JP2005175960A - Electronic camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic camera capable of preventing noise from being recorded in sound recorded during zooming during moving image shooting.
An electronic camera includes a CCD that converts an optical image formed on an imaging surface into a video signal, and obtains a voice at the same time as the CCD converts the optical image into a video signal, thereby converting the optical image into an analog audio signal. A microphone 112 for conversion, and a recording means 105 for recording the video signal photoelectrically converted by the CCD 106 and the audio signal output from the microphone 112 by the signal processing IC 102 and then recording them as video data and video audio data, respectively. The optical zoom by the taking lens 107 or the electronic zoom by the signal processing IC 102 can be performed during moving image shooting. When the electronic camera 1 performs zooming while shooting a moving image, the electronic camera 1 performs electronic zooming before performing optical zooming.
[Selection] Figure 1

Description

  The present invention relates to an electronic camera, and more particularly to an electronic camera such as a digital video camera or a digital camera that performs zooming of a moving image.

  In recent years, digital camcorders, such as digital camcorders and digital cameras, originally recorded video, but those with a still image recording mode have become commonplace. However, those having a moving image recording mode are generalized. For example, the audio encoding / decoding circuit 34 increases the compression rate of the audio signal to increase the output code rate and decreases the output code amount in response to the camera operating signal, and the communication control circuit increases the amount of communication for the image information. An electronic camera that allocates line capacity is disclosed (for example, see Patent Document 1).

  In such an electronic camera such as a video camera or a digital camera, an optical zoom mechanism for zooming an image by enlarging an optical image formed on the imaging surface by changing a focal length of the optical system, and an image A device equipped with both an electronic zoom mechanism for zooming an image by electronically enlarging a part has been generalized. In this case, by performing the zoom of the image by the electronic zoom in addition to the optical zoom, for example, as shown in FIG. 6, the magnification by the optical zoom can be increased by the magnification by the electronic zoom.

  In the case of enlarging an image with the electronic zoom, since an image enlarged from a part of the image to the size of the entire image is generated, there is a disadvantage that the image quality is deteriorated as compared with an image enlarged only with the optical zoom.

For this reason, the conventional electronic camera generally prioritizes the optical zoom when enlarging an image, and generally performs the electronic zoom after the focal point of the optical zoom reaches the tele end.
JP-A-5-300506

  However, when shooting a movie, it is common to record the sound at the same time. When optical zooming is performed at this time, the actuator is driven by a motor or the vibration caused by friction when the lens moves inside the lens barrel. There has been a problem that generated noise is recorded as noise of an audio signal.

  An object of the present invention is to provide an electronic camera that can prevent noise from being recorded in audio recorded during zooming during moving image shooting.

  The electronic camera according to claim 1, zoom means for performing electronic zoom or optical zoom on an optical image formed on an imaging surface, and conversion means for converting the optical image on which the zoom is performed into a video signal; In an electronic camera comprising: an acquisition unit that acquires an audio signal simultaneously with the conversion by the conversion unit; and a recording unit that continuously records the converted video signal and the acquired audio signal as a moving image with audio; The zoom means performs the electronic zoom before performing the optical zoom.

  According to a second aspect of the present invention, in the electronic camera according to the first aspect of the present invention, the scaling factor by the electronic zoom is in a range where interpolation for enlargement is unnecessary.

  According to the electronic camera of claim 1, an audio signal is acquired simultaneously with converting an optical image formed on an imaging surface and subjected to electronic zoom or optical zoom into a video signal, and the converted video signal In addition, when the acquired audio signal is continuously recorded as a moving image with sound, the electronic zoom is performed before the optical zoom, so that it is possible to prevent noise from being recorded in the sound recorded during the zooming of the moving image. .

  According to the electronic camera of the second aspect, since the magnification ratio by the electronic zoom is in a range that does not require interpolation for enlargement, it is possible to prevent the image quality from being deteriorated when the moving image is enlarged by the electronic zoom.

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

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

  In FIG. 1, an electronic camera 1 according to an embodiment of the present invention includes a CPU 101 that controls the entire electronic camera 1, a zoom SW 109, a memory 103, a communication terminal 117, and a signal processing IC 102 that are connected to the CPU 101, and a zoom. The photographing lens 107 connected to the CPU 101 via the motor 108 and the focus motor 110, the microphone 112 connected to the CPU 101 via the A / D converter 111, and the CPU 101 via the D / A converter 113, respectively. A speaker 114 and an audio output terminal 115 are provided, and optical zoom or electronic zoom can be performed during moving image shooting.

  The memory 103 records various data that can be read and written by the CPU 101.

  The photographing lens 107 (zoom means) performs optical zoom by zoom adjustment by the zoom motor 108 and focus adjustment by the focus motor 110. The zoom SW 109 is configured such that the user can set the zoom magnification of the video to an arbitrary magnification between the wide end and the tele end. The CCD 106 (conversion means) converts an optical image formed on the imaging surface into a video signal. The microphone 112 (acquisition means) acquires sound at the same time as the CCD 116 converts the optical image into a video signal, and converts it into an analog sound signal.

