JP2001326902A - Electronic camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic camera capable of performing the recording and display of a moving picture in high image quality. SOLUTION: In the electronic camera capable of recording at least two pieces of image information, namely a still picture and a moving picture, the interpolation processing by the approximate expression of a multinomial of the third or higher order is performed to the image information when the image information of the moving picture is recorded or displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic camera capable of taking both still images and moving images.

[0002]

2. Description of the Related Art Electronic cameras are configured to display and record images. Recently, some electronic cameras can display and record not only still images but also moving images. Therefore, an attempt has been made to record a still image with high image quality while sharing the recording process of a still image and a moving image (Japanese Patent Laid-Open No. 10-108121).

In order to solve the above-mentioned problems, the present inventors have already proposed an electronic camera for recording a still image with high image quality.
An electronic camera capable of recording or displaying with high image quality has not yet been proposed.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has as its object to provide an electronic camera capable of recording and displaying a moving image with high image quality.

[0005]

According to the present invention, the following means have been taken in order to solve the above-mentioned problems.

An electronic camera according to the present invention is an electronic camera capable of recording at least two pieces of image information of a still image and a moving image. And performing an interpolation process using an approximate expression of at least a third-order or higher-order polynomial.

[0007] Another electronic camera according to the present invention is an electronic camera capable of recording and displaying at least two pieces of image information of a still image and a moving image. Interpolation is performed on the image information by using an approximation of at least a third-order or higher-order polynomial.

[0008] Still another electronic camera according to the present invention is an electronic camera capable of recording and displaying at least two pieces of image information of a still image and a moving image, wherein a recording means for recording the image information; Display means for displaying information; and image processing means for performing predetermined image processing on the image information, wherein at least one of a case where the image information is recorded on a recording means and a case where the image information is displayed on a display means For the above, the image information is interpolated by an approximation of at least a third-order or higher-order polynomial.

In the above electronic camera, there is further provided image quality setting means for setting the recording image quality of the moving image, and at least a third-order or higher-order polynomial approximation to the image information of the moving image according to the setting of the image quality setting means. It is characterized by performing an interpolation process by using an equation.

[0010]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic block diagram of an electronic camera according to one embodiment of the present invention. A schematic configuration of an electronic camera according to the present invention will be described with reference to FIG. FIG.
Is a schematic block diagram of an electronic camera capable of recording / displaying both a moving image and a still image, and omits an interface and the like for exchanging data with an external device.

The optical image of the subject having passed through the photographing lens unit 10 is divided into a first path P1 for capturing a still image and a second path P2 including a moving image by a first mirror 21 which is a half mirror. Here, the photographing lens unit 1
0 includes a zoom lens 11a, an aperture 12a, and an AF lens 13a, and further includes a zoom motor 11b, an aperture actuator 12b, and an A for driving them.
And an F motor 13b.

First, image information that has passed through the first mirror 21 will be described. The optical image that has passed through the first mirror 21 is input to the still image capturing unit 30. The still image pickup means 30 includes a mechanical shutter 31a and the first image pickup device 3
The mechanical shutter 31a is driven by a shutter actuator 31b to adjust the amount of light input to the first image sensor 32. The optical image whose exposure is adjusted by the mechanical shutter 31a is converted into an electric signal by the first image sensor 32. The shutter actuator 31b, the above-described zoom motor 11b, the aperture actuator 12b, and the AF motor 13b are driven by a drive circuit 81 that outputs a drive signal based on a control signal from a control circuit 80 described later in detail. You.

The image information converted into an electric signal by the first image pickup device 32 is converted into an analog signal by the first image pickup circuit 33 and then converted into a digital image signal by the first A / D converter 34. Is done. Then, it is temporarily stored in the first DRAM 35 in order to perform the subsequent processing. Here, in the case of recording, image information is read from the first DRAM 35 and the still image compression / expansion circuit 36 performs, for example, JPEG (Joint Photographic).
The compression processing is performed by an Experts Group method. Then, the compressed image information is recorded on the still image recording medium 38 via the still image recording / reproducing circuit 37. When displaying a still image, the first DRAM
The image information is read from 35 and converted into a video image by the first display processing circuit 39 so that it can be displayed on a display device. Then, the converted video image is combined with a moving image, which will be described in detail later, by a selective combining circuit 50, if necessary, and displayed on the display device 51.

