Solid-state color image pickup apparatus
First Claim
1. A signal processing apparatus for obtaining a video signal in which color aliasings were suppressed for a color video camera having an image pickup device consisting of a number of photoelectric converting elements which are two-dimensionally arranged and four kinds of color separation optical filters which are repetitively arranged on the surfaces of said photoelectric converting elements in accordance with a predetermined order, said signal processing apparatus comprising:
- an image pickup device for outputting a first signal, a second signal, a third signal, and a fourth signal respectively corresponding to said four kinds of color separation optical filters; and
color signal producing means for producing a first color signal and a second color signal by processing said first to fourth signals on the basis of arithmetic operations of the following expressions;
space="preserve" listing-type="equation">C.sub.1 =α
S.sub.1 -β
S.sub.2 +γ
S.sub.3 -δ
S.sub.4
space="preserve" listing-type="equation">C.sub.2 32 α
'"'"'S.sub.1 +β
'"'"'S.sub.2 -γ
'"'"'S.sub.3 -δ
'"'"'S.sub.4wherein respective arithmetic operational ratios α
, β
, γ
, δ
, α
'"'"', β
'"'"', γ
'"'"', and δ
'"'"' of said first and second color signals are set so as to substantially satisfy the following condition
space="preserve" listing-type="equation">α
S.sub.1 +β
S.sub.2 =γ
S.sub.3 +δ
S.sub.4 or α
'"'"'S.sub.1 +γ
'"'"'S.sub.3 =β
'"'"'S.sub.2 +δ
'"'"'S.sub.4.
1 Assignment
0 Petitions
Accused Products
Abstract
A color video camera using a solid-state image pickup device having filters of the complementary color system consisting of a filter to transmit the light of all colors, a filter to transmit the yellow light, a filter to transmit the cyan light, and a filter to transmit the green light can obtain color signals having no color aliasing by selecting the conditions of the arithmetic operating processes of the signals corresponding to the respective filters. In these conditions, assuming that the signals corresponding to the four kinds of filters are represented by W, Ye, Cy and G in correspondence to the colors of the respective filters, a red signal and a blue signal are produced by the arithmetic operations represented by the following expressions:
R=αW-βCy+γYe-δG
B=α'"'"'W+β'"'"'Cy-γ'"'"'Ye-δ'"'"'G
wherein the respective arithmetic operational ratios α, β, γ, δ, α'"'"', β'"'"', γ'"'"', and δ'"'"' are set so as to satisfy the condition of the following expression:
αW+βCy=γYe+δG or
α'"'"'W+γ'"'"'Ye=β'"'"'Cy+δ'"'"'G.
This setting is realized by setting the amplification factors of the amplifiers to amplify the respective signals which are output in correspondence to the respective filters so as to meet this condition and by adding and subtracting those outputs.
