JP2006080860A - Camera and camera image transfer system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a camera which can rapidly confirm a photographed image as this countermeasure since it takes a time to confirm all the images photographed by a device at the transfer destination, if the image size is large when the image photographed by a digital camera is transferred to other device directly in a wireless manner, and to provide a camera image transfer system. <P>SOLUTION: Only a specific image (for example, a thumbnail image in regular photographing, or a JPEG image of relatively small image size at a RAW+JPEG photographing time) of the image photographed by a digital camera body is transferred previously. Consequently, this image is confirmed at the transfer destination, and only the finally necessary image is selected, and transferred. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image transfer system using a wireless transmission device built in a digital camera or the like, and particularly proposes an image transfer processing method between a camera and a host device for selectively transmitting a captured image file.

  Conventionally, when an image taken with a digital camera or the like is directly transmitted via a wireless transmission system such as a wireless LAN, the image is transferred by the method shown in FIG.

  In FIG. 4, a photographed image photographed with a digital camera body (not shown) and subjected to predetermined image processing is stored in the order of photographing frames in a card memory attached to the camera body, and is stored in the digital camera body section via an external interface. Similarly, the captured image is transferred to the connected wireless transmission block in the order of the imaging frames.

  First thumbnail image of the first frame (this image is thinned to a predetermined size to reduce the image size. The photographer can observe the image on the TFT display part of the camera body or observe it on the PC to confirm the image. (Normally, it is configured with an image size of several hundred kilobytes). First main image (a captured image that matches the actual number of pixels of the imaging element, and is usually configured with an image size of several megabytes). Image data is sent out to the wireless communication unit 100 in order, such as the second frame thumbnail image, the second frame main image, the third frame, the fourth frame, and the fifth frame.

  This wireless communication unit is composed of a processing unit for converting image data for actual transmission into radio RF data, and conversely, it receives each radio data from the host device and converts it into predetermined data. It consists of a transmission / reception module that is also configured as a processing unit for doing this.

  An actual captured image is subjected to predetermined modulation processing by the wireless communication unit 100, and then transmitted to the host device as actual wireless data via the antenna 101.

  On the other hand, the reception side receives the image data transmitted from the transmission unit via the antenna 103 and inputs this data to the wireless communication unit 102. The wireless communication unit 102 has the same configuration as the wireless communication unit 100. It is possible to transmit and receive image data and the like together.

  The wireless data is demodulated to the original image data via the wireless communication unit 102. In this case as well, the received image is naturally the thumbnail image of the first frame, the main image of the first frame, the thumbnail of the second frame. The image order is the same as the image taken as the second image and the main image, and this is displayed in order on the monitor screen of the host device 104 (for example, only thumbnail images are sequentially divided and displayed on the screen) Will do).

In this way, in the case of a system that performs image transmission with a host device via a wireless communication module built in a conventional digital camera or directly connected to the camera body, all image data is transmitted in the order of the shot frames. In general, a system that sequentially receives the image data on the host side is employed.
JP 2001-016350 A

  As shown in the conventional method, when an image captured with a digital camera is transmitted wirelessly to another host device or host PC via a wireless module built in the camera body or mounted externally, the transmission is performed. Speed becomes a bottleneck.

  In the IEEE802.11 standard wireless LAN that is widely used in the world, the speed is about 10 Mbps to 50 Mbps, and the transmission speed is reduced to a fraction of this in terms of execution speed. In this case, unlike the case of wired communication, the longer the transmission distance is, the more the transmission speed is further lowered due to the decrease in the radio signal level.

  Normally, images taken with a camera are transmitted according to the order of the shot frames. Therefore, the larger the size of the shot image, the more time it takes for the destination host device to check all the shot images. When all of several tens of photographed images are transmitted, a gap of about several minutes occurs between the first image and the last image.

  Therefore, in this application, a camera and a camera image transfer system for effectively functioning under actual use conditions are focused on from the viewpoint of how to quickly check an image taken on the host device side that is located away from the camera body. The purpose is to provide.

