JPH0946565A - Image input device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an image in a still image in a still image area from being decreased in resolution or an image in a dynamic image area from blurring when an image in which a dynamic image area and a still image area coexist is inputted. SOLUTION: When a motion detector 108 detects it that an object is moving, a mode of a CCD 103 is switched into the field storage mode, a changeover device 113 is thrown to the position of a changeover device 112. A motion area detector 110 separates a dynamic image area and a still image area by difference processing between a frame image signal stored in an image memory 111 and a field image signal from a field storage mode image processing circuit 106 to give a selection signal to a changeover device 112 so as to select a delay circuit (DL) 107a in the still image area and a delay circuit 107b in the dynamic image area. As a result, the frame image signal is outputted in the still image area and the field image signal is outputted in the moving image area.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image input device capable of appropriately inputting an image in which a moving image area and a still image area are mixed.

[0002]

2. Description of the Related Art A solid-state image pickup device such as a CCD is used in one of two modes: a field accumulation mode (moving image mode) and a frame accumulation mode (still image mode).
These two modes will be described with reference to FIG. FIG. 5 is a time chart showing the charge accumulation amount of the CCD in the field accumulation mode and the frame accumulation mode. In the field storage mode of FIG. 5A, the adjacent ODD field and EVE are synchronized with the interlaced scanning of the NTSC broadcasting system.
The signal charges of the upper and lower two lines of the N field are added and read every one field period (1/60 seconds). In this field accumulation mode, since all pixels are read in one field period, there is no time lag between pixel signals. Therefore, the field storage mode is normally used for inputting a moving image. On the other hand, however, in the field accumulation mode, since the signal charges of the two adjacent upper and lower lines are added, only a vertical resolution of 250 to 350, which is about half the total number of lines, can be obtained.

On the other hand, in the frame accumulation mode of FIG. 5B, the signal charges of two adjacent lines are independently read out by shifting the exposure time of two field periods by one field period. In this frame accumulation mode, since the signal charges of the upper and lower two lines are not mixed by being added, a vertical resolution of about 480 lines which is almost equal to the horizontal resolution can be obtained. But in frame accumulation mode,
Since the reading of the ODD field and the reading of the EVEN field are shifted by one field period, blurring occurs when a moving image such as a moving image is taken. Therefore, the frame accumulation mode is mainly used for still image input.

In the frame accumulation mode in which pixels are not mixed as described above, image information is sampled by shifting the optical axis of a light beam on the way from the lens to the CCD by 0.5 pixel unit and then stored in the memory. A so-called "pixel shift method" that can obtain a still image of higher resolution without increasing the number of pixels of the CCD can be adopted by synthesizing the image information thus obtained.

FIG. 6 shows a conventional image input apparatus which can input an image in two modes of a field accumulation mode and a frame accumulation mode and adopts a pixel shift system in the frame accumulation mode. In this image input device, a field accumulation mode is used when capturing a moving image, and a frame accumulation mode is used to ensure resolution when capturing a still image. Then, both modes are instantaneously switched in a timely manner in accordance with the scene or the motion of the subject, and the input image is output.

In FIG. 6, light from a subject passes through a lens 101 and a parallel plate glass (PP, parallel plate) 102, enters a CCD 103, and is converted into an electric signal. The parallel plate glass 102 is used for the PP driving unit 11
X motor 201 and Y motor 2 controlled by
Driven by the CCD 103, the image forming positions of the light rays on the image pickup surface of the CCD 103 are set to 0.
The shift control is performed in units of 5 pixels (here, X represents the horizontal coordinate and Y represents the vertical coordinate). Specifically, the light ray passing through the lens 101 is (0, 0): (reference position, reference position) (1, 0): (reference position + 0.5 pixel, reference position) on the imaging surface of the CCD 103. (0,1): (reference position, reference position +0.5 pixel) (1,1): (reference position +0.5 pixel, reference position +0.
(5 pixels).

