JP2007266655A - Thumbnail generating apparatus and imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thumbnail generating apparatus capable of generating thumbnail pictures for moving pictures excellently representing characteristics of moving pictures. <P>SOLUTION: The generating apparatus generates a thumbnail picture once by using the top picture or the like of moving pictures and stores the thumbnail picture to a header file. When a prescribed trigger condition is established during photographing of the moving pictures, the apparatus generates a new thumbnail picture from a frame picture at the establishment of the trigger condition and replaces the thumbnail picture in the header file with the newly generated thumbnail picture. For example, the trigger condition is established when a field angle is fixed for a prescribed time or over after zoom-in or when a prescribed time elapses after focus-lock. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a thumbnail generation device used for an imaging device such as a digital still camera or a digital video camera. The present invention also relates to an imaging apparatus including the thumbnail generation apparatus.

  An imaging device such as a digital video camera is often provided with a mode for displaying thumbnail images. The thumbnail image for moving images is usually an image obtained by reducing the top image of moving images. The user selects a moving image to be reproduced from a plurality of recorded moving images based on the thumbnail images. FIG. 14 is a flowchart showing a conventional thumbnail image generation procedure.

JP 2001-111963 A JP 2005-229236 A JP-A-8-251540

  As described above, a conventional thumbnail image for a moving image is generated based on an image at an appropriate timing regardless of the content of the captured moving image. For this reason, in the conventional imaging apparatus, the thumbnail image often does not represent the characteristics of the captured moving image, and there is a problem that it is difficult to efficiently select and reproduce a desired moving image file.

  SUMMARY An advantage of some aspects of the invention is that it provides a thumbnail generation device that can generate a thumbnail image for a moving image that clearly represents the characteristics of the moving image, and an imaging device including the thumbnail generation device.

  In order to achieve the above object, a thumbnail generating apparatus according to the present invention generates a thumbnail image associated with a captured moving image based on an imaging signal corresponding to a subject from an imaging unit provided in an imaging apparatus capable of capturing the moving image. In the thumbnail generation device to be generated, the thumbnail generation device includes first generation means for generating a first candidate thumbnail image as a candidate for the thumbnail image based on the imaging signal at a predetermined timing, and during shooting of the moving image, When a predetermined trigger condition is satisfied, a second candidate thumbnail image different from the first candidate thumbnail image is generated using the imaging signal at a predetermined timing with reference to the time when the trigger condition is satisfied, and the second The candidate thumbnail images are associated with the moving image as the thumbnail images.

  When configured as described above and appropriately set the trigger condition, it is possible to generate a thumbnail image for a moving image that clearly represents the characteristics of the moving image. For this reason, it is expected that movie files can be easily selected during reproduction.

  Specifically, for example, the imaging apparatus includes an angle-of-view changing unit for enabling change of an angle of view of photographing by the imaging unit, and the trigger condition is predetermined after zooming in to reduce the angle of view. It includes a condition that the angle of view is not changed by the angle-of-view changing means continuously for more than a time.

  More specifically, for example, the image pickup apparatus automatically adjusts the position of a focus lens so that an optical image representing the subject is formed on an image pickup surface of an image pickup element provided in the image pickup unit. The trigger condition includes a condition that the magnitude of the position variation continues for a predetermined time or longer and falls within a predetermined threshold.

  More specifically, for example, the imaging apparatus includes a motion detection unit that detects a motion of an image in a motion detection area based on the imaging signal, and the motion detection area is included in a captured image that forms the moving image. The trigger condition includes a condition that the magnitude of the detected motion continues for a predetermined time or longer and falls within a predetermined threshold.

  More specifically, for example, the imaging apparatus includes face area detection means for detecting a face area of a person existing in a captured image constituting the moving image based on the imaging signal, and the trigger condition is detected. Including a condition that the size of the face area is equal to or greater than a predetermined threshold.

  More specifically, for example, the imaging apparatus includes sound input means for receiving sound input from the outside, and the establishment of the trigger condition is based on the intensity or the magnitude of the sound input during the shooting of the moving image. The imaging signal at a predetermined timing with reference to a timing at which the intensity or the magnitude of the sound or the intensity or the magnitude of the frequency component of the predetermined band of the sound is maximized during the shooting of the moving image. Is used to generate the second candidate thumbnail image.

  Further, for example, when the trigger condition is satisfied during shooting of the moving image, the second candidate thumbnail image is generated based on the imaging signal in a frame including the time when the trigger condition is satisfied or a frame in the vicinity thereof.

  The “neighboring frame” is, for example, a frame several frames before or several frames after the trigger condition is satisfied. However, it may be a frame several tens of frames before or several tens of frames after the trigger condition is satisfied.

  Further, for example, when the trigger condition has never been satisfied during the shooting of the moving image, the first candidate thumbnail image is associated with the moving image as the thumbnail image.

  In order to achieve the above object, an imaging apparatus according to the present invention is an imaging apparatus capable of shooting a moving image, and includes the above imaging unit and the above thumbnail generation apparatus.

  According to the present invention, it is possible to generate a thumbnail image for a moving image that clearly represents the characteristics of the moving image. For this reason, it is possible to easily select a moving image file at the time of reproduction, and an environment that is easy to use can be provided to the user.

  Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. In the drawings to be referred to, the same parts are denoted by the same reference numerals.

  FIG. 1 is an overall block diagram of an imaging apparatus 1 according to an embodiment of the present invention. The imaging device 1 is, for example, a digital still camera or a digital video camera. The imaging device 1 can shoot moving images and still images, and can also shoot still images simultaneously during moving image shooting.

  The imaging device 1 includes an imaging unit 11, an AFE (Analog Front End) 12, a video signal processing unit 13, a microphone (sound input means) 14, an audio signal processing unit 15, a compression processing unit 16, and an internal memory. As an example, an SDRAM (Synchronous Dynamic Random Access Memory) 17, a memory card 18, a decompression processing unit 19, a video output circuit (video output circuit) 20, an audio output circuit 21, and a TG (timing generator) 22 , A CPU (Central Processing Unit) 23, a bus 24, a bus 25, an operation unit 26, a display unit 27, and a speaker 28. The operation unit 26 includes a recording button 26a, a shutter button 26b, an operation key 26c, and the like.

  The bus 24 is connected to the imaging unit 11, AFE 12, video signal processing unit 13, audio signal processing unit 15, compression processing unit 16, expansion processing unit 19, video output circuit 20, audio output circuit 21, and CPU 23. Each part connected to the bus 24 exchanges various signals (data) via the bus 24.

  The bus 25 is connected to the video signal processing unit 13, the audio signal processing unit 15, the compression processing unit 16, the expansion processing unit 19, and the SDRAM 17. Each part connected to the bus 25 exchanges various signals (data) via the bus 25.

  The TG 22 generates a timing control signal for controlling the timing of each operation in the entire imaging apparatus 1, and provides the generated timing control signal to each unit in the imaging apparatus 1. Specifically, the timing control signal is given to the imaging unit 11, the video signal processing unit 13, the audio signal processing unit 15, the compression processing unit 16, the expansion processing unit 19, and the CPU 23. The timing control signal includes a vertical synchronization signal Vsync and a horizontal synchronization signal Hsync.

  The CPU 23 comprehensively controls the operation of each unit in the imaging apparatus 1. The operation unit 26 receives an operation by a user. The operation content given to the operation unit 26 is transmitted to the CPU 23. The SDRAM 17 functions as a frame memory. Each unit in the imaging apparatus 1 temporarily records various data (digital signals) in the SDRAM 17 during signal processing as necessary.