  In order to achieve the above object, an invention according to the present application includes: an imaging unit that captures a subject and outputs imaging data; and an image that performs predetermined image processing on the imaging data to generate a plurality of encoded data. Processing means; image storage means for temporarily storing the plurality of encoded image data; external storage means for storing data stored in the image storage means in a rewritable external memory; and the image storage means or the In a camera composed of wireless transfer means for transferring a plurality of encoded image data stored in the external storage means to an external device by wireless communication, only an image in a specific format among the plurality of encoded image data as image transfer. And a second transfer mode in which only an image selected from an external device is transferred as image transfer.

  According to the invention of the present application, when wirelessly transmitting an image captured on the camera side to the host side, not all the captured images are transmitted at once, but a reduced image such as a thumbnail image is transmitted first to the host. The user on the side immediately checks the captured image, then transmits the entire captured image, or the host user selects only the necessary image while viewing the monitor screen, and the selection information is sent to the camera side. By performing image transmission in which only the image based on the selection information is transmitted from the camera side by wireless notification, it is possible to realize an image transmission system that covers the low transmission speed of the wireless transmission itself.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to examples.

  FIG. 1 is a block diagram showing the overall system configuration of the present invention. In the case of the configuration shown in FIG. 1, the state change of a camera operation switch (not shown) (configured by a camera main switch and a release SW) by the photographer himself is shown. The control CPU 7 detects and starts power supply and initial setting to other circuit blocks, and executes control of each camera system through the camera control means 8.

  A subject image within the photographing screen range is imaged on an image sensor (in this case, CCD) 1 through a main photographing optical system 3 that operates in a predetermined manner via a lens driving means 4 in response to a signal from the overall control CPU 7. The output signal from is subjected to correlated double sampling → gain setting → AD conversion for each pixel via the analog front-end circuit 5 and sequentially converted into a predetermined digital signal.

  Here, the imaging device 1 is driven in a predetermined manner via a driver circuit for horizontal driving and vertical driving for each pixel based on a signal from a timing generator (TG / SSG) 2 that determines the overall driving timing. This generates an image signal output.

  The output signal of the analog front end 5 is input to the DSP 6 that performs actual signal processing, where optical image degradation caused by the combination of the image sensor 1 and the main photographing optical system 3 is corrected, and then Input into the internal color interpolation block and the pixel array of the normal sensor is configured as a Bayer array, and color interpolation processing is performed to convert it into RGB three plane data.

  Following this color interpolation processing, input to a matrix correction block inside the DSP, and matrix correction is performed to output a desired color from the spectral characteristics of the color filter unique to the sensor to perform RGB → RGB conversion.

  Next, the data is input to an internal γ conversion block, and a process of converting the data width of 12 bits converted into digital data by the analog front end circuit 5 into 8 bits is performed so that the data is converted so as to fall within a predetermined dynamic range. Perform gamma conversion.

  Further, after input to the internal RGB → YCrCb conversion block to perform RGB → YCrCb color conversion processing, the input is input to the internal false color removal block to perform false color removal processing on the CrCb component.

  Here, the false color removal processing includes using a median filter (intermediate value filter) for the occurrence of color moiré or the like caused by the so-called relationship between the sampling frequency and the image frequency.

  Further, the image is input to the internal edge emphasis block, and after performing edge emphasis processing for raising the gain near the intermediate frequency of the image and performing processing such as image edge emphasis, the image is input to the internal resolution conversion block and input to a predetermined image. Resize to size.

  Here, when resizing to a predetermined image size, the thinning process is performed after the filter process is actually performed, but the same process is performed in the horizontal and vertical directions.

  The above operation is performed sequentially for one frame, and the result is temporarily stored in the buffer memory 9 connected to the DSP 6 bus.

  The above operation is the actual color processing for the image picked up through the image sensor 1, and the data after color processing developed in the buffer memory 9 is input to the DSP 6 again, and this time the compression processing is executed.

  As this compression process, an irreversible type JPEG compression process based on a normal DCT conversion and a lossless type Lossless compression process are generally used.

  First, data after image processing in the buffer memory 9 storing the result of color processing by the above-described method is read into the DSP 6 and input to an internal raster block conversion block, where the image data is horizontally 8 pixels, It is converted into a block in a two-dimensional unit in a vertical 8-pixel unit.

