Shading correction apparatus

Claim 2

A shading correction apparatus according to claim 1, wherein the memory means (18) is operative to memorize level data of said digital video signal outputted from predetermined ones of said pixels of the image pick-up device (1) while the exposure control means (28) is operative to control said exposure level to be at zero level.

Claim 3

Apparatus according to claim 1 or claim 2, wherein said signal processing means (3) comprises subtracting means (8) for subtracting said shading correction signal from said output signal produced by the image pick-up device (1) while the image pick-up device is exposed to pick up an image.

Claim 4

Apparatus according to claim 1, claim 2 or claim 3, wherein the memory means (18) is operative to memorize level data at predetermined periods adjacent to periods in which shading correction data are memorized in the memory means, the level of said level data being the same as the levels of said digital video signal just after blanking intervals of said digital video signal.

Claim 5

Apparatus according to claim 1, claim 2 or claim 3, wherein the shading correction signal generating means (14) is operative repeatedly to read out the leading data in each line from the armory means (18) during predetermined periods (T) of blanking intervals of said digital video signal.

Claim 6

Apparatus according to any one of claims 1 to 5, wherein the shading correction signal generating means (14) comprises: interpolating means (17) for interpolating data read out from the armory means (18); digital to analog converting means (23) for converting an output signal of the interpolating means (17) into an analog signal; and low-pass filter means (25) connected to an output of the digital to analog converting means (23) for outputting said shading correction signal.

Claim 7

A shading correction apparatus for eliminating a shading signal component from an output signal of an image pick-up device (1) having a plurality of pixels, the apparatus comprising: exposure control means (28) for controlling an exposure level of the image pick-up device (1); analog to digital converting means (12) for converting an output signal of the image pick-up device (1) into a digital video signal; memory means (18) for memorizing level data of said digital video signal outputted from pixels of said image pick-up device while the exposure control means (28) is operative to control said exposure level such that the image pick-up device (1) is uniformly exposed; shading correction signal generating means (14) for generating a shading correction signal according to data read out from the memory means (18) ; and signal processing means (3) for processing an output signal produced by the image pick-up device (1) while the image pick-up device is exposed to pick up an image, according to said shading correction signal, so that said shading signal component is eliminated from said output signal produced by the image pick-up device while the image pick-up device is exposed to pick up an image.

Claim 8

A shading correction apparatus according to claim 7, wherein the memory means (18) is operative to memorize level data of said digital video signal outputted from predetermined ones of said pixels of the image pick-up device (1) while the exposure control means (28) is operative to control said exposure level such that the image pick-up device is uniformly exposed.

Claim 9

Apparatus according to claim 7 or claim 8, wherein the signal processing means (3) comprises dividing means (10) for dividing said output signal, produced by the image pick-up device (1) while the image pick-up device is exposed to pick up an image, by said shading correction signal.

Claim 10

Apparatus according to claim 7, claim 8 or claim 9, wherein the memory means (18) is operative to memorize level data at predetermined periods adjacent to periods in which shading correction data are memorized in the memory means, the level of said level data being the same as the levels of said digital video signal just after blanking intervals of said digital video signal.

Claim 11

Apparatus according to claim 7, claim 8 or claim 9, wherein the shading correction signal generating means (14) is operative repeatedly to read out the leading data in each line from the memory means (18) during predetermined periods of blanking intervals of said digital video signal.

Claim 12

Apparatus according to any one of claims 7 to 11, wherein the shading correction signal generating means (14) comprises: interpolating means (17) for interpolating data read out from the memory means (18); digital to analog converting means (24) for converting an output signal of the interpolating means (17) into an analog signal; and low-pass filter means (26) connected to an output of the digital to analog converting means (24) for outputting said shading correction signal.

Claim 13

A shading correction apparatus for eliminating shading signal components from output signals of first, second and third charge coupled devices (1R, 1G, 1B) of an image pick-up means, each of which devices has a plurality of pixels, the apparatus comprising: exposure control means (28) for controlling an exposure level of the image pick-up means; analog to digital converting means (12) for converting output signals of the first, second and third charge coupled devices (1R, 1G, 1B) into digital video signals; memory means ( 18) for memorizing level data of said digital video signals outputted from predetermined ones of said pixels of said first, second and third charge coupled devices (1R, 1G, 1B)in point sequential manner while the exposure control means (28) is operative to control said exposure level to be at zero level; shading correction signal generating means (14) for generating shading correction signals according to data read out from the memory means (18); and signal processing means (3) for processing output signals produced by the first, second and third charge coupled devices (1R, 1G, 1B) while the image pick-up means is exposed to pick up an image, according to said shading correction signals, so that said shading signal components are eliminated from said output signals produced by the charge coupled devices while the image pick-up means is exposed to pick up an image.

Claim 14

Apparatus according to claim 13, wherein the analog to digital converting means (12) comprises first, second and third analog to digital converting circuits (12R, 12G, 12B) each operative to convert an output signal of a respective one of the first, second and third charge coupled devices (1R, 1G, 1B) into a respective digital video signal, and the signal processing means (3) comprises first, second and third subtracting means (8R, 8G, 8B) each operative to subtract a respective said shading correction signal from a respective one of said output signals produced by the first, second and third charge coupled devices while the image pick-up means is exposed to pick up an image.