  The memory card 18 is an external recording medium, for example, an SD (Secure Digital) memory card. The memory card 18 is detachable from the imaging device 1. The recorded content of the memory card 18 can be freely read out by an external personal computer or the like via a terminal of the memory card 18 or a communication connector (not shown) provided in the imaging device 1. In this embodiment, the memory card 18 is illustrated as an external recording medium. However, the external recording medium is composed of one or a plurality of randomly accessible recording media (semiconductor memory, memory card, optical disk, magnetic disk, etc.). can do.

  FIG. 2 is an internal configuration diagram of the imaging unit 11 of FIG. The imaging unit 11 includes an optical system 35 including a plurality of lenses including a zoom lens 30 and a focus lens 31, an aperture 32, an imaging element 33, and a driver 34. The driver 34 includes a motor for realizing movement of the zoom lens 30 and the focus lens 31 and adjustment of the opening amount of the diaphragm 12.

  Incident light from the subject (imaging target) enters the image sensor 33 through the zoom lens 30 and the focus lens 31 that constitute the optical system 35, and the diaphragm 32. The TG 22 generates a drive pulse for driving the image sensor 33 in synchronization with the timing control signal, and applies the drive pulse to the image sensor 33.

  The image sensor 33 is composed of, for example, a CCD (Charge Coupled Devices), a CMOS (Complementary Metal Oxide Semiconductor) image sensor, or the like. The image sensor 33 photoelectrically converts an optical image incident through the optical system 35 and the diaphragm 32 and outputs an electrical signal obtained by the photoelectric conversion to the AFE 12. More specifically, the imaging device 33 includes a plurality of pixels (light receiving pixels; not shown) that are two-dimensionally arranged in a matrix, and in each photographing, each pixel receives a signal charge having a charge amount corresponding to the exposure time. store. The electrical signal from each pixel having a magnitude proportional to the amount of the stored signal charge is sequentially output to the subsequent AFE 12 in accordance with the drive pulse from the TG 22.

  The image sensor 33 is a single-plate image sensor capable of color photography. Each pixel constituting the image sensor 33 is provided with, for example, one of red (R), green (G), and blue (B) color filters (not shown). Note that a three-plate image sensor can also be adopted as the image sensor 33.

  The AFE 12 includes an amplifier circuit (not shown) that amplifies the analog electrical signal that is an output signal of the imaging unit 11 (that is, an output signal of the imaging device 33), and an A / A that converts the amplified electrical signal into a digital signal. And a D (analog-digital) conversion circuit (not shown). The output signal of the imaging unit 11 converted into a digital signal by the AFE 12 is sequentially sent to the video signal processing unit 13. Further, the CPU 23 adjusts the amplification degree of the amplification circuit based on the signal level of the output signal of the imaging unit 11.

  Hereinafter, a signal corresponding to the subject output from the imaging unit 11 or the AFE 12 is referred to as an imaging signal.

  FIG. 3 is an internal block diagram of the video signal processing unit 13. The video signal processing unit 13 includes a moving image / still image processing unit 41, an AF evaluation value detection unit 42, an AE evaluation value detection unit 43, a motion detection unit 44, a thumbnail generation unit 45, and a face area detection unit 46. .

  The moving image / still image processing unit 41 generates a video signal representing a video (captured image) obtained by shooting by the imaging unit 11 based on the imaging signal from the AFE 12, and sends the generated video signal to the compression processing unit 16. . The video signal is composed of a luminance signal Y representing the luminance of the photographed image and color difference signals U and V representing the color of the photographed image. The moving image / still image processing unit 41 generates both a moving image video signal and a still image video signal.

  The microphone 14 converts the sound (sound) given from the outside into an analog electric signal and outputs it. The audio signal processing unit 15 converts an electrical signal (audio analog signal) output from the microphone 14 into a digital signal. The digital signal obtained by this conversion is sent to the compression processing unit 16 as an audio signal representing the audio input to the microphone 14.

  The compression processing unit 16 compresses the video signal from the video signal processing unit 13 (moving image / still image processing unit 41) using a predetermined compression method. For video, for example, compression of video signals is performed using a compression method such as MPEG (Moving Picture Experts Group), and for still images, for example, a compression method such as JPEG (Joint Photographic Experts Group) is used. To compress the video signal. During video or still image shooting, the compressed video signal is sent to the memory card 18.

  For example, the image size of each captured image constituting the moving image is reduced through thinning processing or the like in the moving image / still image processing unit 41 or the like as necessary. For example, such a reduction process is not performed on the still image (may be performed).

  The compression processing unit 16 compresses the audio signal from the audio signal processing unit 15 using a predetermined compression method such as AAC (Advanced Audio Coding). At the time of moving image shooting, the video signal from the video signal processing unit 13 and the audio signal from the audio signal processing unit 15 are compressed in the compression processing unit 16 while being correlated with each other in time, and the compressed signals are stored in the memory card. 18 is sent.

  The recording button 26a is a push button switch for the user to instruct the start and end of shooting of a moving image (moving image), and the shutter button 26b is a button for the user to instruct shooting of a still image (still image). It is a button switch. Moving image shooting is started and ended according to the operation on the recording button 26a, and still image shooting is performed according to the operation on the shutter button 26b. One frame image is obtained in one frame. The length of each frame is 1/60 seconds, for example. In this case, a collection of frame images (stream images) that are sequentially acquired at a period of 1/60 seconds constitutes a moving image.

  The operation mode of the imaging apparatus 1 includes a shooting mode capable of shooting moving images and still images, and a playback mode for reproducing and displaying moving images or still images stored in the memory card 18 on the display unit 27. The reproduction mode includes a thumbnail image display mode for reproducing and displaying a thumbnail image associated with a moving image or a still image stored in the memory card 18 on the display unit 27. Transition between the modes is performed according to the operation on the operation key 26c.

  When the user presses the recording button 26a in the shooting mode, under the control of the CPU 23, the video signal of each frame after the pressing and the corresponding audio signal are sequentially recorded on the memory card 18 via the compression processing unit 16. Is done. That is, the captured image (that is, the frame image) of each frame is sequentially stored in the memory card 18 together with the audio signal. When the user presses the recording button 26a again after starting the moving image shooting, the moving image shooting ends. That is, recording of the video signal and the audio signal to the memory card 18 is completed, and shooting of one moving image is completed.

  In the shooting mode, when the user presses the shutter button 26b, a still image is shot. Specifically, under the control of the CPU 23, the video signal of one frame immediately after being pressed is recorded on the memory card 18 through the compression processing unit 16 as a video signal representing a still image. It is also possible to simultaneously shoot a still image while shooting a moving image. In this case, signal processing related to the moving image and signal processing related to the still image are performed in parallel based on the imaging signal of the same frame. Note that a common circuit may be used in a time-sharing manner so that signal processing related to moving images and signal processing related to still images may be performed at separate timings. For example, signal processing related to a still image is performed after moving image shooting is completed. In this case, for example, an imaging signal (photographed image) necessary for the signal processing performed afterwards may be temporarily stored in the SDRAM 17.

  When the user performs a predetermined operation on the operation key 26 c in the reproduction mode, a compressed video signal representing a moving image or a still image recorded on the memory card 18 is sent to the expansion processing unit 19. The decompression processing unit 19 decompresses the received video signal and sends it to the video output circuit 20. In the shooting mode, the generation of the video signal by the video signal processing 13 is normally performed regardless of whether or not a moving image or a still image is being shot, and the video signal is sent to the video output circuit 20. It is done.

