JP3130910B2 - Digital electronic still camera - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to a digital electronic still camera configured to digitally process a video signal obtained by imaging an object using an image sensor and record and reproduce a still image. It is about.

[Prior Art] Various proposals have been made for a digital electronic still camera. The outline of the proposal is as follows.

That is, an optical image of a subject is made incident on an image sensor such as a CCD through an optical system including a photographing lens, an aperture, a shutter mechanism, and the like. For the image sensor, a known horizontal and vertical read scan is performed, color signals R, G, and B are read from each pixel of the image sensor, and pre-processing such as gamma correction and contour enhancement is performed. For example, it is converted into a digital signal indicating a gradation of 8 bits (that is, 256 steps). The digitized color signals R, G, and B are supplied to a luminance / color difference signal separation circuit, and the luminance signal Y, the color difference signal R-
Y, BY are formed.

The luminance signal Y and the color difference signals RY and BY of the predetermined frequency components generated in this way are input to a data compression circuit to reduce the number of bits and reduce the storage capacity. The data-compressed luminance signal Y and color difference signals RY and BY are stored in a storage means, for example, a memory cartridge having a semiconductor memory (static RAM), via an input / output interface, and record and reproduce image data. Is made possible. The memory cartridge is configured to record image data of, for example, 26 frames and to be able to freely edit and delete the image data, which is very convenient.

However, according to the study of the present inventor, it has become clear that the digital electronic still camera having the above configuration has a problem to be further improved.

[Problems to be Solved by the Invention] That is, in a digital electronic still camera, various corrections such as contour enhancement and saturation enhancement are performed together with photographing, and the corrected image data is stored (stored) in storage means such as a memory cartridge. Some are configured as follows. However, if the saturation is increased too much, the color of the reproduced image may be saturated. If saturation occurs, the original image data, in other words, the uncorrected image data, is not stored even if an attempt is made to re-saturate, so the image corresponding to the original image data is reproduced. Cannot be re-saturated. Therefore, it is not possible to perform image reproduction and picture creation according to the user's preference during reproduction.

The above-mentioned inconvenience is the same for the outline emphasis, and once the outline emphasis is performed, the outline emphasis cannot be performed according to the preference of the user who reproduces the image.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problem, and an object of the present invention is to provide a digital electronic still camera capable of performing correction such as contour enhancement and saturation enhancement at any time of recording and reproduction. is there.

Means for Solving the Problems In order to achieve such an object, the present invention provides an image sensor, an A / D converter for converting a video signal read from the image sensor into a digital signal, A digital electronic still camera having storage means for storing image data based on a digital signal, wherein whether to perform saturation enhancement adjustment, contour enhancement, or coring level adjustment, which is a desired correction, on the image data during shooting When selecting or, when the correction value input at the time of correction selection and the original image data before correction are separated and stored in the storage means, and when the stored image data is read out and reproduced, When there is no correction, the saturation correction, contour enhancement, or coring level adjustment can be performed based on the new correction value set separately. In which it characterized in that a selection means for selecting Ukainaka.

[Operation] In the present invention having such a configuration, whether or not to correct image data at the time of shooting is selected, and when correction is selected, original image data before correction and a correction value are stored, respectively. The corrected image stored in the means can be reproduced. When non-correction is selected, the original image data that has not been corrected is stored in the storage means, so that when reading and reproducing, it is possible to newly perform desired correction and perform picture making and the like.

Embodiment An embodiment of a digital electronic still camera to which the present invention is applied will be described below with reference to FIG. FIG. 1 is a circuit block diagram of a digital electronic still camera configured to perform photographing and record / reproduce image data.

The lens 1 forms an optical system together with an aperture mechanism, a shutter mechanism, and the like (not shown), and forms an object image on the CCD image sensor 2.

The CCD image sensor 2 performs color signal R (red), G (green), B
(Blue) is supplied to the imaging system circuit 3 including a preamplifier and the like. The imaging system circuit 3 may be provided with a function for performing gamma correction, aperture correction, and the like. The A / D converter 4 converts the color signals R, G, and B into, for example, an 8-bit digital signal Va (25
(6 gradation image data) and output.

The memory control circuit 5 controls image data to be stored in and read from the memory circuit 6, and a luminance / color difference separation circuit 7.
, Control of the supply to the data compression circuit 8, and control of the coder / decoder 9 which performs modulation and demodulation in accordance with the recording / reproducing operation of the image data.

