US5155558A — Method and apparatus for analyzing the appearance…

Claim 1

Independent Claim 228 words

A method for measuring the appearance features of a surface, comprising: (a) generating a spatially coherent and uniform collimated beam of polychromatic light; (b) interposing a beam limiting means into said beam of polychromatic light; (c) directing said beam of polychromatic light, spatially filtered by said beam limiting means, onto a surface at an angle of incidence; (d) detecting and scanning the specularly reflected image of a portion of said beam limiting means with a scanned imaging detector; (e) translating the detector along the optic axis through a sequence of spatially distinct focal planes normal to the optic axis, including focal planes corresponding to said surface and to said beam limiting means; (f) measuring surface reflectance from a plurality of preselected points in each one of said sequence of scanned detected focal plane images; (g) transforming said reflectances into a corresponding sequence of focal plane spatial frequency spectra; (h) selecting focal plane spectral data according to the occurance of maximum and minimum signatures in the power spectra of said focal plane sequence; (i) standardizing said spectral data with the spatial frequency characteristics of a perfect reflecting surface; (j) calculating from said standardized measurements, the optical transfer function (OTF), spatial frequency response, power, and amplitude spectra and in conjunction with the visual spatial frequency response characteristic V(f) and standard psychophysical methodology, mathematically determine the appearance attributes of said surface.

Claim 2

Independent Claim 228 words

A method for measuring the appearance features of a surface, comprising: (a) generating a spatially coherent and uniform collimated beam of polychromatic light; (b) interposing a beam limiting means into said beam of polychromatic light; (c) directing said beam of polychromatic light, spatially filtered by said beam limiting means, onto a surface at an angle of incidence; (d) detecting and scanning the specularly reflected image of a portion of said beam limiting means with a scanned imaging detector; (e) translating the detector along the optic axis through a sequence of spatially distinct focal planes normal to the optic axis, including focal planes corresponding to said surface and to said beam limiting means; (f) measuring surface reflectance from a plurality of preselected points in each one of said sequence of scanned detected focal plane images; (g) transforming said reflectances into a corresponding sequence of focal plane spatial frequency spectra; (h) selecting focal plane spectral data according to the occurance of maximum and minimum signatures in the power spectra of said focal plane sequence; (i) standardizing said spectral data with the spatial frequency characteristics of a perfect reflecting surface; (j) calculating from said standardized measurements, the optical transfer function (OTF), spatial frequency response, power, and amplitude spectra and in conjunction with the visual spatial frequency response characteristic V(f) and standard psychophysical methodology, mathematically determine the appearance attributes of said surface.

Claim 3

Dependent Claim 36 words

The method of claim 1, wherein the surface appearance attributes are defined by quality measures of: orange peel frequency, orange peel amplitude, microwrinkle, cracks and crazes, distinctness of image, gloss, haze, contrast, luster, fog, and texture.

Claim 4

Dependent Claim 68 words

The method of claim 1, wherein calculating specific appearance attributes includes the steps: (a) Weighting the spectral distribution function, F k (f,z) with the visual spatial frequency response function, V(f); (b) determining elementary appearance measures, A k (z), in accordance with: A.sup.k (z)=∫F.sup.k (f,z)V(f)df; (c) transforming the functions A k (z) with algorithms selected from tabulated functions defining quality measures to obtain perceived values of said appearance attributes.

Claim 5

Dependent Claim 78 words

The method of claim 1 wherein selecting said sequence of focal plane positions and spectral data corresponding thereto is based upon the following steps: (a) integrating the Fourier power spectra derived from the scanned and measured intensity values obtained at each of said focal planes in the sequence in accordance with the following equation: T(z)=∫log [P.sup.o (f,z)+1]df; (b) determining the extrema as a function of displacement along the optic axis; (c) positioning the detector according to extrema location.

Claim 6

Dependent Claim 20 words

The method of claim 1 including the step of standardizing the spectral data with the spectral reflectance of black glass.

Claim 7

Dependent Claim 26 words

The method of claim 1 including the step of directing said beam of spatially filtered polychormatic light onto the surface at a normal angle of incidence.

Claim 8

Dependent Claim 33 words

The method of claim 1 including the step of directing said beam of spatially filtered polychromatic light onto the surface at an acute angle of incidence ranging from about 0° to about 50°.

Claim 9

Independent Claim 237 words

A method of measuring the appearance features of a surface, comprising: (a) generating a spatially coherent and uniform collimated beam of polychromatic light; (b) interposing a beam limiting means into said beam of polychromatic light; (c) directing said beam of polychromatic light, spatially filtered by said beam limiting means, onto a surface at an angle of incidence; (d) detecting and scanning the specularly reflected image of a portion of said beam limiting means with a scanned imaging detector; (e) positioning the focal plane of said detector at a first position normal to the ptic axis thereof; (f) measuring the surface reflectance from a plurality of preselected points in the scanned focal plane image; (g) transforming said reflectance values to obtain spatial frequency spectra; (h) standardizing said spectral data with the spatial frequency characteristics of a perfect reflecting surface; (i) calculating from said standardized measurements, power and amplitude spectra; (j) integrating said power spectra to obtain T(z) values to determine the existence of extrema; (k) adjusting the focal plane position of said detector to obtain the extrema positions corresponding to the appearance feature sought; (l) calculating from said standardized measurements, the optical transfer function (OTF), spatial frequency response, power and amplitude spectra and in conjunction with the visual spatial frequency response characteristic V(f) and standard psychophysical methodology, mathematically determine the appearance attributes of the surface dependent upon the spatial frequency feature measured at said focal plane extrema positions.

