JP2005124078A - Reduced image creation method and mobile information apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To dynamically determine a capacitance of a thumbnail image so as not to generate a cluster gap when creating the thumbnail image. <P>SOLUTION: When storing an image, a cluster gap (k) is calculated from a main image and image information and when it is greater than or is the same as a predetermined minimum thumbnail image capacitance (m), a thumbnail image capacitance (n) is changed into the same value as the cluster gap (k). When it is smaller than the minimum thumbnail image capacitance (m), on the other hand, the thumbnail image capacitance (n) is changed into a value that is the sum of the cluster gap (k) and a single cluster size (j). After the size of the thumbnail image is thus determined, a thumbnail image is created and stored in accordance with the thumbnail image capacitance (n). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a reduced image creation method and a portable information device that do not create a cluster gap when creating a thumbnail image from an input image.

2. Description of the Related Art In recent years, mobile information devices such as mobile phones, digital cameras, and PDAs that have a means for inputting an image and have a storage device that can store the input image have been widely used. In such a portable information device, an image of a subject photographed by a camera can be stored and transmitted to another device or printed. When a desired image is selected from a large number of stored images and output, there is a device that creates and stores thumbnail images (reduced images) in advance for use as an output candidate list ( For example, Patent Document 1).

Saving of image data including thumbnail images in a conventional portable information device will be described with reference to FIGS.

FIG. 7 is a block diagram showing a schematic configuration of a conventional mobile phone. Conventional mobile phones
CPU 101, display unit 102, storage unit 103, operation unit 104, communication unit 105, antenna 1
06, the camera 107, and the like. As processing of the image, when an operation for capturing an image (shutter operation) is performed by the operation unit 104 in a state where an image read by the camera 107 is displayed on the display unit 102, the CPU 101 receives the image from the camera 107. The image is read and stored in the storage unit 103. Therefore, when a thumbnail image creation operation is performed on the image stored in the storage unit 103 using the display unit 102 from the operation unit 104, a plurality of captured images are edited so that they can be displayed as a list. In the conventional thumbnail image creation operation, a thumbnail image is created by thinning out a predetermined thumbnail image pixel size in the mobile phone and compressing the thumbnail image by a predetermined compression rate.

Next, FIG. 8 shows a case where new image data 202 having a main image 202b, image information 202a of the main image, and thumbnail images 202c for list display is stored in the storage unit 103. This shows the storage form.

Here, the size of one cluster in the storage unit 103 (the size of one block, hereinafter referred to as one cluster size) is assumed to be 1 kilobyte. Then, a state in which new image data 202 is stored while existing image data 201 is already stored is shown. The new image data 202 includes 128-byte image information 202a and a 5800-byte main image 202b.
And a 600-byte thumbnail image 202c.

In the storage unit 103, file management is performed in cluster units, so one file is 1
It is an integer multiple of the cluster size. In addition, when storing new image data 202, it is necessary to store the image information 202a, the main image 202b, and the thumbnail image 202c as the same file information in the empty area 203. Remembered.

Considering the storage area of the new image data 202, the total image data amount is 6528 bytes (128 + 5800 + 600), and one cluster size is 1 kilobyte. Are stored in the front-end format. Therefore,
A free area of 472 bytes (7000-6528) is a part that cannot be stored as a cluster gap 202d and cannot be used as another file.
Japanese Patent No. 3072852 (FIG. 2A, FIG. 2B, page 5, page 6)

In this conventional portable information device, when image data including thumbnail images is stored in the storage unit, it is stored in units of clusters. Therefore, when saving image data that is less than an integral multiple of one cluster size, an empty area is generated, nothing is stored as a cluster gap, and it cannot be used as another file. Therefore, a portable information device having a small storage unit has a problem that a valuable storage area cannot be effectively used.

