JP3332396B2 - 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 an image pickup apparatus such as a video tape recorder integrated video camera capable of recording a still image together with a moving image , and more particularly to a white balance control at the time of photographing a still image.

[0002]

2. Description of the Related Art In recent years, in the field of magnetic recording, there has been an increasing demand for high-density recording. In a video tape recorder (VTR), the tape traveling speed has been reduced, and higher-density magnetic recording has been performed. Is coming.

[0003] When the running speed of the tape decreases, for example, when an audio signal is recorded using a fixed head, the relative speed cannot be increased so that the reproduced sound quality deteriorates. As one means for solving this problem, there is a method in which the length of a track operated by a rotary head is made longer than before, and an audio signal whose time axis is compressed is sequentially recorded in an extended portion thereof. Specifically, in a rotary two-head helical scan type VTR, a magnetic tape is conventionally wound around a rotary cylinder by 180 degrees or more, but in this method, a magnetic tape is wound by (180 + θ) degrees or more and extraly wound. This is a method of recording an audio signal that has been converted to PCM and compressed on the time axis in the portion of θ ″.

FIG. 1 is a diagram showing a tape running system of a VTR according to such a method, and FIG. 2 is a diagram showing a recording locus on a magnetic tape by the VTR shown in FIG. In FIG. 1, 1
Is a magnetic tape, 2 is a rotary cylinder, 3 and 4 are cylinders 2.
5 is a video signal recording area (video area) of a track formed on the magnetic tape 1, and 6 is a PCM audio signal recording area (audio area). The video area 5 is traced by the heads 3 and 4 by 180 degrees of the rotating cylinder 2,
Further, the audio area 6 is traced by θ of the rotating cylinder 2.

As an example of applying the method of recording a digital signal in another area while recording a video signal as described above, it has been proposed to record a still image in the digital signal recording area 6 as a digital signal. ing. If the image is a still image, it is possible to record all of the information on the magnetic tape 1 by scanning the PCM area a plurality of times. According to this method, not only can a still image be photographed using the same photographing apparatus and the same recording medium as in the case of moving image photographing, but also the tape running in the conventional VTR is stopped and the video signal of the same track is reproduced. It is possible to obtain a higher quality still image than a still image.

[0006]

However, in the above-mentioned conventional example, since a still image is to be photographed by a camera originally designed for moving image photographing, there are the following disadvantages.

(1) If the subject changes suddenly at the moment of photographing a still image, auto white balance adjustment (hue adjustment) cannot keep up with the change, and the hue, saturation, etc., differ from the actual color. It may be shot.

(2) When a so-called color jump occurs due to a sudden change in the color temperature of the light source or the like, it takes a little time to actually reproduce the color, and a still image taken during that time is not acceptable. It becomes a natural color.

(3) Since the white balance is set by making the average of the color signals of one entire screen white, the color of a partial area in the screen may not be reproduced. For example, when photographing a still image in which a person stands in front of a large red building, red is determined to be white, so that the bare color is not a natural color.

[0010] The present invention has been made to solve the points mentioned above, and its object is also a sudden change in color temperature of the rapid change and the light source of the subject at the time of still image photographing or the like occurs, It is an object of the present invention to provide an imaging device capable of obtaining a reproduced image having a natural hue.

[0011]

In order to achieve the above object, an image pickup apparatus according to the present invention comprises: a white balance adjusting means for adjusting a white balance of an image picked up by an image pickup means; Corresponding to the above
Set the setting values of the white balance adjustment means respectively,
By adjusting the white balance adjusting means ,
An image corresponding to each of the serial set plurality of set values
And control means for continuously acquiring.

[0012]

[0013]

[0014]

[0015]

According to the present invention, when the release button is pressed during still image shooting, the white balance setting is changed by using a plurality of white balance setting values set before shooting for each still image shooting. Since multiple screens and still images are shot, only those screens that have been shot well are extracted afterwards, or multiple screens are synthesized by appropriate image processing to obtain a reproduced image with the most natural hue Becomes possible.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 3 shows a circuit configuration of a video camera according to a first embodiment of the present invention. In this figure,
Reference numeral 101 denotes a first group lens for focus adjustment, 102 denotes a variable power lens, 103 denotes a correction lens, 104 denotes an aperture, 105 denotes a fixed fourth group lens, and 106 denotes an image sensor. 107,1
08 and 109 are motors for focus adjustment, magnification adjustment and aperture adjustment, respectively, 110, 111 and 112 are drivers for driving these motors, 113 and 109, respectively.
114 and 115 are encoders for detecting the lens position and the aperture state. 116 is an AGC (automatic gain control) circuit, 117 is a high-pass filter (HPF), 118
Is a comparator (COMP) for adjusting aperture, 119
Are microcomputers (MPU), 120, 121,
122, 123, 128 are pull-up resistors, 124 is a zoom tele switch, 125 is a zoom wide switch, 1
Reference numeral 26 denotes a switch for switching a still / movie shooting mode, and 127 denotes a still image shooting release switch.

