JP6520566B2 - Image recording device - Google Patents

Description

  The present invention relates to recording processing of an image file obtained by an imaging device such as a camera, and more particularly to recording processing of a display image such as a thumbnail image.

  Digital cameras, video cameras, and the like can record and reproduce captured images including moving images and still images. When reproducing and displaying a recorded image, the user can select a desired image from the entire recorded image by collecting representative frame images and displaying them in a list by thumbnail display or the like. Since it takes processing time to generate a display image based on the recorded captured image, a representative frame image (for example, at the start of recording) of the captured image is selected at the same time as recording the captured image. Generate After the display image is compressed, it is recorded in the memory as display image data separately from the moving image data (for example, see Patent Document 1).

  On the other hand, in moving image editing, a user can select a representative frame image to be used for the thumbnail image, and a thumbnail file storing the thumbnail image is created separately from the moving image file, and the frame image and thumbnail image of moving image data Manage files so that they correspond. When a frame image of another scene is made a thumbnail image by editing work, a thumbnail image is generated from the frame image, and the thumbnail image entered first is updated to a new thumbnail image (see Patent Document 2).

JP 2001-238175 A Unexamined-Japanese-Patent No. 2005-33381

  When creating and recording a display image such as a thumbnail image, it is desirable to fix the storage area of the display image from the viewpoint of recording capacity limitation, ease of file management, and the like. However, the color information of the subject differs depending on the frame image, and the compression size of the display image varies depending on the selected representative frame image. Therefore, when the compressed image size of the display image to be updated is larger than the compressed image size of the recorded display image, the update processing becomes complicated.

  Therefore, it is required that the display image can be easily updated without performing complicated processing.

  The image recording apparatus according to the present invention records the photographed image in the photographed image file, and compresses the display image based on the photographed image and records the compressed image in the predetermined file, and the compression ratio of the display image And a recording control unit for adjusting. The image recording device is provided, for example, in an imaging device. The imaging apparatus includes a reproduction display processing unit that displays a plurality of display images corresponding to a plurality of recorded photographed images on a screen, and displays, for example, a list of recorded thumbnail images.

  The image recording processing unit of the present invention updates the display image stored in the display image storage area defined in the predetermined file to a display image based on another captured image. The “another captured image” constituting the display image to be updated corresponds to a frame image of another scene when recording a series of frame images according to a capturing sequence, such as moving image capturing and interval capturing. The image recording processing unit can periodically update the display image while recording the captured image. For example, the display image generated based on the captured image obtained by interval composite imaging is updated every predetermined number of times of imaging. Further, the image recording processing unit can set the display image storage area in the photographed image file at the time of the first recording of the display image.

  The recording control unit of the present invention adjusts the compression ratio of the display image so that the image size after compression processing of the new display image falls within the display image storage area. The recording control unit sets the compression rate at which the image size after compression becomes maximum at the time of the first recording of the display image, and at the time of updating the display image, the compression rate higher than the compression rate determined at the time of the first recording of the display image Can compress the display image. For example, the recording control unit sets the lowest compression rate among the plurality of compression rates determined according to the image compression method. Alternatively, the recording control unit may set a predetermined compression rate at the time of the first display image recording, and determine a compression rate higher than the compression rate determined at the time of the first display image recording at the time of display image update. it can.

  An image recording method according to the present invention records a captured image in a captured image file, compresses a display image based on the captured image and records the compressed image in a predetermined file, and adjusts the compression ratio of the display image. The display image stored in the display image storage area defined in the predetermined file is updated to a display image based on another captured image, and the image size after compression processing of the new display image is The compression ratio of the display image is adjusted so as to be within the display image storage area.

  The program according to the present invention includes an image recording processing unit that records a captured image in a captured image file, compresses the display image based on the captured image, and records the image in a predetermined file, and compression of the display image Image recording means so as to function as a recording control means for adjusting the rate, and update the display image stored in the display image storage area defined in the predetermined file to a display image based on another photographed image Function as the recording control unit so that the compression ratio of the display image is adjusted so that the image size after compression processing of the new display image falls within the display image storage area or less.

  According to the present invention, when the display image is recorded in accordance with the recording of the photographed image, the display image can be easily updated.

It is a block diagram of a digital camera which is this embodiment. It is a figure showing a thumbnail display screen. An image file created by a moving image recording process or the like is shown. FIG. 10 is a diagram showing a thumbnail image update process at the time of interval combination imaging performed by a controller including a recording medium control unit.

  Hereinafter, the digital camera according to the present embodiment will be described with reference to the drawings.

  FIG. 1 is a block diagram of a digital camera according to the present embodiment. FIG. 2 is a diagram showing a thumbnail display screen.

