JP2007221722A - Image processing apparatus and control method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processing apparatus capable of reproducing and displaying an image while suppressing the reduction of operation processing even with a little memory capacity. <P>SOLUTION: A data size of an image to be displayed is confirmed. Based on a relation between the size of image data and a plurality of preset threshold values, it is then judged whether to perform batch read and decode processing, to perform processing while dividing the image data or to display an error message. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image processing apparatus and a control method thereof, and more particularly to an image reproduction processing technique thereof.

  Conventionally, digital cameras that record and reproduce still images and moving images are widely used for semiconductor memory cards and card-type magnetic recording media. Many digital cameras are provided with a display device. By sequentially displaying images taken in real time on the display device, the display device can be made to function as an electronic viewfinder. This display device is also used when a captured image is reproduced and displayed.

  For example, in an operation mode (playback mode) in which captured images are reproduced and displayed, images stored in the recording medium can be freely browsed by button operation.

  In recent years, the number of pixels of a digital camera has increased, and the data size of a captured image has been increasing. However, the price of a digital camera has decreased. When reproducing and displaying a photographed image, a memory area for reading and developing image data from a recording medium is required. In order to reproduce and display a large-sized image, a large-capacity memory corresponding to the large-sized image is required, which causes an increase in cost. However, the price of digital cameras is decreasing and it is not easy to incorporate a large capacity memory.

  In order to perform the reproduction display process at high speed, it is desirable to read the target image data collectively into the memory and perform processes such as decoding and resizing. However, depending on the capacity of the built-in memory, there may occur a situation where the entire image data cannot be read into the built-in memory.

JP 2000-69417 A JP 2005-92007 A

  Various proposals have been made regarding the handling of large-size images. For example, Patent Document 1 discloses a technique in which an image data file is divided and recorded on an external recording medium and displayed in divided units. It has also been proposed that the position of the displayed image in the entire image can be confirmed.

  Patent Document 2 proposes a technique for displaying an image that is extremely large compared to the screen size of a display device and then displaying only a portion necessary for display. However, the techniques described in Patent Document 1 and Patent Document 2 are processes for displaying only a part of a large image, not for displaying the whole.

  As a method for realizing reproduction / display processing of a large image with a small memory capacity, there is a method (divided decoding) of image data reproduction / display processing in units that can be processed by the capacity of a built-in memory. However, there is a problem that processing time is required because it is necessary to repeat processing such as data reading, decoding, and resizing a plurality of times until display of the entire image is completed. In addition, since the data size of the image changes depending on parameters that can be set by the user, such as the encoding compression rate of the captured image and the number of pixels, if division decoding is performed for reproduction of all captured image data, unnecessary processing is performed. There is also a problem that it is slow and slow to use.

  The present invention has been made to solve the above-described problems of the prior art, and provides an image processing apparatus and a control method thereof that can suppress a decrease in reproduction display processing speed even with a small memory capacity. With the goal.

  The above-described object is an image processing apparatus that can read out an image stored in a storage medium and display it on a display device, and reads out the entire image to be displayed from the storage medium and displays it on the display device. A first processing means for performing a second display process for reading out images to be displayed in a plurality of times from a storage medium and sequentially displaying the read partial images on a display device; A third processing unit for performing a third display process for displaying an error message on the display device; a size acquiring unit for acquiring a file size of an image to be displayed; and a file size equal to or less than a predetermined first threshold value In the case of the first processing means, the file size is larger than the first threshold value, and if the file size is equal to or smaller than the second threshold value having a value larger than the first threshold value, the second processing means is designated as the file size. But, Is larger than the second threshold value is achieved by the image processing apparatus of the present invention characterized by a control means to perform the display process of the image data to be displayed using the third processing means.

  Another object of the present invention is to provide an image processing apparatus control method capable of reading an image stored in a storage medium and displaying the image on a display apparatus. The entire image to be displayed is read from the storage medium and displayed on the display apparatus. A first processing step for performing a first display process; and a second processing for performing a second display process for reading an image to be displayed in a plurality of times from a storage medium and sequentially displaying the read partial images on a display device. , A third processing step for performing a third display processing for displaying an error message on the display device, a size acquisition step for acquiring a file size of an image to be displayed, and a file size are determined in advance. If the file size is greater than the first threshold and less than the second threshold having a value greater than the first threshold, And a control step for performing a display process of image data to be displayed using the third process step when the file size is larger than the second threshold. This can also be achieved by the control method of the image processing apparatus of the present invention.