Accordingly, the present invention has been made to solve the above-described problems, and the capacity of the thumbnail image is dynamically changed according to one cluster size or cluster gap so that the storage area of the storage unit in the portable information device can be effectively used. An object of the present invention is to provide a portable information device having a reduced image creation method and a reduced image creation function that can be changed to

In order to achieve the above object, a reduced image creation method of the present invention is a method for creating a reduced image from image data stored in a storage means each composed of a plurality of clusters having the same capacity, Obtaining a number of clusters required for storing image data in the storage means, calculating a capacity at which the image data is not written with a capacity of the obtained number of clusters, and the calculated capacity is determined in advance. If the calculated capacity is equal to or larger than the threshold value, a step of creating a reduced image using the calculated capacity; and if the calculated capacity is smaller than the threshold value, a capacity obtained by adding one cluster to the calculated capacity is calculated. And using the method of creating a reduced image.

Further, the portable information device of the present invention comprises a camera, wireless means for receiving audio or image data transmitted from a base station, and a plurality of clusters each having the same capacity, and image data captured by the camera or Storage means for storing image data received by the wireless means;
A display unit configured to display the image data; and a control unit configured to create a reduced image from the image data. The control unit obtains the number of clusters necessary for storing the image data in the storage unit. , Calculating the capacity of the obtained number of clusters in which the image data is not written, and if the calculated capacity is equal to or greater than the threshold, create a reduced image using the calculated capacity, If the calculated capacity is smaller than the threshold, a reduced image is created using a capacity obtained by adding one cluster to the calculated capacity.

According to the present invention, when creating a thumbnail image, the capacity of the thumbnail image can be dynamically changed according to one cluster size or cluster gap, so that the storage area can be used effectively without waste.

  Embodiments according to the present invention will be described below.

1 to 3 show a reduced image creating method and a portable information device according to a first embodiment of the present invention.
Will be described with reference to FIG.

FIG. 1 is a block diagram showing an internal configuration when the present invention is applied to a mobile phone. Inside the mobile phone are a control unit 1 that controls the entire mobile phone, a thumbnail function control unit 1a that is a part of the control unit 1 and that creates and controls thumbnails when storing images, and a storage unit 2
A display unit 3, an operation unit 4, a communication unit 5, an antenna 6 for transmitting and receiving radio signals to and from a radio base station (not shown), and a camera 7.

The control unit 1 includes a storage unit 2 configured by a RAM, a display unit 3 configured by an LCD, an operation unit 4 configured by a keyboard, a communication unit 5 that performs wireless communication control with the antenna 6,
It is connected to a camera 7 or the like provided in the external casing of the mobile phone and controls the entire mobile phone.

When the thumbnail image control unit 1a in the control unit 1 creates the thumbnail image 12c from the operation unit 4 to the main image 12b stored in the storage unit 2 using the display unit 3, the main image 1 is displayed.
2b is reduced, edited so that it can be displayed as a list, and stored in the storage unit 2. Note that the operation for creating the thumbnail image 12c is not limited to this method, and may be automatically transferred to the creation operation when an image without the thumbnail image 12c is input in the storage unit 2.

The storage unit 2 stores a program executed by the control unit 1, various information data, image data of the embodiment, and the like.

The display unit 3 is an LCD display device, for example, and displays display data output from the control unit 1. As long as there is no new activation from the control unit 1, the same content is displayed on the display unit 3.

The operation unit 4 includes a plurality of keys including numeric keys and function keys for determining and canceling image editing. An identification signal for identifying the key is input to the control unit 1 in accordance with a key input input by the user. The control unit 1 starts its operation.

The communication unit 5 frequency-converts the high-frequency signal received by the antenna 6 from the base station, demodulates the noise-removed sound into a digital signal, and transmits the control signal to the control unit 1. Control unit 1
The control signal output from 1 is modulated, frequency-converted and amplified, and transmitted from the antenna 6 to the base station.

The camera 7 is a CCD camera, for example, and is activated by the control unit 1 in response to an image input instruction using the display unit 3 from the operation unit 4 and performs image input. The input image is displayed on the display unit 3 under the control of the control unit 1. In addition, an image input operation (shutter operation) is performed by the operation unit 4 while an image input by the camera 7 is displayed on the display unit 3.
Then, the control unit 1 can read an image from the camera 7 and store it in the storage unit 2.