  The video output circuit 20 converts a given digital video signal into a video signal (for example, an analog video signal) in a format that can be displayed on the display unit 27 and outputs the video signal. The display unit 27 is a display device such as a liquid crystal display, and displays an image corresponding to the video signal output from the video output circuit 20. That is, the display unit 27 is an image based on the imaging signal currently output from the imaging unit 11 (an image representing the current subject), a moving image (moving image) or a still image (still image) recorded on the memory card 18. Image).

  When a moving image is reproduced in the reproduction mode, a compressed audio signal corresponding to the moving image recorded on the memory card 18 is also sent to the expansion processing unit 19. The decompression processing unit 19 decompresses the received audio signal and sends it to the audio output circuit 21. The audio output circuit 21 converts a given digital audio signal into an audio signal in a format that can be output by the speaker 28 (for example, an analog audio signal) and outputs the audio signal to the speaker 28. The speaker 28 outputs the sound signal from the sound output circuit 21 to the outside as sound (sound).

  It can be considered that the display unit 27 and the speaker 28 are provided in an external television or the like. In this case, the video signal output from the video output circuit 20 and the audio signal output from the audio output circuit 21 are supplied to an external television or the like via a connector (not shown).

  Next, functions of the imaging unit 11 and the video signal processing unit 13 will be further described with reference to FIGS. 2 and 3. The imaging apparatus 1 has a so-called autofocus control function that “forms an optical image representing a subject on the imaging surface (light receiving surface) of the imaging element 33 by automatically controlling the position of the focus lens 31”. . With this function, ideally, the point where the optical image representing the subject is formed coincides with the point on the imaging surface of the imaging element 33.

  The autofocus control function can be realized by various methods. For example, by extracting a predetermined high frequency component from the luminance signal in the video signal and controlling the position of the focus lens 31 in accordance with the level (size) of the high frequency component, an optical image representing the subject is obtained. An image is formed on the imaging surface of the imaging element 33. An autofocus control function may be realized using a distance measuring sensor (not shown) or the like.

  The autofocus control is mainly realized by the AF evaluation value detection unit 42 in FIG. 3, the CPU 23 in FIG. 1, and the driver 34 in FIG. The driver 34 is an axis perpendicular to the imaging surface of the focus lens 31 based on a focus control signal sent from the CPU 23 in order to keep the level (magnitude) of the high frequency component at the maximum value (near). By moving along the optical axis, an optical image of the subject (imaging target) is formed on the imaging surface (light receiving surface) of the image sensor 33.

  FIG. 4 is an internal block diagram of the AF evaluation value detection unit 42. The AF evaluation value detection unit 42 includes an extraction unit 51, an HPF (high pass filter) 52, and an integration unit 53.

  The extraction unit 51 extracts a luminance signal from the video signal generated by the moving image / still image processing unit 41 or the imaging signal from the AFE 12. At this time, only the luminance signal in the focus detection area set in advance in the image is extracted. The focus detection area is, for example, a partial area of the image, and the partial area is provided near the center in the image. The HPF 52 extracts only a predetermined high frequency component from the luminance signal extracted by the extraction unit 51.

  The integrating unit 53 obtains an AF evaluation value corresponding to the contrast amount of the image in the focus detection area by integrating the high frequency components extracted by the HPF 52. The AF evaluation value is calculated for each frame and sequentially transmitted to the CPU 23. The AF evaluation value is approximately proportional to the contrast amount, and increases as the contrast amount increases.

  The CPU 23 temporarily stores sequentially given AF evaluation values, and controls the position of the focus lens 31 via the driver 34 using a so-called hill climbing operation so that the AF evaluation value is maintained at the maximum value (near). . As the focus lens 31 moves, the contrast of the image changes and the AF evaluation value also changes. The CPU 23 controls the position of the focus lens 31 via the driver 34 in the direction in which the AF evaluation value increases. As a result, the contrast amount of the image in the focus detection region with respect to the same optical image is kept at the maximum value (near).

  The imaging apparatus 1 also has a so-called auto iris control function for keeping the brightness of the captured image (substantially) constant. The auto iris control is mainly realized by the AE evaluation value detection unit 43 shown in FIG. 3, the CPU 23 shown in FIG. 1, and the driver 34 shown in FIG.

  The AE evaluation value detection unit 43 extracts a luminance signal from the video signal generated by the moving image / still image processing unit 41 or the imaging signal from the AFE 12. The luminance signal extracted here is, for example, a luminance signal in the entire image. The AE evaluation value detection unit 43 obtains an AE evaluation value proportional to the brightness of the image by integrating the extracted luminance signals over the entire image. The AE evaluation value is calculated for each frame and is sequentially transmitted to the CPU 23.

  The CPU 23 controls the opening amount (size of the opening) of the diaphragm 32 via the driver 34 so that the sequentially given AE evaluation value is maintained at a constant value. When the optical images incident on the optical system 35 are the same, the amount of incident light per unit time on the image sensor 33 increases and the value of the luminance signal increases as the aperture of the diaphragm 32 increases. If the AE evaluation value is only less than the predetermined value even when the aperture of the diaphragm 32 is maximized, the amplification degree of the amplification circuit of the AFE 12 is adjusted to keep the AE evaluation value constant.

  Further, in accordance with a predetermined operation on the operation key 26c, the CPU 23 moves the zoom lens 30 along the optical axis via the driver 34, thereby changing the angle of view of shooting by the imaging unit 11 (in other words, imaging). The image of the subject formed on the imaging surface of the element 33 is enlarged or reduced).

  The video signal processing unit 13 in FIG. 1 also includes a motion detection unit 44 (see FIG. 3). The motion detection unit 44 detects the motion of the subject existing between the images based on the imaging signal. For this detection, for example, a well-known representative point matching method is used. Based on the detected motion (motion vector or the like), so-called camera shake correction or the like is performed.

  When shooting a still image, the thumbnail generation unit 45 in FIG. 3 generates a thumbnail image for the still image based on the imaging signal at the still image shooting timing under the control of the CPU 23. This thumbnail image is a reduced image obtained by reducing one still image (still image) that has been shot and recorded by thinning processing or the like. A thumbnail image of a still image is recorded on the memory card 18 through compression (JPEG or the like) by the compression processing unit 16 while being associated with the captured still image. The thumbnail image associated with the photographed still image is referred to as a still image thumbnail image.

  In addition, when shooting a moving image, the thumbnail generation unit 45 generates a thumbnail image for the moving image based on the imaging signal at a predetermined timing under the control of the CPU 23. This thumbnail image is, for example, a reduced image obtained by reducing an image of one frame (image for one frame) during moving image shooting by thinning processing or the like. The thumbnail image of the moving image is recorded on the memory card 18 through compression (JPEG or the like) by the compression processing unit 16 while being associated with the captured moving image (in principle). The thumbnail image generated for recording in association with the captured moving image is referred to as a moving image thumbnail image. When the image size of the moving image is relatively small, one image itself constituting the captured moving image may be used as a moving image thumbnail image.

  The timing at which the moving image thumbnail image is actually generated is arbitrary. A moving image thumbnail image may be generated by receiving an imaging signal from the AFE 12 during moving image shooting, or an image that becomes a base of the moving image thumbnail image at the time of moving image shooting is selected and later (for example, a display unit) The thumbnail image for moving image may be generated using the image (when displayed on the screen 27). In any case, the imaging signals that are the basis for generating the same moving image thumbnail image are the same. In the present embodiment, a case where a moving image thumbnail image is generated and stored in the memory card 18 at the time of moving image shooting is taken as an example. Similarly, the timing at which the still image thumbnail image is actually generated is also arbitrary.

