Digital camera, storage medium for image signal processing, carrier wave and electronic camera

• US 7,253,836 B1
• Filed: 02/04/2000
• Issued: 08/07/2007
• Est. Priority Date: 06/30/1998
• Status: Expired due to Term

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Juen, Masahiro, Suzuki, Masahiro, Chen, Zhe-Hong, Tamune, Michihiro
• Primary Examiner(s): Srivastava; Vivek
• Assistant Examiner(s): Henn; Timothy J.
• Application Number:
  US09/497,482
• Time in Patent Office: 2,741 Days
• Field of Search: 348/222.1, 348/231.1, 348/234, 382/260, 382/262, 382/264
• US Class Current: 348/234
• CPC Class Codes: H04N 2101/00 Still video cameras
• CPC Class Codes: H04N 23/88 for colour balance, e.g. white-balance circuits or colour temperature control
• CPC Class Codes: H04N 5/765 Interface circuits between an apparatus for recording and another apparatus
• CPC Class Codes: H04N 5/772 the recording apparatus and the television camera being placed in the same enclosure
• CPC Class Codes: H04N 5/775 between a recording apparatus and a television receiver
• CPC Class Codes: H04N 5/781 on disks or drums
• CPC Class Codes: H04N 5/907 using static stores, e.g. storage tubes or semiconductor memories H04N5/91 takes precedence
• CPC Class Codes: H04N 9/7921 for more than one processing mode
• CPC Class Codes: H04N 9/8047 using transform coding

Abstract

A CCD captures a subject image having passed through a taking lens and an image processing circuit performs various types of image pre-treatment including gamma correction and white balance on image data corresponding to n lines×m rows output by the CCD. The image processing circuit also performs format processing on the data. The data are then compressed at a compression circuit. The white balance adjustment and the like are implemented in line sequence at a line processing circuit which engages in signal processing in pixel sequence in units of individual lines in the output from the CCD. The image data having undergone the pre-treatment are then subjected to format processing prior to JPEG compression, at a block processing circuit that engages in signal processing in units of individual blocks each ranging over an n×m (N>n, M>m) block. In other words, the signal processing is performed in block sequence.

Claims

1. A digital camera comprising:

an image-capturing device that captures a subject image having passed through a taking lens and outputs image data;

a first image processing circuit that first performs pre-treatment on image data corresponding to N lines X M rows output by said image-capturing device in line sequence to create a first image data;

a first memory device in which the first image data is temporarily stored;

a second image processing circuit that performs format processing appropriate for recording processing on the first image data stored in said first memory device in units of blocks each ranging over n lines X m rows (N>

n, M>

m, n and m each are equal to or greater than

     2) in block sequence, so as to create a second image data having a block size of (n−

i) X (m−

j), wherein i and j are integers having values of at least 1, in the format processing, the first image data are processed through a plurality of intermediate image processing steps to create the second image data, each of the intermediate image processing steps outputting a block of intermediate image data that is temporarily stored in corresponding memory areas, the block of intermediate image data output from one of the intermediate image processing steps being input to a subsequent one of the intermediate image processing steps to ultimately generate the second image data, a block size of the blocks of intermediate image data output by the intermediate image processing steps becoming smaller sequentially to ultimately obtain the block size of (n−

i) X (m−

j); and

a recording processing circuit that performs recording processing on the second image data, wherein the block size of the (n−

i) X (m−

j) for the second image data is used for the recording processing.

2. A digital camera according to claim 1, wherein:

said recording processing circuit is constituted of a compression circuit that compresses the image data.

3. A digital camera according to claim 2, wherein:

the second image processing circuit creates brightness data represented by (n−

i2) lines X (m−

j2) rows of image data and a color difference data represented by (n−

i3) lines X (m−

j3) rows of image data, based upon a partial image data with n lines X m rows of the first image data, and

both the brightness data and the color difference data are appropriate for compression performed in the compression circuit.

4. A digital camera according to claim 1, wherein:

said pre-treatment includes gamma correction and white balance correction, and said format processing includes interpolation processing, LPF processing, BPF processing and color difference signal calculation processing.

5. A digital camera according to claim 1, further comprising:

a second memory device in which the second image data is temporarily stored, wherein the recording processing circuit performs the recording processing on the second image data stored in the second memory device.