  Next, data is input to an internal DCT conversion block, and here, DCT conversion is performed to convert so-called 8 × 8 data for each frequency component in units of 8 × 8 blocks, and low-frequency components to high-frequency components in two-dimensional units. Calculate the coefficient to

  Next, the coefficient value calculated by the above DCT transform is inputted to the internal quantization block, and the quantization is performed for each coefficient based on the value of the quantization table in which the value is set in advance. This is achieved by dividing

  Further, the quantized result is input to an internal Huffman coding block while reading out data along a predetermined scanning direction, and here, an entropy code according to the value of the Huffman table, which is also set in advance, is used here. To implement.

  A series of compression processing is completed by writing the data compressed by the above method back into the predetermined area of the buffer memory 9 again.

  On the other hand, the lossless compression method is a compression process based on the so-called DPCM. First, the data after image processing in the buffer memory 9 storing the result of color processing by the above-described method is used. The data is read into the DSP 6 and input to the internal DPCM conversion block, and the image data is converted as difference data from the predicted value.

  Next, the DPCM converted data is read and input to the internal Huffman coding block, and here, entropy coding is performed according to the value of the Huffman table in which values are set in advance.

  The data compressed by the above method is written again in another predetermined area of the buffer memory 9 to complete the series of compression processing.

  After compressing data based on a predetermined compression format inside the DSP 6 by the above method, the compressed data is stored in the card memory 11 (usually using a non-volatile memory such as a flash memory) via the card controller 10.

  On the other hand, when observing image data that has already been photographed, the data compressed and stored in the card memory 11 is expanded into data for each ordinary photographing pixel through the JPEG processing block in the DSP 6, and the result is buffered. By transferring the image data to the memory 9, the photographed image can be reduced and externally displayed through the TFT controller control means 12 and the TFT display means 13.

  Also, the thumbnail image created at the same time as the main image processing in the DSP 6 is also stored in the card memory 11 so that the image data is read out and displayed through the TFT display means 13 for confirmation of the photographed image. Things are also possible.

  On the other hand, with respect to the control of the entire camera and the sequence control for the controller, the overall control CPU 7 operates by executing an instruction in accordance with an instruction code stored in an instruction memory (not shown) connected to the bus. 4 performs drive control of the main photographing optical system 3 (focus drive and aperture drive control in the lens), actual shutter exposure control via the shutter control means indicated by the camera control means 8, etc. Header information is added to the photographed image or information such as photographing conditions is added as data in the card memory and recorded.

  Further, the image data stored in the card memory as the data after the photographed image processing can be simultaneously transferred to an externally connected host device or host PC via the IEEE 1394 I / F or USB I / F controller 14. is there.

  In this case, the image data temporarily stored in the buffer memory is transferred to the external device 15 at a very high transfer speed via the high-speed serial I / F configured by the IEEE1394 I / F or USB I / F controller 14. Realized.

  Next, the configuration of the wireless system directly connected to the camera system will be described.

  The wireless transmission unit 16 shown in FIG. 1 is connected to an internal bus commonly used by the camera signal processing DSP 6 and the overall control CPU 7 and the like, and image data and host equipment that are actually transmitted via this bus. It is configured to transfer various received data sent from the side.

  The wireless transmission unit 16 performs primary modulation (for example, OFDM modulation used in IEEE802.11a) so that data information such as actual image data and command data from the host device can be transmitted to obtain an optimum S / N. Etc.), or a baseband processing unit 16a that executes access control for determining transmission / reception timing with other wireless devices, etc., and an RF processing unit 16b that actually converts it into a high-frequency signal in a predetermined radio frequency band. A transmission unit 16c configured with a power amplifier for outputting a signal converted into an RF signal as an actual transmission output; a reception unit 16d configured with a low noise amplifier for receiving a radio signal from the outside with high sensitivity; The antenna switch 16e is used to switch the transmission signal and the reception signal with respect to the antenna. Ahead of the switch 16e is connected to an external antenna 17 for transmitting and receiving actual radio signal.

  The above shows the configuration of a camera system having a wireless transmission unit built in or externally connected to the digital camera body. The same wireless transmission unit is also used for external devices that exchange image data with the digital camera. It has something.

  The external device 20 is configured by a normal PC or the like. A wireless transmission unit 18 is connected to the external expansion bus, and the image data or camera body actually received is exactly the same as the camera body side. It is configured to transfer various data to be transmitted.