The output of the CCD 103 driven and controlled by the timing generator (TG) 116 according to the mode is input to the automatic gain control (AGC) unit 104.
The output of the CCD 103 supplied to the AGC unit 104 is amplified by a predetermined gain and adjusted to a constant level, and then A
It is output to the D converter (ADC) 105, and the AD converter 10
At 5, it is converted to a digital value. The output signal of the CCD 103 converted into a digital value is supplied to the image processing circuit 106 for frame storage mode and the image processing circuit 109 for frame storage mode to which the image storage circuit 106 for field storage mode and the image memory 111 are connected, and subjected to image processing in these circuits 106, 109. After that, either one is output from the switch 113. The image memory 111 is used to eliminate blurring when a moving subject is imaged in the frame accumulation mode. In the frame accumulation mode, the image memory 111 is used.
The image frozen by is output.

The mode switch input section 117 outputs a mode switch signal to the switch 113, the timing generator 116 and the PP drive section 115. The timing generator 116 also supplies a horizontal synchronization signal (H), a vertical synchronization signal (V), and a clock signal (CLK) to the image processing circuit 106 for field storage mode and the image processing circuit 109 for frame storage mode, respectively. . As a result, the field accumulation mode image processing circuit 106 and the frame accumulation mode image processing circuit 10
At 9, horizontal synchronization and vertical synchronization are performed.

In the apparatus of FIG. 6, when the field storage mode is selected, the mode switching input section 117
Supplies a signal to the PP drive unit 115 such that the parallel flat plate glass 102 is fixed at the position (0, 0). Also,
The mode switching input unit 117 outputs a signal for driving the CCD 103 in the field storage mode to the timing generator 116, and further switches the switch 113 to the field storage mode image processing circuit 106 side. As a result, the switching unit 113 outputs the moving image signal subjected to the field image processing.

Next, when the frame accumulation mode is selected, the mode switching input unit 117 causes the CCD 103
Is output to the timing generator 116, and the switch 113 is switched to the frame accumulation mode image processing circuit 109 side. In the mode switching input unit 117, the image forming position of the light beam passing through the parallel plate glass 102 on the image pickup surface of the CCD 103 is (0,0) → (1,0) → (0,1) →
A signal that moves in the order of (1, 1) is applied to the PP drive unit 1
15 Then, the signal charges accumulated at each image forming position are read out one by one every frame period and stored as image information, and finally the image information obtained from the four image forming positions is combined, whereby switching is performed. A high-resolution still image signal subjected to frame image processing is obtained from the device 113.

For example, the order of image output of the combined still image signals is (0,0), (1,0), (0,0), (1,0), ... (0,1), (1,1), (0,1), (1,1), ... (0,0), (1,0), (0,0), (1,0), ... (0,1 ), (1,1), (0,1), (1,1), ... :::::. That is, in the frame accumulation mode that employs the pixel shift method, the data amount is four times as large as that in the field accumulation mode, and the resolution is twice as much in both horizontal and vertical as compared with the field accumulation mode.

As described above, the CCD field accumulation mode and the frame accumulation mode are appropriately switched, and the pixel shifting method is adopted in the frame accumulation mode, so that a moving image and a high-resolution still image can be respectively adapted. You can enter the conditions.

[0013]

However, in the above-described image input device, although no inconvenience occurs when capturing an image of only a moving image area or an image of only a still image area, the moving image area and the still image area are not separated. When capturing an image with a mixture of images, the resolution of the image in the still image area is reduced when the field accumulation mode is used, and the image in the moving image area is blurred when the frame accumulation mode is used. Therefore, the above-mentioned image input device has a problem that it is not always possible to input a high-quality image.

Therefore, an object of the present invention is to provide an image input device capable of switching the mode of an image pickup means such as a CCD between a field storage mode and a frame storage mode, when a moving image area and a still image area are mixed. Even if it is, it is an object of the present invention to provide an image input device capable of inputting a high-quality image in which the resolution of an image in a still image region is not reduced and the image in a moving image region is not blurred.