Reference numeral 128 denotes a color separator for extracting a color signal; 129, a white balance (AWB) circuit;
Is a signal processing circuit for generating a color difference signal and a color signal from a primary color signal. 132, a color sensor for detecting the color temperature of the light source; and 133, a signal processing circuit for synthesizing a signal from the color sensor 132 and a signal from the microcomputer 119.

Reference numeral 134 denotes an encoder for generating an NTSC signal; 135, an image memory for capturing a still image;
Reference numeral 6 denotes a control circuit for controlling the start and clear of recording of the image memory 135 in accordance with the timing of release and recording by the release switch 127, and 137 converts the output of the image memory 135 into a signal suitable for recording on the magnetic tape 140. The signal conversion circuit 138 is an amplifier, and 139 is a head.

When there are a plurality of image memories to be used as indicated by reference numeral 135, the circuit configuration around these image memories is as shown in FIG. In this figure. 1101,
1102 and 1103 are image memories, 1104 is a switch for selecting a memory for storing a still image, 1105
Is a switch for selecting which memory contents are to be read and recorded on the magnetic tape 140. Control circuit 136
Since it is necessary to control the switches 1104 and 1105 in synchronization with the recording and release timings, the microcomputer 119 and the signal conversion circuit 137 communicate with each other.

As shown in FIGS. 1 and 2, when a still image is recorded in the PCM audio signal recording area on the magnetic tape 140 at a head / tape relative speed equal to that at the time of moving image recording and recording, for example, a winding angle of 30 ° If a still image is to be recorded in the PCM audio signal recording area, a recording time of several to several tens of track periods, that is, several to several tens of vertical synchronization periods, is required, and there is a possibility that a photo opportunity cannot be made in the meantime. Come. However, if a plurality of image memories 1101 to 1103 are used as shown in FIG. 4, after storing still image information in one memory, the next still image can be stored in another memory without immediately recording it on a tape. Since it is possible, there is an advantage that a photo opportunity is not missed.

In the first embodiment of the present invention, the current white balance value determined by the hue adjustment (auto white balance) function for moving image shooting and the primary color signal mixing ratio are further changed by a predetermined amount. A plurality of still images are obtained by setting a plurality of white balance values and photographing for each white balance. The setting of this white balance is performed by the microcomputer 119 in accordance with the state signal of the signal processing circuit 133. That is, the microcomputer 119 transmits a selection signal to the signal processing circuit 133 for the setting, and the white signal is transmitted through the signal processing circuit 133. This is performed by controlling the balance circuit 129.

First, a procedure for photographing a still image will be briefly described. FIG. 5 shows the concept of the still image recording method.
When the release button (release switch) 127 is pressed, the field or frame memory 135 for once capturing a still image captures the video at that moment. The captured video signal is in the PCM area 1 as described in the conventional example.
Recorded at 46. At this time, the images are recorded in areas 1201, 1202, and 1203 in order from the first still image. It is said that this recording usually requires a time of ten to several tens of vertical synchronization periods.

FIG. 6 shows the appearance of a video camera incorporating the circuit of FIG. In the figure, reference numeral 201 denotes a whole video camera, and 202 denotes a zoom switch for switching a zoom having the same function as the zoom tele switch (T) 124 and the zoom wide switch (W) 125. Switching of the shooting mode switch 126 or the release switch 12
FIG. 7 shows the procedure for switching the still / moving image shooting mode when 7 is pressed.

In the flowchart of FIG. 7, when the switching processing program is started in step 301, it is determined in step 302 whether the release switch 127 has been pressed during the moving mode or the switch position of the photographing mode switch 126. , Still image mode (S
V) or a moving image mode (MV). That is, in step 302, in addition to the switch state of the shooting mode changeover switch 126, the still image mode is selected if the release switch 127 is pressed even if the switch 126 is on the moving image side. Step 3 when you select the video mode
03, the moving image recording process is performed, and the still image mode is selected.
It is determined whether or not 7 has been pressed. If the determination is affirmative, a still image shooting process is performed in step 305.