  The communication terminal 117 includes a USB terminal that transmits and receives signals between the CPU 101 and a personal computer (not shown), a printer, and other external devices.

  The signal processing IC 102 processes video signals and audio signals from the CCD 106, the microphone 112, a recording unit 105 described later, and the like to generate video data and audio data.

  The recording means 105 (recording means) records the video signal photoelectrically converted by the CCD 106 and the audio signal acquired by the microphone 112 as signal data and video audio data after signal processing by the signal processing IC 102, respectively. The signal processing by the signal processing IC 102 (zoom means) includes electronic zoom adjustment of the video signal.

  The LCD 104 reproduces the video data generated by the signal processing IC 102 or recorded by the recording unit 105. The video output terminal 116 outputs the video data generated by the signal processing IC 102 or recorded by the recording unit 105 to an external image reproduction device.

  The speaker 114 reproduces audio data that has been signal-processed by the signal processing IC 102 or recorded by the recording means 105. The audio output terminal 115 outputs the audio data processed by the signal processing IC 102 or recorded by the recording unit 105 to an external audio reproduction device.

  Hereinafter, the operation of the electronic camera 1 of FIG. 1 will be described.

  The following operations are controlled by the CPU 101 unless otherwise specified.

  In FIG. 1, first, light passing through the photographing lens 107 forms an image on the imaging surface of the CCD 106, the light is photoelectrically converted into a video signal by the CCD 106 and output, and the output video signal is output by the signal processing IC 102. The signal is processed and recorded as video data in the recording device 105.

  Also, an audio signal acquired by the microphone 112 simultaneously with photographing by the CCD 106 is A / D converted by the A / D converter 111 to become a digital signal, which is input to the CPU 101 and recorded as video audio data in the recording device 105. .

  Video data is output from the signal processing IC 102 to the LCD 104 or the video output terminal 116 at the time of shooting using the electronic viewfinder function or at the time of playback, and is played back on the LCD 104 or an external playback device connected to the video output terminal 116. .

  Simultaneously with the reproduction of the video, the audio data for video recorded in the recording device 105 is output to the speaker 114 and the audio output terminal 115 via the D / A converter 113 and connected to the speaker 114 and the audio output terminal 115. It is played back by an external playback device. Thereby, a moving image with sound can be reproduced at the time of shooting using the electronic viewfinder function or at the time of reproduction.

  The video data and video audio data recorded in the recording device 105 can be transferred to an external personal computer or another external device such as a printer via the communication terminal 117. Further, a program used in the electronic camera 1 can be recorded in the memory 103 and the operation of the electronic camera 1 can be controlled by an external personal computer.

  Also, based on the zoom magnification set by the zoom SW 109, a zoom adjustment command in two directions, tele-side and wide-side, is sent to the CPU 101. In response to this command, the CPU 101 determines whether to perform zoom adjustment by optical zoom or electronic zoom.

  When performing zoom adjustment by optical zoom, the zoom motor 108 is driven and controlled to drive a zoom lens (not shown) that constitutes the photographing lens 107, and at the same time, the focus motor 110 is driven and controlled to configure the photographing lens 107. A focus lens (not shown) is driven along the zoom cam locus.

  For example, as shown in FIG. 2, an enlarged image (FIG. 2 (b)) obtained by magnifying the original image (FIG. 2 (a)) by an optical zoom by a factor of 2 was optically enlarged twice. The resolution of the image does not change.

  On the other hand, as shown in FIG. 3, the enlargement by the electronic zoom is an enlarged image obtained by enlarging a part of the image formed based on the image data (FIG. 3A) from the signal processing IC 102 to the size of the entire image. This is done by forming (FIG. 3B).

  This enlarged image by electronic zoom, for example, enlarges a part of the original image so that it becomes the size of the entire image, and the signal of the vacant pixel in between is left and right of the pixel in the horizontal direction. Interpolation is performed with a signal generated by weighting according to the positional relationship with a signal of a non-pixel, and in the vertical direction, interpolation is performed with a signal generated by weighting with a positional relationship with non-free pixel signals above and below the pixel.

  All the signal processing performed at the time of enlargement by the electronic zoom is performed within the signal processing IC 102. The magnification by electronic zoom can be arbitrarily changed by a value given by X / Y (X = 1 to 255, Y = 1 to 255).

  For example, an enlarged image (FIG. 2 (c)) doubled by electronic zoom is obtained by cutting out the central portion of the original image (FIG. 2 (a)) as it is and enlarging the cut out portion. In this case, the enlarged image (FIG. 2C) is interpolated so that the number of pixels is the same, but the original information amount is smaller than in the case of the optical zoom (FIG. 2B). Image quality deteriorates. Therefore, it is desirable that the zoom ratio by the electronic zoom is within a range that does not require interpolation for enlargement.

  Even when the zoom ratio of the electronic zoom is smaller than 1, a reduced image can be obtained in exactly the same manner. However, in this case, the reduced image has a fixed image circle of the image sensor and the optical system, so it does not become wider than that, and a screen with a rough resolution is obtained by reducing the number of pixels.