  The wireless transmission unit 18 performs primary modulation (for example, OFDM modulation used in IEEE802.11a) so that data information such as actual image data and command data from the host device can be transmitted to obtain an optimum S / N. Etc.), or a baseband processing unit 18a that executes access control for determining transmission / reception timing with other wireless devices, etc., and an RF processing unit 18b that actually converts it into a high-frequency signal in a predetermined radio frequency band. A transmission unit 18c configured with a power amplifier for outputting a signal converted into an RF signal as an actual transmission output; a reception unit 18d configured with a low noise amplifier for receiving a radio signal from the outside with high sensitivity; The antenna switch 18e for switching the transmission signal and the reception signal with respect to the antenna comprises the antenna. The previous switch 18e is actually connected external antenna 19 for transmitting and receiving radio signals.

  In this way, the wireless transmission unit connected to the digital camera body side and the wireless transmission unit connected to the host device side have basically the same configuration, and bi-directional data transmission is realized while switching the transmission / reception mode whenever necessary. To do.

  Next, an actual data transmission method will be described with reference to a data transmission image diagram between the camera and the host device in FIG.

  First, on the camera body side, the captured image file created through the image sensor 1 and the signal processing DSP 6 by the method described above is transferred to the camera body via the buffer memory 9 or the card controller 10 in the camera body in the order of the camera frame. It is stored in the directly connected card memory 11.

  Here, like the image file configuration shown by the dotted line portion A in FIG. 2, the memory on the camera body side stores the thumbnail image for the first frame, the main image for the first frame, and the second frame. A thumbnail image for the image, a second frame main image, a third frame thumbnail image, a third frame main image, and the like are stored.

  When shooting is completed and preparation for wireless transmission between both devices is completed, only thumbnail images for all the shooting frames are first transmitted from the camera body side through the wireless communication unit 16 and the external antenna 17. The data is received via the wireless communication unit 18 and the external antenna 19 on the host device 20 side.

  This captured image file has a form in which only thumbnail images are arranged in the order of captured frames as in the image file configuration shown by the dotted line portion B in FIG. 2, and the host device side uses only this thumbnail image information, A list of multiple images is displayed on the monitor screen.

  At this time, only thumbnail images with a small image size are transferred, so even if the execution speed of wireless transmission is reduced, the time until the host device user confirms the captured image is basically so long. You do n’t have to.

  Next, the user on the host device side selects one or a plurality of images (in this example, selects image 5) from among the images displayed as a list on the monitor screen, and selects them as the wireless communication unit 18. To the wireless communication unit 16 on the camera side.

  The camera body side receives this transmission command, and the wireless communication unit 16 selects the main image requested from the host device side (image 5 is selected in this example), assuming that the host device side has requested transmission of the main image. And is received via the wireless communication unit 18 on the host device side.

  As described above, in this embodiment, when shooting on the camera side is completed, only thumbnail images with a small image size are transferred to the host device side first, and a book corresponding to a required shooting frame is sent in response to a main image request signal from the host device side. A minimum necessary image transfer system for transferring only images is configured.

  Next, a second embodiment of the present invention will be described with reference to a data transmission image diagram between the camera and the host device of FIG.

  First, on the camera body side, the captured image file created through the image sensor 1 and the signal processing DSP 6 by the method described above is transferred to the camera body via the buffer memory 9 or the card controller 10 in the camera body in the order of the camera frame. It is stored in the directly connected card memory 11.

  In this case, the shooting mode on the camera side is a so-called JPEG compressed image that performs irreversible compression on an image after image processing, and a RAW compressed image that performs lossless compression as it is without performing image processing. It is assumed that a so-called RAW + JPEG mode for generating two types of main images is set.

  Here, as in the image file structure indicated by the dotted line portion C in FIG. 3, the memory on the camera body side stores the thumbnail image for the first frame, the next JPEG compressed image, and the first frame. RAW compressed image, thumbnail image for the second frame shot image, second frame JPEG compressed image, second frame RAW compressed image, third frame thumbnail image, third frame JPEG compressed image, third frame RAW A file created in the order of photographing frames such as a compressed image is stored.