Claim 15

A shading correction apparatus for eliminating shading signal components from output signals of first, second and third charge coupled devices (1R, 1G, 1B) of an image pick-up means, each of which devices has a plurality of pixels, the apparatus comprising: exposure control means (28) for controlling an exposure level of the image pick-up means; analog to digital converting means (12) for converting output signals of the first, second and third charge coupled devices (1R, 1G, 1B) into digital video signals; memory means (18) for memorizing level data of said digital video signals outputted from predetermined ones of said pixels of said first, second and third charge coupled devices (1R, 1G, 1B) in point sequential manner while the exposure control means (28) is operative to control said exposure level such that the image pick-up means is uniformly exposed; shading correction signal generating means (14) for generating shading correction signals according to data read out from the memory means (18); and signal processing means (3) for processing output signals produced by the first, second and third charge coupled devices (1R, 1G, 1B) while the image pick-up means is exposed to pick up an image, according to said shading correction signals, so that said shading signal components are eliminated from said output signals produced by the charge coupled devices while the image pick-up means is exposed to pick up an image.

Claim 16

A shading correction apparatus for eliminating a shading signal component from an output signal of an image pick-up device (1) having a plurality of pixels, the apparatus comprising: exposure control means (28) for controlling an exposure level of the image pick-up device (1); analog to digital converting means (12) for converting an output signal of the image pick-up device (1) into a digital video signal; shading correction data generating means (17) for generating first and second shading correction data by integrating said digital video signals outputted from predetermined ones of said pixels of the image pick-up device (1) in horizontal and vertical directions, respectively, while the exposure control means (28) is operative to control said exposure level to be at zero level; memory means (18) for memorizing said first and second shading correction data; shading correction signal generating means (17) for generating a shading correction signal according to said first and second shading correction data read out from the memory means (18); and signal processing means (3) for processing an output signal produced by the image pick-up device (1) while the image pick-up device is exposed to pick up an image, according to said shading correction signal, so that said shading signal component is eliminated from said output signal produced by the image pick-up device while the image pick-up device is exposed to pick up an image.

Claim 17

Apparatus according to claim 16, wherein said signal processing means (3) comprises subtracting means (8) for subtracting said shading correction signal from said output signal produced by the image pick-up device (1) while the image pick-up device is exposed to pick up an image.

Claim 18

A shading correction apparatus for eliminating a shading signal component from an output signal of an image pick-up device (1) having a plurality of pixels, the apparatus comprising: exposure control means (28) for controlling an exposure level of the image pick-up device (1); analog to digital converting means (12) for converting an output signal of the image pick-up device (1) into a digital video signal; shading correction data generating means (17) for generating first and second shading correction data by integrating said digital video signals outputted from predetermined ones of said pixels of the image pick up device (1) in horizontal and vertical directions, respectively, while the exposure control means (28) is operative to control said exposure level such that the image pick-up device is uniformly exposed; memory means (18) for memorizing said first and second shading correction data; shading correction signal generating means (17) for generating a shading correction signal according to said first and second shading correction data read out from the memory means (18); and signal processing means (3) for processing an output signal produced by the image pick-up device (1) while the image pick-up device is exposed to pick up an image, according to said shading correction signal, so that said shading signal component is eliminated from said output signal produced by the image pick-up device while the image pick-up device is exposed to pick up an image.

Claim 19

Apparatus according to claim 18, wherein the signal processing means (3) comprises dividing means (10) for dividing said output signal, produced by the image pick-up device (1) while the image pick-up device is exposed to pick up an image, by said shading correction signal.

Claim 20

A shading correction apparatus for eliminating a shading signal component from an output signal of an image pick-up device (101) having a plurality of pixels, the apparatus comprising: exposure control means (108) for controlling an exposure level of the image pick-up device (101); analog to digital converting means (105) for converting an output signal of the image pick-up device (101) into a digital video signal; sampling means (111) for sampling said digital video signal in vertical and horizontal directions at predetermined intervals while the exposure control means (108) is operative to control said exposure level to be at zero level; quadratic curve generating means (112) for generating first and second quadratic curves according to said digital video signal as sampled in the vertical and horizontal directions; sawtooh signal generating means (114) for generating a sawtooth signal; parabolic signal generating means (115) for generating a parabolic signal; first level control means (116) for controlling the level of said sawtooth signal according to coefficients of a second order term of said first and second quadratic curves; second level control means (117) for controlling the level of said parabolic signal according to coefficients of a first order term of said first and second quadratic curves; and signal processing means (103) for processing an output signal produced by the image pick-up device (101) while the image pick-up device is exposed to pick up an image, according to output signals of the first and second level control means (116, 117), so that said shading signal component is eliminated from said output signal produced by the image pick-up device while the image pick-up device is exposed to pick up an image.

Claim 21

A shading correction apparatus for eliminating a shading signal component from an output signal of an image pick-up device (101) having a plurality of pixels, the apparatus comprising: exposure control means (108) for controlling an exposure level of the image pick-up device (101); analog to digital converting means (105) for converting an output signal of the image pick-up device (101) into a digital video signal; sampling means (111) for sampling said digital video signal in vertical and horizontal directions at predetermined intervals while the exposure control means (108) is operative to control said exposure level such that the image pick-up device (101) is uniformly exposed; quadratic curve generating means (112) for generating first and second quadratic curves according to said digital video signal as sampled in the vertical and horizontal directions; sawtooth signal generating means (114) for generating a sawtooth signal; parabolic signal generating means (115) for generating a parabolic signal; first level control means (116) for controlling the level of said sawtooth signal according to coefficients of a second order term of said first and second quadratic curves; second level control means (117) for controlling the level of said parabolic signal according to coefficients of a first order term of said first and second quadratic curves; and signal processing means (103) for processing an output signal produced by the image pick-up device (101) while the image pick-up device is exposed to pick up an image, according to output signals of the first and second level control means (116, 117), so that said shading signal component is eliminated from said output signal produced by the image pick-up device while the image pick-up device is exposed to pick up an image.