JP3292538B2 - Color imaging device using solid-state imaging device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image processing apparatus using a solid-state image pickup device, and more particularly to the contents of color image processing of an image pickup apparatus applied to an electronic endoscope, various cameras and the like.

[0002]

2. Description of the Related Art Conventionally, various cameras such as an electronic endoscope and a television camera for observing a narrow place using a solid-state image pickup device as an image sensor, that is, a CCD (Charge Coupled Device), are well known. In this method, a color image signal obtained by a CCD is processed and displayed on a monitor or the like. As this imaging processing method, a simultaneous method,
There are a dot-sequential type and a plane-sequential type. In the case of a simultaneous type, R (red), G (green), B
(Blue) light is separated and RGB image signals are simultaneously obtained by three CCDs. In the case of a dot sequential method,
For example, a color filter in which predetermined colors are arranged in a mosaic pattern is C
It is formed on a CD, and an image signal of a predetermined color is simultaneously obtained by the CCD. In the case of the frame sequential type, one CCD sequentially obtains RGB image signals based on the sequentially irradiated RGB light.
Since it can be compactly stored in a CD, it is suitable for an electronic endoscope apparatus or the like that requires miniaturization.

[0003] Also, in an image pickup apparatus using the above-mentioned CCD, it is possible to enlarge and reduce an image by a zoom function, whereby it is possible to observe an image from different viewpoints. The electronic endoscope has an advantage that a small lesion can be favorably observed.

[0004]

However, in the above-described conventional color image pickup apparatus, when the subject moves when performing enlargement / reduction by the zoom function, a color shift or an afterimage effect occurs, and the sharpness is reduced. However, there was a problem that was reduced. The decrease in sharpness due to the color shift and the afterimage effect becomes greater as the movement of the subject is faster. Particularly, in the above-described frame sequential imaging apparatus, the influence of the movement is greater than in other apparatuses. That is, as described above, in the field sequential method, R
Each color light of GB is sequentially output by a color disk, and an RGB image signal is sequentially formed for each color light. Therefore, it takes three times as long to obtain image information of one field as compared with other imaging methods. Required. Therefore, in the case of the frame sequential method, although it is a method suitable for miniaturization, if the subject moves, the color shift and the deterioration of sharpness at the time of enlargement are larger than those of other devices.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to eliminate a color shift and an afterimage effect and to obtain an image with high sharpness when a zoom function is used. An object of the present invention is to provide a color imaging device using a solid-state imaging device.

[0006]

In order to achieve the above object, a color image pickup apparatus using a solid-state image pickup device according to the present invention performs predetermined color image processing on an image signal picked up by the solid-state image pickup device. An image processing circuit, a predetermined image signal obtained by the image processing circuit, and a motion detection circuit that detects a motion state or a stationary state from the image signal. A memory that sequentially stores and updates image signals of still images based on the image signals, and an enlargement / reduction processing circuit that inputs image signals read out from the memories and performs enlargement / reduction processing of the images by control signals for enlargement / reduction. It is characterized by comprising.

According to a second aspect of the present invention, there is provided an image processing circuit for performing a predetermined color image processing on an RGB image signal picked up by a frame sequential method using a solid-state image sensor.
A first memory for storing RGB signals obtained by this image processing circuit
A color image pickup device using a plane sequential solid-state image pickup device having a memory; a motion detection circuit for detecting whether the RGB signal output from the image processing circuit is in a motion state or a stationary state; A second memory for sequentially storing and updating the RGB signals of the still image based on the determination of the still state by the circuit, and an RGB signal read out from the second memory which is input and enlarged / reduced by an enlargement / reduction control signal And an enlargement / reduction processing circuit for performing processing. The invention according to a third aspect further comprises a switching circuit for switching between an output from a memory storing the still image signal and an output from the enlargement / reduction processing circuit, and a still image sequentially obtained in the memory. The present invention is characterized in that any one of a frozen image output from the memory based on a freeze control signal and the enlarged / reduced image can be selected.

