JPH0810907B2 - Signal processor - Google Patents

Description

The present invention relates to an apparatus for processing a video signal from a television camera, and more particularly to a signal processing apparatus for correcting camera shake of the television camera.

[Conventional technology]

2. Description of the Related Art Conventionally, television cameras have been put to practical use for image input such as VTR for broadcasting or home use. When this camera is used for hand-held image capturing, especially for a general consumer who is not accustomed to handling the camera, the image is blurred due to camera shake.

Therefore, as a means for removing blurring of this image, conventionally, as described in Japanese Patent Laid-Open No. 61-198879, the imaging range is made larger than the required screen range, and the entire imaging range is imaged. All the image data for the whole image is stored in the memory, and the data in a part of the range is read out so that the read range is changed according to the movement of the camera.

[Problems to be solved by the invention]

As described above, in the above-mentioned conventional technique, all the data of a wide range of imaging area is stored in the memory, and the television signal of the normal screen range is obtained from the memory. Therefore, a very large memory capacity is required. Furthermore, when using a digital memory, it is necessary to A / D convert the image signal, and the quantization bit number directly determines the image quality of the output image, so the quantization bit number of the A / D converter is sufficient. Large, for example, about 8 bits is required. Therefore, there is a problem that the circuit scale of the above-mentioned conventional technology becomes large and is not suitable for integration.

An object of the present invention is to obtain a reproduced image with good image quality regardless of the quantization bit rate and memory capacity of the A / D converter,
Therefore, it is to provide a signal processing device suitable for integration.

[Means for solving problems]

In order to achieve the above object, the present invention provides an image pickup unit capable of picking up an image in a range wider than an image pickup range necessary for a screen, an image output range designation circuit for designating an image output range of the image pickup unit, The signal output from the image pickup unit in the range designated by the image output range designation circuit is digitized.
An A / D converter, a memory for storing the signal output from the A / D converter in the range designated by the image output range designating circuit, and the A in the range designated by the image output range designating circuit. A motion detection circuit that detects the motion of the entire image by comparing the signal output from the / D converter with the signal stored in the memory, and the correction amount determination that determines the correction amount from the detection output of the motion detection circuit. A circuit, the image output range designation circuit changes the image output range of the image pickup unit according to the correction amount, and the image pickup unit changes the image output range designation circuit from a signal of an image pickup device in an image pickup range. The signal within the range specified by is output.

[Action]

The motion detection circuit detects the motion of the entire image by comparing the signal from the imaging range with the signal read from the memory obtained from the imaging region a predetermined period before. The image output range designation circuit changes the image pickup area according to the detected movement.

Therefore, if there is camera shake, the image on the image pickup surface of the image pickup element moves, and along with this, the image also moves entirely within the image pickup range designated by the image output range designation circuit. , The image output range designation circuit is moved in the image movement direction in the image pickup range according to the detected amount of motion. As a result, image blur caused by camera shake is eliminated.

In this case, it is sufficient for the signal supplied to the motion detection circuit to have a data amount such that the motion of the entire image can be detected. Therefore, the memory needs to store a signal including all data from the imaging range. There is no. Therefore, the capacity of the memory and the number of quantization bits for storing the memory can be reduced.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. Here, the image pickup unit will be a MOS image pickup device, and the MOS image pickup device will be described first.

FIG. 2 is an equivalent circuit diagram showing the basic configuration of the light receiving portion in the MOS image pickup device.

In the figure, when the photodiode D1 receives light, it accumulates electric charges according to the amount of received light. Therefore, the vertical selection line VL
And the gate pulse supplied to the horizontal selection line HL turns on the MOSFET switches M1 and M2, the photodiode D
The charge stored in 1 passes through MOSFETs M1 and M2, and amplifier A1
Is converted into a voltage by the feedback resistor R1 and taken out as an output signal.

 FIG. 3 is a basic circuit configuration diagram of a MOS image sensor.

In the figure, a plurality of light receiving portions shown in FIG. 2 are arranged vertically and horizontally, one of which is represented by P1. here,
When the vertical selection circuit VA1 supplies a gate pulse to the vertical selection line VL1 and the horizontal selection circuit HA1 supplies a gate pulse to HL1, respectively, only the light receiving portion P1 is selected and an electric charge is obtained. By selecting each vertical direction selection line and each horizontal direction selection line in order by the vertical direction selection circuit VA1 and the horizontal direction selection circuit HA1, charges are extracted from each light receiving section in a predetermined order, and an image signal is obtained.

FIG. 1 is a block diagram showing an embodiment of a television signal processing device according to the present invention, wherein 1 is an image pickup section, 2 is an A / D converter for converting an output from the image pickup section into a digital signal, and 3
Is a memory for storing images, 4 is a motion detection circuit, 5 is a correction amount determination circuit for determining a correction amount from camera movement, and 6 is an output range designation for designating an output range from the image pickup unit 1 based on the determined correction amount. Circuit. The MOS image pickup device described in FIGS. 2 and 3 is used as the image pickup unit capable of designating the output range.

The operation of this embodiment will be described below with reference to FIG.
In the figure, 21 is an imaging surface of the imaging unit 1, 22 is a range image output, K _H times in the horizontal direction than the imaging range required for the imaging surface 21 is the television screen, K _V fold in the vertical direction (Correctly, K _H and K _V are larger than 1), and the image output range 22 has the same shape and the same area as the imaging range required for the television screen. The image output range 22 is controlled by the output range designating circuit 6. 221, 222 and 223 are output images at times t-1, t and t + 1, respectively.

