JPH10136242A - Digital still camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the image quality of a panoramic image by enlarging the image obtained by eliminating the upper end and the lower end of a standard image in vertical/lateral directions at a specified ratio. SOLUTION: The upper end and the lower end of the standard image is eliminated by 1/n. The obtained first image is multiplied by [n/(n-2)]<1/2> times in the vertical/lateral directions and the panoramic image is generated. CCD14 image-pickup up the standard image, it is photoelectrically converted and it is written into VRAM 22 of 640 image elements ×480 lines. The digital image is read from an area except for 1/4 of the upper end and 1/4 of the lower end of VRAM 22 with (n) as '4', namely, 120 lines for respective parts, and it is set to be first image signal. The first image signal is separated into R, G and B signal in a color separation circuit 26 and they are written into respective VRAM of a zoom circuit 28. Then, they are read by vertical read address VRAD=(1/2)<1/2> ×a and horizontal read address HRAD=(1/2)<1/2> ×b. Then, the panoramic image of 896 image elements × 336 lines, which is V2 times in the vertical/lateral directions, is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital still camera, and more particularly, to a digital still camera for taking a panoramic image, for example.

[0002]

2. Description of the Related Art In a conventional digital still camera of this type, a single panoramic image is generated by connecting a plurality of different images which have been separately photographed.

[0003]

However, in this case, there is a time lag between the images to be connected, and there is a possibility that the image quality of the panoramic image is degraded. That is, if a moving object is included in the subject, the moving object may be shifted at a joint. Therefore, a main object of the present invention is to provide a digital still camera capable of improving the quality of a panoramic image.

[0004]

According to the present invention, there is provided a digital still camera for photographing a panoramic image, a first generating means for generating a first image by deleting 1 / n of a standard image at an upper end and a lower end, respectively. And the first image in the vertical and horizontal directions {n / (n-2)}
^A digital still camera including a second generation unit that generates a panoramic image by multiplying by ^1/2 .

[0005]

First, a first image in which 1 / n of the upper end and the lower end of the standard image is deleted is generated, and then the first image is {n / (n-2)} ^{1/2 in the} vertical and horizontal directions. By multiplying, a panoramic image is generated. In the first generation unit, for example, the output unit outputs a standard image signal, and the writing unit writes the standard image signal in the first video memory.
Then, the reading means reads the first image signal from the first video memory. On the other hand, in the second generation unit, for example, the plurality of color signals included in the first image signal are written into the plurality of second video memories by the writing unit, for example.
The plurality of color signals are read from the plurality of second video memories by the reading means. At the time of reading, the read means reads the vertical read address VRAD according to Equations 3 and 4.
And a horizontal read address HRAD.

[0006]

## EQU3 ## VRAD = {(n-2) / n} ^1/2 × a, where fractions are rounded down a: Integer incremented for each line

[0007]

HRAD = {(n−2) / n} ^1/2 × b where the fractional part is truncated. B: Integer incremented for each pixel

[0008]

According to the present invention, a panoramic image is photographed based on one standard image. Therefore, even if a moving object is included in the subject, the moving object does not shift and the generated panoramic image is generated. Image quality can be improved. Further, while deleting 1 / n of the upper end and the lower end of the standard image, the first image is vertically and horizontally shifted.
Since the size is multiplied by {n / (n-2)}, the file size of the panoramic image becomes the same as that of the standard image, and there is no need to distinguish between the standard image and the panoramic image during data compression.

The above objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

[0010]

Referring to FIG. 1, a digital still camera 10 according to this embodiment includes a wide-angle lens 12, through which a light image of a subject is irradiated onto a CCD 14. Therefore,
The CCD 14 captures a standard image and generates electric charges by photoelectrically converting the standard image. This charge is output in accordance with the horizontal transfer pulse and the vertical transfer pulse from the timing generator 16, and the CDS / AGC is output as a camera signal.
The circuit 18 is provided. The CDS / AGC circuit 16 generates a standard image signal by correlating double sampling of the camera signal, and automatically adjusts the gain thereof. The standard image signal whose gain has been adjusted is then A
/ D converter 20 converts the data into digital data,
According to a write signal from the M control CPU 24, the data is written to the VRAM 22 having a memory capacity equivalent to 640 pixels × 480 lines as shown in FIG. And VRAM
Digital data is read from an area of the VRAM 22 excluding the hatched portion by a read signal from the control CPU 24. That is, digital data is read from the area of the VRAM 22 excluding the upper 120 lines and the lower 120 lines, and becomes the first image signal. Therefore,
The first image is a top 1/4 and a bottom 1 / of the standard image.
4 is the deleted image. In this embodiment, n = 4
The operation will be described as follows.

The first image signal is then applied to a color separation circuit 26 where it is separated into an R signal, a G signal and a B signal.
That is, R, as shown in FIG.
Since the G and B mosaic type color filters 38 are mounted and only one color signal of R, G and B can be obtained from each charge accumulation area, the missing two colors of each pixel are provided. Color separation is performed by interpolating the color signals with the average value of the surrounding color signals of the same color. The R signal, G signal and B signal thus obtained are
VRAM control CPU 28d of zoom circuit 28 shown in FIG.
VRAM 28a for R signal, VRAM for G signal
28b and the B signal VRAM 28c.
Here, an R signal VRAM 28a and a G signal VRAM2
Each of the 8b and B signal VRAMs 28c has a memory capacity corresponding to 640 pixels × 240 lines as shown in FIG. Is written. At the time of reading, the R signal, the G signal, and the B signal are read according to the read enable signal and the address signal from the VRAM control CPU 28d. However, when reading, V
The RAM control CPU 28d specifies the vertical direction read address VRAD and the horizontal direction read address HRAD obtained by Expressions 5 and 6.