The optical image reflected by the first mirror 21 will be described. The optical image reflected by the first mirror 21 is totally reflected by the second mirror 22, the path is changed, and the optical path is adjusted so that the optical path is parallel to the first path P1. This optical image is input to the optical finder 60 via a half mirror or the like. The optical image totally reflected by the second mirror 22 is divided into a third path P3 and a fourth path P4 by a third mirror 23 (half mirror). The third path P3 is an optical path of the optical image transmitted through the third mirror 23, and the fourth path P4 is an optical path of the optical image reflected by the third mirror 23. The optical image transmitted through the fourth path P4 is input to the AF sensor 55. AF sensor 55
The AF circuit 56 determines whether or not the focus detected in the step is the in-focus point, and outputs the result to the control circuit 80. Control circuit 8
0 outputs a control signal to the drive circuit 81 based on the output of the AF circuit 56. Then, the drive circuit 81 drives the AF motor 13b based on the output signal from the control circuit 80, and drives the AF lens 13a to set the focus position.

The optical image transmitted through the third path P3 is divided into a fifth path P5 and a sixth path P6 by a fourth mirror 24 (half mirror). The fifth path P5 is an optical path of the optical image transmitted through the fourth mirror 24, and the sixth path P6 is an optical path of the optical image reflected by the fourth mirror 24. The optical image transmitted through the sixth path P6 is input to a moving image capturing unit 40, which will be described in detail later. The optical image transmitted through the fifth path P5 is further diffused by the diffusion plate 25, for example, divided into a seventh optical path P7 and an eighth optical path P8, and the optical image transmitted through the seventh optical path P7 is, as described above, An input to the optical finder 60 enables direct visual observation. 8th
The optical image transmitted through the optical path P8 of FIG. The AE circuit 62 determines whether the exposure is appropriate based on the detection result of the AE sensor 61, and outputs the result to the control circuit 80. The control circuit 80 outputs a control signal to the drive circuit 81 based on the output of the AE circuit 62. Then, the drive circuit 81 drives the diaphragm actuator 12b based on the output signal from the control circuit 80, and adjusts the diaphragm 12a so that the proper exposure is performed.

The moving image pickup means 40 via a sixth path P6
Is reduced by a reduction optical system 41 (for example, a lens), input to a second image sensor 42, and converted into an electric signal. Further, during the moving image shooting, the focus position and the exposure are set to be automatic, so that the moving image pickup means detection switch 95 is turned on so that manual setting cannot be performed. The image information converted into the electric signal is converted into an analog signal by the second imaging circuit 43 and then converted into a second A / A signal.
The digital signal is converted by the D converter 44. Then, it is temporarily stored in the second DRAM 45 in order to perform subsequent processing. Here, when recording a moving image, the second
The image information is read from the DRAM 45 of the moving image compression / decompression circuit 46, for example, by MPEG (Moving P
icture imagecoding Expert
s Group) or motion JPEG. Then, the compressed image information is transferred to a moving image recording medium 48 via a moving image recording / playback circuit 47.
Will be recorded. When displaying a moving image, the second
Image information is read from the DRAM 45, and is converted by the second display processing circuit 49 into a video image so that it can be displayed on a display device. Then, the converted video image is combined with the still image by the selection combining circuit 50 and displayed on the display device 51.

In the above configuration, the still image recording / reproducing circuit 37 and the moving image recording / reproducing circuit 47 are provided separately, but a common part may be shared. Further, the still image recording medium 38 and the moving image recording medium 48 are configured separately, but of course, a still image and a moving image may be recorded on one medium.

The control circuit 80 controls the entire electronic camera except for the focus position adjustment and the exposure adjustment.
For example, the control circuit 80 controls the first release 80 of the still image.
By inputting a, focus lock at the time of shooting a still image is performed, and by inputting the second release 80b of the still image,
Perform imaging. In addition, when the light quantity at the time of imaging the subject is insufficient, the control circuit 80 requests the strobe control circuit 82 to turn on the strobe of the strobe light emitting unit 83 to perform shooting. When the moving image recording switch 80c is turned on, control is performed so that a moving image can be captured. In addition, by inputting the AF switch 80d, the focus position can be automatically or manually adjusted,
Power on / off is controlled by an input of a power switch 80e, switching between a recording mode and a reproduction mode is performed by inputting a recording / reproduction switch 80f, and a reproduction mode (reproduction of a moving image is In such a case, for example, control of standard, fast forward, frame forward, etc.) is performed.

An external interface (external I / F) not shown has a function of inputting / outputting data to / from an external device.