  In the thumbnail image display mode, the moving image and still image thumbnail images stored in the memory card 18 are displayed on the display unit 27 through the expansion processing by the expansion processing unit 19 and the conversion processing by the video output circuit 20.

  FIG. 5 shows a display example of the display screen of the display unit 27 in the thumbnail image display mode. In FIG. 5, the display area of the display unit 27 is divided into four, and thumbnail images TN1, TN2, TN3, and TN4 are displayed on the upper left, upper right, lower left, and lower right of the display area, respectively. When another thumbnail image is stored in the memory card 18, the other thumbnail image is displayed by performing a predetermined operation on the operation key 26c. A mark 71 attached to the thumbnail images TN2 and TN3 indicates that the thumbnail image is a thumbnail image for a moving image. Therefore, the thumbnail images TN2 and TN3 are moving image thumbnail images, and the thumbnail images TN1 and TN4 are still image thumbnail images.

  In FIG. 5, reference numeral 72 denotes a cursor on the display screen. The cursor 72 moves on the display screen by operating the operation key 26c. FIG. 5 shows a state in which the thumbnail image TN3 is selected by the cursor 72. A number such as “001” displayed at the lower right of each thumbnail image indicates the file number of each thumbnail image.

  When a predetermined key operation is performed while a certain thumbnail image is selected by the cursor 72, a moving image or a still image associated with the thumbnail image is read from the memory card 18. Then, the read moving image or still image is displayed using the entire display screen of the display unit 27. For example, when a key operation is performed so that a moving image corresponding to the thumbnail image TN3 is reproduced, the display screen of the display unit 27 transitions from the state illustrated in FIG. 5 to the state illustrated in FIG. 6, and corresponds to the thumbnail image TN3. The moving image is reproduced and displayed using the entire display screen of the display unit 27. In this state, when a key operation for stopping reproduction is performed, the display screen returns to the state shown in FIG.

[Method of generating thumbnail image for video]
Next, a method for generating a moving image thumbnail image will be described. FIG. 7 is a flowchart showing a procedure for generating a moving image thumbnail image. Hereinafter, unless otherwise stated, description will be made with a focus on a certain moving image.

  When the power supply for each unit in the imaging apparatus 1 is activated by an operation on a power switch (not shown) provided in the imaging apparatus 1, the TG 22 sequentially generates a vertical synchronization signal at a predetermined cycle (for example, 1/60 seconds). . First, in step S1, it is confirmed whether a vertical synchronization signal is output from the TG 22. The vertical synchronization signal is output from the TG 22 at the start time of each frame.

  If the output of the vertical synchronization signal has not been confirmed (No in step S1), the process in step S1 is repeated. If the output of the vertical synchronization signal has been confirmed (Yes in step S1), the imaging apparatus in step S2 It is determined whether 1 is recording (moving video recording). If recording is in progress (Yes in step S2), the process proceeds to step S7. If recording is not in progress (No in step S2), the process proceeds to step S3. In step S3, it is confirmed whether or not the recording button 26a is pressed in the recording mode. If it is confirmed that the recording button 26a is pressed in the recording mode (Yes in step S3), the process proceeds to step S4. If not (No in step S3), the process returns to step S1. In this manner, the loop process including steps S1, S2, and S3 is repeatedly executed until recording is started.

  In step S4, the CPU 23 defines two flags F0 and F1 each having a value of 0 or 1, and assigns 0 to both flags F0 and F1 (that is, resets). The flag F0 is reset every time recording is started. The role of the flag F1 will become clear from the following description.

  In step S5, the process proceeds after step S4, and the thumbnail generation unit 45 generates a moving image thumbnail image based on the imaging signal for one image currently output from the AFE 12. In step S6 following step S5, the CPU 23 creates a header file. The header file stores various information such as the shooting date and time and the file number in addition to the moving image thumbnail image generated in step S5. The created header file is recorded in the SDRAM 17. In this embodiment, a case where one moving image thumbnail image is stored in one header file will be described as an example.

  When step S6 ends, the process returns to step S1, and again waits for the generation of the vertical synchronization signal. When step S2 is reached after passing through steps S4 to S6, the imaging apparatus 1 is recording, and the process proceeds to step S7 (Yes in step S2).

  In step S <b> 7, the CPU 23 creates a stream image file for storing a collection of images representing the captured moving image (that is, a stream image), and records the stream image file on the memory card 18. In the stream image file, a video signal (compressed video signal) representing a captured image of each frame during moving image shooting and a corresponding audio signal (compressed audio signal) are sequentially added. When the recording is finished, finally, the stream image file stores a video signal representing a captured image of each frame from the start of the recording to the end of the recording and an audio signal corresponding thereto.

  In step S8, which is shifted to after the processing of step S7, it is confirmed whether or not the user has pressed the recording button 26a again, that is, whether or not recording has been instructed. When recording stop is not instructed (No in step S8), the process proceeds to step S10. Until the stop of recording is instructed, a loop process including steps S10 to S15 and steps S1, S2, S7 and S8 is repeatedly executed. This loop processing is performed once for each frame.

  If an instruction to stop recording is confirmed in step S8 (Yes in step S8), the process proceeds to step S9, and the header file created in step S6 is added to the stream image file created in step S7. As a result, both files are associated, and the thumbnail image for moving image generated in step S5 and the moving image in the stream image file are associated (as will be apparent from the description below) or generated in step S13 described below. The moving image thumbnail image and the moving image in the stream image file are associated with each other. When the process of step S9 is completed, the process returns to step S1, and the state of the imaging device 1 transitions to a state of accepting the start of shooting of another moving image.

  The process of steps S10 to S15, which is a characteristic part of the present invention, will be described.

  In step S10, it is determined whether the flag F0 is set, that is, whether the flag F0 is 1. When the flag F0 is 1 (Yes in Step S10), the process returns to Step S1, and when the flag F0 is 0 (No in Step S10), the process proceeds to Step S11. In the shooting of one moving image, once the processing in steps S13 and S14 is executed, the determination in step S10 is always affirmative (Yes).

  In step S11, the CPU 23 determines whether or not a predetermined trigger condition is satisfied. This trigger condition will be described in detail later. When the flag F0 is 0, the process of step S11 is performed in each frame during moving image shooting. If the trigger condition is not satisfied (No in step S11), the process proceeds to step S15, zero is substituted for the flag F1, and the process returns to step S1. On the other hand, when the trigger condition is satisfied (Yes in step S11), the process proceeds to step S12, and it is determined whether or not the flag F1 is 1. If the flag F1 is 1 (Yes in step S12), the process returns to step S1, while if the flag F1 is 0 (No in step S12), the process proceeds to step S13.

  In step S <b> 13, a moving image thumbnail image is generated based on the image signal for one image currently output from the AFE 12. As a result, a moving image thumbnail image is generated based on the imaging signal (captured image) of the frame including the timing when the trigger condition of step S11 is satisfied or the next frame. Note that the moving image thumbnail image to be generated in step S13 may be generated based on the imaging signal (captured image) of the frame several frames before and after the trigger condition is satisfied.

  In step S14 following step S13, the moving image thumbnail image already stored in the header file created in step S6 is replaced with the moving image thumbnail image generated in step S13. Further, after substituting 1 for both flags F0 and F1, the process returns to step S1.

  Note that the process of step S10 may be omitted. In this case, if it is determined in step S8 that recording stop is not instructed (No in step S8), the process directly proceeds to step S11. When the process of step S10 is omitted, even after the processes of steps S13 and S14 are performed, the process of step S15 is performed again through the process of step S15 because the trigger condition is not satisfied. Execution of the process of S14 is allowed. In this case, in the second and subsequent processing in step S14, the moving image thumbnail image already stored in the header file is replaced with the “latest” moving image thumbnail image generated in step S13.