26 Citations
10 Claims
-
1. A signal processing apparatus for obtaining a video signal in which color aliasings were suppressed for a color video camera having an image pickup device consisting of a number of photoelectric converting elements which are two-dimensionally arranged and four kinds of color separation optical filters which are repetitively arranged on the surfaces of said photoelectric converting elements in accordance with a predetermined order, said signal processing apparatus comprising:
-
an image pickup device for outputting a first signal, a second signal, a third signal, and a fourth signal respectively corresponding to said four kinds of color separation optical filters; and color signal producing means for producing a first color signal and a second color signal by processing said first to fourth signals on the basis of arithmetic operations of the following expressions;
space="preserve" listing-type="equation">C.sub.1 =α
S.sub.1 -β
S.sub.2 +γ
S.sub.3 -δ
S.sub.4
space="preserve" listing-type="equation">C.sub.2 32 α
'"'"'S.sub.1 +β
'"'"'S.sub.2 -γ
'"'"'S.sub.3 -δ
'"'"'S.sub.4wherein respective arithmetic operational ratios α
, β
, γ
, δ
, α
'"'"', β
'"'"', γ
'"'"', and δ
'"'"' of said first and second color signals are set so as to substantially satisfy the following condition
space="preserve" listing-type="equation">α
S.sub.1 +β
S.sub.2 =γ
S.sub.3 +δ
S.sub.4 or α
'"'"'S.sub.1 +γ
'"'"'S.sub.3 =β
'"'"'S.sub.2 +δ
'"'"'S.sub.4. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A method of producing color signals to produce a color television signal with less aliasing interference in a color video camera having an image pickup device consisting of a number of photoelectric converting elements which are two-dimensionally arranged and four kinds of color separation optical filters which are repetitively arranged on the surfaces of said photoelectric converting elements in accordance with a predetermined order, said color signal producing method comprising the steps of:
-
taking out a first signal, a second signal, a third signal, and a fourth signal respectively corresponding to said four kinds of color separation optical filters from said image pickup device; and producing two color signals by arithmetically operating said first to fourth signals on the basis of the following expressions
space="preserve" listing-type="equation">C.sub.1 =α
S.sub.1 -β
S.sub.2 +γ
S.sub.3 -δ
S.sub.4
space="preserve" listing-type="equation">C.sub.2 =α
'"'"'S.sub.1 +β
'"'"'S.sub.2 -γ
'"'"'S.sub.3 -δ
'"'"'S.sub.4wherein respective arithmetic operational ratios α
, β
, γ
, δ
, α
'"'"', β
'"'"', γ
'"'"', and δ
'"'"' are set so as to substantially satisfy the following condition
space="preserve" listing-type="equation">α
S.sub.1 +β
S.sub.2 =γ
S.sub.3 +δ
S.sub.4 or α
'"'"'S.sub.1 +γ
'"'"'S.sub.3 =β
'"'"'S.sub.2 +δ
'"'"'S.sub.4.
-
-
9. A color video camera having a solid-state image pickup device consisting of a number of photoelectric converting elements which are two-dimensionally arranged and four kinds of color separation optical filters which are repetitively arranged on the surfaces of said photoelectric converting elements in accordance with a predetermined order, said color video camera comprising:
-
a solid-state image pickup device having four kinds of color separation optical filters consisting of a transparent filter to transmit lights of all colors, a yellow filter to transmit a yellow light, a cyan filter to transmit a cyan light, and a green filter to transmit a green light; four amplifiers for respectively amplifying four kinds of signals consisting of a W signal, a Ye signal, a Cy signal, and a G signal corresponding to said four kinds of color separation optical filters which are output from said solid-state image pickup device; a color signal producing circuit for producing a red signal R and a blue B signal by arithmetically operating said four kinds of signals on the basis of the relation of the following expressions
space="preserve" listing-type="equation">R=α
W-β
Cy+γ
Ye-δ
G
space="preserve" listing-type="equation">B=α
'"'"'W+β
'"'"'Cy-γ
'"'"'Ye-δ
'"'"'Gwherein respective arithmetic operational ratios α
, β
, γ
, δ
, α
'"'"', β
'"'"', γ
'"'"', and δ
'"'"' are set so as to substantially satisfy the following condition
space="preserve" listing-type="equation">α
W+β
Cy=γ
Ye+δ
G or α
'"'"'W+γ
'"'"'Ye=β
'"'"'Cy+δ
'"'"'G;a luminance signal producing circuit for producing a first luminance signal having a wide band frequency component and a second luminance signal having a narrow band frequency component which is used to obtain color difference signals on the basis of said four kinds of W, Cy, Ye, and G signals which are output from said solid-state image pickup device; a signal processing circuit for producing a desired luminance signal and two kinds of color difference signals from the red signal, the blue signal, and the first and second luminance signals which are output from said color signal producing circuit and said luminance signal producing circuit; and a color encoder for generating a color television signal in accordance with a desired television system from said desired luminance signal and two kinds of color difference signals which are obtained from said signal processing circuit. - View Dependent Claims (10)
-
Specification