[0015]

In order to solve the above-mentioned problems, the invention of claim 1 has a field accumulation mode in which pixels of all lines are scanned and read every one field period,
In an image input device having an image pickup means for inputting an image in two modes, that is, a frame accumulation mode in which pixels on every other line are interlaced-scanned and read every one field period, an image input from the image pickup means is set as a moving image area. Separated into a still image area, and for the moving image area, output an image signal image-processed in the field accumulation mode,
The still image area is configured to output an image signal subjected to image processing in the frame accumulation mode.

According to a second aspect of the present invention, it is detected whether or not there is a moving image area in the image input from the image pickup means, and if there is a moving image area, the image pickup means is operated in the field accumulation mode. It is characterized in that it is configured as follows.

According to a third aspect of the invention, the image pickup means is provided by comparing the signal image-processed in the field storage mode with the signal image-processed in the frame storage mode stored in the storage means. It is characterized in that the image input from is separated into a moving image area and a still image area.

According to a fourth aspect of the present invention, an image input from the image pickup means is compared by comparing a signal image-processed in the field accumulation mode with a signal obtained by delaying the signal by a predetermined period. It is characterized in that it is configured to be separated into a moving image area and a still image area.

According to a fifth aspect of the present invention, an external area selection signal designating a moving image area and a still image area is used.
It is characterized in that the image inputted from the image pickup means is divided into a moving image area and a still image area.

According to a sixth aspect of the present invention, in the frame accumulation mode, the optical axis of the light beam imaged on the image pickup surface of the image pickup means is set in an arbitrary direction in the image pickup surface of the image pickup means and perpendicular thereto. It is characterized in that the image is input by shifting a minute unit in at least one of the different directions.

[0021]

According to the first aspect of the present invention, the image signal subjected to the image processing in the field accumulation mode is output for the moving image area, and the image signal subjected to the image processing in the frame accumulation mode is output for the still image area. Even when an image in which the moving image area and the still image area are mixed is input, the resolution of the image in the still image area does not decrease and the image in the moving image area does not blur.

Further, according to the second aspect of the present invention, when there is a moving image area, the mode of the image pickup means is switched to the field accumulation mode. Therefore, when inputting an image in which the moving image area and the still image area are mixed, the field accumulation is performed. Image input in mode is performed.

According to the third aspect of the present invention, the image-processed signal in the field storage mode and the image-processed signal in the frame storage mode stored in the storage means are compared, so that the image pickup means The input image can be separated into a moving image area and a still image area.

Further, according to the invention of claim 4, since two signals image-processed in the field storage mode are used to compare them, the moving image area and the still image area can be separated with high accuracy.

According to the invention of claim 5, the moving image area and the still image area can be arbitrarily separated by designation from the outside.

According to the sixth aspect of the invention, since the image is input by the pixel shift method in the frame accumulation mode, it is possible to input a high-definition still image with high resolution.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an image input apparatus according to the first embodiment of the present invention in which an image can be inputted in two modes of a field accumulation mode and a frame accumulation mode, and a pixel shift system is adopted in the frame accumulation mode.

In FIG. 1, light from an object passes through a lens 101 and a parallel plate glass (PP, parallel plate) 102, enters a CCD 103, and is converted into an electric signal. The parallel plate glass 102 is used for the PP driving unit 11
X motor 201 and Y motor 2 controlled by
Driven by the CCD 103, the image forming positions of the light rays on the image pickup surface of the CCD 103 are set to 0.
The shift control is performed in units of 5 pixels (here, X represents the horizontal coordinate and Y represents the vertical coordinate). That is, C
The optical axis of the light beam that forms an image on the image pickup surface of the CD 103 is set to the CCD 1
An image is input by shifting the image plane of image sensor 03 by 0.5 pixel units in the horizontal and vertical directions. Specifically, the light ray passing through the lens 101 is (0, 0): (reference position, reference position) (1, 0): (reference position + 0.5 pixel, reference position) on the imaging surface of the CCD 103. (0,1): (reference position, reference position +0.5 pixel) (1,1): (reference position +0.5 pixel, reference position +0.
(5 pixels).