Next, an image editing operation processed by the thumbnail function control unit 1a of the embodiment is shown in FIG.
This will be described with reference to FIG. In the following, for convenience of explanation, the capacity of one cluster is one cluster size j (sometimes abbreviated as j), and the image information 12 is created without creating the thumbnail image 12c.
The cluster gap when only a and the main image 12b are stored is defined as a cluster gap k (k
In the case where the thumbnail image 12c is displayed on the display unit 3, the image capacity necessary for creating the minimum thumbnail image that can be viewed by the user is the thumbnail image minimum capacity m (m and The capacity of the newly created thumbnail image 12c is assumed to be a thumbnail image capacity n (may be abbreviated as n).

FIG. 2A and FIG. 2B show the storage form of the storage unit 2 when image data including thumbnail images is stored in the storage unit 2 in the embodiment. Control of writing to and reading from the storage unit 2 are all performed by the control unit 1 or the thumbnail function control unit 1a.

The files in the storage unit 2 are managed in units of clusters, and the existing image data 11
When moving a file or sending / receiving a file, it is divided into one or a plurality of clusters. Further, when the new image data 12 is stored in the storage unit 2, the image information 12a, the main image 12b, and the thumbnail image 12c are stored in the same file in the left-justified manner. Image information 1
2a, main image 12b, and thumbnail image 12c may be stored in any order.

FIG. 3 is a flowchart showing an operation procedure of thumbnail image creation and storage by the thumbnail function control unit 1a. The input image is not limited to the camera 7, but the antenna 6 and the communication unit 5.
However, here, an input image taken by the camera 7 will be described as an example.

First, when the camera 7 is activated by the control unit 1, an image input operation is started. That is, the control unit 1 receives an input image obtained from the camera 7 and temporarily stores it in the display storage unit of the storage unit 2. Next, the control unit 1 reads out the image data temporarily stored in the display storage unit of the storage unit 2, and
Displayed on the display unit 3.

When the user performs a shooting determination operation (shutter operation) from the operation unit 4, the control unit 1 determines the image data temporarily stored in the display storage unit of the storage unit 2 at the time of the operation, and the determination The obtained image data is displayed on the display unit 3. The control unit 1 converts the determined image data into the main image 1
2b is stored in the storage unit 2 and the image information 12a is created and stored in the storage unit 2.

Next, when the user gives an instruction to determine image saving from the operation unit 4, the thumbnail function control unit 1a of the control unit 1 reads the main image 12b from the storage unit 2 (step 31).

Next, the thumbnail function control unit 1a calculates the total capacity of the image information 12a and the main image 12b, and calculates the cluster gap k (empty area) (step 32). In this step 32, the calculation of the cluster gap k may be started at the time when the image is determined in step 31.

Next, the thumbnail function control unit 1a determines the thumbnail image capacity n based on the size of the cluster gap k calculated in step 32. As a precondition, it is necessary to determine the minimum thumbnail image capacity m in advance. The thumbnail image minimum capacity m differs depending on the size of the display unit 3, the number of thumbnail images to be displayed at once, the resolution, the number of pixels of the camera, etc., but the thumbnail image 12c is displayed on the display unit 3 and can be viewed by the user. This is the minimum image capacity required to create a thumbnail image and save it. However, the present invention is not limited to this, and any value that is smaller than the image capacity that can be captured by the camera 7 may be set.

Then, the thumbnail function control unit 1a compares the cluster gap k calculated in step 32 with the thumbnail image minimum capacity m (step 33). If the cluster gap k is equal to or larger than the minimum thumbnail image capacity m (k ≧ m), the thumbnail image capacity n is set to the capacity of the cluster gap k calculated in step 32 (n = k) (FIG. 2 (a)) (step 34a). On the other hand, if the cluster gap k is smaller than the thumbnail image minimum capacity m (k <m), the thumbnail gap n is added to the cluster gap k calculated in step 32 and one cluster size j (for example, 1 kilobyte). Capacity (n = k + j
(See FIG. 2B) (step 34b). When the value of (k + j) is still smaller than the thumbnail image minimum capacity m at the stage of adding one cluster size j, the one cluster size j is continuously added until the thumbnail image minimum capacity m is exceeded, and the value (k + xj, x = 1
2, 3...) As a thumbnail image capacity n, and the process proceeds to step 35.

