JP2005352899A - Image recording device and control method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively use a memory area in a storage medium by allowing the storage medium as an object of storage to have a plurality of partition areas and determining an optimum storage destination partition area according to which of a still picture and a moving picture an image to be recorded is. <P>SOLUTION: When a removable medium 107 is connected, a plurality of partition areas set on the removable medium 107 are discriminated, cluster sides of data storage units of each partition area are detected, and the result is stored in an information storage part 111. A system controller 108 when storing a picked-up still picture as a file on the removable medium 107 stores the still picture preferentially from a partition area having a small cluster side. When a moving picture is stored, the picture is stored preferentially from a partition area having a large cluster size. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a technique for recording a moving image or a still image on a storage medium.

  Generally, removable media store information in units of clusters. One cluster is a group of a plurality of sectors. The size of the cluster also changes depending on the file system and media capacity. Since a cluster is the smallest unit for handling a file, even if small data less than the capacity of one cluster is saved as a file, an area of one cluster is used. For this reason, if the number of files stored in one removable medium increases, the total capacity of useless areas also increases, and the total storage capacity of the removable medium cannot be utilized. In other words, if the size of one cluster is small, the wasteful consumption size is also reduced, which means that the recordable capacity can be increased.

  On the other hand, in the case of a series of large data such as a movie, if the file has the same size, the larger the capacity of one cluster, the smaller the number of clusters that make up the file. Get faster. From these facts, it can be said that the data size handled (which may be called the cluster size) and the access speed are in a trade-off relationship with each other.

A technique is known in which a user can change the optimum format of a removable medium in order to improve the access speed of the medium (Patent Document 1). Furthermore, a method is also known in which, when initializing the format of a removable medium, the user can select whether to place importance on capacity or on access speed (Patent Document 2).
Japanese Patent Laid-Open No. 11-12937 JP 2004-80461 A

  However, when using removable media in an imaging device such as a digital camera or digital video camera, the subsequent properties will be determined by the initial format, and this will be handled adaptively according to the properties of the image to be recorded. The current situation is not.

  The present invention has been made in view of such problems, and allows a storage medium to be stored to have a plurality of partition areas, and depending on whether an image to be recorded is a still image or a moving image. It is an object of the present invention to provide a technique for effectively utilizing a memory area of a storage medium by determining an optimum storage destination partition area.

In order to solve this problem, for example, an image recording apparatus of the present invention has the following configuration. That is,
An image recording device for recording still images and moving images as files on a removable and randomly accessible storage medium,
Detecting means for identifying a plurality of partition areas set in the mounted storage medium and detecting a cluster size which is a data storage unit of each partition area;
When storing a still image as a file in the storage medium, still image storage control means for preferentially storing from a partition area having a small cluster size;
When storing a moving image as a file in the storage medium, a moving image storage control unit that preferentially stores a partition area having a large cluster size is provided.

  According to the present invention, the storage medium to be stored is allowed to have a plurality of partition areas, and the optimum storage destination partition area is determined depending on whether the image to be recorded is a still image or a moving image. By determining, it becomes possible to effectively use the memory area of the storage medium.

  Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a block diagram of a digital video camera that captures and records moving images and still images in the embodiment. The configuration will be described below together with the operation process.

  External light taken from an optical unit 101 (comprising a lens, a diaphragm, a motor for driving them, etc.) 101 forms an image on the surface of the image sensor 102 and is converted into an electrical signal. This signal is supplied to the image processing unit 103 and becomes digital image data. The image data is displayed on an image display unit (liquid crystal display device) and can be confirmed as a captured image.

  When the data written to the removable medium (writable storage medium) is a moving image, the data is compressed by the moving image compression / decompression unit 105a. Is written to. Conversely, when data on the removable medium 107 is reproduced, it is decompressed by the compression / decompression units 105 a and 105 b through the media interface 106 and displayed on the video display unit 104 via the image processing unit 103. In some cases, a reproduction signal can be output from an external output terminal to an external device (external display device).

  The system controller 108 includes a microprocessor that stores a microprocessor and a program (corresponding to each flowchart described later) that is a processing procedure thereof, and a RAM that is used as a work area. The system controller 108 controls the image processing unit 103, the moving image compression / decompression unit 105a, the still image compression / decompression unit 105b, the media interface 106, and the optical unit control unit 109. In addition, the user operates the apparatus by operating various switches, buttons, dials, and the like provided on the operation unit 110. The system controller 108 can store information in the information storage unit 111 as necessary.

  FIG. 2 shows the relationship between the data structure of the removable medium and the system controller 108 in the embodiment. In the embodiment, it is assumed that the same removable medium 121 has three partition areas (areas A, B, and C) 123 to 125 and is formatted respectively. Each partition area is assumed to be formatted in FAT16, which is a standard file system for digital cameras, for example.