The output of the CCD 103 driven and controlled by the timing generator (TG) 116 according to the mode is input to the automatic gain control (AGC) unit 104.
The output of the CCD 103 supplied to the AGC unit 104 is amplified by a predetermined gain and adjusted to a constant level, and then A
It is output to the D converter (ADC) 105, and the AD converter 10
At 5, it is converted to a digital value. The output signal of the CCD 103 converted into a digital value is supplied to the image processing circuit 106 for frame storage mode and the image processing circuit 109 for frame storage mode to which the image storage circuit 106 for field storage mode and the image memory 111 are connected, and subjected to image processing in these circuits 106, 109. After that, it is output to the motion area detector 110. The motion region detector 110 distinguishes a moving image region from a still image region by, for example, obtaining a difference from the image signals image-processed by the two circuits 106 and 109 and determining a region having a large difference as a moving image region. Then, the result is sent to the switch 112 as a selection signal, and the switch 112 is controlled so that the delay circuit (DL) 107a side is selected in the still image area and the delay circuit 107b side is selected in the moving image area.

The field accumulation mode image processing circuit 106 and the frame accumulation mode image processing circuit 10 are also provided.
The output signal of 9 is input to the delay circuits 107a and 107b, respectively. Then, the signals from the two circuits 106 and 109 are respectively supplied to the switcher 112 with their timings matched with the selection signals from the motion region detector 110 by the delay circuits 107a and 107b, and one of them is supplied to the switcher 113. Supplied. Further, the output signal of the image processing circuit 109 for the frame accumulation mode is the switch 113.
Is also supplied.

Image processing circuit 10 for field accumulation mode
The image signal from 6 is sent to a motion detector 108 which detects whether it is a moving subject or a stationary subject, and the detection result is used as a switching signal between the field accumulation mode and the frame accumulation mode as a timing generator. 116 and the PP drive unit 115, and is also supplied to the switch 113 as a selection signal of the signal from the switch 112 and the signal from the delay circuit 107b. The image memory 111 is used for synthesizing a plurality of frame images shifted by 0.5 pixel by the above-described pixel shift method.

The timing generator 116 sends a horizontal synchronization signal (H) to the image processing circuit 106 for field accumulation mode and the image processing circuit 109 for frame accumulation mode.
And a vertical synchronizing signal (V) and a clock signal (CLK), respectively. As a result, the field accumulation mode image processing circuit 106 and the frame accumulation mode image processing circuit 109 perform horizontal synchronization and vertical synchronization.

Next, the operation of the apparatus shown in FIG. 1 will be described. In the apparatus of FIG. 1, when the motion detector 108 detects that the subject is stationary, the motion detector 108
The timing generator 116 is instructed to switch to the frame accumulation mode, and the parallel flat glass 102
The image forming position of the light ray passing through the image forming surface of the CCD 103 is (0,0) → (1,0) → (0,1) → (1,
The PP drive unit 115 is controlled so as to move in the order of 1). Then, the signal charges accumulated at each image forming position are sequentially read out for each frame period and stored as image information, and finally the image information obtained from the four image forming positions is combined in the memory 111. Further, the motion detector 108
The switch 113 is switched to the delay circuit 107b side.
As a result, the switching unit 113 outputs a high-resolution still image signal subjected to frame image processing.

For example, the order of image output of the combined still image signals is (0,0), (1,0), (0,0), (1,0), ... (0,1), (1,1), (0,1), (1,1), ... (0,0), (1,0), (0,0), (1,0), ... (0,1 ), (1,1), (0,1), (1,1), ... :::::. That is, in the frame accumulation mode that employs the pixel shift method, the data amount is four times as large as that in the field accumulation mode, and the resolution is twice as much in both horizontal and vertical as compared with the field accumulation mode.