For example, the image information 12a of the new image data 12 is 128 bytes, and the main image 12b is 52
Assuming 00 bytes, the thumbnail image minimum capacity m is 600 bytes, and the cluster size j is 1 kilobyte, 5328 bytes are required as a capacity for storing the image information 12a and the main image 12b. Therefore, six consecutive clusters are required as a capacity for storing the new image data 12, and the cluster gap k is 672 (= 6000−128).
−5200) bytes. When the cluster gap k (= 672 bytes) and the thumbnail image minimum capacity m (= 600 bytes) are compared, the condition of k ≧ m is established. That is,
As shown in FIG. 2A, it can be determined that the thumbnail image minimum capacity m (= 600 bytes) can be stored in the cluster gap k (= 672 bytes). Therefore, in the present embodiment, step 34a is executed, and the thumbnail image capacity n is set to the cluster gap k (=
672 bytes) and proceed to the next step 35.

The image information 12a of the new image data 12 is 128 bytes, and the main image 12b is 580.
Assuming that 0 bytes, thumbnail image minimum capacity m is 600 bytes, and cluster size j is 1 kilobyte, 5928 bytes are required as a capacity for storing image information 12a and main image 12b. For this reason, the area for storing new image data 12 is 6
Two consecutive clusters are required, and the cluster gap k is 72 (= 6000−128−5).
800) bytes. When the cluster gap k (= 72 bytes) and the thumbnail image minimum capacity m (= 600 bytes) are compared, the condition of k <m is satisfied. That is, FIG.
As shown in b), the thumbnail image minimum capacity m is included in the cluster gap k (= 72 bytes).
Since it is not a capacity necessary for storing (= 600 bytes), it can be determined that it is necessary to further secure a capacity for one cluster. Therefore, in the present embodiment, step 34b is executed, and the thumbnail image capacity n is set to a cluster gap k (72 bytes) and one cluster size (1k).
Byte (= 1000 bytes)) is added to 1072 bytes and the next step 35
Proceed to

Next, when the thumbnail image capacity n is determined, the thumbnail function control unit 1a determines the main image 12
The thumbnail image b is created in accordance with the thumbnail image capacity n (step 35). Examples of this creation method include various methods such as a thinning method and a method of compressing after resolution reduction, but are not limited here. Note that, when the compression cannot be made to completely match the thumbnail image capacity n due to the image compression standard, an optimal value that is smaller than the thumbnail image capacity n and closest to the thumbnail image capacity n is set.

Finally, when the thumbnail function control unit 1a completes the creation of the thumbnail image 12c, it stores the image information 12a, the main image 12b, and the thumbnail image 12c as one file in the storage unit 2 (step 36). In this case, the image information 12a, the main image 12b, and the thumbnail image 12c may be stored in any order.

According to the embodiment of the present invention, since the image capacity n of the thumbnail image 12c can be dynamically determined by the total capacity of the main image 12b and the image information 12a and the thumbnail image minimum capacity m, the cluster gap Can be suppressed. In the embodiment of the present invention, a thumbnail image is created with a capacity equal to or greater than the minimum thumbnail image capacity m, and the storage unit 2
Therefore, it is possible to improve the image quality of thumbnail images.

A second embodiment of the reduced image creation method and portable information device according to the present invention will be described with reference to FIGS.

FIG. 4 is a flowchart showing the operation of the thumbnail function control unit when the present invention is applied to a mobile phone. The block diagram of the internal configuration when this second embodiment is applied to a mobile phone is the same as when the first embodiment shown in FIG. 1 is applied to a mobile phone, and the thumbnail function control unit 1a. The internal operation of is different. Also, in the internal operation of the thumbnail function control unit 1a of the second embodiment shown in FIG. 4, the same steps as those of the first embodiment shown in FIG. .