The luminance / color difference separation circuit 7 forms a digitized luminance signal Y and digitized color difference signals RY and BY. In addition, the chroma for the color difference signals RY and BY is also provided. It is configured so that up adjustment, edge enhancement for the luminance signal Y, and coring adjustment can also be performed. still,
The saturation increase adjustment will be described in detail in connection with the input device 21 and the system controller 22 described later.

The interface circuit 10 stores the compressed image data in the memory card 11 and transmits and receives signals when reproducing the image data read from the memory card. The memory card 11 includes a connector 12, an interface 13, a semiconductor memory circuit 14, and a power supply (not shown) for attaching and detaching the memory card 11 to and from the camera body so that signals can be transmitted. Since the memory circuit 14 is configured to store various correction values in the header portion and to store image data in the cluster portion, the memory circuit 14 will be described later in detail together with the circuit operation.

On the other hand, the A / D converter 15 and the encoder 16 constitute a reproduction system. The D / A converter 15 converts the digitized image data into analog image data, and the encoder 16 obtains R, G, B color signal outputs, NTSC television signal outputs, and the like.

The input device 21 corresponds to a selection means in the present invention, and is an input for performing an edge enhancement level, a coring level adjustment, and a saturation increase for the color difference signals RY and BY during recording and reproduction. Is performed, and a selection not to perform the adjustment input can be made. The system controller 22 comprehensively performs control corresponding to correction input by the input device 21, storage of image data from photographing, readout control during reproduction, and the like. Although illustration of the connection relationship between the system controller 22 and other circuit blocks is omitted, the connection is controllably connected to the CCD 2, the A / D converter 4, the memory control circuit 5, the luminance / color difference separation circuit 7, and the like. It is assumed that

 Next, a circuit operation at the time of photographing will be described.

First, a description will be given of a circuit operation in a case where a correction such as an increase in saturation is performed together with shooting. In this case, a correction value for increasing the saturation is input by the input device 21 prior to photographing.
At this time, a correction value for edge enhancement, a correction value for coring, and the like may be input at the same time.

The system controller 22 acts on the luminance / color difference separation circuit 7 in accordance with the correction value for increasing the saturation, so that the color difference signals RY and BY corresponding to the correction value are formed. Then, the CCD 2 is driven by the system controller 22, and the color signals R, G, B read out as described above are supplied to the A / D converter 4 via the imaging system circuit 3. The image data obtained from the A / D converter 4 is once supplied to the memory circuit 6 by the memory control circuit 5. However,
At this stage, the color signals R, G, B are in a field arrangement.

The image data stored in the memory circuit 6 is read out again by the memory control circuit 5 and supplied to the luminance / color difference separation circuit 7, where the luminance signal Y, the color difference signals RY and B-
Y is formed. At this time, the color difference signals RY and BY are corrected according to the correction value for increasing the saturation. Luminance signal Y, chroma-up corrected color difference signal R-
Y and BY are data compressed by a data compression circuit 8,
The image data is stored in the memory circuit 6 separately from the original image data.
The reading of image data from the memory circuit 6, the formation of the luminance signal Y, the color difference signals RY, BY, and the data compression are repeatedly performed, and finally the image data for one frame is stored in the memory circuit 6. .

Next, recording of image data will be described. The image data is modulated by the coder / decoder 9 and supplied to the memory circuit 14 via the interface 10, the connector 12, and the interface 13. The memory circuit 14 includes a plurality of header portions H and a plurality of cluster portions C as shown in an enlarged manner in FIG. Each header No0 to Non has a cluster N
o, an outline enhancement level A, a coring level B, a saturation up level R of the color difference signal RY, a saturation up level b of the color difference signal BY, and the like are stored. On the other hand, each cluster 0
ＮN sequentially store image data for one frame.

Note that the number of bits of the image data differs depending on the captured image. Therefore, in the present embodiment, when the image data for one frame is more than one cluster, the image data is continuously stored in an adjacent cluster, and when the image data for one frame is small, the empty portion is filled, so that the memory capacity can be used efficiently. ing. Further, by storing each correction value in the header portion H, the presence / absence of correction and the correction value can be read first.