  Immediately after the removable medium 107 is installed in the apparatus or when the power of the apparatus is turned on, the system controller 108 recognizes the file system existing in the medium and detects the cluster sizes of the areas A to C. This detection information is stored in the information storage unit 111 and held until the removable medium is removed or the apparatus is turned off.

  In the case of the FAT16 file system, the cluster size is 32 KB when the region size is more than 1 GB to 2 GB, the cluster size is 16 KB when the region size is more than 512 MB to 1 GB, and the cluster size is 8 KB when the region size is more than 256 MB to 512 MB.

Below, the cluster size of each partition area is
A>B> C
It is assumed that the relationship is

In the case of a still image, the result of JPEG encoding of each image is stored as a file. However, since JPEG encoding generally employs variable length encoding, the JPEG file size is not fixed. Assuming that one still image data (JPEG image data) is 500 KB and is stored in a partition having a cluster size of 32 KB,
500/32 = 15 remainder 20
Thus, 16 clusters are consumed, and 12 KB (= 32-20) in 32 KB of the last cluster is consumed as a useless area.

If the cluster size is 8KB under the same conditions,
500/8 = 62 remainder 4
Thus, 63 clusters are consumed, and 4 KB in 8 KB of the last cluster becomes a useless area. That is, it can be seen that the memory size that is wasted is different depending on the cluster size.

In the case of a still image, the size is not fixed as described above. The amount of data consumed wastefully per file is half of the cluster size on average. That is, when there are N files and the cluster size is C, the amount of memory that is wasted is approximately N × C / 2.
It becomes. That is, the wasteful memory size is proportional to the cluster size and the number of files.

  In the case of a still image, each file size is smaller than that of a moving image, but the number of files tends to increase. Further, in the case of a still image, a high-speed writing / reading is not required for a removable medium as with a moving image.

  As described above, it can be understood that use of a still image storage destination in a partition area having a small cluster size can reduce wasteful memory consumption and is convenient.

  On the other hand, in the case of a moving image file, the file size depends on the imaging time, but is much larger than that of a still image. In general, the number of files tends to be smaller than that of still images. In other words, since the ratio of the wastefully consumed area to one moving image file is small, it does not matter so much even if the cluster size is large, and the cluster size is also small in terms of access speed. A larger size is desirable (the number of accesses decreases as the cluster size increases).

  Return explanation. The cluster sizes of the partition areas A, B, and C of the removable medium 107 in the embodiment have a relationship of A> B> C, and this information is stored in the information storage unit 111.

  Therefore, when writing a moving image, the system controller 108 selects the area A having the largest cluster size (and hence the fastest access speed) of the removable medium 107 as the writing destination based on the information in the information storage unit 111, and Data is recorded through the interface 106. When there is no recordable remaining capacity in the area A, when the next moving image recording starts, the area having the fastest access speed (partition area B in the embodiment) is selected from the areas other than the area A and recording is performed.

  On the other hand, when writing a still image, the system controller 108 selects a partition area C having the smallest cluster size of the removable medium 107 as a write destination based on information in the information storage unit 111 and records data through the media interface 106. To do. When there is no recordable remaining capacity in the partition area C, the partition area B having the smallest cluster size is selected from areas other than the area C and recorded when the next moving image recording starts.

  The outline of the embodiment has been described above, but details of the processing of the system controller 108 will be described below.

  First, processing in the initial stage when the power of the apparatus is turned on and when the removable medium is inserted / removed in the power-on state (detected by a sensor (not shown)) will be described with reference to the flowchart of FIG.

  First, the partition analysis of the removable media loaded in step S1 is performed, and the cluster size of each partition is detected in step S2. The cluster size can be detected from the total capacity of the partition.

  Next, the process proceeds to step S3, and information for identifying each partition (partition name or start address in the removable medium of each partition area) is stored in the information storage unit 111 in descending order of cluster size. Next, the process proceeds to step S 4, where the recording mode of each of the still image and moving image is set to “automatic recording mode” as a default, and is stored in the information storage unit 111.

  When the removable medium is inserted or removed, the information storage unit 111 is automatically rewritten. At this time, it is desirable to display a message indicating that the automatic recording mode is set as the recording mode. The reason will become clear from the description to be described later, because the user may set the order of partitions to be stored.

  FIG. 4 shows the state of the information storage unit 111 immediately after the above processing. As shown in the figure, an automatic recording mode flag is provided in the first record, and a recording mode for still images and moving images is stored (two bits are sufficient).