[0008]

According to the above arrangement, in a simultaneous or dot-sequential type apparatus, for example, the luminance signal between fields is compared based on a detection pulse for motion detection, thereby determining whether the current image is in a still state. It is determined whether there is a motion.
Then, when there is a motion, the image signal (information)
Is not updated, and when still, the image information at that time is recorded in the memory, and the still images are sequentially updated.
When the enlargement / reduction control signal is output, a process for enlargement / reduction is performed based on the still image information updated and stored in the memory, and the image is enlarged / reduced and monitored. Displayed to

Further, in the frame sequential type apparatus, since an RGB image signal is obtained, for example, a G (green) signal between fields is compared on the basis of a detection pulse, and thereby, a stationary state or a moving state is determined. A determination is made. Then, the image information in the stationary state is sequentially updated and stored in the second memory, and in the case of the zoom operation, the enlargement / reduction processing is similarly performed based on the image information in the second memory. . Therefore, when the zoom operation is performed in a state of movement, an enlarged / reduced image of the image in the still state immediately before the zoom operation is displayed.

Further, a still image in the memory can be displayed as it is, or a frozen image can be formed based on the still image. A switching circuit is used for these images and enlarged / reduced images. Thus, a desired image can be selectively output.

[0011]

FIG. 1 shows a configuration of a color image pickup apparatus using a solid-state image pickup device according to a first embodiment.
The embodiment is a frame sequential type electronic endoscope apparatus. In the figure, the light source unit includes a light source 10, R (red), G (green), B
A color disk 11 having a color filter of (blue) is provided, and an optical fiber 12 is disposed up to the tip of the electronic endoscope which is an insertion portion, and each color light of RGB is sequentially transmitted to the optical fiber by rotation of the color disk 11. The light is radiated into the body to be observed through 12. A CCD 14, which is a solid-state image sensor, is arranged at the tip of the electronic endoscope.
4 is connected to a process circuit 15 and an A / D converter 16. The process circuit 15 performs image processing such as amplification, clamping, white balance processing, and gamma correction.

Further, the A / D converter 16 is provided with first memories 17R, 17G, 17B for respective colors of RGB, and the first memories 17R, 17G, 17B are obtained in the order of irradiation of the respective colors of RGB. The stored RGB image signals are stored, for example, for one field. This first memory 17R, 1
7G and 17B have RGB changeover switch 18, D / A
The converter 19 and the first monitor 20 are connected, and an image of the inside of the object to be observed is displayed on the first monitor 20.

On the other hand, in the first embodiment, the motion detection circuit 22 and the second memory 23R,
23G and 23B, and the second memory 23
Enlargement / reduction control processing circuit 2 after R, 23G, 23B
4 are arranged. That is, first, in the motion detection circuit 22,
By extracting only the G (green) signal from the image signals and comparing the G signal during a predetermined field, it is detected whether or not the subject being imaged at present has a motion. The motion detection circuit 22 outputs a write (command) pulse to the second memories 23R, 23G, and 23B when determining that the motion is in a stationary state. Thereby, the second memory 23
R, 23G, and 23B store image signals in a still state (still image), which are executed each time a still state is detected. The latest still image is stored in the second memories 23R, 23G, and 23B. The image information is updated and recorded.

When the zoom control signal is input from the control unit, the enlargement / reduction control processing circuit 24 executes a write / read process for enlargement / reduction, and this process is performed in the second memory. This is immediately performed based on the image signals of 23R, 23G, and 23B. Therefore, when the zoom is executed, the latest still image in the second memory 23 is enlarged / reduced.

The embodiment also has a freeze function. For this purpose, a freeze command control circuit 26 is provided, and outputs from the second memories 23R, 23G, and 23B and an enlargement / reduction control processing circuit 24 are provided. And a selection switch 27 for switching between the outputs. This selection switch 2
7 is connected to an RGB switch 18 and
The recording device 29 and the second monitor 3 via the D / A converter 28
Connected to 0. Accordingly, the selection switch 27 is switched and controlled by the zoom control signal, and the enlarged / reduced image is supplied to the recording device 29 and the second monitor 30 side. On the other hand, the freeze command control circuit 26 sends the second memory 23
By outputting a freeze control signal to R, 23G and 23B, a freeze image is supplied to the recording device 29 and the second monitor 30. By outputting a freeze control signal to the RGB changeover switch 18, the freeze image signal becomes It is supplied to the first monitor 20.

