JP2011130309A - Video signal output device and imaging apparatus including the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a video signal output device which can output image data of optimum display quality. <P>SOLUTION: The video signal output device includes: an input/output means for performing communication with an external apparatus; a determination means for determining whether first image data can be converted into a second video format or not based on video format information of the first image data; a video format conversion means for converting the video format of the first image data from a first video format into the second video format to form second image data; and a control means which receives information on the video format corresponding to the external apparatus from the external apparatus connected to the input/output means, allows the video format conversion means to perform conversion processing to output the second image data to the external apparatus when the external apparatus corresponds to the second video format and the determination means determines that the conversion is possible, and outputs the first image data to the external apparatus when the external apparatus corresponds to the first video format and the determination means determines that the conversion is not possible. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a video signal output apparatus that converts a video format of a digital video signal and outputs the converted video format to the outside, and an imaging apparatus including the same.

  In recent years, with the start of high-definition digital broadcasting, devices that can handle a plurality of video formats have become widespread. On the other hand, there has been proposed an enjoyment method in which a digital camera or the like is connected to an external device such as a television having a larger display screen, and image data is output and displayed on the external device. An external device may be able to handle a higher resolution video format than a digital camera. In such a case, a technique is known in which image data is subjected to format conversion (up-conversion) and output on the digital camera side (see, for example, Patent Document 1).

  As a specific example to which the above-described prior art is applied, for example, a case where image data of 1280 × 720 pixels and 30 frames per second (hereinafter referred to as 720 / 30p) captured by a digital camera is displayed on a television is considered. . If the TV supports a video format of 1920 × 1080 pixels and 60 fields per second (hereinafter referred to as 1080 / 60i), the digital camera up-converts 720 / 30p image data to 1080 / 60i. Output. Thereby, 1080 / 60i video is displayed on the television.

  The reason for up-conversion on the digital camera side in this way is related to OSD (On Screen Display) display. OSD is superimposed on the image data output from the digital camera. The OSD is an image including a setting screen of a digital camera and an icon indicating information on image data currently displayed. When the image data output from the digital camera is up-converted and displayed on the television side, the image data including the superimposed OSD is up-converted and displayed. Since the contour (edge) of OSD is clearer than that of image data, the up-converted OSD is more likely to feel strange than image data. On the other hand, in the case of up-conversion on the digital camera side, after up-converting the image data, the OSD is superimposed and output. At this time, since the icons and menus are displayed with an appropriate resolution and size, such a sense of incongruity does not occur.

JP 2003-299039 A

  However, such a conventional video signal output device has a problem in that up-conversion in real time may not be possible depending on image data to be output. Hereinafter, a specific example will be described. For example, when the video format of the image data to be output is 1280 × 720 pixels and 60 frames (hereinafter referred to as “720 / 60p”), in order to output this while performing up-conversion in real time, 60 frames per second are output. A processing capacity sufficient for processing sheets is required. If the processing capability is insufficient, real-time conversion will not be in time, and if displayed on an external device, problems such as dropped frames will occur.

  The present invention has been made in view of such a problem, and an object thereof is to provide a video signal output apparatus capable of outputting image data with optimum display quality.

  In order to solve the above-described problem, the present invention provides first input image data based on input / output means for communicating with an external device and information on the video format of the first image data stored in the storage means. Determination means for determining whether or not conversion to the second video format is possible; video format conversion means for converting the video format of the first image data from the first video format to the second video format to obtain second image data; and input / output When the information regarding the video format supported by the external device is received from the external device connected to the means, and the external device supports the second video format and the determination means determines that conversion is possible, the video format conversion means performs conversion processing. The second image data is output to the external device, and the external device corresponds to the first video format and the judging means converts it. If it is determined not to be the ability is obtained by a video signal output device and a control means for outputting a first image data to the external device.

  According to the video signal output device of the present invention, it is possible to output image data with optimum display quality.

Diagram showing the video signal output device connected to an external device 1 is a block diagram showing a configuration of a video signal output device according to a first embodiment; 3 is a flowchart showing the operation of the video signal output apparatus according to the first embodiment. Diagram showing combination of format conversion

[Embodiment 1]
[1. Constitution〕
FIG. 1 is a diagram illustrating a state in which a digital camera 100 as a video signal output device is connected to a television 400 as an external device. As described above, the digital camera 100 according to the present embodiment is connected to the television by wire or wirelessly, and image data that is a moving image or a still image is output from the digital camera 100. In particular, when the image data to be output is a moving image, the digital camera 100 can display the image data with the optimum display quality on the screen of the television 400 by appropriately performing the format conversion process. Note that the television 400 connected to the digital camera 100 corresponds to at least 480 / 60p (720 × 480 pixels, 60 frames / second) as a video format, and any one of 720 / 60p and 1080 / 60i or In some cases, both are supported. Further, the television 400 can respond to an inquiry about the corresponding video format from the connected digital camera 100 and transmit information on the corresponding video format to the digital camera 100.

