Electric still camera having a plurality of image pickup elements with color filters

• US 5,528,292 A
• Filed: 12/20/1994
• Issued: 06/18/1996
• Est. Priority Date: 03/13/1991
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Ikeda, Keiichi
• Primary Examiner(s): Metjahic, Safet
• Assistant Examiner(s): HSIA, SHERRIE Y
• Application Number:
  US08/359,848
• Time in Patent Office: 546 Days
• Field of Search: 348/222, 348/273, 348/272, 348/395, 348/403, 348/607, 348/616, 348/619, 348/240, 348/239, 348/231, 348/233, 358/41-44, 358/133, 358/909, 358/136, 358/335, 358/310, 358/909.1, 358/906
• US Class Current: 348/222.1
• CPC Class Codes: G06T 3/4007 based on interpolation, e.g. bilinear interpolation image demosaicing G06T3/4015; edge-driven or edge-based scaling G06T3/403
• CPC Class Codes: G06T 3/4015 Image demosaicing, e.g. colour filter arrays [CFA] or Bayer patterns
• CPC Class Codes: H04N 1/648 Transmitting or storing the primary (additive or subtractive) colour signals; Compression thereof H04N1/642 - H04N1/646 take precedence
• CPC Class Codes: H04N 2209/046 Colour interpolation to calculate the missing colour values
• CPC Class Codes: H04N 23/10 for generating image signals from different wavelengths
• CPC Class Codes: H04N 23/843 Demosaicing, e.g. interpolating colour pixel values
• CPC Class Codes: H04N 25/134 based on three different wavelength filter elements
• CPC Class Codes: H04N 9/804 involving pulse code modulation of the colour picture signal components

Abstract

An electronic still camera includes a plurality of image pickup elements having color filters of a plurality of colors; a color separation unit for separating outputs from the image pickup elements into each color signal; an interpolation unit for receiving an output from the color separation unit and interpolating missing part of each color image data; an orthogonal transformation unit for dividing respective color image data interpolated by the interpolation unit into a plurality of blocks and performing orthogonal transformation, a coding unit for coding an output from the orthogonal transformation unit; and a storage unit for storing an output from the coding unit.

Claims

1. An electronic still camera comprising:

a plurality of image pickup elements having color filters of a plurality of colors, said color filters including filter portions whose positions in the horizontal direction are different from each other for every horizontal line;

color separation means for separating outputs from said image pickup elements into each color signal;

interpolation means for correcting the difference between the positions of the filter portions by interpolating an output signal of said separation means using a predetermined interpolation method, said interpolation means comprising interpolation changing means for changing the predetermined interpolation method; and

orthogonal transformation means for dividing respective color image data interpolated by said interpolation means into a plurality of blocks and performing orthogonal transformation.

2. An electronic still camera according to claim 1, wherein said interpolation means interpolates missing part of the image data for only one color of said plurality of colors.

3. An electronic still camera according to claim 1, wherein said orthogonal transformation means comprises discrete cosine transformation.

4. An electronic still camera according to claim 1, further comprising storage means for storing a coded output of said orthogonal transformation means.

5. An electronic still camera according to claim 4, wherein said storage means comprises a memory card as a storage medium.

6. An image pickup device comprising:

(a) image pickup means for converting light incident to pixels via a color filter into an electrical signal, said color filter including filter portions for passing different colors for every pixel, whose positions in the horizontal line are different from each other for every horizontal line;

(b) interpolation means for correcting the difference between the positions of said filter portions by interpolating the electrical signal converted from the light incident through said filter portions by said image pickup means using a predetermined interpolation method, said interpolation means comprising interpolation changing means for changing the predetermined interpolation method; and

(c) orthogonal transformation means for performing orthogonal transformation of the interpolated electrical signal by dividing said signal into a plurality of blocks.

7. An image pickup device according to claim 6, wherein said different colors of said color filter are disposed in a Bayer matrix.

8. An image pickup device according to claim 6, wherein said orthogonal transformation means comprises discrete cosine transformation.

9. An image pickup device according to claim 6, wherein said interpolation changing means comprises interpolation switching means for switching the predetermined interpolation method to be used by said interpolation means.

10. An image pickup device according to claim 6, further comprising storage means for storing coded output of said orthogonal transformation means.

11. An image pickup device according to claim 10, wherein said storage means comprises a memory card as a storage medium.

12. An apparatus comprising:

(a) input means for inputting an image signal, said input means inputting respective components of said image signal in a predetermined order;

(b) interpolation means for interpolating the image signal by a predetermined interpolation method, the predetermined interpolation method being changeable;

(c) means for designating the predetermined interpolation method according to the predetermined order; and

(d) orthogonal transform means for orthogonally transforming an output signal of said interpolation means.

13. An apparatus according to claim 12, wherein said orthogonal transform means comprises a discrete cosine transform circuit.

14. An apparatus according to claim 12, wherein said input means comprises a CCD and a color filter provided in front of said CCD, and an arrangement of the color filter corresponds to the predetermined order.

15. An apparatus according to claim 12, wherein said designating means automatically designates the predetermined interpolation method according to the image signal.