Next, the reproducing operation will be described. The system controller 22 switches to the reproducing operation. In this case, the presence / absence of the correction such as saturation enhancement and the correction level are read from the memory card 11 and the digital image data is output from the interface 10, so that the display device (not shown)
Can be monitored by

Next, the case of monitoring while taking a picture will be described. As described above, the luminance signal Y, the color difference signals RY, and BY formed by the luminance / color difference separation circuit 7 are converted by the D / A converter 15.
Is converted into an analog video signal. Therefore, it can be output as a luminance signal Y and color difference signals RY and BY, and further can be output as color signals R, G and B by the encoder 16 and also as an NTSC television signal.

Next, a description will be given of a circuit operation when the saturation increase correction or the like is not performed.

In this case, the correction value input by the input device 21 is not performed.
The system controller 22 does not perform correction control on the luminance / color difference separation circuit 7, but performs a series of controls for photographing on the CCD 2 and the like. And the memory controller 5
Is performed in the same manner as described above, and the luminance / color difference separation circuit 7
Signal Y, color difference signals RY, BY formed by
Is data-compressed as described above and stored in the memory card 11. However, since there is no input for correcting the saturation increase or the like, the saturation increase levels R and B are not stored in the header portion H, and the image data is stored in the cluster portion C.

At the time of reproduction, the image data stored in the cluster C is read and can be input from the interface circuit 10 to, for example, a personal computer or a workstation. At this time, if the user does not need to create a special picture, the picture may be displayed on the display device as it is.

However, there are naturally cases where it is desired to perform special picture making or to perform other image quality corrections, not limited to increasing the saturation. In such a case, it is very inconvenient if correction is not possible,
The present embodiment is configured so that desired correction can be performed during reproduction.

That is, the input device 21 is configured to be able to input a correction value for a saturation increase correction or the like even during reproduction.
Therefore, when performing special picture creation such as increasing the saturation or enhancing the contour during reproduction, a desired correction value is input through the input device 21. As a result, the luminance / color difference separation circuit 7 is controlled by the system controller 22 to perform the saturation up correction and the like, and supplies the saturation up correction value to the interface circuit 10.

The digital output output from the interface circuit 10 is corrected, such as increasing the saturation, and desired picture creation is performed. It should be noted here that the original image data stored in the cluster portion C does not change even if the above-described correction is performed during reproduction. Therefore, if the desired picture creation cannot be performed, the original image data can be read again, and the correction value can be changed to repeatedly perform the picture creation.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above, and various modifications are possible.

For example, the input device 21 may be configured to input a correction value for gamma correction.

Further, the memory card 11 may use a memory cartridge.

[Effects of the Invention] As described above, the digital electronic still camera according to the present invention stores the correction value and the image data or only the image data by the selection unit when storing the digitized image data in the storage unit. And the desired correction can be selectively performed by the selecting means when the image data is read out and reproduced.

Therefore, the original image data can be corrected for the purpose of creating a special picture at the time of reproduction, and the multi-purpose use and the usability of the digital electronic still camera can be improved.

[Brief description of the drawings]

FIG. 1 is a basic circuit block diagram of a digital electronic still camera to which the present invention is applied. Reference numerals in the drawing: 1 ... Lens, 2 ... CCD image sensor, 3 ... Imaging system circuit, 4 ... A / D converter, 5 ... Memory controller, 6, 14 ... Memory circuit, 7 ... Luminance / color difference separation circuit, 8 Data compression circuit, 9 Coder / decoder, 10, 13 Interface circuit, 11 Memory card, 12 Connector, 15 D / A converter, 16 ... Encoder, 21 ... Input device, 22 ... System controller, Y ... Brightness signal, RY, BY ... Color difference signal.

Claims (1)

(57) [Claims] A digital system comprising: an image sensor; an A / D converter for converting a video signal read from the image sensor into a digital signal; and a storage unit for storing image data based on the digital signal. In the electronic still camera, the user selects whether or not to perform saturation enhancement adjustment, contour enhancement, or coring level adjustment that is a desired correction on the image data at the time of shooting, and determines whether the correction value input at the time of correction selection and the correction value before correction. Is separated from the original image data and stored in the storage means, and when the stored image data is read out and reproduced, based on a new correction value set separately when there is no correction. Digital means provided with a selection means for selecting whether or not to perform saturation enhancement adjustment, contour enhancement, or coring level adjustment for desired correction. Le electronic still camera.