  As understood from the above processing procedure, each moving image thumbnail image generated in steps S5 and S13 is a candidate for a moving image thumbnail image to be associated with the captured moving image. If the trigger condition is not satisfied even once during the shooting period of one moving image, the moving image thumbnail image generated in step S5 is finally the moving image thumbnail image associated with the moving image. Become.

  If the trigger condition is satisfied in step S11, the moving image thumbnail image generated in step S13 is finally associated with the captured moving image. When the process of step S10 is omitted, the latest moving image thumbnail image generated in step S13 is finally associated with the captured moving image.

  The trigger condition is determined so that the moving image thumbnail image generated in step S13 well represents the characteristics of the captured moving image. Hereinafter, as determination methods for whether or not the trigger condition in step S11 is satisfied, first, second, third, fourth, and fifth determination methods are exemplified. FIG. 8 shows typical examples of trigger conditions in the first to fifth determination methods.

[First judgment method]
First, the first determination method will be described. The trigger condition of step S11 when the first determination method is adopted is referred to as a first trigger condition. If the first trigger condition is satisfied, the process proceeds to step S12. If the first trigger condition is not satisfied, the process proceeds to step S15.

  In the case of adopting the first determination method, in step S11, for example, “After the most recent zoom-in is performed, the angle of view is not changed by zoom-in or zoom-out continuously for a predetermined time T1 or more (that is, It is determined whether or not the first trigger condition is satisfied. This determination is made based on the current time (current frame). The time T1 is, for example, several seconds (such as 1 to 2 seconds).

  For example, as shown in FIG. 9, when the zoom-out is performed without waiting for the elapse of time T <b> 1 immediately after the first zoom-in after the start of the movie shooting, and then the second zoom-in is performed, The passage of time T1 is determined from the end point of zoom-in (corresponding to “most recent zoom-in”).

  The zoom-in is an operation for enlarging an image of a subject formed on the imaging surface of the image sensor 33, and the angle of view of shooting by the imaging unit 11 decreases with this operation. Zooming out is an operation for reducing the image of the subject formed on the imaging surface of the image sensor 33, and the angle of view of imaging by the imaging unit 11 increases with this operation. The zoom-in and zoom-out are executed according to a predetermined operation on the operation key 26c.

  Users often magnify a subject such as a person of interest by zooming in. When the user determines that an appropriate angle of view has been set by zooming in, the user stops changing the angle of view. An image photographed in this state is often a characteristic image that largely captures the subject that the user is paying attention to. For this reason, by adopting the first determination method, it is possible to acquire a thumbnail image that clearly represents the characteristics of the moving image. As a result, it is possible to facilitate the search for a desired moving image.

  Note that the first trigger condition is: “After the most recent zoom-out, the angle of view is not changed by zoom-in or zoom-out for a predetermined time T1 or more (that is, the angle of view is fixed). It is also possible to change the condition to

[Second Judgment Method]
Next, the second determination method will be described. The trigger condition in step S11 when the second determination method is employed is referred to as a second trigger condition. If the second trigger condition is satisfied, the process proceeds to step S12. If the second trigger condition is not satisfied, the process proceeds to step S15.

  When the second determination method is adopted, in step S11, it is determined whether or not the focus is achieved and the state where the focus is (substantially) locked is continued for a certain time or more. More specifically, in step S11, for example, the second trigger condition that “the magnitude of the fluctuation of the position of the focus lens 31 continues within a predetermined time T2 and stays within a predetermined threshold” is satisfied / Failure is determined. This determination is made based on the current time (current frame). The time T2 is, for example, several seconds (such as 1-2 seconds).

  As described above, the CPU 23, via the driver 34, the focus lens 31 so that an optical image representing the subject is formed on the image pickup surface (light receiving surface) of the image pickup device 33 based on the AF evaluation values calculated sequentially. Adjust the position. Therefore, the CPU 23 naturally recognizes the position of the focus lens 31. The position of the focus lens 31 is, for example, the position of the focus lens 31 with reference to the imaging surface of the imaging element 33.

  With reference to FIG. 10, an example of a method for determining whether the second trigger condition is satisfied or not will be described in detail. Curves 75 and 76 in FIG. 10 represent temporal changes in the AF evaluation value and the position of the focus lens 31 (for example, the distance between the focus lens 31 and the imaging surface) during moving image shooting, respectively. FIG. 10 shows a state in which the AF evaluation value takes the maximum value of the hill-climbing curve at the timing t1, and the state is maintained until the timing t2. The time between timings t1 and t2 coincides with time T2.

At timing t2, the CPU 23 compares the magnitude of fluctuation (the magnitude of the fluctuation range) of the position of the focus lens 31 during the period from timing t1 to t2 with a predetermined reference value _BREF . If the former is less than or equal to the latter (B _REF ), it is determined that the second trigger condition is satisfied, and otherwise, it is determined that the second trigger condition is not satisfied. In order to enable the above determination, the CPU 23 sequentially records information for specifying the position of the past focus lens 31 for time T2 in the SDRAM 17.

In addition, when the position of the focus lens 31 is completely stopped in a focused state, the reference value B _REF can be set to zero. In this case, the second trigger condition is expressed as “the position of the focus lens 31 is fixed for a predetermined time T2 or more”. When the fluctuation of the AF evaluation value is within a certain range (the size of the range is, for example, a threshold value A _REF described later), a position control method of fixing the position of the focus lens 31 can be employed. In this case, the threshold value B _REF is set to zero.

In addition, as shown in FIG. 10, the AF evaluation value and the position of the focus lens 31 are usually linked. For this reason, the branch determination in step S11 may be performed based on the AF evaluation value. That is, for example, at the timing t2, the CPU 23 compares the magnitude of the AF evaluation value fluctuation (the magnitude of the fluctuation range) from the timing t1 to the time t2 with a predetermined reference value A _REF . If the former is equal to or less than the latter (A _REF ), the process proceeds from step S11 to step S12. If not, the process proceeds from step S11 to step S15. In this case, the CPU 23 sequentially records the past AF evaluation values for the time T2 in the SDRAM 17 so that the above determination is possible.

In this way, whether or not the condition that the magnitude of the fluctuation of the AF evaluation value continues within the predetermined reference value A _REF for a predetermined time T2 or more is satisfied or not is determined in step S11. May be. Considering that the AF evaluation value and the position of the focus lens 31 are linked, it can be said that this condition is equivalent to the second trigger condition.

  After starting moving image shooting, the user often moves the imaging apparatus 1 frequently while considering the shooting composition. When the shooting composition is confirmed, the user fixes (substantially) the imaging device 1 to the subject. In this state, while the focus is normally locked, the imaging device 1 captures the subject that the user is paying attention to. For this reason, by adopting the second determination method, it is possible to acquire a thumbnail image that clearly represents the characteristics of the moving image. As a result, it is possible to facilitate the search for a desired moving image.

[Third Judgment Method]
Next, the third determination method will be described. The trigger condition in step S11 when the third determination method is employed is referred to as a third trigger condition. If the third trigger condition is satisfied, the process proceeds to step S12. If not, the process proceeds to step S15.

  When the third determination method is adopted, in step S11, it is determined whether or not the state in which the movement in the captured image is (substantially) stopped continues for a certain time or more. More specifically, in step S11, for example, it is determined whether or not the third trigger condition that “the magnitude of motion in the motion detection region continues within a predetermined time T3 and falls within a predetermined threshold” is satisfied / not satisfied. Is done. This determination is made based on the current time (current frame). The motion detection area is provided in the captured image of each frame constituting the moving image. The motion detection area is an entire or a partial area of the captured image (can also be regarded as an entire or partial area of the imaging area of the image sensor 33). The time T3 is, for example, several seconds (1 to 2 seconds or the like).