  Immediately after the processing of FIG. 3, the recording mode of each of the still image and the moving image is the automatic recording mode. The next second record is an area indicating the number of partitions of the removable medium. After that, the order of partitions for storing moving images and the order of partitions for storing still images are stored. The last “-” indicates a predetermined code indicating that there is no significant data thereafter. As shown in the figure, the order of the partition areas for recording the moving image and the still image is reversed.

  Normally, the information storage unit 111 may be as described above, but depending on the user, the contents of the information storage unit 111 can be changed in order to respond to a request to set a partition area for storing a moving image and a still image. I made it.

  FIG. 5A shows a menu displayed on the image display unit 104 when the menu display instruction key is pressed from the operation unit 110. As shown in the figure, menus of large items such as camera settings, card settings, audio settings, and system settings are displayed as setting items. The user operates the cross key provided on the operation unit 110 to move the cursor 50 to a desired item, and then presses the “OK” key to display a further detailed setting menu for the item. It is possible. In “camera setting”, the compression rate, the imaging resolution, and the like can be set, but here, “card setting”, that is, the case where the setting for the mounted removable medium is selected will be described. At this time, the submenu shown in FIG. Here, the partition & format, the moving image and still image recording modes are displayed as selection items, and the current mode (either auto or manual) is displayed for the moving images and still images. When the partition & format is selected, it is possible to delete a partition of the mounted removable medium, create a new one (area size), and format for creating a FAT16 file system in the partition.

  Here, a case where the “moving image recording mode” is selected will be described. When this is selected, the screen shown in FIG. 5C is displayed, and the order for recording moving images can be set. For example, since the cursor is in the partition A in the state shown in FIG. 3C, the array can be exchanged with the adjacent partition by operating the change key and the up / down key in this state. When “Auto” is selected, the set order is ignored and the cluster is rearranged in descending order of cluster size.

  When the order of recording moving images is determined in this way, if the determined order is different from the order of the default automatic mode, the flag of the moving image recording mode in the first record of the information storage unit 111 is determined. And change the area that stores the set partition order.

  Note that it is easy to understand that when the “still image recording mode” is selected in FIG. 5B, it is substantially the same as the “moving image recording mode”. Therefore, the description is omitted.

  Next, the overall processing in the imaging apparatus according to the embodiment will be described with reference to the flowchart of FIG.

  First, in step S11, an input from the operation unit 110 is awaited. If any input is made, the process proceeds to step S12 to determine whether the mode is the still image shooting mode, the moving image shooting mode, or the other mode. In the case of an instruction input other than the shooting mode, the process proceeds to step S13 to perform a corresponding process (for example, various setting processes using the menu shown in FIG. 5A).

  If it is determined in step S12 that the still image shooting mode has been instructed, processing for searching for a storage destination partition of the still image captured in step S14 is performed. Then, in step S15, it is determined whether or not the storage destination partition has been successfully searched (if there is no free space to store, the search for the storage destination partition is treated as failure). If the storage partition can be searched, the process proceeds to step S16, and a still image is captured and the captured image is encoded in response to pressing of a shutter button or the like provided on the operation unit 110, and the search is performed in step S14. Stored as a still image file in the partition area of the removable media. Note that AF, AE processing, and the like are performed at the time of imaging, but since they are not directly related to the present invention, description thereof is omitted.

  On the other hand, if the moving image shooting mode is selected, the process proceeds to step S17 to search for a moving image storage destination partition. In step S18, it is determined whether the search for the storage destination partition has succeeded. If the search for the storage destination partition is successful, the process proceeds to step S19, and moving image shooting and encoding processing and the determined removable media are performed in response to pressing of the recording start instruction button provided on the operation unit 110. Start storing video files in the partition area. Then, in step S20, moving image capturing is continued until it is determined that an instruction indicating the end of recording has been input. It should be noted that the end is also determined when the corresponding partition area becomes full while moving images are being accumulated.

  Next, the storage location search processing of the still image data storage destination partition in step S14 will be described with reference to the flowchart of FIG.

  First, in step S21, the order information of the partition area in which the still image is recorded is read from the information storage unit 111. Note that the cluster size is small unless the partition order is changed on the display screen (user interface) shown in FIG. 5C when the power is turned on or a removable medium is mounted. They are in order.

  Next, in step S22, “1” is set as an initial value for the variable i, and the first partition order of the still image storage destination stored in the information storage unit 111 is set to be different.

  In step S23, it is determined whether or not there is a free area in the i-th partition area of interest. If there is no free space, the process proceeds to step S24 to check whether or not all partitions have been checked (since in the embodiment, there are three examples, it is determined whether the variable i is “3”). judge. If this determination is negative, the variable i is increased by “1” in step S25, and the process returns to step S23. If there is no free space in all partitions, error processing (displaying a message indicating that photography is not possible, etc.) is performed, a search failure is notified to the call source of this processing, and this processing ends.

