Digital camera and image pickup device

• US 20030193580A1
• Filed: 03/28/2003
• Published: 10/16/2003
• Est. Priority Date: 03/29/2002
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: Okamoto, Satoru
• Granted Patent: US 7,333,139 B2
• Time in Patent Office: Days
• US Class Current: 348/222.1
• CPC Class Codes: H04N 23/84 for processing colour signals
• CPC Class Codes: H04N 25/134 based on three different wavelength filter elements
• CPC Class Codes: H04N 25/46 by combining or binning pixels
• CPC Class Codes: H04N 25/70 SSIS architectures; Circuits associated therewith
• CPC Class Codes: H04N 25/73 using interline transfer [IT]

Abstract

In a digital camera by the use of a CCD of a honeycomb array, the center positions of mixed pixels of colors B and G are fixed in (4k+1)th and (4k+2)th rows, wherein k represents an integer 0 or more, while the center positions of mixed pixels (mixed pixels R11 and R15) of a color R in the (4k+1)th row are required to be shifted to positions indicated by circles drawn by dotted lines in FIG. 4, as indicated by arrows in FIG. 4. For example, pixel values of the mixed pixels R11 and R15 are weighed in a weighing ratio of 1:3 so as to take a weighted average (i.e., (R11+3R15)/4) in such a manner that the center position of the mixed pixel R15 is shifted to a position obtained by dividing the distance between the center positions of the mixed pixels R11 and R15 at 3:1.

Claims

1. A digital camera for picking up an image of a subject by using an image pickup element provided with groups of pixels in a predetermined pixel array, so as to acquire image data representing the image of the picked-up subject, wherein

when the image data representing the subject and having a resolution lower than a highest resolution is generated by mixing pixels of the same color, center positions of the pixels of respective colors, which center positions are shifted by the mixing, are corrected so as to be uniformly arranged at least within respective rows.

3. A digital camera according to claim 1, wherein the center positions of the pixels of the respective colors are corrected such that an array of the corrected center positions of the pixels of the respective colors accords with the predetermined pixel array.

4. A digital camera according to claim 1, wherein each of the pixels in the pixel array receives light of one of first, second, and third colors;

and in the pixel array, a first row is composed of pixels for the first color and pixels for the second color disposed in alternation, a second row is composed of pixels for the second color and pixels for the third color disposed in alternation, and subsequent rows are alternating repetitions of the first row and the second row, in a first direction and in a second direction perpendicular to the first direction.

5. A digital camera according to claim 1, wherein each of the pixels in the pixel array receives light of one of first, second, and third colors;

and in the pixel array, each row is composed of pixels for the same color in a first direction, and pixels for the first, second, and third colors are disposed in alternation in a second direction perpendicular to the first direction.

2. A digital camera comprising:

an image pickup unit which is provided with groups of pixels in a predetermined pixel array, for receiving light corresponding to a subject via each of the pixels so as to pick up the subject, and which is able to pick up the subject at a resolution lower than a highest resolution by mixing the pixels of the same color; and

a correcting unit for correcting a result of picking-up by the image pickup unit such that center positions of the pixels of respective colors, which are shifted by the mixing, can be uniformly arranged at least within respective rows in the case where the subject is picked up by the image pickup unit at a resolution lower than the highest resolution.

6. A digital camera according to claim 2, further comprising a setting unit for setting an image pickup resolution of the image pickup element, wherein the image pickup element does not mix pixels in a case where the resolution set by the setting unit is the highest resolution, and the image pickup element mixes the pixels according to the set resolution in a case where the resolution set by the setting unit is lower than the highest resolution.

7. An image pickup device comprising:

an image pickup unit for picking up an image of a subject via a plurality of pixels in a predetermined pixel array, and obtaining pixel values of mixed pixels by mixing a plurality of pixel values for each group of a plurality of pixel groups, each of which is composed of a plurality of pixels acquired by the image pickup; and

a correcting unit for calculating a pixel value of a corrected pixel positioned among the plurality of mixed pixels obtained by the image pickup unit, based on positional information of the corrected pixel with respect to positions of the plurality of mixed pixels and the pixel values of the plurality of mixed pixels.

8. An image pickup device according to claim 7, wherein

the correcting unit weighs the pixel value of each of the plurality of mixed pixels based on the positional information of the corrected pixel with respect to the plurality of mixed pixels, so as to calculate the pixel value of the corrected pixel.

9. An image pickup device according to claim 8, wherein the positional information represents a ratio of distances from the corrected pixel to each of the plurality of mixed pixels.

10. An image pickup device according to claim 9, wherein a pixel value z of the corrected pixel located at a position dividing a distance between a first mixed pixel having a pixel value of x and a second mixed pixel having a pixel value of y at a ratio of a:

b is expressed by the following equation;

z=(bx+ay)/(a+b)

11. An image pickup device according to claim 7, wherein the image pickup unit outputs the pixel values of the mixed pixels as signals, and the correcting unit calculates the pixel value of the corrected pixel based on the pixel values of the mixed pixels, the signals of which have been output from the image pickup unit and have been subjected to signal processing.

12. An image pickup device according to claim 7, wherein the image pickup unit outputs the pixel values of the mixed pixels as signals, and the correcting unit calculates the pixel value of the corrected pixel based on the pixel values of the mixed pixels, the signals of which have been output from the image pickup unit and have not been subjected to a signal processing.