First, the input image is confirmed and read (step 31), and the cluster gap k is calculated (step 32). The steps so far are the same as those in the first embodiment.

After that, the main image 12b is converted into a thumbnail image pixel size (hereinafter referred to as vertical f1) determined for the device.
In step 43, the thumbnail image capacity (hereinafter referred to as n1) when the image is compressed at a predetermined compression rate p is obtained.

Here, the predetermined compression rate p is preferably the highest compression rate at which the thumbnail image 12c is displayed on the display unit 3 and visually distinguishable from other images by the user. Not limited.

Next, the thumbnail image capacity n1 obtained in step 43 is compared with the cluster gap k calculated in step 32 (step 44). If n1 obtained in step 44 is smaller than the cluster gap calculated in step 32 (n1 <k), the thumbnail image capacity n is set to the cluster gap k capacity (n = k) calculated in step 32. (See FIG. 2A) (step 45a). On the other hand, when n1 is greater than or equal to the cluster gap k, (n
1 ≧ k), and the thumbnail image capacity n is set to a capacity (n = k + j) obtained by adding the cluster gap k calculated in step 32 and one cluster size j (for example, 1 kilobyte) (FIG. 2B).
)) (Step 45b).

Next, when the thumbnail image capacity n is determined, the thumbnail function control unit 1a determines the main image 12
b is compressed in accordance with the thumbnail image capacity n (step 46). When compressing,
If the image compression standard does not match the thumbnail image capacity n, the thumbnail image capacity n
It is set to an optimum value that is smaller and closest to the thumbnail image capacity n.

Finally, after completing the creation of the thumbnail image 12c, the thumbnail function control unit 1a stores the image information 12a, the main image 12b, and the thumbnail image 12c as one file in the storage unit 2 (step 47). In this case, the image information 12a, the main image 12b, and the thumbnail image 12c may be stored in any order.

Further, after step 32, the following may be performed. FIG. 5 is a flowchart showing the operation of the thumbnail function control unit 1a when the present invention is applied to a mobile phone.

When step 32 is completed, the main image 12b is thinned out in accordance with the thumbnail image pixel size (f1 × f2) determined for the device, and the thumbnail image capacity n is set to the cluster gap k calculated in step 32 (n = k) (step 53). Then, a thumbnail image is created by compressing it so as to fit the thumbnail image capacity n. Further, the compression rate at the time of creation is also obtained (hereinafter, this compression rate is referred to as p1) (step 54). Thereafter, the compression rate p1 obtained in step 54 is compared with a predetermined compression rate p (step 55). Here, the predetermined compression rate p is preferably the highest compression rate at which the thumbnail image 12c is displayed on the display unit 3 and visually distinguishable from other images by the user. There is no particular limitation.

Thereafter, when the compression rate p1 obtained in step 54 is larger than the predetermined compression rate p (p1> p), the value of the thumbnail image capacity n is changed to a capacity obtained by adding one cluster size j (n = k + j), the main image 12b is thinned again according to the thumbnail image pixel size (f1 × f2) determined for the device, compressed according to the thumbnail image capacity n, and the process returns to step 54 (step 56). Also, the compression rate p1 obtained in step 54
Is equal to or less than a predetermined compression ratio p (p1 ≦ p), the image compressed in step 54 is used as the thumbnail image 12c, and the image information 12a, the main image 12b, and the thumbnail image 12c are stored as one file. 2 (step 56). In this case, the image information 12a, the main image 12b, and the thumbnail image 12c may be stored in any order.

According to the second embodiment of the present invention, the image capacity n of the thumbnail image 12 c is set to the main image 12.
Since it can be determined dynamically by the capacity of b and the compression rate p, the occurrence of a cluster gap can be suppressed. Further, without changing the number of clusters necessary for storing an image in the storage unit 2 by a conventional thumbnail image creation method (thumbnail image method with a predetermined thumbnail image pixel size or a predetermined compression rate), Since the thumbnail image can be created with the compression ratio reduced to the maximum and stored in the storage unit 2, the image quality of the thumbnail image can be improved.