  With such a configuration, according to the present invention, it is possible to realize an image processing apparatus capable of suppressing a decrease in reproduction display processing speed even with a small memory capacity.

Hereinafter, the present invention will be described in detail based on preferred embodiments with reference to the drawings.
FIG. 1 is a diagram illustrating a configuration example of a digital still camera (DSC) as an example of an image processing apparatus according to an embodiment of the present invention.

(Configuration of DSC)
10 is a photographing lens, 12 is a shutter having an aperture function, 14 is an image sensor such as a CCD or CMOS sensor that converts an optical image into an electrical signal, and 16 is an A / A that converts an analog signal output of the image sensor 14 into a digital signal. D converter.

The timing generator 18 supplies a clock signal and a control signal to the image sensor 14, the A / D converter 16, and the D / A converter 26, and is controlled by the memory controller 22 and the system controller 50.
The image processing unit 20 performs predetermined pixel interpolation processing and color conversion processing on the data from the A / D converter 16 or the data from the memory control unit 22.

  Further, the image processing unit 20 performs predetermined calculation processing using the captured image data. Then, based on the obtained calculation result, the system control unit 50 controls the exposure control unit 40 and the distance measurement control unit 42, and TTL (through the lens) AF (autofocus), AE (automatic exposure). , EF (flash pre-emission) function is realized.

Further, the image processing unit 20 performs predetermined calculation processing using the captured image data, and also performs TTL AWB (auto white balance) processing based on the obtained calculation result.
The memory control unit 22 controls the A / D converter 16, the timing generation unit 18, the image processing unit 20, the image display memory 24, the D / A converter 26, the memory 30, and the compression / decompression unit 32.

  The output data of the A / D converter 16 is sent to the image display memory 24 or the memory 30 via the image processing unit 20 and the memory control unit 22 or the output data of the A / D converter 16 is directly sent to the memory control unit 22. Is written to.

Display image data written in the image display memory 24 is displayed by an image display unit 28 such as an LCD or an organic EL display via a D / A converter 26. If the captured image data is sequentially displayed on the image display unit 28, an electronic viewfinder (EVF) function can be realized.
The image display unit 28 can arbitrarily turn on / off the display according to an instruction from the system control unit 50. When the display is turned off, the power consumption of the DSC 100 can be greatly reduced.

The memory 30 is a storage device for storing captured still images and moving images, and has a storage capacity sufficient to store a predetermined number of still images and a predetermined time of moving images. Therefore, even in continuous shooting or panoramic shooting in which a plurality of still images are continuously shot, it is possible to write a large amount of images to the memory 30 at high speed.
The memory 30 can also be used as a work area for the system control unit 50.

  The compression / decompression unit 32 reads an image stored in the memory 30, performs well-known data compression processing or decompression processing using adaptive discrete cosine transform (ADCT), wavelet transform, etc., and stores the processed data in the memory 30. Write to.

The exposure control unit 40 controls the shutter 12 having a diaphragm function, and also has a flash light control function in cooperation with the flash 48.
The distance measurement control unit 42 controls focusing of the photographing lens 10, and the zoom control unit 44 controls zooming of the photographing lens 10. The barrier control unit 46 controls the operation of the protection unit 102 that is a lens barrier for protecting the photographing lens 10.

The flash 48 functions as an auxiliary light source at the time of photographing and also has a light control function. It also has a function of projecting AF auxiliary light.
The exposure control unit 40 and the distance measurement control unit 42 are controlled using the TTL method. Based on the calculation result obtained by calculating the captured image data by the image processing unit 20, the system control unit 50 performs the exposure control unit 40 and the distance measurement. The controller 42 is controlled.

  The system control unit 50 is a CPU, for example, and controls the entire DSC 100 by executing a program stored in the memory 52. The memory 52 stores constants, variables, programs, etc. for operating the system control unit 50.

  The display unit 54 is configured by a combination of output devices such as an LCD, an LED, and a speaker, for example, and outputs an operation state, a message, and the like using characters, images, sounds, and the like in accordance with execution of a program by the system control unit 50. . One or a plurality of display units 54 are installed at a position in the vicinity of the operation unit 70 of the DSC 100 that is easily visible. A part of the display unit 54 is installed in the optical viewfinder 104.