  An electrical configuration of the digital camera 100 according to the present embodiment will be described with reference to FIG. FIG. 2 is a block diagram showing the configuration of the digital camera 100. The digital camera 100 captures a subject image formed by an optical system 110 including one or a plurality of lenses with a CCD image sensor 140. The image data generated by the CCD image sensor 140 is subjected to various processes by the image processing unit 160 and stored in the memory card 200. Hereinafter, the configuration of the digital camera 100 will be described in detail.

  The optical system 110 includes a zoom lens and a focus lens. The subject image can be enlarged or reduced by moving the zoom lens along the optical axis. Further, the focus of the subject image can be adjusted by moving the focus lens along the optical axis.

  The lens driving unit 120 drives various lenses included in the optical system 110. For example, a zoom motor that drives a zoom lens, and a focus motor that drives a focus lens correspond to this.

  The diaphragm 300 adjusts the amount of transmitted light by adjusting the size of the opening in accordance with the setting of the user or automatically.

  The shutter 130 is a means for blocking the light transmitted through the CCD image sensor 140.

  The CCD image sensor 140 captures the subject image formed by the optical system 110 and generates analog image data. The CCD image sensor 140 performs various operations such as exposure, transfer, and electronic shutter. The CCD image sensor 140 generates and outputs analog image data of 1280 × 720 pixels every 1/30 seconds or 1/60 seconds. The user sets in advance which frame rate to use.

  The A / D converter 150 converts analog image data generated by the CCD image sensor 140 into digital image data.

  The image processing unit 160 performs processing on the image data generated by the CCD image sensor 140, image data to be displayed on the display monitor 220, and image data to be output to the outside via the input / output I / F 250. , And image data to be stored in the memory card 200 is generated. For example, the image processing unit 160 performs various processes such as gamma correction, white balance correction, and flaw correction on the image data generated by the CCD image sensor 140. The image processing unit 160 performs an encoding process on the image data generated by the CCD image sensor 140. At this time, if the image data is a still image, an encoding format based on the JPEG standard or the like is used. If the image data is a moving image, an encoding format that conforms to the MPEG standard is used. The image processing unit 160 performs a decoding process on the encoded image data. The image processing unit 160 performs video format conversion on the image data as necessary, and then outputs the image data to the outside via the input / output I / F 250. Here, video format conversion refers to processing for converting the resolution and frame rate of image data. In this embodiment, the image processing unit 160 can perform conversion processing from 720 / 30p to 1080 / 60i, 720 / 60p, and 480 / 60p, and conversion processing from 720 / 60p to 480 / 60p in real time. However, it is assumed that conversion processing from 720 / 60p to 1080 / 60i cannot be performed in real time due to processing performance limitations. Information relating to a combination of video formats that can be converted in real time by the image processing unit 160 (hereinafter referred to as conversion enable / disable information) is stored in the internal memory 240. The image processing unit 160 can be realized by a DSP, a microcomputer, or the like.

  The controller 180 is a control means for controlling the whole. The controller 180 also performs OSD superimposition processing on image data. The image data superimposed with the OSD is displayed on the display monitor 220 and is output to the outside. The OSD is used to display a menu screen for performing various settings of the digital camera, icons indicating information on the currently displayed image data, and the like. In addition, the controller 180 communicates with the television 400 as an external device connected via the input / output I / F 250 to obtain information regarding the video format supported by the television 400.

  The buffer 170 functions as a work memory for the image processing unit 160 and the controller 180. The buffer 170 can be realized by, for example, a DRAM or a ferroelectric memory.

  The card slot 190 is detachable from the memory card 200. The card slot 190 can be mechanically and electrically connected to the memory card 200. The memory card 200 includes a flash memory, a ferroelectric memory, and the like, and can store data such as an image file generated by the image processing unit 160.

  The operation member 210 is a generic name for a user interface that receives an operation from a user. For example, a cross key, a determination button, a shutter button, a power button, and the like that accept an operation from the user correspond to this.

  The display monitor 220 can display image data (through image) generated by the CCD image sensor 140 and image data read from the memory card 200. The through image means an image that is not finally recorded on the memory card 200.