The first embodiment has the above configuration, and its operation will be described with reference to FIG. First, when a vertical synchronization pulse shown in FIG. 2A is output from a timing pulse circuit (not shown) at a period of, for example, 1/60 second, an odd (Odd) field and an even (Even) field are output as shown in the figure. Image information is obtained alternately. In the first embodiment, FIG.
R1, G1, B1, R2, G2, B2 shown in FIG.
.. Are sequentially obtained. That is, in the case of the frame sequential method, for example, each color light of RGB obtained by the color disk 11 rotating at a cycle of 1/20 second is sequentially output, so that the CCD 14 obtains an image signal of a different color for each field. The RGB image signal is subjected to A / D conversion after predetermined image processing is performed by the process circuit 15.
First memory 17R, 17G, 17B via converter 16
Is output to the first monitor 20 based on the image information stored in the memories 17R, 17G, and 17B.

At the same time, the output of the A / D converter 16 is
The G signal shown in FIG. 2C is supplied to the motion detection circuit 22.
The motion state is determined by using the detection pulse shown in (D). That is, in the embodiment, every other G1,
The signals are compared for G3, G5,..., In the case of the figure, for example, the levels of the G1 signal and the G3 signal are compared, and when the levels do not match, it is determined that there is a motion.
Otherwise, it is determined to be in a stationary state.

When it is determined that the apparatus is in the stationary state, the write pulse Pr shown in FIG. 2E is output. At this time, the recordable RGB signals obtained for each vertical scanning period are as shown in FIGS. 2F to 2H. By the write pulse Pr, the R3 signal is sent to the memory 23R and the G3 signal is sent to the memory 23R. The B3 signal is stored in the memory 23G and the memory 23B. Since this storage information is updated each time the above-mentioned stationary state is determined, the memory 23
Inside, the latest still image is stored.

During the above operation, when a control signal of, for example, an enlargement zoom is output by the zoom operation, the enlargement / reduction control processing circuit 24 sets the latest stationary state stored in the memories 23R, 23G, 23B. The image signal is read out, and a predetermined enlargement process is executed based on the image signal. For example, an enlarged image signal is formed by supplementing the same pixel information as adjacent pixel information in the horizontal and vertical directions (interpolation calculation may be performed). At the same time, the selection switch 27 is switched to the a side by the zoom control signal, and the image signal after the enlargement processing is supplied to the recording device 29 and the second monitor 30 via the D / A converter 28. An enlarged image is displayed on the second monitor 30. This enlarged image is formed based on an image signal in a still state, and is an image with high sharpness in which color misregistration has been satisfactorily eliminated.

In the embodiment, a freeze function is also supported. When a freeze operation (freeze on / off signal) is executed, a control signal from the freeze command control circuit 26 is transmitted to the second memories 23R, 23G, 23B. And the latest still image signal is read out in this case as well. When the zoom operation is not performed, the selection switch 27 is switched to the b side, and the RGB changeover switch 18 is also switched to input the output of the selection switch 27 by the freeze control signal.
As a result, a freeze image is displayed on the first monitor 20 and the second monitor 20.

Further, when the zoom operation and the freeze operation are not performed, the still image (quasi-freeze image) that is sequentially updated is supplied to the recording device 29 and the second monitor 30.
The image information recorded in the recording device 29 will be used for later detailed image analysis and the like. Therefore, by using the selection switch 27, a still image obtained each time a still state is detected, a frozen image formed by freeze control, and an enlarged / reduced image can be selected.

FIG. 3 shows the configuration of the second embodiment, which is a dot-sequential or simultaneous apparatus.
In FIG. 3, a CCD having a mosaic color filter is used as the CCD 32 in the case of the dot-sequential type, and three CCDs are used as the CCD 32 in the case of the simultaneous type, and a beam splitter and the like are provided. This CC
A process circuit 33 and an A / D converter 34 are connected to D32, and the process circuit 33 executes image processing suitable for each system.
Therefore, in the second embodiment, the RY and BY signals (color difference signals)
And a Y signal (luminance signal). And the above Y
A motion detection circuit 35 for inputting a signal, a memory 36 for storing field information, an enlargement / reduction control processing circuit 37, a selection switch 38, and a changeover switch 39 are provided.
Other circuits are the same as in the first embodiment.