  The display content of the display unit 54 includes, for example, single shot / continuous shooting display, self-timer display, compression rate display, recording pixel number display, recording number display, remaining image number display, shutter speed display, aperture value display, Exposure compensation display, flash display, red-eye reduction display, macro shooting display, buzzer setting display, clock battery level display, battery level display, error display, information display with multiple digits, and attachment / detachment status of recording media 200 and 210 Display, communication I / F operation display, date / time display, connection status display with external computer, focus display, shooting preparation completion display, camera shake warning display, flash charge display, recording medium writing operation display, etc. is there. A part of this is displayed in the optical viewfinder 104.

  Further, among the display contents of the display unit 54, what is displayed by an LED or the like includes, for example, in-focus display, shooting preparation completion display, camera shake warning display, camera shake warning display, flash charge display, flash charge completion display, recording medium There are a writing operation display, a macro shooting setting notification display, a secondary battery charge state display, and the like.

Of the display contents of the display unit 54, what is displayed by a lamp or the like includes, for example, a self-timer notification lamp. This self-timer notification lamp may be used in common with AF auxiliary light.
The nonvolatile memory 56 is an electrically erasable / recordable memory, and for example, an EEPROM or the like is used.

  The power ON / OFF switch 59, the mode dial 60, the shutter switches 62 and 64, the image display ON / OFF switch 66, the flash setting button 68, and the operation unit 70 are operations for inputting various operation instructions to the system control unit 50. Constituting means, consisting of one or a plurality of combinations such as buttons, switches, dials, touch panels, pointing by line-of-sight detection, and voice recognition devices.

Here, a specific description of these operating means will be given.
The power ON / OFF button 59 is a switch for instructing power ON / OFF of the DSC 100.
The mode dial switch 60 is a switch for switching and setting each function mode such as an automatic shooting mode, a program shooting mode, a panoramic shooting mode, a playback mode, a multi-screen playback / erase mode, and a PC connection mode.

  The first shutter switch SW1 (62) is turned on during halfway operation of a shutter button (not shown) provided in the DSC 100, and AF (autofocus) processing, AE (automatic exposure) processing, AWB (automatic) Instructs the start of operations such as white balance processing and EF (flash pre-emission) processing.

  The second shutter switch SW2 (64) is turned on when the operation of a shutter button (not shown) is completed (fully pressed), and the signal read from the image sensor 12 is stored in the memory 30 via the A / D converter 16 and the memory control unit 22. Exposure processing to be written as image data, development processing using computations in the image processing unit 20 and memory control unit 22, image data is read from the memory 30, compressed by the compression / decompression unit 32, and recorded on the recording medium 200 or 210. It instructs the start of a series of processes called recording processes for writing data.

  The image display ON / OFF switch 66 is a display ON / OFF setting switch of the image display unit 28. When shooting using the optical viewfinder 104, it is possible to save power by turning off the display of the image display unit 28 made of, for example, a TFT LCD or the like to cut off the current supply.

  The quick review ON / OFF switch 68 sets a quick review function for automatically reproducing image data taken immediately after photographing. In the present embodiment, in particular, a function for setting a quick review function when the image display unit 28 is turned off is provided.

  The operation unit 70 includes various buttons, a touch panel, and the like. A menu button, a set button, a macro button, a multi-screen playback page break button, a single shooting / continuous shooting / self-timer switching button, a menu movement + (plus) button, a menu movement− There are a (minus) button, a playback image shift + (plus) button, a playback image shift- (minus) button, a shooting image quality selection button, an exposure correction button, a date / time setting button, a compression mode switch, and the like.

  The compression mode switch is a switch for selecting a compression rate for JPEG (Joint Photographic Expert Group) compression, or for selecting a RAW mode in which a signal from an image sensor is directly digitized and recorded on a recording medium.

  In the present embodiment, for example, a normal mode and a fine mode are prepared as JPEG compression modes. The user of the DSC 100 can shoot by selecting the normal mode when importance is attached to the data size of the photographed image and the fine mode when importance is attached to the image quality of the photographed image.