A third embodiment of the reduced image creating method and portable information device according to the present invention will be described with reference to FIG.

FIG. 6 is a flowchart showing the operation of the thumbnail function control unit 1a when the present invention is applied to a mobile phone. The block diagram of the internal configuration when this third embodiment is applied to a mobile phone is the same as when the first embodiment shown in FIG. 1 is applied to a mobile phone, and the thumbnail function control unit 1a Only the internal operation of is different. Further, in the internal operation of the thumbnail function control unit 1a of the third embodiment shown in FIG. 6, the same steps as those of the first embodiment shown in FIG. .

First, the input image is confirmed and read (step 31), and the cluster gap k is calculated (step 32). The steps so far are the same as those in the first embodiment.

Thereafter, the main image 12b is converted into a thumbnail image pixel size (hereinafter referred to as vertical f) determined for the device.
The thumbnail image capacity (hereinafter, this capacity is referred to as n1) when compressed at a predetermined compression rate p is obtained (step 63).
. Here, the predetermined compression rate p is preferably the highest compression rate at which the thumbnail image 12c is displayed on the display unit 3 and visually distinguishable from other images by the user. Not limited.

Thereafter, the capacity n1 obtained in step 63 is compared with the cluster gap k obtained in step 32 (step 64). If the cluster gap k is greater than or equal to the capacitance n1, n1 ≦
k), with the thumbnail image capacity n as the value of the cluster gap k (n = k), step 66
(Step 65a). If the cluster gap k is smaller than the capacitance n1, (n
1> k), the thumbnail image capacity n is set to a value obtained by adding one cluster size j to the value of the cluster gap k (n = k + j), and the process proceeds to Step 66 (Step 65b). When the value of (k + j) is still smaller than the capacity n1 at the stage of adding the one cluster size j, the one cluster size j is continuously added until the capacity n1 is exceeded, and the value (k + xj, x = 1, 2, 3) is assumed to be the thumbnail image capacity n, and the process proceeds to step 65.

Next, the predetermined thumbnail image pixel size used in step 63 (f1 × f
2) (vertical is f1, horizontal is f2) is set to a larger value by 1 and is fr1 and fr2, respectively (fr
1 = f1 + 1, fr2 = f2 + 1) (step 66). Thereafter, using the thumbnail image pixel size (fr1 × fr2) calculated in step 66 and the predetermined compression ratio p used in step 63, the image capacity when the thumbnail image of the main image 12b is created is calculated. The calculated image capacity is set to n2 (hereinafter referred to as capacity n2) (step 67).

Thereafter, the capacity n2 obtained in step 67 and the step 65a or step 65b.
The thumbnail image capacity n obtained in step (1) is compared (step 68). At this time, step 6
When the capacity n2 obtained in step 7 is smaller than the thumbnail image capacity n obtained in step 65a or step 65b (n2 <n), the values of the thumbnail image pixel sizes fr1 and fr2 used in step 67 are increased by 1 ( fr1 = fr1 + 1, fr2 = fr2 +
1) (direction a in FIG. 6, step 68a). Thereafter, the process returns to step 67 and the operation of step 67 is performed again.

Further, as a result of comparing n2 and n, the capacity n obtained in step 67 is equal to step 65a.
Alternatively, if it is equal to the thumbnail image capacity n obtained in step 65b (n2 = n), the thumbnail image pixel sizes fr1 and fr2 used in step 67 and a predetermined compression rate p are used to generate a thumbnail image. A thumbnail image is created so as to match the capacity n, and the process proceeds to step 69 (direction b in FIG. 6, step 68b).

Further, as a result of comparing n2 and n, the capacity n2 obtained in step 67 is equal to step 65.
If the thumbnail image capacity n obtained in step a or step 65b is larger than (n2> n
), The thumbnail image pixel sizes fr1 and fr2 used in step 67 are reduced by 1 (fr1 = fr1-1, fr2 = fr2-1), and the obtained thumbnail image pixel sizes fr1 and fr2 are Using the predetermined compression ratio p used, a thumbnail image is created so as to fit the thumbnail image capacity n obtained in step 65a and step 65b, and the process proceeds to step 69 (direction c in FIG. 6, step 68c). ).