Each part of the electronic camera basically includes a battery 8.
6, and each part of the camera is driven by electric power from a battery 86 via a power supply circuit 85. The battery state detection circuit 87 detects the remaining battery level and the state of charge at the time of charging. The battery 86 is chargeable under the control of the power supply circuit 85. Further, the battery 86 may be an external power supply. In addition to the battery 86, power can be supplied to the power supply circuit 85 from an external terminal 88.

In the electronic camera configured as described above, the present invention is characterized in that, when recording or displaying a moving image, interpolation using an approximate expression of a third-order or higher-order polynomial is applied. . An interpolation model applied to the present invention will be described with reference to FIGS.

FIG. 2 is a diagram showing a one-dimensional interpolation model. Conventionally, as shown in FIG. 2A, linear interpolation for calculating an output value at a desired position by a straight line connecting two points has been generally used. In this way, the position having a known output value required for calculation may be two points. However, since the output value of the proportional average between the two points is determined, for example, the maximum value or the maximum value between the two points is obtained. Even if there is a minimum value, it cannot be detected. In the present invention, in order to increase the interpolation accuracy, an output value at a desired position is obtained by using an approximation formula using at least a third-order or higher-order polynomial. FIG. 2 shows an example in which a coefficient of a third-order polynomial is obtained from the values of four points, and position data is inserted into an approximate expression based on the obtained third-order polynomial to obtain an output. Note that the interpolation using the approximate expression using the third-order polynomial is also referred to as “Cubic interpolation”. In FIG. 2, a coefficient of a third-order polynomial is obtained from output values of four points at positions n-1, n, n + 1, and n + 2, and an output value at a position x 'is obtained from the third-order polynomial to obtain an interpolation value at a desired position. Is obtained. In consideration of the case where this is performed by, for example, linear interpolation, the position having the maximum value is n + 1. Therefore, it is clear that an accurate position cannot be obtained unlike the case of the present invention.

FIG. 3 shows an interpolation operation circuit 90 according to the present invention.
It is a block diagram of. The interpolation calculation circuit 90 includes an interpolation position calculation unit 91, an interpolation position correction unit 92, and an interpolation coefficient table 9
3, the interpolation calculation unit 94, and the buffer memory 31. The functions of the interpolation position calculation unit 91 to the interpolation calculation unit 94 are performed by the control circuit 80. Specifically, the interpolation operation circuit 90 performs the following operation.

The original image data from the second DRAM 45 is input to the interpolation position calculator 91 and the interpolation calculator 94. The interpolation position calculation unit 91, for example, based on the input data,
In FIG. 2B, an interpolation position x 'between the point n and the point n + 1 is calculated. Next, in order to simplify the calculation, the interpolation position correction unit 92 sets, for example, 1 between the point n and the point n + 1.
The interpolation position is corrected based on the data from the second DRAM 45 to a point closest to the x 'point in the case of dividing into six. By correcting the interpolation position in this way, it is possible to calculate the output at the corrected interpolation position using the interpolation coefficient table 93 prepared in advance, so that the interpolation position can be calculated at high speed without performing complicated calculations. The output value can be calculated. It should be noted that the error caused by the correction of the interpolation position is not realistic because the interpolation coefficient is given in the table. If the position is equally divided, the accuracy is sufficient,
Since the data volume is not so large, it can be said that it is realistic.

FIG. 4 shows an example in which the above interpolation operation is applied to a moving image. FIG. 4 is a diagram showing an embodiment in which the above interpolation model is applied to a moving image to improve the possibility for time.
As described above, the MPEG method and the Motion JPEG method are typical examples of the moving image compression recording method. The MPEG method is a standard method for compressing and expanding a color moving image by using difference information. The MPEG method has a slightly inferior image quality but is easy to process, such as MPEG1, high-quality MPEG2 used in DVD software, and mobile communication. There is a standard such as MPEG4, which is being standardized.
The motion JPEG method is a method of compressing and recording each frame constituting a series of video moving images by the JPEG method. The compressed color still image is reproduced as a moving image by continuous reproduction. MP that uses difference information because still images of one frame are compressed independently
There is an advantage that a moving image can be easily edited as compared with the EG method or the like.

FIG. 4 is a schematic diagram for explaining the present embodiment. In the motion JPEG system, a still image is recorded, for example, every 1/60 second, and is recorded every 1/60 second (or By continuously displaying a plurality of photographed still images, the still images can be handled as moving images. In the MPEG system, considering a case where a certain pixel position is targeted, a temporal change in luminance at the pixel point is recorded or displayed at a predetermined time interval (for example, 1/60 second similar to the above). By applying the temporal change of the luminance of this pixel to all pixels,
A moving image can be displayed.

