyzed by comparing the intensity values of corresponding pixels from corresponding locations to determine an amount of specular component. The amount of specular component may, for example, be the difference between the maximum intensity value for that pixel and the minimum intensity value. If said difference is above a pre-determined threshold, then the pixel is characterized as being strongly specular.

[0075] An agglomeration technique is used to collect pixels which are adjacent, and which are strongly specular so as to form a specular clump. This technique may be modified so that a second pre-determined threshold is applied for pixels that are adjacent to other pixels which are above the first threshold. The agglomeration technique may include a step of binary morphological operations so as to fill in pixels that are surrounded by pixels that are strongly specular. Morphological operations may also join together nearby specular clumps.

[0076] A determination of whether the clump is deemed perceptible is then made. The pixel count of the specular clumps is then determined. If the pixel count is above a given threshold, then all the pixels in the clump are characterized as being part of a specular highlight. The specular highlight characterization may also take into account some measure of the shape of the specular clump. For example, if the ratio of the number of pixels in the clump that are at the edge of the specular clump (as opposed to having all neighboring pixels as part of the specular clump) may further be used to distinguish between clumps that are perceptible and those which are not.

[0077] Finally, all the pixels that have not been characterized as belonging to a perceptible clump are submitted to a processing step to determine a color of the region of interest. This processing step may include black level correction, non-linearity correction, white level calibration, correction for uneven illumination and vignetting of the lens, averaging, and conversion of intensity values to a color measurement. All of these processing steps are well-known in the art.

[0078] Turning now to Figures 4 and 5, a surface property capture device 400 for use with the smart phone 60 of Figure 1 or other digital image/data gathering device, according to another embodiment of the present invention is illustrated. In an embodiment, the digital data gathering device may be a single image or video capturing device functioning as standalone digital camera, or an RGB sensor or digital video or single image camera integrated into and contained within a computing tablet, smart phone, a wearable garment or personal accessory like a watch, bracelet or necklace. The RGB sensor or digital camera could also be integrated into a UAV (Unmanned Aerial Vehicle).

[0079] The surface property capture device 400 enables a digital data gathering device to gather accurate and consistent dimensional, topographical and tonal properties and characteristics by precisely controlling the primary factors needed to capture consistent data, as discussed hereinafter. Some of these primary factors include the volume, angle, geometry, surface uniformity and the color temperature of the light(s) used to

illuminate the surface or item being captured, and the ambient light environment surrounding and illuminating the surface being measured.

[0080] In addition to the points above, the surface property capture device 400 also integrates a means by which the data captured, i.e., the surface properties and

characteristics data obtained by the digital data gathering device, can be referenced to, and compared against, known and standardized dimensional, topographical and tonal references, thereby standardizing the captured data to known predefined standards for all image capturing devices, as discussed in detail below. This is achieved through integration of a surface reference device or calibration disk, incorporating standardized surface topographic, dimension and tonal references. The intent of this reference device is to surround, or be located adjacent to the surface being captured, and positioned within the focal image area of the digital data gathering device, thereby incorporating the standardized surface reference device into each and every capture of surface image data by the digital data gathering device.

[0081] With particular reference to Figures 4 and 5, in an embodiment, the surface property capture device 400 may be generally cylindrical in shape and includes a fixture 410 defining a housing or shroud combining electronic and digital circuitry and a light source including one or more light emitters 417. The light emitters 417 may be light emitting diodes (LEDs), although the light emitters 417 may take other forms known in the art without departing from the broader aspects of the invention. The fixture 410 may also integrate optics to prevent chromatic aberrations, filters to control surface glare and various forms of batteries or charging systems. As used herein, the fixture 410 may also be referred to as "lighting fixture 410". The surface property capture device 400 is configured to be removably attached to the digital data gathering device (e.g., a smart phone, tablet or the like) via a mating surface 412 on the lighting fixture 410. An aperture in the mating surface 412 allows a line of sight from the lens of the digital data gathering device into the surface property capture device 400, to allow for viewing of the surface via the digital data gathering device.