In step 68a, step 68b, and step 68c, step 6 is performed.
When there are a plurality of fr1 and fr2 values used in step 7, the last used one is adopted.

Finally, after completing the creation of the thumbnail image 12c, the thumbnail function control unit 1a stores the image information 12a, the main image 12b, and the thumbnail image 12c as one file in the storage unit 2 (step 69). In this case, the image information 12a, the main image 12b, and the thumbnail image 12c may be stored in any order.

In steps 66 to 69, a predetermined compression rate p is fixed, and the thumbnail image pixel size (f1 × f2) is increased by 1 at a time in the vertical and horizontal directions so as to fit the thumbnail image capacity n (fr1). Although the thumbnail image was created at xfr2), the pixel size of the thumbnail image is not limited to incrementing by 1 at the same time in the vertical and horizontal directions, but the vertical size is increased by 1 or the horizontal size is increased by 1 (fr1 and fr2 are made variable May be applied within a range not departing from the spirit.

According to the third embodiment of the present invention, the image capacity n of the thumbnail image 12 c is set to the main image 12.
Since it can be dynamically determined by the capacity of b and the thumbnail image pixel sizes fr1 and fr2, the occurrence of a cluster gap can be suppressed. Then, the thumbnail image pixel size can be changed without changing the number of clusters when the image is stored in the storage unit 2 by a conventional thumbnail image creation method (a thumbnail image method with a predetermined thumbnail image pixel size or a predetermined compression rate). Can be created and saved in the storage unit 2, so that the thumbnail image displayed on the display unit 3 can be enlarged.

The first to third embodiments described above are assumed to be mobile phones among portable information devices, but can be applied to digital cameras, PDAs, and the like.

1 is a block diagram of Embodiment 1 when a reduced image creation method of the present invention is applied to a mobile phone. The figure which shows the file structure of the memory | storage part of Example 1 at the time of applying the reduction image creation method of this invention to a mobile telephone. 6 is a flowchart showing the operation of the thumbnail function control unit of the first embodiment when the reduced image creation method of the present invention is applied to a mobile phone. 12 is a flowchart showing the operation of the thumbnail function control unit of the second embodiment when the reduced image creation method of the present invention is applied to a mobile phone. 12 is a flowchart showing the operation of the thumbnail function control unit of the second embodiment when the reduced image creation method of the present invention is applied to a mobile phone. 10 is a flowchart showing the operation of the thumbnail function control unit of the third embodiment when the reduced image creation method of the present invention is applied to a mobile phone. The file structure of the memory | storage part in the conventional mobile telephone. The internal block diagram of the conventional mobile telephone.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Control part 1a Thumbnail function control part 2 Memory | storage part 3 Display part 4 Operation part 5 Communication part 6 Antenna 7 Camera 11 Existing image data 12a Image information 12b Main image 12c Thumbnail image 13 Empty area

Claims (8)