  In the digital camera 10, photographing, recording, reproduction, mode setting and the like are performed in accordance with input operations to the mode dial, the release button, the cross button, the execution button (all not shown) and the like. The controller 30, which includes a CPU, a RAM, and the like, outputs control signals to the image signal processing circuit 20 and the like, and performs exposure control and recording operations according to operations on the release button and other buttons detected by the release switch 37 and button switch 45. Performs operation control of the entire camera such as playback display operation. The camera operation control program is stored in a storage medium such as a ROM (not shown).

  When the power is turned on and the shooting mode is set, a through image is displayed on the LCD 60. The imaging optical system 12 forms an image of light on the image sensor 14 when light from an object is incident, whereby an object image is formed on the image sensor 14. The image sensor 14 is configured by a CCD, a CMOS sensor, etc., and color filter arrays (not shown) such as R, G, B, etc. are arranged on the light receiving surface of the image sensor 14.

  Pixel signals of one field or one frame are read from the image sensor 14 at predetermined time intervals (for example, 1/60 seconds or 1/30 seconds), and the read pixel signals are AFE circuits (not shown). Are sent to the image signal processing circuit 20 via In the image signal processing circuit 20, gain processing, color conversion processing, white balance adjustment, and the like are performed on the pixel signal. Thereby, R, G, B color image signals are generated.

  The generated R, G, B color image signals are temporarily stored in an image memory (not shown) of the controller 30, and then sent to the LCD drive circuit 39. The LCD drive circuit 39 drives the LCD 60 based on the image data, whereby a real-time moving image is displayed on the LCD 60.

  When the release button is pressed halfway, the contrast AF process is performed based on the pixel signal read from the image sensor 14. The controller 30 controls the lens driving unit 36 to drive the photographing optical system 12, and detects a focusing position at which the contrast value reaches a peak. Further, the brightness of the subject image is detected based on the pixel signal read from the image sensor 14 together with the contrast AF process, and the exposure value is calculated.

  When the release button is fully pressed, the exposure control unit 32 drives a shutter, an aperture, and the like (not shown) based on the exposure value to perform exposure control. Thus, pixel signals for one frame are read out from the image sensor 14. The image signal processing circuit 20 generates still image data based on the read pixel signals for one frame and performs compression processing. Here, compression processing is performed according to the JPEG method. The recording medium control unit 49 records the compressed still image data on the memory card 48.

  In the digital camera 10, it is possible to set a moving image mode, an interval shooting mode, a multiple exposure mode, and an interval composite shooting mode as well as a normal shooting mode. In the moving image mode, a moving image recording process is executed in response to the depression of the release button. The image signal processing circuit 20 generates image data based on pixel signals of one frame read out from the image sensor 14 at intervals of 1/30 seconds, and the Motion JPEG method, H.264, H.264, and the like. It is sequentially compressed according to a moving image compression standard such as H.264. The recording medium control unit 49 records the compressed frame image data on the memory card 48.

  When the interval shooting mode is set, when the release button is full-pressed, the shooting operation is performed according to a predetermined time interval (for example, several seconds to several tens of seconds). The recording medium control unit 49 compresses the frame image data obtained by the photographing operation performed periodically, and sequentially records the frame image data in the memory card 48. In the multiple exposure shooting mode, the shooting operation is repeatedly performed by an arbitrary number of shots, and an image obtained by combining the obtained shot images is recorded.

  When the interval composite photographing mode is set, a photographing operation combining multiple exposure and interval photographing is executed. That is, captured images obtained by interval shooting are sequentially combined with each other, and an image obtained by combining all the captured images finally is recorded. Thus, it is possible to obtain a photograph or the like in which the locus of stars extending over the entire shooting period is shown.

  When the reproduction mode is set, when the multi-screen display is set, the recorded image is displayed as a thumbnail as shown in FIG. Here, thumbnail images are displayed in the order of recording of photographed images such as still images and moving images. The size of the thumbnail image can be variously set, and the image size may be larger than that in FIG. For example, the thumbnail images may be displayed in a list in a size corresponding to about 1⁄4 of the entire LCD screen 60S. When a predetermined thumbnail image is selected by the user, image data corresponding to the thumbnail image selected from among the photographed image data recorded in the memory card 48 is restored and displayed on the entire screen 60S of the LCD 60.

  Photographed image data recorded by moving image photographing, interval photographing, and interval combination photographing are composed of a series of time-series frame images (sequence images). In the thumbnail display, thumbnail images based on representative frame images in the series of frame images are displayed. In the case of moving image shooting, a thumbnail image corresponding to a frame image obtained at the start of recording is reproduced and displayed. On the other hand, in the case of interval composite photography, a thumbnail image corresponding to the finally obtained composite image is reproduced and displayed.