  For example, a reduced image (FIG. 4B) obtained by halving the original image (FIG. 4A) by optical zoom has 2 × 2 CCD elements on the imaging surface of the CCD 106. It is obtained by receiving light received by one CCD element and performing photoelectric conversion. Therefore, as shown in FIG. 4B, an image having a smaller number of pixels than the number of pixels of the original video is recorded.

  On the other hand, the reduced image (FIG. 4C) reduced to 1/2 times by electronic zoom is an image formed by the original image (FIG. 4A) formed of 2 vertical pixels × 2 horizontal pixels. It can be obtained by grouping into individual pixels. Therefore, as shown in FIG. 4 (c), an image having a smaller number of pixels than the original image is recorded, but the number of pixels is reduced by the optical zoom and reduced (see FIG. 4). Since it is the same as (b)) and has the same amount of information, an image equivalent to that obtained when optical zooming is performed can be obtained in terms of image quality.

  FIG. 5 is a flowchart of zoom processing executed by the electronic camera 1 of FIG.

  This process is executed by the CPU 101 of the electronic camera 1. In this processing, the electronic camera 1 has a photographing / reproducing selection switch (not shown), and one of a photographing mode and a reproducing mode is designated in advance by this switch. The electronic camera 1 also has a moving image still image selection switch (not shown), and either one of recording an image as a still image or a moving image is designated in advance by this switch.

  In FIG. 5, first, when an arbitrary zoom magnification is set by the zoom SW 109 (YES in step S201), it is determined whether or not designation by the shooting / playback selection switch is a shooting mode (step S202). Instead, in the playback mode, the video data is played back on the LCD 104, the played back video is enlarged or reduced (step S202), and this process is terminated.

  On the other hand, if the result of determination in step S202 is that it is in shooting mode, it is determined whether or not it is in movie mode (step S204), and in movie mode, shooting using the electronic viewfinder function is started and the electronic camera 1 It is determined whether or not the zoom state is a state where electronic zoom is possible (step S205). Specifically, the setting of the zoom SW 109 is “tele side” and the zooming magnification by the electronic zoom is at the limit tele end, or the setting of the zoom SW 109 is “wide side” and the zooming magnification by the electronic zoom is set. Is at the limit wide end, it is determined that electronic zoom is impossible.

  If the result of determination in step S205 is that electronic zoom is not possible, optical zoom is performed (step S207). On the other hand, if electronic zoom is possible, electronic zoom is performed (step S206). finish.

  As a result of the determination in step S204, if the still image mode is selected instead of the moving image mode, it is determined whether the zoom state of the electronic camera 1 at that time is an optical zoom enabled state (step S208). Specifically, if the zoom SW 109 is set to tele and the optical zoom is set to the tele end, or if the zoom SW 109 is set to wide and the optical zoom is set to the wide end, the optical zoom is impossible. Determine.

  If the result of determination in step S206 is that optical zoom is not possible, electronic zoom is performed (step S210). On the other hand, if optical zoom is possible, optical zoom is performed (step S209), and this process ends. .

  According to this process, when the shooting mode is set (YES in step S202) and the moving image mode is set (YES in step S204), if the electronic zoom is possible (YES in step S205), the zoom adjustment is performed with the optical zoom. Since the electronic zoom is used instead (step S206), it is possible to prevent noise from being recorded in the sound recorded during zooming during moving image shooting.

It is a block diagram of the electronic camera which concerns on embodiment of this invention. 2A and 2B are diagrams illustrating an image reproduced on the LCD 104 in FIG. 1, in which FIG. 1A illustrates an original image, FIG. 1B illustrates an image enlarged by optical zoom, and FIG. 2C illustrates an image enlarged by electronic zoom. Show. It is a figure explaining the electronic zoom performed with the electronic camera of FIG. 1, (a) shows the image before zoom, (b) shows the image after zoom. 2A and 2B are diagrams illustrating an image reproduced on the LCD 104 in FIG. 1, in which FIG. 1A illustrates an original image, FIG. 1B illustrates an image reduced by an optical zoom, and FIG. 2C illustrates an image reduced by an electronic zoom. Indicates. 3 is a flowchart of zoom processing by the electronic camera 1 in FIG. 1. It is a graph explaining the relationship between the optical zoom and the electronic zoom by the conventional electronic camera.

Explanation of symbols

1 Electronic camera 101 CPU
102 Signal processing IC
104 LCD
105 Recording means 106 CCD
107 Photo lens 112 Microphone

Claims (2)

Zoom means for performing electronic zoom or optical zoom on the optical image formed on the imaging surface, conversion means for converting the optical image on which the zoom is performed into a video signal, and simultaneously with the conversion by the conversion means In an electronic camera comprising acquisition means for acquiring an audio signal, and recording means for continuously recording the converted video signal and the acquired audio signal as a moving image with audio,
The electronic camera according to claim 1, wherein the zoom means performs the electronic zoom before the optical zoom.   2. The electronic camera according to claim 1, wherein the zooming ratio by the electronic zoom is within a range where interpolation for enlargement is unnecessary.

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