According to the configuration of the second embodiment, the R-
The Y signal, the BY signal, and the Y signal are obtained at the same time, and the Y signal is input to the motion detection circuit 35. This motion detection circuit 3
5, in the same manner as in the first embodiment, the Y signals between predetermined fields are compared with each other to determine whether the state is a stationary state or a moving state. 36. Therefore, the memory 36
Then, the latest RY when the write pulse is input is
The signal, the BY signal, and the Y signal are stored, and the stored information is updated each time a stationary state is detected.

When the zoom operation is performed, as in the case of the first embodiment, enlargement / reduction processing is executed based on the stationary image information stored in the memory 36, and this image signal is output. Is supplied to the second monitor 30 and the like via the selection switch 38 and the D / A converter 28. In addition,
The freeze operation can also be performed, and this operation is the first
This is similar to the embodiment. Also in the second embodiment, the enlargement / reduction processing is performed based on the image information having no motion, and an image with no afterimage effect and high sharpness can be obtained.

In the above embodiment, the enlarged / reduced image is
Although the image is displayed on the monitor 30, all the images that can be formed on one monitor may be selectively displayed, and various other combinations are possible. In the second embodiment, the image processing is performed using the color difference signal and the luminance signal.
It is also possible to adopt a configuration in which image processing is performed using a GB signal.

[0026]

As described above, according to the present invention,
A motion state or a stationary state is detected from an image signal obtained by the solid-state imaging device, an image signal in the stationary state is stored, and image enlargement / reduction processing is performed based on the image signal of the still image. Since the execution is performed, the color shift or the afterimage effect at the time of executing the zoom function can be satisfactorily eliminated, and an image with high sharpness can be obtained. In particular, in the case of a frame-sequential type apparatus, there is an advantage that the effect of the motion is great, and the effect is great, and good image quality can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a color imaging device using a solid-state imaging device according to a first embodiment of the present invention.

FIG. 2 is a waveform chart showing image signal processing of the first embodiment.

FIG. 3 is a block diagram illustrating a configuration of a color imaging apparatus according to a second embodiment.

[Explanation of symbols]

 11 ... color disc, 14, 32 ... CCD, 15, 33 ... process circuit, 17R, 17G, 17B ... first memory, 18 ... RGB changeover switch, 22, 35 ... motion detection circuit, 23R, 23G, 23B ... second Memory, 24, 37 ... enlargement / reduction control processing circuit, 27, 38 ... selection switch, 36 ... memory, 39 ... changeover switch.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ identification code FI H04N 7/18 H04N 7/18 U 9/04 9/04 Z (58) Fields surveyed (Int.Cl. ⁷ , DB name) H04N 5/228 H04N 5/225 H04N 5/262 H04N 7/18 H04N 9/04

Claims (3)

(57) [Claims] An image processing circuit for performing predetermined color image processing on an image signal picked up by a solid-state image sensor, and a predetermined image signal obtained by the image processing circuit are input, and a motion based on the image signal A motion detection circuit that detects whether the state is a still state or a still state, a memory that sequentially stores and updates the image signal of a still image based on the determination of the still state by the motion detection circuit, and a read image signal from the memory, A color imaging apparatus using a solid-state imaging device, comprising: an enlargement / reduction processing circuit for performing image enlargement / reduction processing in accordance with an enlargement / reduction control signal. 2. An image processing circuit for performing a predetermined color image processing on an RGB image signal picked up by a frame sequential method using a solid-state image pickup device, and an R signal obtained by the image processing circuit.
In a color imaging apparatus using a plane sequential solid-state imaging device having a first memory for storing a GB signal, a motion for detecting whether the RGB signal output from the image processing circuit is in a motion state or a stationary state. A detection circuit, a second memory for sequentially storing and updating the RGB signals of the still image based on the determination of the still state by the motion detection circuit, and inputting an RGB signal read from the second memory to control enlargement / reduction A color image pickup apparatus using a solid-state image pickup device, comprising: an enlargement / reduction processing circuit for performing image enlargement / reduction processing by a signal. 3. A switching circuit for switching between an output from a memory storing the still image signal and an output from the enlargement / reduction processing circuit, based on a still image and a freeze control signal sequentially obtained in the memory. 3. A color image pickup apparatus using a solid-state image pickup device according to claim 1, wherein either the freeze image output from the memory or the enlarged / reduced image can be selected.