As an example, a camera having three image memories as shown in FIG. 4 will be described. When the still mode is selected in step 302, the process waits until the release button 127 is pressed in step 304. During this standby, in step 306, for example, processing as shown in FIG. 8 is performed. That is, in step 401, the current white balance set value determined by the automatic white balance (AWB) is read from the signal processing circuit 133, and the set value is set as the white balance B to the microcomputer 11
9 in the RAM area B in the RAM area. Next, in step 402, the ratio of the R signal (red signal) is set to be, for example, relatively 20% larger than the white balance B set in step 401, and is set as white balance A.
RAM in RAM area in microcomputer 119
・ Store in A. In the next step 403, step 40
2, the B signal (blue signal) or the green signal is increased by, for example, 20%, and the white signal
And stored in the RAM / C in the microcomputer 119. The ratio of the color change and the combination of colors in steps 402 and 403 are not limited to these, and can be set arbitrarily. While performing the processing from step 401 to step 403, the process waits until the release button 127 is pressed. When the release button 127 is pressed during the moving image mode, it is necessary to perform the processing from step 401 to step 403 at least once.

When the release button 127 is depressed and the release is determined, the still photographing process of step 305 is performed. Step 305 further includes step 404,
The processing is divided into 405, 406, 407, 408, and 409 processing. In steps 404, 405, and 406, the set values are called from the RAM in the microcomputer 119 to set the white balance to the set values of A, B, and C, and three still images are shot. These are stored in the field memories 1101, 1102 and 1103, respectively. In the next step 407, recording on the magnetic tape 140 is permitted. Next step 408
Then, it is determined whether or not the recording from the field memory operated by another program to the magnetic tape is completed based on the presence or absence of the recording completion signal. Step 1 when recording is completed
The flow shifts to 409, where recording on the magnetic tape 140 is prohibited, and the flow returns to step 302 in FIG. In the processing so far,
By pressing the release button 127 once, three still images with different white balance settings are recorded.

Next, the field memories 1101, 110
An example of the recording operation from the second and 1103 to the magnetic tape 140 will be briefly described with reference to the flowchart in FIG. When the program is started in step 1301, it is determined in step 1302 whether or not recording permission has been output, and when recording is permitted in step 407, step 13 is executed.
Shift to 03. In step 1303, the counter n is set to n
= 11101, and in the next step 1304, the contents of the memory n at the address indicated by the counter n are stored on the magnetic tape 140.
Is recorded in the area 146. In the next step 1305, it is determined whether or not the recording on the magnetic tape 140 has been completed. If the recording has not been completed, the process in step 1304 is continued.
If it is determined in step 1305 that the recording is to be ended, in the next step 1306, the value of n is incremented by 1 and n =
If n + 1 is not satisfied in step 1307, the processing from step 1304 is performed, and n = 1102,
The still image shooting of 1103 is repeated. Step 130
7, when n = 1104, recording is completed in step 1308, and a recording completion signal is output. Whether or not this recording has been completed is determined in step 408 in FIG. 8 described above.
If it is determined that the recording is completed, steps 408 to 40
9 while the program of FIG.
Then, the process returns to step 1302, and waits for the next recording permission.

Thus, according to the present embodiment, AWB
Based on the current white balance setting value automatically determined by (automatic white balance), a still image that is slightly bluish and a still image that is slightly redder than the current white balance are obtained. Therefore, even if there is a sudden movement of the subject or a change in the light source during the shooting of a still image, a plurality of still images can be taken with a plurality of white balance settings, thereby reducing shooting failures and naturally increasing the hue of the subject. The user can select the reproduced still image later.

(Second Embodiment) FIGS. 10, 11 and 12 show a main part configuration and an operation procedure of a second embodiment of the present invention. A second embodiment of the present invention divides a shooting screen into a plurality of regions, performs white balance setting independently in each region,
This is an embodiment in which a plurality of still images are obtained with a plurality of white balance settings.