  In the JPEG compression mode, the compression / decompression unit 32 reads the image data written in the memory 30, compresses it to the set compression rate, and then records it on the recording medium 200, for example.

  In the RAW mode, the image data is read as it is for each line according to the pixel arrangement of the color filter of the image sensor 14, and the image data written in the memory 30 is read via the A / D converter 16 and the memory control unit 22. Read and record on the recording medium 200.

  The power supply control unit 80 includes a battery detection unit, a DC-DC converter, a switch unit that switches a block to be energized, and the like, detects whether or not a battery is installed, the type of battery, and the remaining battery level. The DC-DC converter is controlled based on an instruction from the system control unit 50, and a necessary voltage is supplied to each unit including the recording medium for a necessary period.

  The power source 86 includes a primary battery such as an alkaline battery or a lithium battery, a secondary battery such as a NiCd battery, a NiMH battery, or a Li battery, or an AC adapter, and is attached to the DSC 100 by connectors 82 and 84.

  The recording media 200 and 210 such as a memory card and a hard disk have recording units 202 and 212 constituted by a semiconductor memory and a magnetic disk, interfaces 204 and 214 and connectors 206 and 216 with the DSC 100. The recording media 200 and 210 are attached to the DSC 100 via media-side connectors 206 and 216 and DSC 100-side connectors 92 and 96. Interfaces 90 and 94 are connected to the connectors 92 and 96. Whether or not the recording media 202 and 212 are attached is detected by the recording medium attachment / detachment detection unit 98.

In the present embodiment, the DSC 100 is described as having two systems of interfaces and connectors for attaching a recording medium. However, any number of interfaces and connectors for attaching a recording medium can be provided. Different standard interfaces and connectors may be used for each system.
As the interface and connector, for example, a PCMCIA card, a CF (Compact Flash (registered trademark)) card, or the like conforming to a standard can be used.

  Further, when the interfaces 90 and 94 and the connectors 92 and 96 are configured using a PCMCIA card, a CF (Compact Flash (registered trademark)) card, or the like, a LAN card, a modem card, a USB card, IEEE1394. Image data and management information attached to image data are transferred to and from peripheral devices such as other computers and printers by connecting various communication cards such as cards, P1284 cards, SCSI cards, and PHS communication cards. I can meet each other.

The barrier 102 covers the imaging unit including the lens 10 of the DSC 100, thereby preventing the imaging unit from being dirty or damaged.
The optical finder 104 is, for example, a TTL finder, and forms an image of a light beam that has passed through the lens 10 using a prism or a mirror. By using the optical viewfinder 104, it is possible to take a picture without using the electronic viewfinder function of the image display unit 28. Further, as described above, some functions of the display unit 54 such as an in-focus display, a camera shake warning display, a flash charge display, a shutter speed display, an aperture value display, an exposure correction display, etc. are provided in the optical viewfinder 104. Information is displayed.

The communication unit 110 performs various communication processes such as RS232C, USB, IEEE1394, P1284, SCSI, modem, LAN, and wireless communication.
A connector (antenna in the case of wireless communication) 112 connects the DSC 100 to other devices via the communication unit 110.

FIG. 2 is a perspective view showing an example of the appearance of the DSC according to the present embodiment having the configuration described in FIG. 1, and shows a state where the DSC is viewed from the back side.
The power button 59 is used to start and end the DSC 100. A menu button 112 is used to instruct display of a setting menu such as change of shooting conditions, date setting, image protection or deletion. The menu button 112 may also be used to end various setting modes.

  The determination button 113 is used for determining a selection item or executing an instruction on a menu screen or the like. The display button 114 is used for an instruction to switch display / non-display of shooting information regarding an image or display / non-display of the electronic viewfinder. The left button 115 is used for moving the selection item to the left or for image forwarding. The right button 116 is used for moving the selection item to the right or for image forwarding. The up button 117 is used to move the selection item up. The lower button 118 is used to move the selection item downward. The shutter button 119 is a button used at the time of shooting, and the two switches SW1 (62) and SW2 (64) are provided therein as described above. The zoom button 110 is a button for driving the zoom lens, and the zoom control unit 44 changes the angle of view of the zoom lens in response to the left and right movement. The mode switch 60 is used for switching between the photographing mode and the reproduction mode. Reference numeral 28 denotes an image display unit, which is used as EVF in the shooting mode and for displaying a shot image in the playback mode. A GUI for performing various settings and the like is also displayed on the image display unit 28.