  The internal memory 240 stores a control program for controlling the entire digital camera 100, conversion enable / disable information, and the like. The internal memory 240 is composed of a flash memory or a ferroelectric memory.

  The CCD image sensor 140 is an example of an imaging unit of the present invention. The input / output I / F 250 is an example of the input / output means of the present invention. The memory card 200 is an example of a storage unit of the present invention. The image processing unit 160 is an example of a video format conversion unit of the present invention. The controller 180 is an example of a determination unit of the present invention. The controller 180 is an example of the control means of the present invention.

[2. Operation)
The digital camera 100 can read out image data recorded in the memory card 200, decode it, and reproduce it. The digital camera 100 can display the reproduced image data on the display monitor 220 and output it to an external device via the input / output I / F 250. When outputting image data that is a moving image to an external device, the digital camera 100 communicates with the external device, performs an appropriate video format conversion process as necessary, and outputs it. Hereinafter, an operation when the digital camera 100 outputs image data to an external device will be described.

  When the user operates the operation member 210 to switch the operation mode to the external device connection mode, the controller 180 starts output processing of image data to the television 400 that is an external device.

  FIG. 3 is a flowchart showing a flow of image data output processing of the digital camera 100 to the television 400.

  First, the controller 180 communicates with the television 400 via the input / output I / F 250 and inquires about a video format supported by the television 400. The television 400 responds to this inquiry and transmits information on the corresponding video format to the digital camera 100. The controller 180 receives this information and stores it in the buffer 170 as external device information (S301).

  The user operates the operation member 210 to select image data to be reproduced. When the image data to be output to the external device is determined by this operation, the controller 180 reads information on the video format of the image data from the memory card 200 (S302). The video format information may be recorded in an image data file to be output, or may be recorded in another file associated with the image data file. The video format information includes the resolution and frame rate of image data. In this embodiment, it is assumed that the resolution of the image data is 1280 × 720 pixels and the frame rate is 30 frames / second or 60 frames / second.

  Next, the controller 180 determines whether or not the image data can be converted into 1080 / 60i and output (S303). First, the controller 180 refers to the external device information to check whether the external device is compatible with 1080 / 60i. If it is not compatible (“NG” in S303), the controller 180 proceeds to step S306. If it is compatible, then the format of the image data is checked, and it is determined whether format conversion is necessary, and if real time conversion is possible. In the present embodiment, the resolution of the image data is 1280 × 720 pixels, and the frame rate is 30 frames / second or 60 frames / second. Further, the conversion availability information is stored in the internal memory 240. Based on this information, if the video format of the image data is 720 / 30p (1280 × 720 pixels, 30 frames / second), it is determined that the video format conversion to 1080 / 60i in real time is possible (“OK” in S303). "), The output resolution is set to 1080 / 60i (S304). On the other hand, if the video format of the image data is 720 / 60p (1280 × 720 pixels, 60 frames / second), it is determined that the amount of data to be processed is large and the video format cannot be converted in real time (“NG” in S303). Proceed to step S306.

  If it is determined that 1080 / 60i cannot be output, then the controller 180 determines whether the image data can be converted into 720 / 60p and output (S306). With reference to the external device information, it is confirmed whether the external device is compatible with 720 / 60p. If not compatible (“NG” in S306), the output resolution is set to 480 / 60p (S308). If this is the case, the video format of the image data is checked next. In this embodiment, the format of the image data is 720 / 30p or 720 / 60p, and each video format conversion (specifically, frame rate) (2) pull-down conversion (so-called 2: 2 pull-down) or no conversion is possible, and in either case, the output resolution is set to 720 / 60p (S307).

  When the output video format is set as described above based on the external device information and the video format information of the image data, the controller 180 controls the image processing unit 160 to perform the setting while performing the video format conversion as necessary. The image data is output in the output video format thus made (S305). At that time, the controller 180 superimposes the OSD on the image data after the video format conversion (performed as necessary). At this time, the OSD is set to an optimum size and arrangement in accordance with the video format of the image data to be superimposed. The image data on which the OSD is superimposed is output to the television 400 via the input / output I / F 250. The television 400 displays image data sent from the digital camera 100.

  If the connection with the television 400 is continued, the external device information acquisition process (S301) can be omitted when reproducing the second and subsequent image data.

  FIG. 4 is a diagram showing a combination of format conversions. More specifically, the video format after conversion according to the corresponding status of the external device when the resolution of the image data to be output is 1280 × 720 pixels is shown. The conversion enable / disable information stored in the internal memory 240 is specifically a table as shown in FIG.