  When shooting is completed and preparation for wireless transmission between both devices is completed, first, only thumbnail images and JPEG compressed images for all shooting frames are transmitted from the camera body through the wireless communication unit 16 and the external antenna 17. This is received via the wireless communication unit 18 and the external antenna 19 on the host device 20 side.

  This captured image file has a form in which only thumbnail images and JPEG compressed images are arranged in the order of the captured frames as in the image file configuration indicated by the dotted line portion D in FIG. To display a list of multiple images on the monitor screen.

  Since only thumbnail images with a small image size and JPEG compressed images with a relatively small image size are transferred at this point, the user on the host device side basically takes a picture, no matter how slow the execution speed of wireless transmission is. The time until the image is confirmed does not have to be so long.

  Next, the user on the host device side selects one or a plurality of images (in the case of this example, selects image 3) from among the images displayed in a list on the monitor screen, and selects them as the wireless communication unit 18. To the wireless communication unit 16 on the camera side.

  The camera body side receives this transmission command, and the RAW compressed image requested from the host device side (image 3 is selected in this example) is wirelessly communicated as a request for RAW compressed image transmission from the host device side. The data is transmitted via the unit 16 and is received via the wireless communication unit 18 on the host device side.

  As described above, in this embodiment, when shooting on the camera side is completed, only thumbnail images having a small image size and JPEG compressed images having a relatively small image size are first transferred to the host device side, and a RAW compressed image from the host device side is transferred. A minimum necessary image transfer system is configured to transfer only a RAW compressed image for a necessary photographing frame in response to a request signal.

1 is an overall system configuration diagram according to a first embodiment and a second embodiment of the present invention. FIG. It is a figure explaining the actual operation | movement which concerns on 1st Example of this invention. It is a figure explaining the actual operation | movement which concerns on 2nd Example of this invention. It is a figure explaining operation | movement of the conventional system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image pick-up element 2 Timing generator 3 Main imaging | photography optical system 4 Lens drive means 5 Analog front end circuit 6 DSP
7 CPU
8 Camera control means 9 Buffer memory 10 Card controller 11 Card memory 12 TFT controller control means 13 TFT display means 14 I / F controller 15, 20 External device 16, 18 Wireless transmission unit 17, 19 External antenna

Claims (4)

  Imaging means for photographing a subject and outputting imaging data, image processing means for performing predetermined image processing on the imaging data to generate a plurality of encoded data, and temporarily storing the plurality of encoded image data Wirelessly storing image storage means stored in the image storage means, external storage means for storing data stored in the image storage means in a rewritable external memory, and a plurality of encoded image data stored in the image storage means or the external storage means In a camera configured by wireless transfer means for transferring to an external device by communication, a first transfer mode for transferring only a specific format image among the plurality of encoded image data as image transfer, and external as image transfer A camera having a second transfer mode for transferring only an image selected from a device.   As the plurality of image encoded data, a main image obtained by encoding an image corresponding to the number of photographing pixels of the image pickup means and a thumbnail image obtained by encoding an image obtained by thinning out the number of photographing pixels of the image pickup means at a predetermined magnification. The camera according to claim 1, comprising:   2. The plurality of encoded image data includes an image obtained by compressing imaging data of the imaging unit by an irreversible compression method and an image compressed by a reversible compression method. Camera described in.   Imaging means for photographing a subject and outputting imaging data, image processing means for performing predetermined image processing on the imaging data to generate a plurality of encoded data, and temporarily storing the plurality of encoded image data Wirelessly storing image storage means stored in the image storage means, external storage means for storing data stored in the image storage means in a rewritable external memory, and a plurality of encoded image data stored in the image storage means or the external storage means A camera configured by wireless transfer means for transferring to an external device by communication, and image encoded data transferred from the camera are received by wireless communication and a predetermined command is transmitted to the camera by wireless communication. In a camera image transmission system configured with a wireless transmission external device, a predetermined image is transmitted to the camera immediately after taking a release of the camera. After transmitting to the wireless transmission external device and then storing the image in the internal storage means and displaying the image on the external display means on the wireless transmission external device side, and then selecting the image on the wireless external device side A camera image transfer system, wherein the image selection information is notified to the camera side by wireless transmission, and the camera side selectively transmits a predetermined image to a wireless transmission external device based on the notification result.

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