  With reference to FIG. 11, an example of a method for determining whether the third trigger condition is satisfied or not will be described in detail. FIG. 11 shows detection blocks in the captured image defined by the motion detection unit 44 in FIG. The motion detection unit 44 provides nine detection blocks BL1 to BL9 in the captured image of each frame. The nine detection blocks BL1 to BL9 form the “motion detection area” described above.

  Then, the motion detection unit 44 detects a motion vector for each of the detection blocks BL1 to BL9 using a well-known representative point matching method based on the comparison between captured images acquired sequentially. This motion vector detection is performed for each frame. The motion vector of the detection block BL1 is a vector indicating the motion of the image in the detection block BL1. The same applies to the motion vectors of the detection blocks BL2 to BL9. In addition, the motion vectors detected by the detection blocks BL1 to BL9 are referred to as motion vectors VC1 to VC9, respectively.

  The CPU 23 determines whether the third trigger condition is satisfied or not based on the motion evaluation value based on the magnitudes of the motion vectors VC1 to VC9 detected for each frame. The motion evaluation value is calculated for each frame. The motion evaluation value is, for example, an average value or an integrated value of the magnitudes of the motion vectors VC1 to VC9. The magnitudes of the motion vectors VC1 to VC9 may be used as the motion evaluation value. In this case, the motion evaluation value is composed of nine values for one frame.

A curve 77 in FIG. 12 represents a temporal change in the motion evaluation value during moving image shooting. At timing t3, as the reference value C _REF or less from the motion estimation value is a predetermined reference value C _REF greater, then, assuming a state in which motion estimation value continues being kept below the reference value C _REF to timing t4 To do. The time between timings t3 and t4 coincides with time T3.

At timing t4, the CPU 23 compares each motion evaluation value from timing t3 to t4 with the reference value _CREF . In the period from timing t3 to t4, it is determined that the third trigger condition is satisfied when the former is always kept below the latter (C _REF ), otherwise the third trigger condition is not satisfied. to decide. In order to enable the above determination, the CPU 23 sequentially records the past motion evaluation values for the time T3 in the SDRAM 17.

  As understood from the above description, the third trigger condition is “the motion evaluation value according to the magnitude of motion in the motion detection area of the moving image continues for a predetermined time T3 or more and falls within a predetermined threshold value. In other words, the condition is “contains”.

  It can be inferred that the state in which the motion in the captured image of the moving image has stopped for a certain time or more coincides with the state where the subject such as the person of interest is captured in a stationary state. Therefore, by adopting the third determination method, it is possible to acquire a thumbnail image that clearly represents the characteristics of the moving image, and as a result, it is possible to facilitate the search for a desired moving image.

  When the imaging apparatus 1 is supported by hand, the subject in the image slightly moves due to so-called camera shake. The above threshold value is appropriately set through an experiment using an actual machine so as to avoid that the third trigger condition is not satisfied at all due to the movement caused by the camera shake.

  In addition, as a technique for detecting the motion in the motion detection region (the magnitude of the motion), the technique using the representative point matching method has been exemplified, but various other detection techniques can be employed.

  For example, as is well known, the brightness (luminance signal) is compared for each detection block between the frames constituting the moving image, and the motion in the motion detection area (the magnitude of the motion is based on the change in brightness in each detection block. May be detected. In addition, for example, as is well known, the colors (colors are specified from the video signal) are compared for each detection block between the frames constituting the moving image, and the motion detection area in the motion detection area is determined based on the color change in each detection block. You may make it detect a motion (magnitude | size of a motion).

[Fourth Judgment Method]
Next, the fourth determination method will be described. The trigger condition in step S11 when the fourth determination method is adopted is referred to as a fourth trigger condition. If the fourth trigger condition is satisfied, the process proceeds to step S12. If not, the process proceeds to step S15.

  In the fourth determination method, a face area detection function for detecting a face area of a person existing in a captured image of each frame is used. A face area detection unit 46 necessary for realizing the face area detection function is provided in the video signal processing unit 13 (see FIG. 3). When the fourth determination method is adopted, in step S11, for example, it is determined whether or not the fourth trigger condition that “the size of the detected face area is equal to or larger than a predetermined threshold (reference size)” is satisfied. The

  Various methods can be employed as a method for detecting a face area. For example, as is well known, the face area detection unit 46 determines the size of the face area by extracting the skin color of the captured image. That is, for example, an area having a video signal classified as skin color is extracted as a face area from the captured images of each frame constituting the moving image, and the size of the face area is determined based on the size (for example, area) of the extracted area. Is detected (detected). The extraction and detection of the size of the face area are performed for each frame. Note that what video signals are classified as skin colors is determined in advance.

  As is well known, the size of the face area may be detected using a pattern matching method. At this time, information on various face area patterns is stored in the memory in the imaging apparatus 1, and the face area is detected and the size of the face area is detected by comparing the pattern and the captured image. To do.

  In the actual processing, for example, the face area detection unit 46 calculates a face area value corresponding to the size of the face area for each frame and sequentially transmits it to the CPU 23. The CPU 23 determines that the fourth trigger condition is satisfied when the successively transmitted face area value is equal to or greater than a predetermined threshold value, and determines that the fourth trigger condition is not satisfied otherwise. This face area value is a value that increases as the size of the detected face area increases.

  It can be estimated that the state in which the size of the face in the image is relatively large matches the state in which the face of the person that the user is paying attention is greatly projected. For this reason, by adopting the fourth determination method, it is possible to acquire a thumbnail image that clearly represents the characteristics of the moving image, and as a result, it is possible to facilitate the search for a desired moving image.

  An upper limit may be set for the size of the face area or the face area value that satisfies the fourth trigger condition. That is, when “the size of the detected face area or the face area value is not less than a predetermined first threshold and not more than the second threshold”, in other words, “the size of the detected face area or the face If the region value is within a predetermined range, the process may proceed to step S12, and if not, the process may proceed to step S15. However, the second threshold value is larger than the first threshold value.

  If a thumbnail image is generated based on an image in which the size of the face occupying the image is too large, it may be difficult to capture the feature of the moving image. Considering this, the upper limit may be determined as described above.

[Fifth determination method]
Next, the fifth determination method will be described. The trigger condition in step S11 when the fifth determination method is adopted is referred to as a fifth trigger condition. If the fifth trigger condition is satisfied, the process proceeds to step S12. If the fifth trigger condition is not satisfied, the process proceeds to step S15. In addition, when employ | adopting a 5th determination method, the process of step S10 is abbreviate | omitted.

  In the fifth determination method, attention is focused on the intensity of sound input through the microphone 14 during moving image shooting. The audio signal processing unit 15 has a function of sequentially detecting the intensity of sound or the frequency component of a predetermined band of sound input via the microphone 14 during moving image shooting. The detected sound intensity or the intensity of the frequency component of the predetermined band of the sound is sequentially transmitted to the CPU 23 as a sound intensity value.

  Alternatively, the sound intensity may be detected instead of the sound intensity, and a value corresponding to the detected sound intensity or the frequency component in a predetermined band of the sound may be used as the sound intensity value. In this case, the following “sound intensity” and “intensity of frequency components in a predetermined band of sound” are read as “sound volume” and “amplitude of frequency components in a predetermined band of sound”, respectively. .