FIG. 10 shows processing portions related to the white balance setting of FIG.
The signal system shown by the symbol is added. That is, as shown in FIG. 10, a vertical synchronizing signal (VD) 501 and a horizontal synchronizing signal (HD) 502 are transmitted from the microcomputer 119 to the signal processing circuit 133 for the area division. The synchronization signals 501 and 502 are the microcomputer 1
VD and HD signals controlled in step S19, and from these signals 501 and 502, for example, reference numerals 604 and 60 in FIG.
Since the horizontal and vertical coordinates in the screen shown by 3 are known, the area 601 on one frame of the stationary surface can be determined. Then, the signal processing circuit 133 extracts only the color signals in the region 601 from the color signals from the image sensor 106 , so that the white balance circuit 129 outputs the white balance only in the region 601 where the subject exists, for example. Value can be set. Conversely, if the color signal of the area 602 corresponding to the outer frame is extracted, for example, the white balance of the area 602 corresponding to the background of the subject can be determined.

Using a signal processing circuit capable of setting a white balance for each area as described above, for example, processing as shown in FIG. 12 is performed. Next, this processing procedure will be described.

As in the first embodiment, step 3 in FIG.
When the still mode is selected in 02, the process stands by in step 304 until the release button 127 is pressed. During this standby, for example, the processing shown in FIG. 12 is performed. That is, if the release button 127 is not depressed, step 701 is performed.
Then, in step 701, a white balance calculated from the entire current screen is set, and this set value is set as a white balance B in the RA in the microcomputer 119.
Store in MB. Next, in step 702, VD501,
The white balance in the central area 601 is set based on the synchronization signal of the HD 502, and the set value is set as white balance A, and the white balance A
Store in A. Further, in the next step 703, a white balance in the outer frame area 602 is set, and the set value is set as the white balance C as the microcomputer 1
19 is stored in the RAM C. Step 701 above
While waiting for the release button 127 to be released, the process waits until the release button 127 is pressed while performing the processing from step 703 to step 703.
If the release button 127 is pressed during the moving image mode, at least one of the steps 701 to 701 is performed.
It is necessary to perform the processing up to 03.

When the release button 127 is depressed and the release is determined in step 304, the still photographing process of step 305 is performed. Step 305 is the first in FIG.
The processing is divided into steps 404 to 409 as in the embodiment. First, steps 404, 405, 40
In step 6, the set value of the white balance is called from the RAM in the microcomputer 119, and the white balance is adjusted to the set value, whereby A, B and C are respectively set.
, A still image is shot with each of the set white balances, and the information of the shot still image is stored in each of the field memories 1101, 1102, and 1103. Next, step 407
Then, the recording of the magnetic tape 140 is permitted, and in step 408, the process waits for the completion of the recording. When the recording completion is notified by, for example, the microcomputer 119 of the recording system, step 4 is executed.
08, the recording to the tape 140 is prohibited in step 409 until the writing to the next memory is completed.

Recording from the image memories 1101 to 1103 onto the magnetic tape 140 is controlled by a control system shown in FIG. 9 by a microcomputer 119 of a recording system, for example, as in the first embodiment.

In the present embodiment, a plurality of still images can be obtained while sequentially changing the white balance set for each area by the above-described operation. Therefore, a still image having a natural hue independent of the background color of the subject can be obtained. You can select a picture later. Further, it is also possible to obtain a reproduced image in which natural colors are reproduced in a wide range by combining a plurality of screens by image processing.

(Third Embodiment) FIGS. 13 and 14 show the operation procedure of a third embodiment of the present invention. The third embodiment is an embodiment in which the white balance can be set for each area and only one field memory is used, as in the second embodiment.

In this embodiment, as in the second embodiment, FIG.
For example, the white balance of the areas 601 and 602 shown in FIG. 11 is determined by the signal processing circuit system shown in FIG.
Then, as in the first and second embodiments, if the still mode is selected in step 302 in FIG. 7, the process waits in step 304 until the release button 127 is pressed. During this standby, for example, the processing shown in FIG. 13 is performed. That is, a white balance calculated from the entire current screen is set in step 1001 in FIG.
9 is stored in the RAM 2. Next, in step 1002,
The central area 6 based on the synchronization signals of VD501 and HD502
01 is set, and the set value is stored in the RAM 1 of the microcomputer 119 as the white balance A. In the next step 1003, the white balance in the outer frame area 602 is set, and the set value is stored in the RAM 3 in the microcomputer 119 as the white balance C. Step 100 above
While performing the processing from step 1 to step 1003, the process stands by until the release button 127 is pressed to release the image. When the release button 127 is pressed during the moving image mode, it is necessary to perform the processing from step 1001 to step 1003 at least once.