  If it is determined that there is a free area in the i-th partition area, the process proceeds from step S23 to step S27, the i-th partition area is returned to the caller as a search result, and the process ends.

  Next, the storage location search process for the storage location partition for moving image data in step S17 in FIG. 6 will be described with reference to the flowchart in FIG.

  This process is almost the same as in FIG. First, in step S31, the order information of the partition area in which the moving image is recorded is read from the information storage unit 111. As long as the order of the partitions is not changed when the power is turned on to the apparatus or after the removable media is mounted, the clusters are arranged in the descending order of the cluster size.

  Next, in step S32, “1” is set as an initial value for the variable i, and is set so that the first partition order of the moving image storage destination stored in the information storage unit 111 is added.

  In step S33, it is determined whether or not there is a free area in the i-th partition area of interest. If there is no free space, the process goes to step S34 to check whether all partitions (in the embodiment, there are three examples, so whether the variable i is “3” or not) are checked. judge. If this determination is negative, the variable i is increased by “1” in step S35, and the process returns to step S33. If there is no free space in all partitions, error processing (displaying a message indicating that photography is not possible, etc.) is performed, a search failure is notified to the call source of this processing, and this processing ends.

  If it is determined that there is a free area in the i-th partition area, the process proceeds from step S33 to step S37, the i-th partition area is returned to the caller as a search result, and the process ends.

  As described above, according to the present embodiment, in view of the fact that the number of moving image files obtained by imaging tends to be small and that the file size is large and access speed is required, the cluster size By storing in a large partition area, it is difficult to cause a problem in terms of memory use efficiency, and it becomes possible to make it difficult to occupy a still image storage area.

  On the other hand, in the case of still images, although the individual file size is much smaller than the moving image file size, in consideration of the tendency to increase the number of files to be recorded, partition with a small cluster size is preferentially stored. Thus, the memory usage efficiency of the storage medium can be improved.

  In the embodiment, the storage medium is not particularly specified, but the type is not limited as long as it is a randomly accessible and removable storage medium. For example, a semiconductor memory card or a spindle storage medium may be used.

  In the embodiment, the FAT 16 is described as an example of the partition file system provided in the storage medium. However, the present invention is not limited to this, and other file systems may be used, or different file systems may be mixed. In short, in the case of a still image, a file system with a small cluster size may be given priority, and for a moving image, a file system having the opposite property may be given priority.

  In addition, by dividing the memory area of one storage medium into a plurality of partition areas, it is possible to use a storage medium having a capacity exceeding the maximum accessible size of the file system as a secondary function. Succeed in playing. For example, FAT16 has a maximum of 2 GB due to its standard. Therefore, in the case of a storage medium having a memory capacity exceeding 2 GB, if one partition is set with FAT16, the remaining memory space becomes an unused area. In this respect, a large-capacity storage medium can be used by setting a plurality of partition areas.

It is a block block diagram of the imaging device in an embodiment. It is a figure which shows typically the access process with respect to the removable medium of the system controller in the imaging device in embodiment. 10 is a flowchart showing the processing contents when a device is turned on or a removable medium is mounted. It is a figure which shows the example of the memory content of the information storage part in embodiment. It is a figure which shows transition until it arrives at GUI for setting the partition storage order in embodiment. It is a flowchart which shows the whole process of the imaging device in embodiment. It is a flowchart which shows the detail of step S14 of FIG. It is a flowchart which shows the detail of step S17 of FIG.

Claims (4)

An image recording device for recording still images and moving images as files on a removable and randomly accessible storage medium,
Detecting means for identifying a plurality of partition areas set in the mounted storage medium and detecting a cluster size which is a data storage unit of each partition area;
When storing a still image as a file in the storage medium, still image storage control means for preferentially storing from a partition area having a small cluster size;
An image recording apparatus comprising: a moving image storage control unit that preferentially stores a moving image as a file in the storage medium, and stores the moving image with priority from a partition area having a large cluster size.   The image recording apparatus according to claim 1, further comprising an imaging unit that captures a moving image and a still image to be stored in the storage medium.   The image recording apparatus according to claim 1, wherein the detection unit is executed at an initial stage when the power of the apparatus is turned on and when a storage medium is detached. A control method of an image recording apparatus for recording still images and moving images as files on a removable and randomly accessible storage medium,
A detection step of identifying a plurality of partition areas set in the mounted storage medium and detecting a cluster size which is a data storage unit of each partition area;
When storing a still image as a file in the storage medium, a still image storage control step for preferentially storing a partition area having a small cluster size;
A method for controlling an image recording apparatus, comprising: a moving image storage control step for preferentially storing a moving image as a file in the storage medium, wherein the moving image is stored in priority from a partition area having a large cluster size.

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