[0082] With further reference to Figures 4 and 5, the surface property capture device 400 also includes a calibration disk or surface property reference disk 414 permanently or removably attached to the lighting fixture 410 opposite the mating surface 412. The surface property reference disk 414, on its inner surface, includes information or indicia 413 relating to standardized dimensional, topographical, and tonal references (e.g., hue, saturation, brightness). As also shown therein, the surface property reference disk 414 also includes a central viewing window 416, the purpose of which will be described hereinafter.

[0083] The surface property reference disk 414 (and the inner surface thereof) is fixedly positioned at a predetermined distance away from the lighting fixture 410 and lighting arrangement thereof. Importantly, therefore, the surface property reference disk 414 is in fixed position, at a predetermined and constant distance from the lens and imaging sensor of the digital data gathering device to which the surface property capture device 400 is attached, to enable the digital data gathering device to adequately focus on the surface being captured.

[0084] As will be evident, the appropriate, adequate focusing distance (i.e., the focal length distance) can be altered in dependence upon the operational characteristics of the digital data gathering device to which the surface property capture device is attached. In an embodiment, the distance of the surface property reference disk to the lens of the digital data gathering device may be selected to be substantially equivalent to the focal length a lens of the digital data gathering device.

[0085] The combined integration of the lighting fixture 410 and the surface property reference disk 414 enables a user of a digital data gathering device to simply attach the surface property capture device 410 to the digital data gathering device, position the surface property reference disk 414 over or next to the surface to be captured, and capture the image and data using the standard imaging capabilities of the digital data gathering device.

[0086] As best shown in Figure 5, the surface property capture device 400 also includes a small space or opening 418 that allows ambient light to enter the surface property capture device 400 and illuminate the inner surface of the surface property reference disk 414 and reference information thereon. For example, in an embodiment, the opening 418 may be formed between the surface property reference disk 414 and the lighting fixture 410. In an embodiment, the opening 418 may be a plurality of openings spaced about the outer periphery of the surface property capture device 400.

Importantly, by permitting ambient light to enter the surface property capture device 400, a user can visually position the surface property capture device 400 and window 416 in registration with a target area of a surface without needing to illuminate the surface with the light fixture 410 or other non-ambient light source.

[0087] In operation, therefore, a user may attach the surface property capture device 400 to a digital data gathering device via the mating surfaces on the surface property capture device 400 and digital data gathering device. Looking through the screen on the digital data gathering device, a user can then position or center the window 416 in the surface property reference disk 414 over a target area on a surface. This step is possible due to the ambient light that is allowed to enter the surface property capture device 400 and illuminate the surface. Importantly, at the moment of image capture, the lighting fixture 410 generates a volume of light necessary to significantly minimize the detrimental effects of the uncontrolled environmental ambient light illuminating the surface being captured. In particular, the light emitters of the integrated lighting fixture 410 generate light having properties sufficient to substantially 'wash out' or eliminate the effects of the ambient light on the target surface (as well as on the information contained on the inner surface of the surface property reference disk 414). This method effectively provides a controlled and consistently lighted environment in which to capture the surface properties and characteristics of any surface being imaged by the image capturing device.

[0088] In addition, to further reduce and counter the effects of the uncontrolled environmental ambient light illuminating the surface to be captured, an image capture may be taken of the surface while illuminated by only ambient light. This captured image can be used to evaluate the volume, color temperature and uniformity of the uncontrolled ambient light. This light evaluation data can then be used to measure the effects it may have on the light being emitted from the lighting fixture 410, and subsequently accounted for and calculated into (or out of) the final lighting data to further refine and minimize the effects of the ambient light.