  In the “External Device Correspondence” column, the compatibility status of each format of the television 400 which is an external device is shown. In the “number of effective frames per second of image data” column, here, the frame rate of image data to be output is simply shown.

  When the video format of the image data to be output is 720 / 60p (FIGS. 4A to 4D), even if the television 400 supports 1080 / 60i, the video format cannot be converted in real time. If it is determined and the television 400 is compatible, the data is output as it is at 720 / 60p (FIG. 4A). If the television 400 does not support 720 / 60p, the video format is converted to 480 / 60p (down-converted) and output (FIG. 4B). If the television 400 is not compatible with 1080 / 60i, it is converted into a corresponding format as necessary (FIGS. 4C and 4D).

  When the format of the image data to be output is 720 / 30p (FIGS. 4E to 4H), format conversion (up-conversion) is performed when the television 400 supports 1080 / 60i. Output (FIGS. 4E and 4F). If the television 400 does not support 1080 / 60i, it is converted into a corresponding format as necessary and output (FIGS. 4G and 4H).

[3. (Summary)
When the digital camera 100 outputs the image data as described above, the following effects can be obtained. When the television 400 supports a plurality of video formats, the digital camera 100 preferably converts the image data into any one of the video formats and outputs the still image and the moving image. This is because, when the user sequentially displays a plurality of image data, if different video formats are mixed, the video format is switched each time on the television 400 side, or the display is disturbed for a moment, or the display in between This is because a phenomenon such as the screen becoming dark for a moment occurs due to not performing the operation. On the other hand, it is desirable to display the image data on the television 400 with the highest possible resolution. In particular, in the case of still images, if there are many images taken at a resolution higher than 1920 × 1080 pixels, the video format for displaying on the television 400 is the video format having the highest resolution supported by the television 400. It is desirable to display.

  However, depending on the processing performance of the digital camera 100, it may not be possible to achieve both. For example, in the present embodiment, since it is assumed that 720 / 60p image data cannot be converted to 1080 / 60i in real time, all image data including still images are output in a 1080 / 60i video format and output to the television 400. Cannot be displayed. Therefore, the digital camera 100 according to the present embodiment basically outputs image data in 1080 / 60i which is a video format having the highest resolution, and it is determined that real-time conversion cannot be performed among moving image data. Is displayed without converting the video format. Thereby, it is possible to display the image data with the highest possible resolution while minimizing the video format switching process in the television 400, and to output the image data with the optimum display quality.

[4. Other Embodiments]
The first embodiment of the present invention has been described above. However, the present invention is not limited to these. Therefore, other embodiments of the present invention will be described collectively in this section.

  The digital camera 100 according to the first embodiment has been described assuming that the resolution is fixed at 1280 × 720 pixels as the format information of the image data, and the output video format is set according to the frame rate. Is not limited to this. For example, image data pull-down information may be included as video format information, and an effective frame rate of image data may be calculated from frame rate information and pull-down information, and an output resolution may be set based on the effective frame rate. When the digital camera 100 records moving image data, a pull-down process may be performed on the image data captured at a certain frame rate and recorded at a frame rate higher than the imaging frame rate. In such a case, the video format information is recorded including pull-down information indicating how the video is pulled down. For example, when image data captured at 30 frames / second is recorded by pulling down to 60 frames / second, “2: 2 pulldown” is recorded as the pull-down information. When image data captured at 24 frames / second is recorded by pulling down to 60 frames / second, “2: 3 pulldown” is recorded as pull-down information. If the recording is performed without pulling down, “no pull-down” is recorded as pull-down information. Since image data with pull-down information “2: 2 pull-down” appears repeatedly every two frames, if the pull-down information is “2: 2 pull-down” in 60 frames / second image data, The number of effective frames is 30. Therefore, in such a case, that is, when the video format is 720 / 60p and the effective frame is one frame every two frames, it is determined that the format conversion is possible, and the format conversion to 1080 / 60i is performed. Can be output. If the video format is 720 / 60p and all the frames are valid frames, it is determined that the video format cannot be converted in real time, and the image data of 720 / 60p is output as it is. When pull-down information is taken into consideration in this way, the conversion availability information may be referred to as “the number of effective frames per second of image data” in FIG.

