JP2008235969A - Video camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a video camera capable of easily deleting a low-luminance image from recorded images. <P>SOLUTION: The video camera 10 includes an image sensor 14 for repeatedly outputting a field image. A CPU 30 of the video camera 10 applies recording processing to the field image outputted from the image sensor 14. The CPU 30 also repeatedly discriminates as to whether the field image outputted from the image sensor 14 is a dark image, and creates timing information indicating a time point when the result of discrimination has changed from a negative result to a positive result. When the existing conditions are satisfied, the CPU 30 invalidates the recording processing, and executes deletion processing for deleting a part of the recorded field image on the basis of the created time information after the invalidating processing. Thus, the dark image can be easily deleted from the recorded images. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a video camera, and more particularly to, for example, a video camera that repeatedly captures an image of a scene and records the captured scene image as a moving image.

As this type of video camera, the one disclosed in Patent Document 1 is known. In this background art, when it is evaluated that the object scene image is dark, imaging or recording is stopped. Thereby, an attempt is made to avoid the adverse effect of dark images being accumulated on the recording medium.
JP 2006-165770 A [H04N 5/232, 5/225, 5/91]

  However, it is necessary to provide a certain grace period until the recording operation is stopped after the object scene is evaluated to be dark. This is because the continuous recording operation is hindered in response to the momentary decrease in luminance. For this reason, even in the background art, a dark image of an amount corresponding to the grace period is recorded. In short, if a continuous recording operation is to be ensured, a considerable amount of dark image recording cannot be avoided.

  Note that the situation of recording a dark image includes, for example, a scene in which a video camera is put in a bag without performing a stop operation, and a scene in which fireworks are shot at night. The dark image of the former scene is meaningless, but the dark image of the latter scene is meaningful. In the background art, such a meaningful dark image may not be recorded.

    Therefore, a main object of the present invention is to provide a video camera capable of easily deleting a low brightness image from a recorded image.

  A video camera (10) according to the present invention has an imaging surface (14f) on which an optical image representing an object scene is irradiated, an image pickup means (14) that repeatedly outputs the object scene image, and is output from the image pickup means Recording means (S11) for performing recording processing on the object scene image, determination means (S13) for repeatedly determining whether or not the object scene image output from the imaging means is a low luminance image, and the determination result of the determination means is Creation means (S7, S17, S19, S23) for creating timing information indicating the time point when the negative result is updated to a positive result, and disabling means for disabling the recording means when the predetermined condition is satisfied ( (S29, S31), and a deletion means for executing a deletion process for deleting a part of the object scene image recorded by the recording means based on the timing information created by the creation means after the disabling process of the disabling means ( S39).

  The imaging means has an imaging surface on which an optical image representing the scene is irradiated, and repeatedly outputs the scene image. The object scene image output from the imaging means is subjected to recording processing by the recording means. The discriminating unit repeatedly discriminates whether or not the object scene image output from the imaging unit is a low luminance image. The creating unit creates timing information indicating a point in time when the determination result of the determining unit is updated from a negative result to a positive result. The disabling unit disables the recording unit when the predetermined condition is satisfied. The deletion means executes a deletion process for deleting a part of the object scene image recorded by the recording means based on the timing information created by the creation means after the disabling process of the disabling means.

  The timing information indicates a point in time when the object scene image output from the imaging unit is changed to a low luminance image. A part of the recorded scene image is deleted based on such timing information. As a result, the low-luminance image can be easily deleted from the recorded image.

  In the video camera, the predetermined condition further includes a time condition that a positive continuation time in which the determination result of the determination unit continuously indicates a positive result has reached the first specified time.

  Therefore, the recording process is interrupted when the positive continuation time reaches the first specified time. As a result, it is possible to avoid accumulation of low-luminance images while ensuring a continuous recording operation.

  The video camera further includes measurement means (S21) for measuring the affirmative continuation time and reset means (S41) for resetting the measurement process of the measurement means when the continuation operation is performed.

  The positive duration is measured by the measuring means. The measurement process of the measurement unit is reset by the reset unit when the continuation operation is performed. Therefore, if the operator performs a continuous operation, satisfaction of the time condition is prevented. Thereby, the interruption of the recording process based on the satisfaction of the time condition is avoided, and the subsequent deletion process is not executed. In this way, recording of a low-luminance image that is meaningful to the operator is ensured.