Here, assuming that the image output range 22 is set at time t−1, the output image 221 resulting therefrom is converted into a digital signal by the A / D converter 2 and written in the memory 3. Next, at time t, the image stored in the memory 3
An image 222 output from 221 and the imaging unit 1 is a motion detection circuit 4
Are input to the motion vector and the motion vectors of these images are obtained. Based on this motion vector, the correction amount determination circuit 5 determines the correction of the image output range from the image pickup unit 1, and the image output range at time t + 1 can be designated by the output range designation circuit 6 as 22 '. 223 is obtained.

In this way, unnecessary movement of the camera can be eliminated, and a still image can be obtained.

In this embodiment, since the television signal from which unnecessary movement of the camera is removed is directly output from the image pickup unit 1,
The number of quantization bits of the D converter 2 is sufficient to be the lowest number of bits capable of detecting a motion vector. FIG. 5 shows S / N of an output image according to the number of quantization bits in a conventional example in which a television signal is A / D converted and then D / A converted again. The solid line 31 is the case of this embodiment, and the broken line 32 is the case of the conventional example. Also, the memory 3 need not store the entire image,
Therefore, the number of quantization bits also decreases. From the above, the circuit scale of this embodiment is small, and the configuration is suitable for integration.

FIG. 6 is a block diagram showing another embodiment of the television signal processing apparatus according to the present invention, in which 51 is an LPF and 52 is a subtracter, and the parts corresponding to those in FIG. .

When the camera is intentionally moved, camerawork and camera shake occur, but it is necessary to separate the camerawork component and camera shake component and correct only the camera shake component. Seventh
The figure shows the movement of the camera in this case. The figure (a) shows the movement of the entire camera, the figure (b) shows the original camera work, and the figure (c) shows the movement due to camera shake (camera shake component).

In FIG. 6, the LPF 51 extracts the camera work component (FIG. 7 (b)) from the entire camera motion (FIG. 7 (a)), and subtracts this camera work component from the entire camera motion. A hand-shake component (FIG. 7 (c) is obtained by subtracting 52. The image output range is determined by this hand-shake component. This makes it possible to obtain an unnecessary blur-free image from which the hand-shake is removed.

The same effect can be obtained by using HPF instead of LPF 51 and subtractor 52.

FIG. 8 is a block diagram showing still another embodiment of the television processing apparatus according to the present invention, in which 7 is an output signal limiting circuit, and the parts corresponding to those in FIG.

In the figure, the imaging unit 1 outputs all images during the operation cycle T _F of the television signal. The output signal limiting circuit 7 performs time-axis expansion on the output captured image signal using only the signal of the portion designated by the output range designating circuit 6. As a result, even if the image pickup unit 1 cannot specify the image output range, it is possible to obtain the same effect as that of the previous embodiment.

In the above embodiment, it is obvious that the same effect can be obtained by moving the position of the image pickup unit 1 or changing the optical path with a lens or the like. Further, by making the scanning cycle of the image pickup unit 1 scan with 1 / K _F , (K _F is an integer of 2 or more) of the television signal, it is possible to make finer correction. Furthermore, in each of the embodiments, the image pickup unit 1 is a MOS image pickup device, but other image pickup devices (for example, an image pickup tube) may be used.

〔The invention's effect〕

As described above, according to the present invention, when a hand-held image is picked up or an image is picked up by a television camera mounted on an automobile or the like, unnecessary blurring is caused for an image including a blurring unrelated to the original camera work. Can be removed, so that the playback screen can be made clear and easy to see.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a television signal processing device according to the present invention, FIG. 2 is an equivalent circuit diagram showing a basic configuration of a light receiving portion in a MOS image pickup device, and FIG. 3 is a basic circuit of a MOS image pickup device. FIG. 4 is a block diagram showing the operation of the embodiment of FIG. 1, and FIG. 5 is a comparison of the S / N ratios of the output images depending on the number of quantization bits between the conventional example and the embodiment shown in FIG. Figure showing,
FIG. 6 is a block diagram showing another embodiment of the television signal processing device according to the present invention, FIG. 7 is an operation explanatory diagram thereof, and FIG. 8 is a further embodiment of the television signal processing device according to the present invention. It is a block diagram shown. 1 ... Imaging unit, 2 ... A / D converter, 3 ... Image memory, 4
...... Motion detection circuit, 5 …… Correction amount determination circuit, 6 …… Output range designation circuit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hironori Hanabusa, Inventor Hironori Hanafusa, 292 Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Nikko Video Engineering Co., Ltd. (72) Ryuichi Ikeda 292, Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Video Engineering Co., Ltd. (56) Reference JP-A-61-198879 (JP, A)

Claims (1)

[Claims] 1. An image pickup unit capable of picking up an image in a range wider than a necessary image pickup range on a screen, an image output range designation circuit for designating an image output range of the image pickup unit, and an image output range designation circuit. An A / D converter for digitizing a signal output from the imaging unit in a specified range, and the range in a range specified by the image output range specification circuit
A memory for storing the signal output from the A / D converter, and the memory within the range designated by the image output range designating circuit.
A motion detection circuit that detects the motion of the entire image by comparing the signal output from the A / D converter with the signal stored in the memory, and a correction amount that sets a correction amount from the detection output of the motion detection circuit. A determination circuit, the image output range designating circuit designates an image output range of the image pickup unit according to the correction amount, and the image pickup unit designates the image output range from a signal of an image pickup device in an image pickup range. A signal processing device which outputs a signal in a range designated by a circuit.