JP3295951B2 - Electronic camera - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic camera provided with a gamma correction device.

[0002]

2. Description of the Related Art Conventionally, as an electronic camera provided with a gamma correction device, there is an electronic camera configured as shown in FIG.

In FIG. 1, reference numeral 1 denotes a CCD.
Captures an image of a subject (not shown) via the lens 2. C
An image signal picked up by the CD 1 is supplied to the amplifier 3 and amplified, and is supplied to the analog gamma correction circuit 4. Then, the analog gamma correction circuit 4 applies gamma correction to the input signal from the amplifier 3 so that the luminance signal is correctly proportional to the input signal. Then, the analog signal is supplied to the A / D converter 5 and converted into a digital signal.

In this state, when the electronic camera performs video through before capturing a still image,
When viewing images from a CD, the switches 61 and 62
The contact a is selected, and the image signal digitized by the A / D converter 5 is directly supplied to the enhancer unit 7 through the switches 61 and 62, and is output as a luminance signal with the outline emphasized. In the case of still image shooting,
First, in the switch 61, the contact c is selected, the image signal of the odd field is stored in the memory 8 via the switch 61, and then the contact b of each of the switches 61 and 62 is selected, and the image signal of the even field is switched. The signal is supplied to the adder 9 via the switch 61, where it is added to the image signal of the odd field stored in the memory 8, and the result is added as a frame still image signal via the switch 62 to the enhancer unit 7.
And output as a luminance signal in which the contour is emphasized.

[0005]

However, according to the electronic camera constructed as described above, since the image signals of the odd field and the even field are respectively added with the gamma-corrected image signals, the result is as follows. As a result, the faithful gamma correction is not performed on the frame still image signal, which may cause significant deterioration of the frame image.

The present invention has been made in view of the above circumstances. For example, a gamma capable of performing gamma correction suitable for each of still image signals in different situations such as video through and recording of a still image. An object of the present invention is to provide an electronic camera including a correction unit.

[0007]

SUMMARY OF THE INVENTION According to the present invention, there is provided an image pickup means for picking up an image of a subject, and a field picked up by the image pickup means.
A first gamma correction means for applying gamma correction to the field image signal from the image signal captured by the imaging means
Means for generating a frame still image signal, a second gamma correction means for applying gamma correction to the still image signal generated by this means, when video through and still
The first gamma correction means and the second
Switch means for switching the gamma correction means .

[0008]

As a result, according to the present invention, for example, at the time of video through, the captured image captured by the imaging means is captured.
The first gamma correction unit applies gamma correction to the image signal, and during still image capturing and recording, a frame still image signal is converted from the image signal captured by the image capturing unit.
Is generated and gamma correction is performed by the second gamma correction means, so that appropriate gamma correction can be performed, so that high-quality images can be obtained.

[0009]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a schematic configuration of the embodiment. In the figure, reference numeral 11 denotes a CCD, which captures an image of a subject (not shown) via a lens 12. C
The image signal picked up by the CD 11 is supplied to the amplifier 13 and amplified.

The output of the amplifier 13 is given to a switch 14. The switch 14 has contacts a and b. When the contact a is selected, the output of the amplifier 13 is changed to the analog gamma correction circuit 1.
5, and when the contact b is selected, the signal is applied to the switch 16.

Here, the analog gamma correction circuit 15
Gamma correction is performed so that the luminance signal is correctly proportional to the input signal from the amplifier 3. Switch 16
Has switching contacts a and b, outputs the image signal corrected by the analog gamma correction circuit 15 when the contact a is selected, and outputs the image signal from the switch 14 as it is when the contact b is selected. . The output that has passed through the switch 16 is provided to an A / D converter 17 and converted into a digital signal. Then, it is given to the switch 18.

The switch 18 has contacts a, b, and c.
The output from the / D converter 17 is given to the switch 19 when the contact a is selected, and is given to the adder 20 when the contact b is selected.
When the contact b is selected, it is given to the memory 21.