Next, when the subject begins to move, the motion detector 1
08 detects that the subject is moving. The motion detector 108 instructs the timing generator 116 to switch to the field accumulation mode, and
The parallel plate glass 102 is controlled by controlling the drive unit 115 (0,
It is fixed to the image forming position of 0). As a result, the field accumulation mode image processing circuit 106 outputs a moving image signal subjected to field image processing. Also, the motion detector 108
Switches the switch 113 to the switch 112 side.

At the same time, the motion area detector 110 outputs the output signal of the field accumulation mode image processing circuit 106 and the memory 1 via the frame accumulation mode image processing circuit 109.
The difference from the output signal of 11 is obtained, the area having a large difference is determined to be the moving image area, and the result is given to the switch 112 as a selection signal. Therefore, the switcher 113 outputs the image signal subjected to the frame image processing stored in the memory 111 by the pixel shift method as an image signal of the still image area, and the image subjected to the field image processing by the image processing circuit 106 for field storage mode. The signal is output as an image signal in the moving image area.

FIG. 2 shows an example of image output when a subject moves. FIG. 2A shows a high-resolution still image output when a character document is imaged in the frame accumulation mode which adopts the pixel shift method. Here, when the black subject moves from the upper right into the screen, the motion detector 108 detects a motion vector as indicated by an arrow in FIG.
The mode of D103 is changed to the field accumulation mode. At the same time, the motion area detector 110 operates, and
As shown in FIG. 2C, the image of FIG.
The image is divided into a moving image region and a still image region according to the magnitude relationship between the absolute value of the image difference in (A) and the constant K. By switching the output image based on this result, as shown in FIG.
The image shown in (B) is obtained.

As described above, according to the image input apparatus of the present embodiment, even if the moving image area and the still image area are mixed in the image, the field image processed signal is output to the moving image area, Since a signal that has undergone frame image processing is output to the still image area, the resolution of the image in the still image area will not decrease and the image in the moving image area will not be blurred, so input a high quality image. Will be possible. Moreover, since the pixel shift method is adopted, a high-resolution still image can be obtained in the frame accumulation mode.

In this embodiment, the motion area detector 110 performs the difference calculation to discriminate between the moving image area and the still image area. However, the motion area detector 110 may perform a method such as image correlation or contour extraction. . Further, without using the motion area detector 110, the moving image area and the still image area may be discriminated by control scanning from the outside.

Next, a second embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG.

FIG. 3 is a block diagram showing the schematic arrangement of the image input apparatus according to this embodiment. The image input device of FIG.
The output signal of the field accumulation mode image processing circuit 106 is input to the field memory (MEM) 200, and its output is input to the motion area detector 110, and the output signal of the frame accumulation mode image processing circuit 109 moves. The difference from the image input device of the first embodiment described with reference to FIG. 1 is that the image is not input to the area detector 110. Therefore, in the present embodiment, explanations other than those related to these are omitted.

In FIG. 3, the field memory 200
Supplies the signal subjected to the field image processing from the field accumulation mode image processing circuit 106 to the motion area detector 110 after delaying it by one field period. Further, the motion area detector 110 is directly supplied with a field image processed signal from the field accumulation mode image processing circuit 106. Then, the motion area detector 110
The difference between these two input signals is obtained, the area having a large difference value is determined as the moving image area, and the result is output as the selection signal of the switch 112. That is, in the present embodiment, since the motion area detector 110 distinguishes the moving image area and the still image area based on the two field image processed signals, it is possible to separate the moving image area and the still image area with high accuracy. You can Therefore, the image quality of the finally obtained image is further improved.

Next, a third embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG.

FIG. 4 is a block diagram showing the schematic arrangement of the image input apparatus of this embodiment. The image input device of FIG.
The motion region detector 110 is eliminated, and instead, a region selection signal generator 118 for distinguishing a moving image region and a still image region by an external signal input is provided, and from the timing generator 116 to the region selection signal generator 118. Only the point that the horizontal synchronizing signal (H), the vertical synchronizing signal (V), and the clock signal (CLK) are supplied is the first described in FIG.
This is different from the image input device of the embodiment. Therefore, in the present embodiment, explanations other than those related to these are omitted.