[0089] Importantly, by having openings 418 in the shroud/housing that allow ambient light from outside the device to illuminate the window 416 in the surface property reference disk 414, the device 400 may be precisely aligned with the target area of the surface to be analyzed under direct visualization by a user (by looking through the screen of the digital data gathering device), without requiring any integrated or 'artificial' light source to be utilized. This is in contrast to the existing devices which require a substantially light-tight environment within the shroud for image capture, which prevents accurate initial alignment of the device on a surface without using integrated LEDs or the like. Moreover, by using an illumination source within the light fixture 410 that can sufficiently negate the effects of any ambient light on the target surface, there is no need to provide a light-tight shroud which, as discussed above, allows for better alignment under direct visualization and thus renders the device, overall, easier to use. In an embodiment, rather than being integrated into a

shroud/housing as discussed above, the illumination source capable of pushing an adequate volume of light to negate the effects of the ambient light may alternatively be integrated into the digital data gathering device itself. In particular, in certain embodiments, the surface property capture device may be entirely omitted from the system so long as the digital data capture device has an illumination source sufficient to substantially negate the effects of the ambient light on the target surface.

[0090] Once an image of the target surface and surface property reference disk 414 is captured under illumination from the illumination source, the digital data gathering device may harmonize this consistent multi-dimensional surface light data through comparison to the multi-dimensional surface property reference disk 414. This enables the digital data gathering device to gather accurate and consistent dimensional, topographical and tonal properties and characteristics by precisely controlling the primary factors needed to capture consistent data. In addition to harmonizing the multi-dimensional light data from the target surface through comparison to the indicia on the multi-dimensional surface property reference disk 414, the digital data gathering device or networked server can also then identify and correct spectral highlights using the method hereinbefore described, in order to obtain even more precise, consistent and correct image data.

[0091] In an embodiment, the lighting fixture 410 can additionally be configured to contain, direct and angle the light being emitted onto the surface being captured, as well as to illuminate the areas surrounding the surface property capture device 400 (e.g., outside the surface property capture device 400). Accordingly, the lighting fixture 410 can therefore be operable to project controlled light at the surface to be captured as well as around the outside of the surface property capture device 400 which would, in effect, create a more controlled 'ambient light environment' surrounding the surface property capture device 400 and surface to be captured.

[0092] In an embodiment, the light emitters contained in the lighting fixture 410 can be controlled and affixed in many ways to capture specific and different dimensional, topographical and tonal property and characteristic data. For example, in certain embodiments, one or more light emitters may emit light at a 0/45 ² geometry to match measurement conditions used in industrial applications, one or more light emitters may emit light at a pre-determined geometry to illuminate a sample area and reference targets with separate illumination volume, angle, geometry, surface uniformity and the color temperature, and/or one or more light emitters may emit light of a scene-aware intensity to match the variable measurement conditions required for that individual situation.

[0093] In an embodiment, one or more light emitters of the lighting fixture 410 may emit light with various color temperatures and colors separately, together or in a controlled sequence that is used by software and mathematical methods described herein to detect the possibility of metamers. It is contemplated that the various light colors may be achieved by using various colored light emitters or placing various color filters in front of the light emitters.

[0094] While the embodiments herein show the light fixture 410 and surface property reference disk 414 as distinct components, it is contemplated that the light fixture 410 and surface property reference disk 414 may be integrated so as to form a single housing containing the light source and associated circuitry (wherein the light source is positioned at a first end of the housing and the surface property reference disk is positioned at an opposite, second end of the housing). Moreover, while the

embodiments described herein disclose image capture occurring when the digital data gathering device and surface property capture device are stationary, in certain embodiments, data capture may take place as the digital data gathering device and attached surface property capture device are moved across a surface. In this

embodiment, the digital data gathering captures frames as it is moved across a surface, and the frames are then stitched into one larger image, thereby reducing the need for the window in the surface property reference disk to be made larger to capture a larger surface area.

[0095] While the invention has been described with reference to the preferred

embodiments, it will be understood by those skilled in the art that various obvious changes may be made, and equivalents may be substituted for elements thereof, without departing from the essential scope of the present invention. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed, but that the invention includes all embodiments falling within the scope of the appended claims.