The present invention is applicable to both the motion JPEG system and the MPEG system, and improves the time resolution by taking the following means.

In FIG. 4, the image n at time t is recorded or displayed from the start of photographing, and the next image n + 1 is recorded or displayed after 1/60 second. Normal,
With such a time resolution, a sufficiently smooth moving image can be displayed. However, for example, in the case of slow reproduction, it may be preferable to display an image every 1/120 second for more smooth display. At this time, there is a possibility that a preferable image cannot be obtained by normal linear interpolation, for example, when the subject moves rapidly. Therefore, in the present invention, Cubic interpolation with high accuracy is used for interpolation between the image n at the time t and the image n + 1 at the time t + 1/60. An interpolated image is formed such that it is recorded every 120 seconds, and in the case of display, an interpolated image is formed such that a still image recorded (or photographed) every 1/120 second is displayed. . Therefore, the time resolution is improved by the Cubic interpolation in the time axis direction according to the present invention, so that a smoother moving image can be recorded and displayed.

In the above description, the motion JPE
Although the case of the G method has been described, in the case of the MPEG method, when a certain pixel is viewed, a moving image appears as a time change of the pixel (that is, difference information). Therefore, Cubic interpolation of the difference information is performed. By doing so, the time resolution can be increased as in the case of the motion JPEG method.

FIG. 5 shows Cub for improving the spatial resolution.
FIG. 9 is a diagram illustrating an example in which ic interpolation is applied to recording and display of a moving image. As shown in FIG. 5, image n at time t is output as an even field, image n + 1 at time t + 1/60 is output as an odd field, and image n-1 at time t-1 / 60 is output as an even field. Consider the case of output.

In the prior art, since one frame is composed of an odd field ± an even field and an image is generated every 1/30 second, the output of an image every 1/60 second is half the original number of pixels. At this time, with respect to the image n, even field data is created from odd fields by Cubic interpolation. Similarly, in the images n-1 and n + 1, odd field data is created from even field data by Cubic interpolation. By the above processing, a full size image every 1/60 second is obtained.

Since the processing shown in FIGS. 4 and 5 is performed continuously, parallel processing using a pipeline is usually performed. FIG. 6 is a schematic block diagram for performing pipeline processing at the time of recording. In FIG. 6,
2 shows a processing block for recording a motion JPEG.

As shown in FIG. 6, the bus 1 includes a CPU 2, a preprocessing unit 3, a frame memory 4,
The image processing unit 5 and the JPEG 6 are connected. Image information from the CCD is converted into a digital signal or the like by the pre-processing unit 3 and is temporarily stored in the frame memory 4. This frame memory 4 stores the second D in FIG.
RAM 45 (in the case of a still image, the first DRAM 3
This corresponds to 5). The image processing unit 5 is a part that sequentially performs image processing. For example, specifically, “white balance correction processing” — “color correction processing” — “gradation correction processing” —
For example, n image processings are sequentially performed in accordance with processing such as “edge correction processing”-“YcrCb conversion” (this processing may include Cubic correction), and the first image processing 5-1 to the n-th image processing are performed, respectively. Are sequentially sent to the image process 5-n to perform necessary processing. When the image processing in the image processing unit 5 is completed, the processed image is output to JPEG6, compressed by the JPEG method, and recorded in a detachable memory such as a smart media or CompactFlash (registered trademark) not shown.

Since image processing is performed in parallel by such pipeline processing, recording of moving images can be performed with a minimum configuration. In the case of displaying, the image processed by the image processing unit 5 may be converted into a video signal by an image display circuit or the like (not shown) and displayed continuously.

The present invention is not limited to the above embodiments of the present invention, but can be, of course, carried out in various modifications without departing from the spirit of the present invention.

[0036]

According to the present invention, the following effects can be obtained.

In the electronic camera according to the present invention, at the time of recording image information of a moving image, the image information is interpolated by an approximation of at least a third-order or higher-order polynomial. A moving image with excellent resolution or spatial resolution, that is, a high-quality moving image can be recorded.

In another electronic camera according to the present invention, at the time of displaying image information of a moving image, the image information is interpolated by an approximation of at least a third-order or higher-order polynomial. In addition, a moving image excellent in time resolution or spatial resolution, that is, a high-quality moving image can be displayed.