  In the present embodiment, the conversion availability information is stored in the internal memory 240, and the output video format is set based on this information and the combination of the video format before conversion and the video format compatible with the television. However, the amount of processing required for video format conversion can be calculated from information on the combination of the video format before conversion (including pull-down information or information on the number of valid frames, if any) and the video format compatible with the TV. You may make it determine based on estimation and conversion based on this. In short, it is only necessary to determine whether real-time video format conversion is possible from the video format of the image data to be output and the converted video format.

  In this embodiment, the television 400 also responds to an inquiry from the connected digital camera 100 and transmits information related to the corresponding video format to the digital camera 100. However, the digital camera 100 As long as information on the corresponding video format can be obtained from the television 400, the method and timing are not limited. For example, at the time of processing such as negotiation when the television 400 and the digital camera 100 are connected, the television 400 may transmit this information to the digital camera 100 and the digital camera 100 may receive this information.

  In the present embodiment, the CCD image sensor 140 generates and outputs analog image data of 1280 × 720 pixels every 1/30 seconds or every 1/60 seconds. The format is not limited to this. For example, image data such as 1080 / 60i may be output. In this case, if the television 400 as an external device is compatible with 1080 / 60i, the image data may be output as it is, and if it is not compatible, the image data may be converted into a corresponding image format and output.

  In the present embodiment, the image processing unit 160 has been described using the MPEG standard as the moving image encoding format, but other encoding formats such as Motion JPEG and AVCHD may be used.

  In the present embodiment, when the operation mode is switched to the external device connection mode, the controller 180 starts output processing of image data to the television 400. However, the operation mode of the digital camera 100 is the playback mode. Sometimes, when the digital camera 100 is connected to the television 400, output processing of image data to the television 400 may be started.

  In the first embodiment, the CCD image sensor 140 is exemplified as the imaging unit, but the present invention is not limited to this. For example, it may be composed of a CMOS image sensor or an NMOS image sensor.

  In the first embodiment, the image processing unit 160 and the controller 180 may be configured by one semiconductor chip or may be configured by separate semiconductor chips. Further, the sharing of the processing contents of the image processing unit 160 and the controller 180 in the first embodiment is merely an example, and the processing content in the image processing unit 160 may be executed by the controller 180, or conversely, the controller 180 The image processing unit 160 may execute the processing content.

  Since the present invention can output image data with optimum display quality, it can be applied to an imaging device such as a digital still camera or a digital video camera that can display an image by connecting an external device such as a television. is there.

DESCRIPTION OF SYMBOLS 100 Digital camera 110 Optical system 120 Lens drive part 130 Shutter 140 CCD image sensor 150 A / D converter 160 Image processing part 170 Buffer 180 Controller 190 Card slot 200 Memory card 210 Operation member 220 Display monitor 240 Internal memory 250 Input / output I / F
400 TV

Claims (4)

Input / output means for communicating with external devices;
Determination means for determining whether the first image data can be converted into the second video format based on information of the video format of the first image data stored in the storage means;
Video format conversion means for converting the video format of the first image data from the first video format to the second video format to obtain second image data;
When receiving information related to the video format supported by the external device from the external device connected to the input / output unit, and the external device supports the second video format and the determination unit determines that conversion is possible The video format conversion means performs conversion processing to output the second image data to the external device, and the external device corresponds to the first video format and the determination means determines that conversion is not possible. Control means for outputting the first image data to the external device,
A video signal output device comprising: An imaging device comprising the video signal output device according to claim 1,
Imaging means for imaging light from a subject and outputting the first image data;
Recording means for storing the first image data in the storage means;
An imaging apparatus comprising: Determining whether the first image data can be converted to the second video format in real time based on the video format of the first image data;
A receiving step of receiving information on a video format supported by the external device from an external device connected to the input / output means;
A second image obtained by converting the video format of the first image data from the first video format to the second video format when the external device determines that it corresponds to the second video format and can be converted in the determining step. Output data to the external device, and output the first image data to the external device when it is determined that the external device corresponds to the first video format and cannot be converted in the determination step. An output step to
A video signal output method comprising: Input / output means for communicating with external devices;
Determination means for determining whether the first image data can be converted into the second video format based on the video format of the first image data input from the outside;
Video format conversion means for converting the video format of the first image data from the first video format to the second video format to obtain second image data;
When information regarding the video format supported by the external device is received from the external device connected to the input / output means, and the external device corresponds to the second video format and the determination means determines that conversion is possible The video format conversion means performs conversion processing to output the second image data to the external device, and the external device corresponds to the first video format and the determination means determines that conversion is not possible. Control means for outputting the first image data to the external device,
A resolution conversion apparatus comprising:

Images