6. A digital camera according to claim 5, wherein:

the first memory device and the second memory device are the same memory device.

7. A digital camera according to claim 1, wherein:

the first memory device temporarily stores at least one frame of the first image data.

8. A digital camera according to claim 1, wherein:

the format processing includes a median processing on the first image data, which have undergone the pre-treatment, corresponding to an n X m pixel area block.

9. A digital camera according to claim 8, wherein:

the median processing is performed on (n−

i1) X (m−

j1) sets of image data extracted from the first image data corresponding to the n X m pixel area.

10. A digital camera according to claim 1, wherein:

the image capturing device captures a subject image to output an analog imaging signal and includes an A/D converter that converts the analog imaging signal to the image data that is digital.

11. A computer-readable recording medium that stores an image processing program that is executable by a computer, the image processing program comprising:

a first image processing instruction that causes the computer to perform pre-treatment on image data corresponding to N lines X M rows of image data captured by an imaging device, in line sequence to create a first image data;

a storing instruction that causes the computer to temporarily store the first image data in a first memory device;

a second image processing instruction that causes the computer to perform format processing appropriate for recording processing on the first image data stored in the first memory device, in units of blocks each ranging over n lines X m rows (N>

n, M>

m, n and m each are equal to or greater than

     2) in block sequence, so as to create a second image data having a block size of (n−

i) X (m−

j), wherein i and j are integers having values of at least 1, in the format processing, the first image data are processed through a plurality of intermediate image processing steps to create the second image data, each of the intermediate image processing steps outputting a block of intermediate image data that is temporarily stored in corresponding memory areas, the block of intermediate image data output from one of the intermediate image processing steps being input to a subsequent one of the intermediate image processing steps to ultimately generate the second image data, a block size of the blocks of intermediate image data output by the intermediate image processing steps becoming smaller sequentially to ultimately obtain the block size of (n−

i) X (m−

j); and

a recording processing instruction that causes the computer to perform recording processing on the second image data, wherein the block size of the (n−

i) X (m−

j) for the second image data is used for the recording processing.

12. A computer-readable recording medium according to claim 11, wherein:

said recording processing is compression processing in which the second image data are compressed.

13. A computer-readable recording medium according to claim 11, wherein:

said pre-treatment includes gamma correction and white balance correction and said format processing includes interpolation processing, LPF processing, BPF processing and color difference signal calculation processing.

14. A digital camera comprising:

an image-capturing device that captures a subject image having passed through a taking lens and outputs image data;

a recording processing circuit that performs recording processing on image data; and

an image processing circuit that, with the image data output by said image-capturing device input as data corresponding to n lines X m rows, calculates color difference signals based upon the image data thus input, performs interpolation processing and low pass filtering processing simultaneously on said color difference signals using filter coefficients for interpolation/low pass filtering and then performs matrix processing appropriate for recording performed at said recording processing circuit to generate a formatted signal, wherein

the interpolation processing and the low pass filtering processing are carried out by an arithmetic operation and further color difference signals obtained by the interpolation processing are assigned to pixels originally having no color difference signal.

15. A digital camera according to claim 14, wherein:

said recording processing circuit is constituted of a compression circuit that compresses the image data.

16. A digital camera according to claim 14, further comprising:

a median processing circuit that performs a median processing on images having undergone the interpolation processing and the low pass filtering processing.

17. A computer-readable storage medium that stores an image processing program that is executable by a computer, the program having instructions that cause the computer to perform:

format processing to format image data of an image captured at an image-capturing device for recording, in which color difference signals corresponding to n lines X m rows are calculated using image data that are input, interpolation processing and low pass filtering processing are performed simultaneously on the color difference signals corresponding to n lines X m rows using filter coefficients for interpolation/low pass filtering and then a formatted signal is generated by implementing matrix processing; and

recording processing in which image data having undergone said format processing are recorded, wherein

the interpolation processing and the low pass filtering processing are carried out by an arithmetic operation and further color difference signals obtained by the interpolation processing are assigned to pixels originally having no color difference signal.

18. A computer-readable storage medium according to claim 17, wherein:

said recording processing is compression processing in which said image data are compressed.

19. A computer-readable storage medium according to claim 17, wherein the program further causes the computer to perform:

a median processing on images having undergone the interpolation processing and the low pass filtering processing.