Here, the memory 21 stores the A / D converter 17
An odd-numbered image signal provided from the memory is stored. Further, the adder 20 includes an A / D converter 17.
Image signal of even field given from memory and memory 21
Is added to the image signal of the odd-numbered field stored in the memory and output as a frame still image signal.
The output of the adder 20 is output to a digital correction circuit 22.
Give to. The digital gamma correction circuit 22 performs gamma correction so that the luminance signal is correctly proportional to the frame still image signal from the adder 20.

On the other hand, the switch 19 has switching contacts a,
When the contact a is selected, the image signal from the switch 18 is output as it is, and when the contact b is selected, the frame still image signal corrected by the digital gamma correction circuit 22 is output. Then, the output that has passed through the switch 19 is provided to the enhancer unit 23, and is output as a luminance signal whose outline is emphasized.

With such a configuration, first, when the electronic camera performs video through before capturing a still image, the contacts a are selected for the switches 14 and 16, and the switches 18 and 19 are also set for the switches 18 and 19, respectively. Contact a is selected.

In this state, the lens 12 is moved by the CCD 11.
When an image of a subject (not shown) is taken through the interface, the taken image signal is supplied to the amplifier 13 and amplified, and supplied to the analog gamma correction circuit 15 through the switch 14.

The analog gamma correction circuit 15 performs gamma correction so that the luminance signal is directly proportional to the input signal from the amplifier 13. The gamma-corrected image signal is supplied to an A / D converter 17 via a switch 16.
It is digitized here. Further, the digitized image signal is sent directly to the enhancer section 23 through the switches 18 and 19, where it is output as a luminance signal whose outline is emphasized.

Next, in the case of still image pickup, the switch 1
4 and 16, the contact b is selected, and the switch 18 selects the contacts c and b alternately.
Selects the contact b.

In this state, the lens 12 is moved by the CCD 11.
When an image of a subject (not shown) is taken through the camera, the taken image signal is applied to an amplifier 13 and amplified, applied to an A / D converter 17 through switches 14 and 16, and converted into a digital signal. . As for the digitized image signal, the odd-field image signal is stored in the memory 21 via the contact c of the switch 18 and the subsequent even-field image signal is sent to the adder 20 via the contact b of the switch 18. Can be

Then, in the adder 20, the image signal of the odd field and the image signal of the even field stored in the memory 21 are added and output as a frame still image signal. Given to.

The digital gamma correction circuit 22 performs gamma correction so that the luminance signal is correctly proportional to the frame still image signal. Then, the gamma-corrected image signal is sent to the enhancer unit 23 through the switch 19, where it is output as a luminance signal whose outline is emphasized.

Accordingly, in the case of video through, a signal obtained by adding gamma correction to the image signal picked up by the CCD 11 by the analog gamma correction circuit 15 at the time of video through is obtained. The odd-field and even-field image signals separated and taken by the CCD 11 are added to the adder 20.
After being added as a frame still image signal to generate a still image signal, a digital gamma correction circuit 22 can apply a gamma correction to the frame still image signal. It is possible to perform faithful gamma correction, thereby obtaining a high-quality frame image.

[0024]

According to the present invention, for example, at the time of video through, a field taken by the image pickup means is taken.
Gamma correction is performed on the scanned image signal by the first gamma correction unit, and during still image capturing and recording, a frame still image signal is generated from the image signal captured by the image capturing unit.
If the gamma correction is performed by the second gamma correction means and appropriate gamma correction can be performed, good quality images can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a schematic configuration of an example of a conventional electronic camera.

[Explanation of symbols]

11 CCD, 12 lens, 13 amplifier, 14, 1
6, 18, 19: switch, 15: analog gamma correction circuit, 17: A / D converter, 20: adder, 21: memory, 22: digital gamma correction circuit, 23: enhancer unit.

Claims (2)

(57) [Claims] 1. A imaging means for imaging an object, a first gamma correction means for applying gamma correction to the field image signal imaged by the imaging means, Flames from the image signal captured by the imaging means
In the means for generating a chill image signal, a second gamma correction means for applying gamma correction to the still image signal generated by this means, when video through and that during still image capturing, the first moth
Switching between the gamma correction means and the second gamma correction means
An electronic camera, characterized in that provided with the switch means that. 2. The gamma correction means according to claim 1, wherein said first gamma correction means comprises analog gamma correction means, and said second gamma correction means comprises digital gamma correction means.
Electronic camera as described.