In FIG. 4, the area selection signal generator 118 is shown.
For this, a region selection signal indicating which region of the screen is to be the moving image region or the still image region is supplied as an external input from the console. The area selection signal generator 118 outputs the input area selection signal as a selection signal for the switch 112 according to the horizontal synchronizing signal (H), the vertical synchronizing signal (V) and the clock signal (CLK) from the timing generator 116. That is, in the image input device according to the present embodiment, a moving image area can be arbitrarily determined by a control operation from the outside, and a field image processed moving image signal is output for an area set outside, and other areas are output. For, it is possible to output a high-definition still image signal subjected to frame image processing.

[0047]

As described above, according to the present invention,
An image signal in which the image processing is performed in the field storage mode is output for the moving image area, and an image signal in which the image processing is performed in the frame storage mode is output for the still image area. Therefore, an image in which the moving image area and the still image area are mixed is output. Even when inputting, the resolution of the image in the still image area does not decrease and the image in the moving image area does not blur. Therefore, it is possible to always input a high quality image. Further, by performing the pixel shift method in the frame accumulation mode, it is possible to obtain a still image with high resolution and high definition.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of an image input device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an example of image output when a subject moves in the first embodiment of the present invention.

FIG. 3 is a block diagram showing a schematic configuration of an image input device according to a second embodiment of the present invention.

FIG. 4 is a block diagram showing a schematic configuration of an image input device according to a third embodiment of the present invention.

FIG. 5 is a diagram for explaining a field storage mode and a frame storage mode.

FIG. 6 is a block diagram showing a schematic configuration of a conventional image input device.

[Explanation of symbols]

 101 lens 102 parallel plate glass (PP) 103 CCD 104 automatic gain control (AGC) unit 105 AD converter (ADC) 106 image processing circuit for field accumulation mode 107a, 107b delay circuit (DL) 108 motion detector 109 frame accumulation mode Image processing circuit 110 motion area detector 111 image memories 112 and 113 switcher 115 PP drive unit 116 timing generator (TG) 201 X motor 202 Y motor

Claims (6)

[Claims] 1. An image in two modes: a field accumulation mode in which pixels of all lines are scanned and read every 1 field period and a frame accumulation mode in which pixels of every other line are interlaced scanned and read every 1 field period. In an image input device having an image pickup means for inputting, an image input from the image pickup means is separated into a moving image area and a still image area, and an image signal image-processed in the field accumulation mode is output for the moving image area. The image input device is characterized in that the still image area is configured to output an image signal subjected to image processing in the frame accumulation mode. 2. It is configured to detect whether or not there is a moving image area in the image input from the image pickup means, and to operate the image pickup means in the field accumulation mode when there is a moving image area. The image input device according to claim 1. 3. Comparing the image-processed signal in the field accumulation mode with the image-processed signal stored in the storage means in the frame accumulation mode,
The image input device according to claim 1, wherein the image input device is configured to separate an image input from the image pickup unit into a moving image region and a still image region. 4. An image input from the image pickup means is divided into a moving image area and a still image area by comparing a signal image-processed in the field accumulation mode with a signal obtained by delaying the signal by a predetermined period. The image input device according to claim 1 or 2, wherein the image input device is configured to be separated. 5. An image input from the image pickup means is separated into a moving image area and a still image area by an area selection signal from the outside which specifies a moving image area and a still image area. The image input device according to claim 1, wherein the image input device is an image input device. 6. In the frame accumulation mode, an optical axis of a light beam formed on an image pickup surface of the image pickup means is at least one of an arbitrary direction within the image pickup surface of the image pickup means and a direction perpendicular to the arbitrary direction. The image is input by shifting the image by a small unit in the direction of.
The image input device according to any one of items 1 to 5.