Next, an image display processing operation in the DSC 100 of the present embodiment will be described using the flowchart of FIG.
The image display process is executed when an image recorded on the recording medium 200 or 210 is displayed in the playback mode, for example.

  It is assumed that the image is encoded and recorded in a predetermined data file format (for example, JPEG format) together with the attached information. In the recording media 200 and 210, the data file of each image is recorded in a directory structure according to a predetermined file system standard such as DCF.

  First, the system control unit 50 acquires the file size of an image to be displayed (S301). The file size may be acquired in any way, but can be inquired from the OS or file management program running on the DSC 100 or can be obtained from information recorded in the file header.

  Next, the system control unit 50 compares the acquired file size with a preset decoding upper limit size (first threshold) (S302). If the file size is smaller than the decoding upper limit size, the normal decoding upper limit size (second threshold value) is further compared in S303.

  If it is determined in S303 that the file size is larger than the normal decoding upper limit size, the decoding and display are performed for each predetermined size, thereby performing division decoding for decoding and displaying the entire image. In S304, the image division unit (block size) is set to 512 kilobytes (KB), and the variable N indicating the number of loops is set to 0.

  Then, the system control unit 50 reads the file into the work area of the memory 30 by the block size from the (N × block size) position of the file (strictly, the actual image data portion) (S305). Note that a work area used for reading a file is assigned an area that does not overlap with an area used for a file cache described later, preferably an area that is not adjacent.

  Next, the system control unit 50 uses the compression / decompression unit 32 to perform decoding processing on the read partial image, and stores the decoding result in the memory 30 (S306). Then, the system control unit 50 resizes the partial image at a scale that allows the entire image to fit within the display size of the image display unit 28 (S307). Further, the resized partial image data is written in the corresponding area of the image display memory 24 and displayed (S308).

  After the display, the system control unit 50 determines whether or not the entire image has been decoded and displayed (S309). If there is a part that has not been decoded yet, the system control unit 50 adds 1 to the variable N in S328, returns to S305, and repeats the above-described division decoding process. On the other hand, if the decoding and display of the entire image has been completed, the process ends.

  If it is determined in step S303 that the file is smaller than the normal decoding upper limit size, the entire file is decoded at once. First, the system control unit 50 reads the entire file into the file cache area of the memory 30 (S310), decodes the entire image using the compression / decompression unit 32 (S311), and writes it to the work area of the memory 30. Thereafter, the system control unit 50 resizes the decoded image in accordance with the display size of the image display unit 28 (S312), writes it in the image display memory 24, and displays it (S321).

  In S302, when the file size is larger than the decoding upper limit size, the system control unit 50 reads a thumbnail from the image file. The thumbnail is an image used as a heading of the main image, and usually has a sufficiently small file size than the main image. In addition, for example, in a JPEG format file or an Exif format image file, thumbnails are recorded separately from the main image, so there is no need to generate thumbnails from the main image.

The system control unit 50 reads a thumbnail from the image file into the file cache area of the memory 30 (S313). If the thumbnail is compressed and encoded, it is decoded (S314) using the compression / decompression unit 32. Furthermore, if the thumbnail size is larger than the display size of the image display unit 28, the system control unit 50 resizes the thumbnail to a size smaller than the display size so that the thumbnail is recognized (S315). Then, the bitmap data of a message that the main image is too large to display the main image is written into the image display memory 24 and displayed (S316).
If the thumbnail is uncompressed data, or if the thumbnail is smaller than the display size of the image display unit 28, the processing of S315 and S316 may be skipped.

FIG. 4 schematically shows a display process according to the size of the image file, which is realized by the process of FIG.
Images 401, 403, and 405 having different sizes are displayed as display target images. The decoding upper limit size is 6 MB, and the normal decoding upper limit size is 4 MB. In this case, an image 401 having a file size of 3 MB is displayed by performing a normal decoding process (S310, S311, S312 and S321) (402). An image 403 having a file size of 5 MB normally exceeds the code upper limit size and cannot be normally decoded. However, since it is smaller than the decoding upper limit size, the division decoding process (S304 to S308, S320) is performed, and sequentially displayed in block size units (404). Since the image 405 having a file size of 10 MB exceeds the decoding upper limit size, a thumbnail display process (S313 to S316) is performed to notify that the main image cannot be displayed by displaying a thumbnail and a message (406).