In still another electronic camera according to the present invention, recording means for recording image information, display means for displaying the image information, and image processing means for performing predetermined image processing on the image information are provided. In the case where at least one of the case where the image information is recorded on the recording unit and the case where the image information is displayed on the display unit, the image information is interpolated by an approximation formula of at least a third order or higher order polynomial. Since this is performed, the same effect as above can be obtained.

Further, the above-mentioned electronic camera further comprises image quality setting means for setting the recording image quality of the moving image, and at least a third-order or higher-order polynomial in the image information of the moving image according to the setting of the image quality setting means. Since the interpolation process is performed using the approximate expression, it is possible to obtain a high-quality moving image corresponding to the set image quality at the time of recording and different from, for example, pixel thinning.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of an electronic camera according to an embodiment of the present invention.

FIG. 2 is a diagram showing a one-dimensional interpolation model.

FIG. 3 is a block diagram of an interpolation operation circuit 90 according to the present invention.

FIG. 4 shows an interpolation model according to the present invention applied to a moving image,
The figure which shows embodiment which improved possibility for time.

FIG. 5 is a diagram showing an example in which Cubic interpolation is applied to recording and display of a moving image in order to increase spatial resolution.

FIG. 6 is a schematic block diagram for performing pipeline processing during recording.

[Explanation of symbols]

 Reference numeral 10 denotes a photographing lens unit, 11a denotes a zoom lens, 11b denotes a zoom motor, 12a denotes an aperture, 12b denotes an aperture actuator, 13a denotes an AF lens, 13b denotes an AF motor, 13b denotes an AF motor, 21 denotes a first mirror, and 22 denotes a second mirror. 2 mirror, 23 third mirror, 24 fourth mirror, 25 diffuser plate, 30 still image capturing means, 31a mechanical shutter, 31b shutter actuator, 32 first image sensor 33 ... 1 imaging circuit, 34 first A / D converter, 35 first DRAM, 36 still image compression / expansion circuit, 37 still image recording / reproduction circuit, 38 still image recording medium, 39 first , A display processing circuit of 40, a moving image pickup means 41, a reduction optical system, 42, a second image pickup device, 43, a second image pickup circuit, 44, a second A / D converter, 5: second DRAM, 46: moving image compression / expansion circuit 47: moving image recording / reproducing circuit, 48: moving image recording medium, 49: second display processing circuit 50: selective combining circuit, 50: selective combining circuit, 51: display device 55, AF sensor, 56, AF circuit, 60, optical finder, 61, AE sensor, 62, AE circuit, 80, control circuit, 80a, first release of still image, 80b, second release of still image 80c: moving image recording switch, 80d: AF switch, 80e: power switch, 80f: recording / playback switch, 80g: playback mode switch, 81: drive circuit, 82: strobe control circuit, 83: strobe light emitting unit, 86 ... Battery, 85 ... Power supply circuit, 87 ... Battery state detection circuit, 88 ... External terminal, 95 ... Video image pickup means detection switch

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 5/91 Z F term (Reference) 5C022 AA13 AB68 AC02 AC03 AC09 AC42 AC55 AC80 5C053 FA07 FA27 GA11 GA19 GB04 GB36 GB37 HA23 HA33 KA04 KA08 KA24 LA01 LA06

Claims (4)

[Claims] An electronic camera capable of recording at least two pieces of image information of a still image and a moving image, wherein when recording the image information of the moving image, at least a third order or higher order image information is stored in the electronic camera. An electronic camera which performs an interpolation process using a polynomial approximation. 2. An electronic camera capable of recording and displaying at least two pieces of image information of a still image and a moving image, wherein when displaying the image information of the moving image, at least tertiary or higher order image information is displayed. An electronic camera which performs an interpolation process using an approximate expression of a high-order polynomial. 3. An electronic camera capable of recording and displaying at least two pieces of image information of a still image and a moving image, wherein: a recording unit for recording the image information; a display unit for displaying the image information; Image processing means for performing predetermined image processing on at least one of a case where the image information is recorded on a recording means and a case where the image information is displayed on a display means. An electronic camera which performs the above-described interpolation processing using an approximate expression of a higher-order polynomial. 4. The electronic camera according to claim 3, further comprising image quality setting means for setting a recording image quality of the moving image, wherein the image information of the moving image is at least tertiary or higher according to the setting of the image quality setting means. An electronic camera which performs an interpolation process using an approximate expression of a high-order polynomial.