When the release button 127 is depressed and it is determined in step 304 that the release has been made, the still photographing process in step 305 'is performed. Step 305 'is divided into steps 1004 to 1011. First, in step 1004, n = 1, and in step 1
In 005, the set value of the white balance written in the RAMn is called (this set value is initially A),
Adjust the white balance to that value. Then step 1
In step 006, a still image is photographed with the white balance setting, and the photographed still image information is stored in the image memory 135. Subsequently, in step 1007, recording from the memory 135 to the tape 140 is permitted, and in the next step 1008, the process waits until recording is completed.

If it is determined that the recording is completed, step 1
In 009, recording on the tape 140 is prohibited until the next still image information is stored in the memory 135. Next step 101
0 = n = n + 1 by addition, and the following step 101
At step 1, a determination is made as to whether n = 4. If n ≠ 4, the flow returns to step 1005 to set the white balance to the set value stored in the next RAM in step 1005, and execute the processing from step 1006 again. If n = 4, the processing of step 305 'is terminated and step 30
Return to 2.

The recording procedure from the image memory 140 to the magnetic tape in this case is as shown in FIG. 14, for example. First,
This processing is started in step 1401, and
In step 2, it is determined whether or not recording is permitted. If the recording is permitted, the content of the memory 135 is recorded on the tape in the next step 1403, and it is determined whether or not the recording is completed in a succeeding step 1404, and the process returns to step 1402 when the recording is completed.

In this embodiment, due to the above operation, although there is a time lag of the weak crown due to the still image to be shot,
Since it is not necessary to use a plurality of memories as in the first and second embodiments, the manufacturing cost can be reduced, and the color of the intended subject is not affected by the background other than the subject. The most beautiful still image can be selected later. Further, by combining a plurality of screens by image processing, it is possible to obtain a reproduced image in which natural hues are reproduced in a wide range.

[0043]

As described above, according to the present invention,
Since multiple still images can be obtained while sequentially changing the white balance with the set value set for each area of the shooting screen, you can later select a natural hue still image that is not affected by the background color of the subject, In addition, an effect that a reproduced image in which natural colors are reproduced over a wide screen area can be obtained by combining a plurality of screens by image processing or the like is obtained.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing a tape running system of a conventional VTR.

FIG. 2 is an explanatory diagram showing a recording locus on the magnetic tape of FIG. 1;

FIG. 3 is a block diagram showing a circuit configuration of the video camera according to the first embodiment of the present invention.

FIG. 4 is a block diagram showing a detailed configuration around the image memory of FIG. 3;

FIG. 5 is a diagram showing a recording mode according to the first embodiment of the present invention.

FIG. 6 is a schematic front view showing the appearance of the video camera according to the first embodiment of the present invention.

FIG. 7 is a flowchart showing the overall operation of the first embodiment of the present invention.

FIG. 8 is a flowchart showing a detailed procedure of a standby process and a still photographing process of FIG. 7;

FIG. 9 is a flowchart illustrating a recording operation procedure on a magnetic tape according to the first embodiment of the present invention.

FIG. 10 is a block diagram showing a main circuit configuration of a second embodiment of the present invention.

FIG. 11 is a plan view showing an example of area division on a photographing screen according to a second embodiment of the present invention.

FIG. 12 is a flowchart illustrating a detailed procedure of a standby process and a still shooting process according to the second embodiment of the present invention.

FIG. 13 is a flowchart illustrating a detailed procedure of a standby process and a still shooting process according to the third embodiment of the present invention.

FIG. 14 is a flowchart illustrating a recording operation procedure on a magnetic tape according to a third embodiment of the present invention.

[Explanation of symbols]

 101 to 103, 105 Lens 106 Image sensor 116 Automatic gain control circuit 119 Microcomputer 124 Zoom tele switch 125 Zoom wide switch 126 Shooting mode changeover switch 127 Release button 128 Color separator 129 White balance circuit 130, 133 Signal processing circuit 132 Color sensor 135 Image memory 136 Control circuit 140 Magnetic tape 202 Zoom switch 501 Vertical synchronization signal 502 Horizontal synchronization signal 601 Central area 602 Outer frame area 1104, 1105 Switch 1201, 1202, 1203 Recording area

Claims (1)

(57) [Claims] And a white balance adjusting means for adjusting a white balance of an image picked up by an image pick-up means.
Control means for setting a set value of each of the plurality of set values , and continuously acquiring images corresponding to each of the set values by adjusting the white balance adjusting means. An imaging device characterized by the above-mentioned.