  The image signal processing circuit 20 performs resolution conversion of a frame image (a typical frame image in the case of a moving image or the like) during recording processing of a still image, a moving image or the like, and generates a thumbnail image. The recording medium control unit 49 compresses the thumbnail image data and records it on the memory card 48. On the other hand, in the case of interval composite shooting, thumbnail images are generated and compressed at predetermined shooting frequency intervals, and thumbnail image data recorded on the memory card 48 is updated.

  FIG. 3 shows an image file created by a moving image recording process or the like. The image file 70 includes a header section 72 including management information and the like, a display image data section 74 storing thumbnail image data, a moving image data section 76 storing photographed image data composed of a series of frame images, and an audio It comprises a data unit 78. The size of the memory area (the display image storage area) for storing the compressed thumbnail image data provided in the display image data portion 74 is determined by the compressed image size (data capacity) when the compressed thumbnail image data is first recorded. Be done.

  In the present embodiment, in the case of interval composite shooting, the thumbnail images are sequentially updated each time a shooting operation is performed (a composite image is obtained). At this time, for the thumbnail images stored after the second shooting, the compression ratio is adjusted in the display image data unit 74 so as not to exceed the image area size determined at the time of the first storage. This will be described in detail below.

  FIG. 4 is a diagram showing a thumbnail image update process at the time of interval combination imaging performed by the controller 30 including the recording medium control unit 49. As shown in FIG. The process is started as the interval shooting operation is performed.

  In step S1, it is determined whether it is time to update the thumbnail image. Here, since the configuration is such that the thumbnail image is updated each time the predetermined number of photographing operations is reached, it is determined whether or not the predetermined number has been reached. The number of imaging operations may be determined according to the imaging interval, and may be updated for each imaging.

  If it is determined that it is the update time, a thumbnail image is created based on the obtained captured image of one frame (S2). At this time, if resolution conversion is necessary, resolution conversion processing is executed (S3, S4). Here, since the thumbnail image obtained by reducing the captured image is displayed, resolution conversion processing is performed. When the photographed image is displayed on the entire LCD screen 60S, resolution conversion may not be performed.

  In step S5, in the display image data portion 74 of the image file to which the thumbnail image is to be written, it is determined whether the display image area has already been defined, ie, whether the thumbnail image is to be written for the first time. When the thumbnail image is written for the first time, the compression process is performed on the thumbnail image obtained by resolution conversion with the compression ratio at which the image size (data capacity) after compression becomes maximum, that is, the lowest compression ratio (S6).

  The lowest compression ratio is set to the compression ratio that is the lowest among the plurality of compression ratios set by the JPEG method, that is, the ratio of the image size after compression to the image size before compression is the largest. Ru. In the JPEG method, generally, three compression rates of low compression rate, medium compression rate and high compression rate are defined, and are standardized as IJG image quality 96, IJG image quality 90, IJG image quality 75 in ascending order of compression rate. . Therefore, the IJG image quality 96 (the image size after compression is 12 to 20% of the image before compression) with the lowest compression rate is determined.

  When the thumbnail image is compressed at the lowest compression rate, the image storage area in the display image data unit 74 is determined to be the image size of the compressed thumbnail image, and the compressed thumbnail image data is stored in the image area ( S7, S8).

  On the other hand, if it is determined in step S5 that the display image area has already been determined, that is, the thumbnail image has already been recorded, the compression rate for the newly generated thumbnail image is set (S9). At this time, the compression rate is set so as not to exceed the size of the display image storage area determined in step S7. Since the lowest compression rate (maximum image size) is determined in step S6, the compression rate of the IJG image quality 90 may be set as in step S6. However, a higher compression rate (IJG image quality 90, IJG image quality 75) may be set, which is higher than that.

  When the thumbnail image is compressed based on the compression rate set in step S9, the compressed thumbnail image is overwritten and stored in the display image storage area set in step S7 (S10, S11). Since the thumbnail image is compressed at the compression rate set in step S9 to the display image storage area according to the JPEG maximum image size, the image size of the newly generated compressed thumbnail image is equal to or less than the image display storage area. Fit.

  As described above, according to the present embodiment, in the interval composite shooting, the captured image is recorded, and the resolution of the captured image is converted to generate a thumbnail image in which the image size is reduced, and the captured image file created on the memory card 48 Is recorded in the display image data section 74 of Then, the thumbnail image is periodically updated and overwritten. At this time, the compression ratio of the thumbnail image is determined so as not to exceed the display image storage area size determined at the time of the first recording.

