Image signal processing apparatus having a color filter with offset luminance filter elements

• US 5,323,233 A
• Filed: 07/25/1991
• Issued: 06/21/1994
• Est. Priority Date: 07/31/1990
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Sasaki, Takashi, Suga, Akira, Yamagami, Taku
• Primary Examiner(s): Groody, James J.
• Assistant Examiner(s): HSIA, SHERRIE Y
• Application Number:
  US07/735,796
• Time in Patent Office: 1,062 Days
• Field of Search: 358/41, 358/42, 358/43, 358/44
• US Class Current: 348/277
• CPC Class Codes: H04N 2209/046 Colour interpolation to calculate the missing colour values
• CPC Class Codes: H04N 23/84 for processing colour signals
• CPC Class Codes: H04N 25/133 including elements passing panchromatic light, e.g. filters passing white light
• CPC Class Codes: H04N 25/134 based on three different wavelength filter elements
• CPC Class Codes: H04N 25/135 based on four or more different wavelength filter elements

Abstract

An image detection apparatus includes a color filter for receiving light and for passing luminance components and color components of the light. The color filter has first and second lines which filter elements for luminance components disposed in each line and offset from filter elements for luminance components in an adjacent line, the first line including filter elements for two color components, and the second line including filter elements for a single color component. An image sensor unit receives the luminance and color components passed by the color filter, and outputs signals corresponding to the respective luminance components and color components. A signal processing unit receives the signal output by the image sensor unit, and generates a color difference signal from the received signals.

Claims

1. An image detection apparatus comprising:

color filter means for receiving light and for passing luminance components and color components of the light, said color filter means having first and second lines with filter elements for luminance components disposed in each line and offset from filter elements for luminance components in an adjacent line, said first line including filter elements for two color components, and said second line including filter elements for a single color component;

image sensor means for receiving the luminance components and the color components passed by said color filter means, and for outputting a plurality of signals corresponding to the respective luminance components and color components; and

signal processing means for receiving the plurality of signals output by said image sensor means, and for generating a color difference signal from the received plurality of signals.

2. An image detection apparatus according to claim 1, wherein the plurality of signals received by said signal processing means to generate the color difference signal saturate at substantially similar levels of image brightness.

3. An apparatus according to claim 1, wherein said signal processing means generates the color difference signal independent of a subset of the plurality of signals output by said image sensor means which correspond to the luminance components.

4. An apparatus according to claim 1, wherein said filter elements for luminance components comprise holes through said color filter means.

5. An apparatus according to claim 1, wherein said filter elements for luminance components comprise neutral density filter elements.

6. An apparatus according to one of claim 1, claim 4 or claim 5, wherein said color filter means comprises a set of color filter elements for color components of the light, and wherein said signal processing means generates the color difference signal from a subset of the plurality of signals output by said image sensor means which correspond to the color components.

7. An apparatus according to claim 6, wherein said set of color filter elements passes at least one of a cyan component, a yellow component, and a magenta component.

9. An apparatus according to claim 3 or claim 8, wherein each of the color components comprises one of a red component, a green component, and a blue component.

8. An image detection apparatus comprising:

color filter means for receiving light and for passing components of the light, said color filter means having first, second and third sets of filter elements for passing a first color component, a second color component and a third color component, respectively, of the light, and a fourth set of filter elements for passing a luminance component of the light, said first, second, third and fourth sets of filter elements being arranged to form first and second lines with said fourth set of filter elements for passing other luminance component disposed in each line and offset from said fourth set of filter elements for passing the luminance component in an adjacent line, said first line including said first and second sets of filter elements, and said second line including only said third set of filter elements in addition to said fourth set;

image sensor means for receiving the light components passed by said color filter means, and for outputting each of (i) a first color signal corresponding to the first color component passed by said first set of filter elements, (ii) a second color signal corresponding to the second color component passed by said second set of filter elements, (iii) a third color signal corresponding to the third color component passed by said third set of filter elements, and (iv) as luminance signal corresponding to the luminance component passed by said fourth set of filter elements; and

signal processing means for receiving the first, second and third color signals output by said image sensor means, and for generating, independent of the luminance signal, color difference signals from the first, second and third color signals.

10. A color filter for an image sensor, comprising:

a plurality of luminance filter elements for passing a luminance component of an image; and

first, second, and third color filter elements for passing first, second, and third color components, respectively, of the image,

wherein said color filter has first and second lines with luminance filter elements disposed in each line and offset from luminance filter elements in an adjacent line, said first line including two of said first, second, and third color filter elements, and said second line including a single one of said first, second, and third color filter elements.

11. A color filter according to claim 10, wherein the first, second, and third color components comprise a red component, a blue component, and a green component, respectively.

12. A color filter according to claim 10, wherein the first, second, and third color components comprise a cyan component, a yellow component, and a magenta component, respectively.

19. A color filter according to any one of claims 10, 13, 14, and 17, wherein said luminance filter elements comprise holes through said color filter.

20. A color filter according to any one of claims 10, 13, 14, and 17, wherein said luminance filter elements comprise neutral density elements.

13. A color filter for an image sensor, comprising:

a plurality of luminance filter elements for passing a luminance component of an image; and

first, second and third color filter elements for passing first, second and third color components, respectively, of the image, wherein at least one of the first, second and third color components comprises one of a cyan component, a yellow component, and a magenta component,

said color filter having first and second lines with luminance filter elements disposed in each line and offset from luminance filter elements in an adjacent line, said first line including said first and second color filter elements, and said second line including said third color filter elements.

14. A color filter for an image sensor, comprising:

first, second and third adjacent lines, each line comprising (i) luminance filter elements for passing luminance components of an image and (ii) color filter elements for passing a single color component of the image, said luminance filter elements being interleaved between each of said color filter elements, and said first, second, and third adjacent lines being arranged such that said luminance filter elements of said first line are offset from said luminance filter elements of said second line, and luminance filter elements of said second line are not offset from said luminance filter elements of said third line.

15. A color filter according to claim 14, wherein said color filter elements of said first and second lines are arranged in an offset pattern.

16. A color filter according to one of claim 14 or claim 15, wherein said color filter elements of said second and third lines comprise the same pattern without offset.

17. A color filter for an image sensor, comprising:

a plurality of luminance filter elements for passing a luminance component of an image;

a plurality of color filter elements for passing first, second and third color components of the image; and

first and second lines having said plurality of luminance filter elements and said plurality of color filter elements disposed in each line and offset from respective luminance filter elements and color filter elements in an adjacent line, said first line including color filter elements for passing said first and second color components of the image, and said second line including only said color filter elements for passing said third color component of the image in addition to said luminance filter elements.

18. A color filter according to claim 17, wherein said color filter elements for passing the third color component are arranged in an offset pattern from the color filter elements for passing said first and second color components of the image.