1. Transducer means determining the relative brightness and color tones of articles to predetermined standards and classifying same into categories comprising: a background surface having a predetermined color; source means impinging polychromatic light on the obverse face of said background surface to reflect light therefrom in both the presence and absence of articles on said obverse face; detector means receiving reflected light from said obverse face in first, second and third bands of the spectrum and producing, for each band, first output parameters representative of the respective intensities of reflected light in each said band in the presence of an article on said obverse face of said background reference; reference means storing a second parameter for each band representative of the intensity of reflected light in each band in the absence of an article over siad obverse face; differential means operating on said parameters and producing, for each band, a third parameter representing the magnitude of the difference of said first and second parameters; means modulating said third parameter for each band to vary the magnitude thereof by predetermined interrelated scalar multipliers; summing means operating on said modulated third parameters and producing the sum thereof; control means providing, as said predetermined standards, comparison parameters defining divisions of relative brightness and color tones, said divisions defining a plurality of quality zones of known color characteristics for which said articles might qualify; selection means designating said zones as acceptable and unacceptable; comparison means comparing said comparison parameters and said sums of said third parameters determining the presence and absence of said articles over siad obverse face of said background surface and the zone for which said articles qualify; and correlating means responsive to said selection means and said comparison means classifying said articles into acceptable and unacceptable categories.

38. Means selectively grading articles by brightness and two color tones relative to predetermined standards as said articles traverse a background surface of known color illuminated by polychromatic light, comprising: detecting and calculating means receiving reflected light from said articles and said background in three distinct spectral bands R, F and I and deriving for each said article a linear summation of the intensities of reflected light in the form rR'' + fF'' + iI'', for determining brightness and each of said color tones, wherein r, f and i are predetermined scalar multipliers respectively associated with said bands and R'', F'' and I'' are functions of the intensity of reflected light in said bands from said articles and said background surface; control means generating said scalar multipliers and a brightness and two color tone standards comprising division lines in the form rR'' + fF'' + iI'' + or - d where d is a predetermined constant, said division lines intersecting to form a plurality of color quality zones; and means comparing said linear summations with the correlative ones of said brightness and color tone standards, determining the relative magnitudes of said summations to that of the quantity + or - d and identifying the color quality zones characterizing each said article as a function of said relative magnitudes.

50. Means selectively grading articles by brightness and two color tones relative to predetermined standards as said articles traverse one or more background surfaces of known color illuminated by polychromatic light comprising: at least one detecting and calculating means associated with each said background surface receiving reflected light from said articles and said background in three distinct spectraL bands R, F and I and deriving for each said article a linear summation of the intensities of reflected light in the form rR'' + fF'' + iI'', for determining brightness and each of said color tones, wherein r, f and i are predetermined scalar multipliers respectively associated with said bands and R'', F'' and I'' are functions of the intensity of reflected light in said bands from said articles and said background surface; control means common to all said detecting and calculating means generating said scalar multipliers and a brightness and two color tone standards comprising division lines in the form rR'' + fF'' + iI'' + or - d where d is a predetermined constant, said division lines intersecting to form a plurality of color quality zones; means in each said detecting and calculating means comparing said linear summations with the correlative ones of said brightness and color tone standards, determining the relative magnitudes of said summations to that of the quantity + or - d and identifying the color quality zones characterizing each said article as a function of said relative magnitudes; and encoding means for each detecting and calculating means encoding and storing data characterizing said quality zone identities.

74. Means selectively grading articles by brightness and two color tones relative to predetermined standards as said articles traverse a background surface of known color illuminated by polychromatic light and wherein said light is driven by an alternating current source, compRising: detecting and calculating means performing calculations for brightness and said two color tones of each said article in each of two consecutive half cycles of said alternating current source; logic means controlling said detecting and calculating means constraining storage of said calculations in the first said half cycle, a reverse logic for said calculations in the second said half cycle, and a summation of like ones of said first and second half cycle calculations; said summation, for each such calculation, providing resultant calculations for said brightness and said color tones compensated for alternating current induced variations in said polychromatic light and operating offsets in said detecting and calculating means; and means comparing said summations to said predetermined standards.

76. Means grading and sorting tobacco leaves in reference to predetermined standards of brightness, greenness and redness, comprising: a background surface of known color; conveyor means constraining tobacco leaves to traverse the obverse face of said background surface; optical means impinging said obverse face and said leaves with polychromatic light and receiving reflected light therefrom in red, green and infrared bands of the spectrum; control means providing first, second and third reference parameters representative of the said standards of brightness, greenness and redness, respectively; calculating means responsive to said reflected light received by said optical means providing first, secoud and third operating parameters representative of the brightness, greenness and redness, respectively, of each said leaf traversing said obverse face of said background; comparator means responsive to said control means and said calculating means providing first, second and third resultant parameters representing, respectively, the relative brightness, greenness and redness of said leaves to said standards; and reject selection means operating on said leaves in response to said resultant parameters when the latter represent predetermined deviations from said standards.

80. Transducer means for classifying an object with reference to allowable deviations from predetermined standards of brightness and first and second color tones, comprising: a background surface of known color having an obverse face over which said object is positioned; optical means impinging said obverse face and said object with polychromatic light and receiving reflected light therefrom in three distinct bands of the spectrum; control means providing first, second and third reference parameters representative of the said standards of brightness and first and second color tones, respectively; calculating means respective to said reflected light received by said optical means providing first, second and third operating parameters representative of the brightness and first and second color tones, respectively, of said object; comparator means responsive to said control means and said calculating means providing first, second and third resultant parameters representing, respectively, the relative brightness and first and second color tones of said object to said standards; and means responsive to said resultant parameters to indicate when at least one of said relative brightness and first and second color tones of said object exceeds the corresponding one of said allowable deviations from said predetermined standards.

81. Means classifying a succession of objects with reference to allowable deviations from predetermined standards of brightness and first and second color tones, comprising: a background surface of known color having an obverse face over which said objects are successively positioned; optical means impinging said obverse face and said objects with polychromatic light and receiving reflected light therefrom in first, second and third bands of the spectrum; control means providing first, second and third reference parameters representative of the said standards of brightness and first and second color tones, respectively; calculating means responsive to said reflected light received by said optical means providing first, second and third operating parameters representative of the brightness and first and second color tones, respectively, of each said object over said obverse face of said background; comparator means responsive to said control means and said calculating means providing first, second, and third resultant parmeters representing, respectively, the relative brightness and first and second color tones of said objects to said standards; and means responsive to said resultant parameters for each said object to indicate when at least one of said relative brightness and first and second color tones of a said object exceeds the corresponding one of said allowable deviations from said predetermined standards.