  The sound intensity value is, for example, an average value for one frame of detected sound intensity or a peak value in the frame. Alternatively, the sound intensity value is, for example, an average value for one frame of the intensity of a frequency component in a predetermined band of the detected sound or a peak value in the frame. Therefore, the sound detection value is detected for each frame. The sound intensity value increases as the sound intensity increases. The frequency component of the predetermined band is, for example, a human voice frequency band component or an audible frequency band component. The audio signal processing unit 15 extracts the frequency component of the predetermined band from the audio signal input via the microphone 14 using a bandpass filter or the like.

  The CPU 23 determines whether the sound intensity value of the current frame is the maximum among the sound intensity values from the frame at the start of moving image shooting to the current frame. Then, when the sound intensity value of the current frame is the maximum, it is determined that the fifth trigger condition is satisfied, and otherwise, it is determined that the fifth trigger condition is not satisfied.

  When shooting a concert or party venue, it can be considered that the state in which the sound intensity is high coincides with the state in which the shooting site is exciting. Therefore, by adopting the fifth determination method, it is possible to acquire a thumbnail image that clearly represents the characteristics of a moving image, and as a result, it is possible to facilitate the search for a desired moving image.

  When the fifth determination method is employed, the moving image thumbnail image generation procedure illustrated in the flowchart of FIG. 13 may be employed instead of the moving image thumbnail image generation procedure illustrated in the flowchart of FIG. 7. It is.

  The generation procedure shown in FIG. 13 will be described. In FIG. 7 and FIG. 13, the process in the step which attached | subjected the same symbol is the same. That is, in steps S1 to S3, S5 to S9, and S13 in FIG. 13, the same processes as those in FIG. 7 are performed. In the procedure shown in FIG. 13, step S21 is executed instead of step S4 in FIG. 7, steps S22 and S23 are executed instead of steps S10 to S12 and S15 in FIG. 7, and step S24 is executed instead of step S14 in FIG. The

  If it is confirmed in step S3 that the recording button 26a has been pressed in the recording mode, the process proceeds to step S21. In step S21, an initial value Sinit (for example, 0) is substituted for variable Smax, and the process proceeds to step S5. If it is determined in step S8 that the recording stop is not instructed (No in step S8), the process proceeds to step S22. Until stop of recording is instructed, a loop process including steps S22, S23, S13, and S24 and steps S1, S2, S7, and S8 is repeatedly executed. This loop processing is performed once for each frame.

  In step S22, it is determined whether the sound intensity value Sin of the current frame is greater than the variable Smax. If the inequality: Sin> Smax is satisfied (Yes in step S22), the process proceeds to step S23. If not satisfied (No in step S22), the process returns to step S1. In step S23, the sound intensity value Sin of the current frame is substituted for the variable Smax, and the process proceeds to step S13. After the moving image thumbnail image is generated in step S13, the process proceeds to step S24. The process of step S24 is obtained by removing the processes for the flags F0 and F1 from the process of step S14 of FIG. When the process of step S24 is completed, the process returns to step S1.

[Additional conditions]
You may make it add arbitrary additional conditions with respect to each of the 1st-5th trigger conditions illustrated above. That is, for example, in addition to the establishment of the k-th trigger condition described above (k is an arbitrary integer in the range of 1 to 5), the process proceeds to step S12 only when the additional condition is further established, and the k-th trigger condition is established. Even if the trigger condition is satisfied, if the additional condition is not satisfied, the process may proceed to step S15.

  For example, an additional condition that “the imaging apparatus 1 is not panned or tilted” may be added to the first trigger condition described above. That is, in the first determination method described above, “after the most recent zoom-in is performed, the angle of view is not changed by zoom-in or zoom-out for a predetermined time T1 or more, and the imaging apparatus 1 is panned. Alternatively, the process may proceed to step S12 when “not tilted”, or may proceed to step S15 if not.

  This is because it is considered that an image acquired without panning or tilting, that is, an image acquired with the imaging device 1 fixed, more appropriately captures the subject focused on by the user. .

  Pan (panning) means that the casing (not shown) of the imaging apparatus 1 is shaken in the left-right direction, and tilt (tilting) means that the casing of the imaging apparatus 1 is shaken in the vertical direction. .

  The state of movement of the imaging apparatus 1 (the state of movement of the casing of the imaging apparatus 1) is determined as follows: a stationary state where the casing of the imaging apparatus 1 is stationary; A camera shake state that is finely oscillating in a direction, a pan state in which a pan operation (pan operation) is performed on the imaging device 1, and a tilt operation (tilt operation) on the imaging device 1 are performed. The tilt state is roughly divided into two. For this reason, the additional condition is also paraphrased as “the imaging apparatus 1 is in a stationary state or a shaking state”.

  When determining whether or not the additional condition is satisfied, the CPU 23 functions as a motion detection unit that determines whether the motion state of the imaging apparatus 1 is a stationary state, a hand shake state, a pan state, or a tilt state. .

  For example, as is well known, the CPU 23 performs the above determination based on an output signal indicating the angular velocity from an angular velocity sensor (gyro sensor; not shown) that detects the angular velocity of the housing of the imaging apparatus 1.

  For example, considering the pan direction, the output signal of the angular velocity sensor takes a positive value when the housing of the imaging apparatus 1 is shaken leftward, takes a negative value when the case is shaken rightward, and is fixed. Consider the case of taking a zero value when In this case, if the output signal of the angular velocity sensor is zero or substantially zero, it is determined that it is in a stationary state, and if the output signal of the angular velocity sensor vibrates little by little and takes a positive or negative value, it is in a shake state. If the output signal of the angular velocity sensor within a predetermined time continues to take a positive or negative value, it is determined that the camera is in the pan state. The same applies to the tilt direction.

  Further, as is well known, the state of motion of the imaging device 1 may be determined based on the detection result of the motion of the image by the motion detector 44 of FIG. For example, the CPU 23 refers to the motion vectors VC1 to VC9 described in the third determination method. For example, when the respective directions of the motion vectors VC1 to VC9 are maintained in the same direction (for example, leftward) for a predetermined time or longer, it is determined that the panning state or the tilting state is satisfied. Or it is determined that it is in a stationary state.

  Further, for example, an additional condition that “the imaging apparatus 1 is not panned or tilted” may be added to the above-described second trigger condition. In other words, in the second determination method described above, “the magnitude of the variation in the position of the focus lens 31 continues for a predetermined time T2 or more and stays within a predetermined threshold, and the imaging apparatus 1 is panned or tilted. If not, the process may proceed to step S12, and if not, the process may proceed to step S15. When shooting a distant view, the focus is often locked even in a pan state.

<< Deformation, etc. >>
In addition, you may enable it for a user to set what kind of trigger conditions the trigger conditions employ | adopted in step S11 are used. For example, the user may be able to set which of the above first to fifth trigger conditions is used as the trigger condition in step S11. This setting is performed, for example, through an operation on the operation unit 26.

  Moreover, it is also possible to freely combine any two or more of the above-described first to fifth determination methods. For example, when combining the first determination method and the second determination method, in step S11, it is determined whether the first trigger condition and the second trigger condition are satisfied or not. Then, when either one of the first and second trigger conditions is satisfied, the process proceeds to step S12, and when both are not satisfied, the process proceeds to step S15. Alternatively, the process proceeds to step S12 only when both the first and second trigger conditions are satisfied, and otherwise, the process proceeds to step S15.