  As described above, according to the present embodiment, by changing the size of the decoding unit in accordance with the data size of the display target image, high-speed display processing can be realized within the range allowed by the capacity of the built-in memory. It is also possible to display an image having a size that cannot be displayed by the batch decoding process. Furthermore, since thumbnails are displayed for images of a size that cannot be displayed even by the division decoding process, the user can check at least an outline of the images.

  In addition, since the image processing apparatus automatically performs such a change in display method, the user only has to give a normal reproduction instruction without worrying about the size of the image. In addition, even an image captured by another imaging device having a large number of recording pixels can be browsed by attaching a recording medium and setting the playback mode, which is convenient.

  Note that the image processing apparatus according to the present embodiment is configured so that a file cache area is provided in the memory 30 and an image that can be normally decoded is read into the file cache. The following is a supplementary explanation of the use of this file cache and the effects thereof.

  5 and 6 are schematic diagrams showing a flow of file cache processing in the image processing apparatus of the present embodiment. Here, a file cache area of the memory 30 and a control program for controlling file read / write using the file cache area are schematically shown as a file cache 501.

  As shown in FIG. 5, the system control unit 50 instructs the file cache 501 to read a file when it is necessary to read an image (file A). If the instructed file exists in the cache, the file cache 501 returns the start address of the memory from which the file is read to the system control unit 50.

  As shown in FIG. 6, when there is an instruction to read file A, the file cache 501 refers to the file cache area 601 and checks whether the file A exists. If the file A has not been read, the file A is read from the recording medium and read into the file cache area 601 (602). Then, the head address of the file A (602) in the file cache area 601 is returned. Next, when reading of the file A is instructed, the head address of the file A (603) already read in the cache area 601 is returned without accessing the recording medium. As a result, it is possible to speed up the process when reading the file read once.

  By using such a file cache and pre-reading the image in the file cache, the image processing apparatus of the present embodiment executes the reproduction process at a high speed and improves the convenience for the user.

FIG. 7 shows an overview of the prefetch process.
The pre-reading process is a process of reading an image that can be instructed to be displayed next into a file cache in advance in order to realize high-speed image browsing. For example, it is assumed that file A (701), file B (702), and file C (703) are continuously present in the recording medium, and file B (702) is currently displayed. In this case, the file A (701) and the file C (703) that can be the next display target images by reading the left and right buttons are read into the file cache. As a result, it is possible to realize display processing that is significantly faster than accessing the storage medium after the display image switching is displayed and reading the image.

FIG. 8 is a flowchart for explaining the operation of the prefetch process.
This process is started in parallel with the process of S311 after the process of S310 is completed in FIG. 3, for example.

  First, the system control unit 50 reads the size of the file A to be prefetched (S801). Then, similarly to S303, the file size is compared with the normal decoding upper limit size (S802). If the size of the prefetch target file A is larger than the normal decode upper limit size, the prefetch process is stopped. If the normal decoding upper limit size is not reached, the system control unit 50 reads the file A from the storage medium into the file cache (S803).

  When the reading is completed, the system control unit 50 acquires the size of the next prefetch target file C (S804) and compares it with the normal decoding upper limit size (S805). When the size of the prefetch target file C is larger than the normal decoding upper limit size, the prefetch process is stopped. When the size is less than the normal decoding upper limit size, the system control unit 50 reads the file C from the storage medium into the file cache (S806).

  When the left button 115 is pressed, the file A is read from the cache and the above-described reproduction process is performed. In this case, since it is not necessary to perform the process of S310 and the decoding process of S311 can be performed immediately, the file A can be displayed immediately. Similarly, when the right button 116 is pressed, file C display processing is performed.

  If the display target image changes, prefetch processing is performed for a new adjacent image accordingly. However, as described above, in the present embodiment, since the display target image is read into the cache, among the adjacent files to be prefetched in the display state of the file A, the file B has already been read. Therefore, prefetch processing is actually performed only on the image before file A.

Needless to say, the number of images to be prefetched may be increased according to the capacity of the cache.
As described above, by using the file cache and the prefetching process, the response of the reproduction display process is improved, and the usability of the user can be improved.