A method for creating a reduced image from image data stored in a storage means each composed of a plurality of clusters having the same capacity,
Obtaining the number of clusters required when storing the image data in the storage means, and calculating a capacity at which the image data is not written with a capacity of the obtained number of clusters;
If the calculated capacity is greater than or equal to a predetermined threshold, creating a reduced image using the calculated capacity; and
And a step of creating a reduced image using a capacity obtained by adding one cluster to the calculated capacity when the calculated capacity is smaller than the threshold. A camera,
Wireless means for receiving audio or image data transmitted from the base station;
Storage means for storing image data captured by the camera or image data received by the wireless means, each consisting of a plurality of clusters of the same capacity,
Display means for displaying the image data;
Control means for creating a reduced image from the image data,
The control means includes
Obtaining the number of clusters required when storing the image data in the storage means, and calculating the capacity at which the image data is not written with the capacity of the determined number of clusters,
If the calculated capacity is equal to or greater than a predetermined threshold, a reduced image is created using the calculated capacity,
When the calculated capacity is smaller than the threshold, a reduced image is created using a capacity obtained by adding one cluster to the calculated capacity. A method for creating a reduced image from image data stored in a storage means each composed of a plurality of clusters having the same capacity,
Obtaining a number of clusters required when storing the image data in the storage means, and calculating a first capacity in which the image data is not written with a capacity of the obtained number of clusters;
Calculating a second capacity of an image obtained by compressing the image data at a predetermined compression rate;
If the first capacity is greater than or equal to the second capacity, creating a reduced image using the first capacity;
And a step of creating a reduced image using a capacity obtained by adding one cluster to the first capacity when the first capacity is smaller than the second capacity. A camera,
Wireless means for receiving audio or image data transmitted from the base station;
Storage means for storing image data captured by the camera or image data received by the wireless means, each consisting of a plurality of clusters of the same capacity,
Display means for displaying the image data;
Control means for creating a reduced image from the image data,
The control means includes
Obtaining the number of clusters required when storing the image data in the storage means, and calculating a first capacity in which the image data is not written with a capacity of the obtained number of clusters,
Calculating a second capacity of an image obtained by compressing the image data at a predetermined compression rate;
If the first capacity is greater than or equal to the second capacity, a reduced image is created using the first capacity,
When the first capacity is smaller than the second capacity, a reduced image is created using a capacity obtained by adding one cluster to the first capacity. A method for creating a reduced image from image data stored in a storage means each composed of a plurality of clusters having the same capacity,
Obtaining the number of clusters required when storing the image data in the storage means, and calculating a capacity at which the image data is not written with a capacity of the obtained number of clusters;
Creating a reduced image using the calculated capacity;
When the compression rate of the created reduced image is equal to or greater than a predetermined compression rate, the method further comprises the step of creating a reduced image again by replacing the calculated capacity with a capacity obtained by adding one cluster. Reduced image creation method. A camera,
Wireless means for receiving audio or image data transmitted from the base station;
Storage means for storing image data captured by the camera or image data received by the wireless means, each consisting of a plurality of clusters of the same capacity,
Display means for displaying the image data;
Control means for creating a reduced image from the image data,
The control means includes
Obtaining the number of clusters required when storing the image data in the storage means, and calculating the capacity at which the image data is not written with the capacity of the determined number of clusters,
Create a reduced image using the calculated capacity,
When the compression rate of the generated reduced image is equal to or higher than a predetermined compression rate, the calculated capacity is replaced with a capacity obtained by adding one cluster, and a reduced image is generated again. machine. A method for creating a reduced image from image data stored in a storage means each composed of a plurality of clusters having the same capacity,
Obtaining a number of clusters required when storing the image data in the storage means, and calculating a first capacity in which the image data is not written with a capacity of the obtained number of clusters;
Calculating a second capacity when a reduced image is created with a predetermined pixel size and a predetermined compression rate;
When the second capacity is larger than the first capacity, creating a reduced image using a capacity obtained by adding one cluster to the first capacity and the compression ratio;
And a step of creating a reduced image using the first capacity and the compression ratio when the second capacity is equal to or less than the first capacity. A camera,
Wireless means for receiving audio or image data transmitted from the base station;
Storage means for storing image data captured by the camera or image data received by the wireless means, each consisting of a plurality of clusters of the same capacity,
Display means for displaying the image data;
Control means for creating a reduced image from the image data,
The control means includes
Obtaining the number of clusters required when storing the image data in the storage means, and calculating a first capacity in which the image data is not written with a capacity of the obtained number of clusters,
Calculate the second capacity when creating a reduced image with a predetermined pixel size and a predetermined compression rate,
When the second capacity is larger than the first capacity, a reduced image is created using the capacity obtained by adding one cluster to the first capacity and the compression ratio,
When the second capacity is equal to or less than the first capacity, a reduced image is created using the first capacity and the compression rate.

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