  The storage area of the thumbnail image is set in association with the compression ratio at the time of the first recording, and the compression image is adjusted without changing or changing the display image storage area by adjusting the compression ratio at the time of updating thereafter. Processing is complete just by overwriting the image. As a result, the thumbnail image can be recorded and updated without complicated file management such as newly creating a photographed image file. In addition, since the thumbnail image is compressed with the JPEG maximum image size, even if the compressed image size slightly differs due to differences in color information of the subject between frame images such as color information, it may exceed the display image storage area. There is no

  In addition, it is also possible to arbitrarily set the compression rate at the time of storing the first thumbnail image. In this case, the thumbnail image may be compressed at a compression rate equal to or higher than that of the first time so as not to exceed the memory size of the display image storage area when the thumbnail image is updated. Moreover, it is also possible to apply a compression method other than JPEG (such as a lossless coding method).

  In the present embodiment, the thumbnail image is updated in the interval composite shooting mode, but the thumbnail image may be updated similarly to a shooting mode in which a shooting operation sequence such as interval shooting, moving image shooting, or continuous shooting is repeatedly performed. . When the thumbnail image is updated for moving image shooting, the display image area may be reduced to a predetermined size or less using a fixed bit rate. In addition, it is also possible to adjust the number of frames of the moving image to a certain size or less.

  Alternatively, the size may be made smaller than or equal to a certain size by selecting frame images which have few differences between frame images and are easily compressed. As a result, even when the user wants to change the thumbnail image in video editing, overwrite update is required without newly creating a display image area, and file management does not have to be complicated. In addition, regardless of the format of the thumbnail image, the present invention can be applied to all display images other than the captured image to be recorded, such as a representative image and a reduced image.

  The display image data portion including the display image area may be configured to be included in the header or at the end of the file, or another file storing the display image data may be created and associated with the photographed image file. Good. And it is also possible to apply to computers other than an imaging device.

10 Digital Camera (Imaging Device)
30 Controller (Recording control unit, image recording processing unit)
49 Recording medium control unit (image recording processing unit)

Claims (10)

An image recording processing unit that records a captured image in a captured image file and compresses a display image based on the captured image and records the compressed image in a predetermined file;
A recording control unit for adjusting the compression rate of the display image;
The image recording processing unit updates the display image stored in the display image storage area defined in the predetermined file to a display image based on another captured image,
The image recording apparatus, wherein the recording control unit adjusts the compression ratio of the display image so that the image size after compression processing of the new display image falls below the display image storage area.   The recording control unit sets a compression ratio at which the image size after compression becomes maximum at the time of the first recording of the display image, and at the time of display image updating, compression higher than the compression ratio set at the time of the first recording of the display image The image recording apparatus according to claim 1, wherein the display image is compressed according to the rate.   3. The image recording apparatus according to claim 2, wherein the recording control unit sets the lowest compression rate among a plurality of compression rates determined according to an image compression method.   The recording control unit sets a predetermined compression rate at the time of the first display image recording, and determines a compression rate equal to or higher than a compression rate determined at the time of the first display image recording at the time of display image update. The image recording apparatus according to claim 1.   The image recording apparatus according to any one of claims 1 to 4, wherein the image recording processing unit sets the display image storage area in the photographed image file at the time of the first recording of the display image.   The image recording apparatus according to any one of claims 1 to 5, wherein the image recording processing unit records a series of frame images according to a photographing sequence and periodically updates a display image during recording. . An imaging apparatus comprising the image recording apparatus according to any one of claims 1 to 6, wherein
An image pickup apparatus characterized in that the image recording processing unit updates a display image generated based on a photographed image obtained by interval composite photographing every predetermined number of times of photographing.   8. The image pickup apparatus according to claim 7, further comprising a reproduction display processing unit for displaying on the screen a plurality of display images corresponding to the plurality of photographed images recorded. While recording the captured image in a captured image file, the display image based on the captured image is compressed and recorded in a predetermined file,
An image recording method for adjusting a compression rate of a display image, comprising:
Updating the display image stored in the display image storage area defined in the predetermined file to a display image based on another captured image;
An image recording method comprising: adjusting a compression ratio of a display image so that an image size after compression processing of a new display image falls below the display image storage area. An imaging device,
An image recording processing unit that records a captured image in a captured image file and compresses a display image based on the captured image and records the compressed image in a predetermined file;
Function as recording control means for adjusting the compression rate of the display image,
It functions as the image recording processing means so as to update the display image stored in the display image storage area defined in the predetermined file to a display image based on another captured image,
A program which functions as the recording control unit so as to adjust the compression ratio of the display image so that the image size after compression processing of the new display image falls below the display image storage area.

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