  The video camera further includes initialization means (S5) for initializing the timing information created by the creation means in association with the reset process of the reset means.

  The timing information created by the creation unit is initialized by the initialization unit in association with the reset process of the reset unit. Therefore, even when the object scene image changes from a low-brightness image to a high-brightness image and then changes again from a high-brightness image to a low-brightness image after the continuation operation, accurate deletion can be performed.

  In the video camera, the predetermined condition further includes an operation condition that the interruption operation is performed. Therefore, the recording process is interrupted when an interruption operation is performed.

  The video camera further includes notifying means (S27) for executing a notifying process for prompting the operator to continue at least when the affirmative continuation time reaches a second specified time shorter than the first specified time.

  The notification process by the notification means is executed when the positive continuation time reaches a second specified time shorter than the first specified time. Therefore, a time equal to the difference between the first specified time and the second specified time is given to the operator as a grace time for performing the continuous operation.

  A control program according to the present invention includes a processor (10) of a video camera (10) having an imaging surface (14f) on which an optical image representing an object scene is irradiated, and including image pickup means (14) that repeatedly outputs the object scene image ( 30), a recording step (S11) for performing a recording process on the object scene image output from the imaging means, and a determination step for repeatedly determining whether or not the object scene image output from the imaging means is a low-luminance image (S13), creation step (S7, S17, S19, S23) for creating timing information indicating when the discrimination result of the discrimination step is updated from a negative result to a positive result, when a predetermined condition is satisfied The disabling step (S29, S31) for disabling the recording step, and a deletion process for deleting a part of the object scene image recorded by the recording step based on the timing information created by the creating step. Run after disabling Delete step (S39).

  Even in the control program, a low-intensity image can be easily deleted from a recorded image in the same manner as the video camera described above.

  A control method according to the present invention is a method for controlling a video camera (10) having an imaging surface (14f) on which an optical image representing an object scene is irradiated, and including image pickup means (14) that repeatedly outputs the object scene image. A recording step (S11) for performing a recording process on the object scene image output from the image pickup means, and a determination step for repeatedly determining whether or not the object scene image output from the image pickup means is a low-intensity image. (S13), creation step (S7, S17, S19, S23) for creating timing information indicating when the discrimination result of the discrimination step is updated from a negative result to a positive result, when a predetermined condition is satisfied The disabling step (S29, S31) for disabling the recording step, and a deletion process for deleting a part of the object scene image recorded by the recording step based on the timing information created by the creating step. Delete after disabling process Step comprises a (S39).

  Even in the control method, a low-intensity image can be easily deleted from a recorded image, as in the video camera described above.

  According to the present invention, a low-luminance image such as a dark image can be easily deleted from a recorded image.

  The above object, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

  Referring to FIG. 1, the video camera 10 of this embodiment includes an optical lens 12. The optical image of the object scene is irradiated onto the imaging surface 14f of the image sensor 14 through the optical lens 12 and subjected to photoelectric conversion. Thereby, a charge representing the object scene, that is, a raw image signal is generated.

  When the power is turned on, the CPU 30 instructs the image sensor 14 to repeat the exposure process and the charge readout process in order to execute the through image process. The image sensor 14 performs an exposure process and a process for reading out the electric charge obtained thereby. The raw image signal generated by the image sensor 14 is read in an order according to raster scanning in response to a vertical synchronization signal (Vsync) generated by a timing generator (not shown) once every 1/30 seconds.

  The raw image signal output from the image sensor 14 is subjected to processing such as A / D conversion, color separation, and YUV conversion by the camera processing circuit 16. The camera processing circuit 16 writes the thus obtained YUV format image data into the SDRAM 20 through the memory control circuit 18.

  The LCD driver 24 reads the image data stored in the SDRAM 20 through the memory control circuit 18 every 1/30 seconds, and drives the LCD monitor 26 with the read image data. As a result, a real-time moving image (through image) representing the scene is displayed on the LCD monitor 26.