[0012]

VRAD = (1/2) ^1/2 × a where the fractional part is truncated. A: Integer incremented from 0 to 239 for each line

[0013]

HRAD = (1/2) ^1/2 × b where the fractional part is truncated. B: An integer incremented from 0 to 639 for each pixel. Therefore, the same data is read from the address a plurality of times depending on the address. As a result, the image composed of the read R signal, G signal and B signal is obtained by multiplying the first image by 縦 2 in the vertical and horizontal directions.
A panoramic image of 6 pixels × 336 lines is obtained.

The R signal, the G signal and the B signal are then applied to a YUV conversion circuit 30, and the respective data are substituted into Equation 7 for each pixel to convert the data into a Y signal, a U signal and a V signal. Is converted.

[0015]

## EQU7 ## Y = 0.2990 × R + 0.5870 × G +
0.1140 × BU = −0.1684 × R−0.3316 × G + 0.50
00 × B V = 0.5000 × R−0.4187 × G−0.081
3 × B Each data of the Y signal, U signal and V signal is compressed by the compression circuit 32 by the JPEG system, and the compressed image data generated by this is stored in the memory control CP.
The data is written to the memory 34 by U36. The number of pixels and the number of lines of the panoramic image are added to the header of the compressed image data.

By generating a panoramic image based on one standard image in this way, even if a moving object is included in the subject, the moving object does not shift as in the prior art, and the image quality of the panoramic image is improved. Can be done. In addition, a first image is generated by deleting 1 / n of the upper end and the lower end of the standard image written in the VRAM 22, and the first image is vertically and horizontally shifted by √ ｛n / (n -2) By multiplying by｝, the file size of the generated panoramic image becomes the same as the standard image, so that the image data can be compressed by the common JPEG method without distinguishing the standard image and the panoramic image.

In this embodiment, the first image is obtained by reading out the standard image written in the VRAM 22 except for 1 / n of the upper end and the lower end. However, the VRAM having a capacity corresponding to the first image is obtained. Prepare the first
Only the image signal may be selectively written. Further, only the charge corresponding to the first image may be output from the CCD 14.

The color separation circuit 26 may generate the R, B, and G signals in the following manner. That is, focusing on any four pixels (two vertical pixels × two horizontal pixels) of the mosaic filter 38 shown in FIG. 3, the average value of the two G pixels included therein is set as the G signal at the center of the four pixels. Also, B at the center of the four pixels
The signal doubles the value of one B pixel included in the four pixels and doubles the value of the two B pixels closest to the center of the four pixels in the horizontal and vertical directions of the B pixel. Is added to the value of the B pixel, and the addition result is 1 /
It is obtained by setting it to 4. The R signal is obtained similarly to the B signal.

For example, considering a block surrounded by a thick line in FIG. 3, the average of two G pixels included in the block is a G signal at the center of the block. Also, by adding a value twice as large as the B pixel included in the block and the value of the B pixel located at the second pixel in the rightward and downward directions of the B pixel, and 、 the added value, The B signal at the center of the block is obtained. Further, by adding the value twice as large as the R pixel included in the block and the R pixel located at the second pixel in the left direction and the upper direction of the R pixel and reducing the added value to 1/4, R signal at the center of is obtained.

By generating the R, B, and G signals in this manner, an image with excellent image quality can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is an illustrative view showing a VRAM;

FIG. 3 is an illustrative view showing a mosaic type color filter;

FIG. 4 is a block diagram illustrating a zoom circuit.

FIG. 5 is an illustrative view showing a VRAM used in the zoom circuit 28;

[Explanation of symbols]

 14: CCD 22: VRAM 24: VRAM control CPU 28: Zoom circuit 32: Compression circuit

Claims (3)

[Claims] 1. A digital still camera for taking a panoramic image, wherein a first generating means for generating a first image by deleting 1 / n of a standard image at an upper end and a lower end, respectively.
And the first image is vertically and horizontally shifted by ｛n / (n
-2) A digital still camera, comprising: second generation means for generating the panoramic image by multiplying by｝ ^1/2 . A first video memory for storing the standard image signal; a first video memory for storing the standard image signal; a writing unit for writing the standard image signal in the first video memory; 2. The digital still camera according to claim 1, further comprising a reading unit that reads a first image signal from the first memory. 3. A second video memory for storing a correlation signal correlated with a first image signal, a writing unit for writing the correlation signal in the second video memory, and the second video memory. VRAD = {(n−2) / n} ^1/2 × a where the fractional part is truncated. A: Integer incremented for each line HRAD = {(n−2) / n} ^1/2 × b where the fractional part is rounded down. B: an integer that is incremented for each pixel. 3. The digital still camera according to claim 1, wherein a direction read address HRAD is specified.