  In addition, the example in which one moving image thumbnail image is stored in the header file and one stored moving image thumbnail image is associated with one moving image has been described above. However, a plurality of moving image thumbnail images are stored and stored in the header file. The plurality of moving image thumbnail images may be associated with one moving image. In this case, in step S14, instead of replacing the moving image thumbnail image already stored in the header file with the (latest) moving image thumbnail image generated in step S13, the moving image thumbnail image generated in step S13 is replaced. Add to the header file.

  In a case where a plurality of moving image thumbnail images are associated with one moving image, for example, when the cursor 72 in FIG. 5 is moved to the thumbnail TN3 portion, each moving image thumbnail image constituting the plurality of moving image thumbnail images is predetermined. Are updated and displayed on the part of the thumbnail TN3 in order.

  Related to this, the moving image thumbnail image may be a moving image (hereinafter referred to as a thumbnail moving image). A thumbnail sound may be created based on an audio signal corresponding to the captured moving image, and the thumbnail sound may be simultaneously output via the speaker 28 when displaying the thumbnail moving image. Even when the thumbnail image is a still image, the thumbnail sound can be output.

  Also, if the trigger condition is not satisfied even once during the shooting period of one moving image, the moving image thumbnail image (first candidate thumbnail image) generated in step S5 is finally converted into the moving image. As described above, the example is a thumbnail image for a moving image associated with. This moving image thumbnail image is created based on the imaging signal at the moving image shooting start timing (the shooting start frame or the frame immediately before the shooting start).

  The moving image thumbnail image associated with the moving image when the trigger condition is not satisfied even once during the shooting period of one moving image is not limited to the above. The moving image thumbnail image may be generated based on an imaging signal at an arbitrary predetermined timing (frame). For example, it may be generated based on an imaging signal immediately before or after moving image shooting or an imaging signal of any frame during moving image shooting.

  As described above, the recorded contents of the memory card 18 can be freely read by an external personal computer or the like. As described above, the recorded content of the memory card 18 can be reproduced (video display and audio output) by the display unit 27 and the speaker 28. However, the recorded content of the memory card 18 is reproduced by a personal computer including the display unit and the speaker. It can be similarly realized by a computer or the like.

  In the present embodiment, the part that functions as the angle of view changing means includes a driver 34. The operation key 26c and / or the CPU 23 in FIG. 1 or the zoom lens 30 in FIG. 2 can also be regarded as components of the field angle changing unit. Further, the autofocus control means is mainly realized by the AF evaluation value detection unit 42 in FIG. 3, the CPU 23 in FIG. 1, and the driver 34 in FIG.

  In the present embodiment, the thumbnail generation device is mainly formed by the thumbnail generation unit 45 (or the video signal processing unit 13 including the thumbnail generation unit 45) and the CPU 23. In addition to this, an angle of view changing means, an autofocus control means, a motion detection means (corresponding to the motion detection section 44 in FIG. 3), a face area detection means (corresponding to the face area detection section 46 in FIG. 3), and a sound input means Any one or more (corresponding to the microphone 14 in FIG. 1) can be regarded as a component of the thumbnail generation apparatus. 7 and 13, the thumbnail generation unit 45 functions as a first generation unit.

1 is an overall block diagram of an imaging apparatus according to an embodiment of the present invention. It is an internal block diagram of the imaging part of FIG. FIG. 2 is an internal block diagram of a video signal processing unit in FIG. 1. FIG. 4 is an internal block diagram of an AF evaluation value detection unit in FIG. 3. It is a figure which shows the example of a display of the display screen of the display part of FIG. 1 in thumbnail image display mode. It is a figure which shows the reproduction | regeneration display screen of a moving image which can be changed from the display screen of FIG. 3 is a flowchart showing a procedure for generating a moving image thumbnail image in the imaging apparatus of FIG. 1. It is the figure which illustrated the trigger condition in Step S11 of FIG. It is a figure for demonstrating the 1st judgment method regarding establishment / non-establishment of the trigger condition in step S11 of FIG. It is for demonstrating the 2nd judgment method regarding establishment / non-establishment of the trigger condition in step S11 of FIG. It is a figure for demonstrating the 3rd judgment method regarding establishment / non-establishment of the trigger condition in step S11 of FIG. It is a figure for demonstrating the 3rd judgment method regarding establishment / non-establishment of the trigger condition in step S11 of FIG. It is a figure for demonstrating the 5th judgment method regarding establishment / non-establishment of the trigger condition in step S11 of FIG. It is a flowchart which shows the production | generation procedure of the thumbnail image for moving images in the conventional imaging device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Imaging device 11 Imaging part 12 AFE
13 Video signal processing unit 14 Microphone 15 Audio signal processing unit 26 Operation unit 26a Recording button 26b Shutter button 26c Operation key 41 Video / still image processing unit 42 AF evaluation value detection unit 43 AE evaluation value detection unit 44 Motion detection unit 45 Thumbnail generation 46 Face area detection unit

Claims (9)

In a thumbnail generation device that generates a thumbnail image associated with a captured moving image based on an imaging signal corresponding to a subject from an imaging unit provided in the imaging device capable of moving image shooting,
A first generation unit configured to generate a first candidate thumbnail image as a candidate for the thumbnail image based on the imaging signal at a predetermined timing;
When a predetermined trigger condition is satisfied during shooting of the moving image, a second candidate thumbnail image different from the first candidate thumbnail image is used by using the imaging signal at a predetermined timing with respect to when the trigger condition is satisfied. , And associating the second candidate thumbnail image with the moving image as the thumbnail image. The imaging apparatus includes an angle-of-view changing unit for enabling change of an angle of view of photographing by the imaging unit,
2. The trigger condition includes a condition in which the angle of view is not changed by the angle of view changing unit for a predetermined time or more after zooming in to reduce the angle of view. The thumbnail generation device described. The imaging apparatus includes an autofocus control unit that automatically adjusts a position of a focus lens so that an optical image representing the subject is formed on an imaging surface of an imaging element included in the imaging unit,
The thumbnail generation apparatus according to claim 1, wherein the trigger condition includes a condition that the magnitude of the position variation continues for a predetermined time or longer and falls within a predetermined threshold. The imaging apparatus includes a motion detection unit that detects a motion of an image in a motion detection area based on the imaging signal, and the motion detection area is provided in a captured image constituting the moving image,
The thumbnail generation apparatus according to claim 1, wherein the trigger condition includes a condition that the magnitude of the detected movement continues for a predetermined time or longer and falls within a predetermined threshold. The imaging apparatus includes a face area detection unit that detects a face area of a person existing in a captured image constituting the moving image based on the imaging signal,
The thumbnail generation apparatus according to claim 1, wherein the trigger condition includes a condition that a size of the detected face area is equal to or greater than a predetermined threshold. The imaging device includes sound input means for receiving sound input from the outside,
The establishment of the trigger condition is determined based on the intensity or magnitude of the sound input during the shooting of the video,
Using the imaging signal at a predetermined timing with reference to a timing at which the intensity or the magnitude of the sound or the frequency component intensity or the magnitude of the predetermined band of the sound is maximized during shooting of the moving image, The thumbnail generation apparatus according to claim 1, wherein a second candidate thumbnail image is generated. When the trigger condition is satisfied during shooting of the moving image, the second candidate thumbnail image is generated based on the imaging signal in a frame including the time when the trigger condition is satisfied or a frame in the vicinity thereof. The thumbnail generation device according to any one of claims 1 to 6. 8. The first candidate thumbnail image is associated with the moving image as the thumbnail image when the trigger condition has never been satisfied during the shooting of the moving image. A thumbnail generation device according to any one of the above. In an imaging device capable of video recording,
An imaging apparatus comprising the imaging means and thumbnail generation apparatus according to claim 1.