  When a recording start operation is performed by the key input device 28, the CPU 30 instructs the JPEG codec 36 to perform JPEG compression. The JPEG codec 36 reads image data stored in the SDRAM 20 through the memory control circuit 18 every 1/30 seconds, compresses the read image data by the Motion-JPEG method, and compresses the compressed image data, that is, Motion-JPEG data. Are written into the SDRAM 20 through the memory control circuit 18 in units of frames. The header attached to each frame is created by the CPU 30. The header describes the frame number, creation time, etc. of the frame of interest.

  In this manner, Motion-JPEG data having the structure shown in FIG. The Motion-JPEG data in the SDRAM 20 is then read by the CPU 30 and recorded on the recording medium 40 in a file format via the I / F 38.

  In such a recording process, the luminance evaluation circuit 22 generates a luminance evaluation value indicating the brightness of the scene for each frame based on the image data output from the camera processing circuit 16, and the generated luminance evaluation value Is given to the CPU 30. The CPU 30 repeatedly determines whether or not the given luminance evaluation value is below the threshold, and the frame number at the time when the luminance evaluation value changes from a high luminance state where the luminance evaluation value exceeds the threshold to a low luminance state where the luminance evaluation value falls below the threshold. Is detected. The detected frame number is held by the flash memory 34 as the dark start frame number N.

  The CPU 30 also starts a timer T in response to the above state change, and instructs a CG (Character Generator) 32 to display a selection screen when the timer T indicates 10 seconds. The CG 32 displays the selection screen shown in FIG. On this selection screen, a notification that a dark image is being recorded and an inquiry as to whether or not to continue recording are presented. Each of the continuation operation and the interruption operation is accepted for 30 seconds from the display of the selection screen, that is, until the timer T indicates 40 seconds.

  When the operator performs a continuous operation using the key input device 28, that is, when “Yes” is selected on the selection screen, the recording process is continued.

  When the operator performs an interruption operation using the key input device 28, that is, when “NO” is selected on the selection screen, the recording process is immediately interrupted. If no operation is performed by the operator, the recording process is interrupted when the timer T indicates 40 seconds.

  As shown in FIG. 4A, the recorded image at the time of interruption includes a normal image with high luminance and a dark image following the normal image. The boundary between the normal image and the dark image is indicated by the dark start frame number N. The CPU 30 deletes the dark image after the Nth frame from the recording medium 40. As a result, the recorded image at the time of closing the file is only a normal image as shown in FIG.

  When the playback mode is selected by the key input device 28, a playback process of a desired Motion-JPEG file is executed. The CPU 30 accesses the recording medium 40 through the I / F 38 and reads the Motion-JPEG data stored in the desired Motion-JPEG file. The read Motion-JPEG data is written into the SDRAM 20 through the memory control circuit 18.

  The JPEG codec 36 reads the Motion-JPEG data from the SDRAM 20 through the memory control circuit 18, decompresses the read Motion-JPEG data, and writes the decompressed image data into the SDRAM 20 through the memory control circuit 18.

  The LCD driver 24 reads the image data stored in the SDRAM 20 through the memory control circuit 18 at the timing of Vsync, and drives the LCD monitor 26 with the read image data. As a result, the playback moving image is displayed on the monitor screen.

  When the recording start operation is performed, the CPU 30 executes the recording process shown in FIGS. The control program corresponding to these flowcharts is stored in the flash memory 34.

  Referring to FIG. 5, in step S1, an initial process is executed. In the initial process, a new file is opened in the recording medium 40 and the timer T is reset. File open processing includes processing such as file path creation and handle number assignment. In step S3, a compression start command is issued to the JPEG codec 36. Then, the process proceeds to step S5.

  The JPEG codec 36 reads out the image data stored in the SDRAM 20 through the memory control circuit 18, compresses the read-out image data by the Motion-JPEG method, and compresses the compressed image data, that is, Motion-JPEG data through the memory control circuit 18. Write to SDRAM 20 in frame units.

  In step S5, “999999” is set to the variable N. In step S7, “0” is set to the flag Ft. In step S9, it is determined whether or not the Motion-JPEG data has been written into the SDRAM 20 for one frame. If “YES” in the step S 9, the process shifts to a step S 11 to read one frame of Motion-JPEG data from the SDRAM 20 and record the read Motion-JPEG data on the recording medium 40. In this recording process, a header describing a frame number and the like is created, and the created header is stored in the file opened in step S1 (hereinafter “target file”) together with the read Motion-JPEG data. Is done.