In this embodiment, the block size is 512 KB, but it is also possible to allow the user to make settings within the range allowed by the memory capacity.
Of course, there is no problem even if the recording media 200 and 210 are composed of a micro DAT, a magneto-optical disk, an optical disk such as a CD-R or CD-WR, a phase change optical disk such as a DVD, or the like.

  Of course, there is no problem even if the recording media 200 and 210 are composite media in which a memory card and a hard disk are integrated. Further, there is no problem even if a part of the composite medium is detachable.

  In the description of the embodiment, the recording media 200 and 210 have been described as being separated from the DSC 100 and can be arbitrarily connected. However, any or all of the recording media remain fixed to the DSC 100. Of course there is no problem.

Further, the recording medium 200 or 210 may be connected to the DSC 100 in an arbitrary number or plural numbers.
In the above description, the recording media 200 and 210 are mounted on the DSC 100. However, the recording medium may have any combination of a single or a plurality of recording media.

It is a figure which shows the structural example of the digital still camera as an example of the image processing apparatus which concerns on embodiment of this invention. It is a perspective view which shows the external appearance example of DSC which has the structure demonstrated in FIG. It is a flowchart explaining the image display processing operation in DSC100 which concerns on embodiment of this invention. It is a figure which shows typically the display process according to the magnitude | size of the image file implement | achieved by DSC100 which concerns on embodiment of this invention. It is a figure which shows the outline | summary of the file cache which DSC100 which concerns on embodiment of this invention uses. It is the schematic which shows the flow of a process of the file cache in DSC100 which concerns on embodiment of this invention. It is a figure which shows the outline | summary of the prefetch process in DSC100 which concerns on embodiment of this invention. It is a flowchart explaining operation | movement of the prefetch process in DSC100 which concerns on embodiment of this invention.

Claims (6)

An image processing device capable of reading an image stored in a storage medium and displaying the image on a display device,
A first processing means for performing a first display process of reading an entire image to be displayed from the storage medium and displaying the image on the display device;
A second processing means for performing a second display process of reading an image to be displayed in a plurality of times from the storage medium and sequentially displaying the read partial images on the display device;
Third processing means for performing a third display process for displaying an error message on the display device;
Size acquisition means for acquiring the file size of the image to be displayed;
When the file size is equal to or smaller than a predetermined first threshold value, the first processing means is used, and the file size is larger than the first threshold value and has a value larger than the first threshold value. Display of the image data to be displayed using the second processing means when the threshold is less than or equal to 2, and the third processing means when the file size is larger than the second threshold. An image processing apparatus comprising: control means for performing processing.   The image processing apparatus according to claim 1, wherein the third processing unit reads a thumbnail of the image to be displayed from the storage medium and displays the thumbnail together with the error message. A first storage area for storing an image read by the first or third processing means; a second storage area for storing an image read by the second processing means; Further has a memory means allocated,
The image processing apparatus according to claim 1, wherein the first storage area and the second storage area are assigned so as not to overlap each other.   When it is decided to display by the first processing means, at least one image that may be displayed next is read out from the storage medium and stored in the first storage area. 4. The image processing apparatus according to claim 3, further comprising pre-reading means.   The prefetching unit acquires a file size by the size acquisition unit for at least one image that may be displayed next, and performs the reading when the file size is larger than the first threshold. The image processing apparatus according to claim 4, wherein there is no image processing apparatus. An image processing apparatus control method capable of reading an image stored in a storage medium and displaying the image on a display apparatus,
A first processing step of performing a first display process of reading an entire image to be displayed from the storage medium and displaying the image on the display device;
A second processing step of performing a second display process of reading an image to be displayed in a plurality of times from the storage medium and sequentially displaying the read partial images on the display device;
A third processing step for performing a third display process for displaying an error message on the display device;
A size acquisition step of acquiring a file size of an image to be displayed;
When the file size is equal to or smaller than a predetermined first threshold value, the first processing step is performed. The file size is larger than the first threshold value and has a value larger than the first threshold value. Display the image data to be displayed using the second processing step when the threshold value is equal to or smaller than the threshold value of 2, and use the third processing step when the file size is larger than the second threshold value. And a control step for performing the processing.