Claim 10

Independent Claim 237 words

A method of measuring the appearance features of a surface, comprising: (a) generating a spatially coherent and uniform collimated beam of polychromatic light; (b) interposing a beam limiting means into said beam of polychromatic light; (c) directing said beam of polychromatic light, spatially filtered by said beam limiting means, onto a surface at an angle of incidence; (d) detecting and scanning the specularly reflected image of a portion of said beam limiting means with a scanned imaging detector; (e) positioning the focal plane of said detector at a first position normal to the ptic axis thereof; (f) measuring the surface reflectance from a plurality of preselected points in the scanned focal plane image; (g) transforming said reflectance values to obtain spatial frequency spectra; (h) standardizing said spectral data with the spatial frequency characteristics of a perfect reflecting surface; (i) calculating from said standardized measurements, power and amplitude spectra; (j) integrating said power spectra to obtain T(z) values to determine the existence of extrema; (k) adjusting the focal plane position of said detector to obtain the extrema positions corresponding to the appearance feature sought; (l) calculating from said standardized measurements, the optical transfer function (OTF), spatial frequency response, power and amplitude spectra and in conjunction with the visual spatial frequency response characteristic V(f) and standard psychophysical methodology, mathematically determine the appearance attributes of the surface dependent upon the spatial frequency feature measured at said focal plane extrema positions.

Claim 11

Dependent Claim 45 words

The method of claim 8, further including the steps of: (a) repositioning said detector at a second focal plane position; (b) repeating steps (f) through (l) to mathematically determine the appearance attributes dependent upon the spatial frequency feature measured at said second focal plane position.

Claim 12

Dependent Claim 39 words

The method of claim 8 or claim 9 wherein the surface appearance attributes are defined by quality measures of: orange peel frequency, orange peel amplitude, distinctness of image, gloss, haze, contrast, microwrinkle, texture, luster, fog, and cracks and crazes.

Claim 13

Dependent Claim 71 words

The method of claim 8 or claim 9, wherein calculating specific appearance attributes include the steps: (a) weighting the spectral distribution function F k (f,z), with the visual spatial frequency response function, V(f); (b) determining elementary appearance measures, A k (z), in accordance with: A.sup.k (z)=∫F.sup.k (f,z)V(f)df; (c) transforming the functions A k (z) with algorithms selected from tabulated functions defining quality measures to obtain perceived values of said appearance attributes.

Claim 14

Dependent Claim 21 words

The method of claim 8 or claim 9 wherein the integrating step includes the use of the equation: T(z)=∫log[P.sup.o (i f,z)+1]df

Claim 15

Dependent Claim 23 words

The method of claim 8 or claim 9 including the step of standardizing the spectral data with the spectral reflectance of black glass.

Claim 16

Dependent Claim 29 words

The method of claim 8 or claim 9 including the step of directing said beam of spatially filtered polychromatic light onto the surface at a normal angle of incidence.

Claim 17

Dependent Claim 36 words

The method of claim 8 or claim 9 including the step of directing said beam of spatially filtered polychromatic light onto the surface at an acute angle of incidence ranging from about 0° to about 50°.

Claim 18

Independent Claim 89 words

An apparatus for measuring the appearance features of a surface, comprising: (a) a source for generating a spatially coherent and uniform collimated beam of polychromatic light; (b) means for holding the surface flat; (c) beam limiting means for spatially filtering said beam of polychromatic light to be interposed between said source and the surface; (d) detector means for receiving the specularly reflected image of a portion of said beam limiting means from the surface; (e) means for translating said detector means relative to the surface along the optic axis.

Claim 19

Independent Claim 89 words

An apparatus for measuring the appearance features of a surface, comprising: (a) a source for generating a spatially coherent and uniform collimated beam of polychromatic light; (b) means for holding the surface flat; (c) beam limiting means for spatially filtering said beam of polychromatic light to be interposed between said source and the surface; (d) detector means for receiving the specularly reflected image of a portion of said beam limiting means from the surface; (e) means for translating said detector means relative to the surface along the optic axis.

Claim 20

Dependent Claim 18 words

The apparatus of claim 16, wherein: (a) said beam limiting means includes an optical mask with a slit.

Claim 21

Dependent Claim 26 words

The apparatus of claim 16, wherein: (a) said beam limiting means is selected from geometries comprising step, pulse, polar, semi-polar, Ronchi Ruling and grid masks, respectively.

Claim 22

Dependent Claim 17 words

The apparatus of claim 16, and including: (a) means for processing information sensed by said detector means.

Claim 23

Dependent Claim 35 words

The apparatus of claim 16, wherein: (a) said beam generating means is positioned so as to direct the beam onto said surface at an acute angle of incidence ranging from about 0 to about 50.

Claim 24

Dependent Claim 28 words

The apparatus of claim 16, wherein: (a) said beam generating means is positioned so as to direct the beam onto said surface at a normal angle of incidence.

Claim 25

Dependent Claim 17 words

The apparatus of claim 21, and (a) beam splitter means positioned between said source and said surface.

Claim 26

Dependent Claim 15 words

The apparatus of claim 16, wherein: (a) said detector means comprises a scanned imaging detector.

Claim 27

Dependent Claim 14 words

The apparatus of claim 23, wherein: (a) said detector is a charged coupled camera.

Claim 28

Dependent Claim 18 words

The apparatus of claim 19, wherein: (a) said information processing means includes means for generating a three-dimensional image.

Claim 29

Dependent Claim 35 words

The apparatus of claim 19 and including: (a) auto-accommodation means for adjusting the focal plane of said detector means to at least one detected image that corresponds with the predetermined image of a surface feature.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1995-10-13	1996-04-13	1996-10-13	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1999-10-13	2000-04-13	2000-10-13	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2003-10-13	2004-04-13	2004-10-13	$7700.00	Window Closed / Lapsed

Method and apparatus for analyzing the appearance features of a surface

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