  In step S13, a luminance evaluation value is acquired from the luminance evaluation circuit 22, and it is determined whether or not the acquired luminance evaluation value is below a threshold value. If “YES” here, the process proceeds to a step S17, and if “NO”, the process proceeds to a step S15 to further determine whether or not the flag Ft is “1”. If YES in step S15, the process returns to step S5, and if NO, the process returns to step S9.

  Referring to FIG. 6, in step S17, it is determined whether or not flag Ft is “0”. If NO, the process proceeds to step S25. If “YES” in the step S17, the process proceeds to a step S25 through a series of processes of the steps S19 to S23.

  In step S19, the current frame number, that is, the frame number described in the header in the latest step S11 is set in the variable N. In step S21, the timer T is started. In step S23, “1” is set to the flag Ft.

  Therefore, the value of the timer T indicates the duration of the state where the luminance evaluation value is below the threshold, in other words, the continuous recording time of the dark image. The variable N indicates the frame number at the moment when the luminance evaluation value falls below the threshold, that is, the image dark start frame number. The flag Ft indicates whether a dark image is being recorded or a normal image is being recorded.

  In step S25, it is determined whether or not the value of timer T has exceeded 10 seconds. If NO, the process returns to step S9. If “YES” in the step S25, the process shifts to a step S27 to display the selection screen shown in FIG. 3 on the LCD monitor 26 via the CG 32.

  Referring to FIG. 7, in step S29, it is determined whether or not the value of timer T has exceeded 40 seconds. If NO, the process proceeds to step S31. In step S31, the presence / absence of the interruption operation is determined based on the signal from the key input device 28. If NO, the process proceeds to step S33. In step S33, the presence / absence of a continuing operation is determined based on the signal from the key input device 28. If NO, the process returns to step S9.

  If “YES” in the step S33, the process returns to the step S5 after executing the process of the step S41. In step S41, the timer T is reset.

  If YES is determined in either step S29 or step S31, the series of processes in steps S35 to S39 is executed, and then the recording process is terminated.

  In step S35, a compression stop instruction is issued to the JPEG codec 36. The JPEG codec 36 stops the compression operation.

  In step S37, the frame-by-frame header (see FIG. 2) attached to the Motion-JPEG data in the recording medium 40 is searched to specify the position of the frame having the number that matches the value of the variable N, that is, the Nth frame. The Motion-JPEG data after the Nth frame is deleted from the recording medium 40 (see FIG. 4A).

  In step S41, the target file is closed. This file close process includes a process for describing the number of frames, the amount of data, and the like in the file header.

  As is apparent from the above, the video camera 10 of this embodiment includes an image sensor 14 that repeatedly outputs an object scene image. The CPU 30 of the video camera 10 performs a recording process on the object scene image output from the image sensor 14 (S11). Further, it is repeatedly determined whether or not the object scene image output from the image sensor 14 is a low luminance image (dark image) (S13), and the determination result is updated from a negative result to a positive result. Timing information (N) indicating the time is created (S7, S17, S19, S23).

  In addition, an affirmative continuation time (T) that continuously shows a positive result of the determination result is measured (S21), a time condition that the affirmative continuation time has reached the first specified time (40 seconds), and a positive continuation If any of the operation conditions that the interruption operation is performed before the time reaches the first specified time is satisfied, the recording process is disabled (S29, S31). Then, a deletion process for deleting a part of the recorded object scene image based on the created timing information is executed after the disabling process (S39).

  The timing information indicates a point in time when the object scene image output from the image sensor 14 changes to a low luminance image. A part of the recorded scene image is deleted based on such timing information. As a result, the low brightness image can be easily deleted from the recorded image.

  In addition, since the recording process is interrupted when the positive continuation time reaches the first specified time, it is possible to ensure a continuous recording operation while avoiding accumulation of low-luminance images.

  Further, the CPU 30 resets the measurement process when the continuation operation is performed before the positive continuation time reaches the first specified time (S41). Therefore, if the operator performs a continuous operation, satisfaction of the time condition is prevented. Thereby, the interruption of the recording process based on the satisfaction of the time condition is avoided, and the subsequent deletion process is not executed. In this way, it is possible to avoid deleting a low-luminance image that is meaningful to the operator.

  Further, the CPU 30 initializes the created timing information in relation to the reset process (S5). Therefore, even when the object scene image changes from a low-brightness image to a high-brightness image after a continuous operation and then changes again from a high-brightness image to a low-brightness image, accurate deletion can be performed.

  In this embodiment, the low-intensity image is deleted immediately after the recording process is stopped, but this may be executed after the file is closed. In this case, the timing information is described in the file header when the file is closed. Then, after the file is closed, for example, when the playback mode is selected, a notification that a low-brightness image has been recorded is given. If a deletion operation is performed, the low-brightness image is deleted.

  In this embodiment, the Motion-JPEG method is used for compression of moving image data, but other methods such as MPEG may be used.

It is a block diagram which shows one Example of this invention. It is an illustration figure which shows the structure of the moving image data applied to the FIG. 1 Example. It is an illustration figure which shows an example of the monitor screen applied to the FIG. 1 Example. (A) is an illustrative view showing the structure of a recorded image at the end of recording, and (B) is an illustrative view showing the structure of the recorded image when a file is closed. It is a flowchart which shows a part of CPU operation | movement applied to FIG. 1 Example. It is a flowchart which shows a part of other CPU operation | movement applied to FIG. 1 Example. It is a flowchart which shows a part of other CPU operation | movement applied to FIG. 1 Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Video camera 14 ... Image sensor 14f ... Imaging surface 18 ... Memory control circuit 20 ... SDRAM
22 ... Luminance evaluation circuit 26 ... LCD monitor 28 ... Key input device 30 ... CPU
32 ... Character generator (CG)
34: Flash memory 40: Recording medium

Claims (8)

An imaging means having an imaging surface on which an optical image representing the object scene is irradiated, and repeatedly outputting the object scene image;
Recording means for performing recording processing on the object scene image output from the imaging means;
Discriminating means for repeatedly discriminating whether or not the object scene image output from the imaging means is a low luminance image;
Creating means for creating timing information indicating a time point when the determination result of the determination means is updated from a negative result to a positive result;
A disabling unit for disabling the recording unit when a predetermined condition is satisfied, and a deletion process for deleting a part of the object scene image recorded by the recording unit based on the timing information generated by the generating unit A video camera comprising: deletion means for executing after the disabling process of the disabling means.   The video camera according to claim 1, wherein the predetermined condition includes a time condition that an affirmative continuation time in which a determination result of the determination unit continuously indicates a positive result has reached a first specified time. The video camera according to claim 2, further comprising: a measurement unit that measures the affirmative duration time; and a reset unit that resets the measurement process of the measurement unit when a continuation operation is performed.   The video camera according to claim 3, further comprising initialization means for initializing timing information created by the creation means in association with reset processing of the reset means.   The video camera according to claim 2, wherein the predetermined condition further includes an operation condition that an interruption operation is performed.   6. The information processing apparatus according to claim 3, further comprising notification means for executing a notification process for prompting an operator to perform the continuation operation at a time point when the positive continuation time reaches a second specified time shorter than the first specified time. A video camera according to any of the above. In a processor of a video camera having an imaging surface on which an optical image representing an object scene is irradiated and having an imaging means for repeatedly outputting the object scene image,
A recording step of performing a recording process on the object scene image output from the imaging means;
A determination step of repeatedly determining whether or not the object scene image output from the imaging means is a low-luminance image;
Creating step for creating timing information indicating a time point when the determination result of the determination step is updated from a negative result to a positive result;
A disabling step of disabling the recording step when a predetermined condition is satisfied, and a deletion process of deleting a part of the object scene image recorded by the recording step based on the timing information created by the creating step A control program for causing a deletion step to be executed after the disabling process of the disabling step. A control method of a video camera having an imaging surface on which an optical image representing an object scene is irradiated, and including an imaging means for repeatedly outputting the object scene image,
A recording step of performing a recording process on the object scene image output from the imaging means;
A determination step of repeatedly determining whether or not the object scene image output from the imaging means is a low-luminance image;
Creating step for creating timing information indicating a time point when the determination result of the determination step is updated from a negative result to a positive result;
A disabling step of disabling the recording step when a predetermined condition is satisfied, and a deletion process of deleting a part of the object scene image recorded by the recording step based on the timing information created by the creating step A control method, comprising: a deletion step that executes after the disabling process of the disabling step.

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