JP2005056430A - Image display control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To display an image in an easy-to-see form on a display screen by devising the display screen so as to automatically display the image at an optimum variable power rate in displaying the image on the display screen. <P>SOLUTION: This image display control device is equipped with: a character size detection part 15 for acquiring the size of each character in an image; a calculation part 14b for calculating a variable power rate of the image so as to display each character in the image at a predetermined size on the display screen based on the character size detected by the detection part 15; and a display control part 7 for displaying the image on the display screen 11 at the variable power rate calculated by the calculation part 14b. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image display control apparatus suitable for use in displaying an image on a small display screen in an image display device such as a portable terminal device (PDA: Personal Digital Assistant).

In recent years, portable information devices that have been reduced in size and weight have become widespread. These portable information devices have a small display screen such as a liquid crystal display (LCD), and the user can store images stored in the storage device of such portable information devices. Is displayed on the display screen and used for various purposes such as browsing.
At this time, the user can select a desired image from a plurality of images stored in advance by operating the operation buttons, the touch panel, etc. of the information device body, and the image thus selected can be displayed on the display screen. A desired portion in the image is displayed by enlarging / reducing or the like above. In such an information device, the image display control device controls display of image data on a display screen.

  However, when such a conventional image display control apparatus performs reduction / enlargement display of the screen, for example, the image displayed on the display screen is 1/8 times, 1/4 times, or 1/2 times. , 1 ×, 2 ×, 4 ×, 8 ×, etc., a reduced / enlarged display is performed at a predetermined variable magnification. Therefore, in order to display such an image on the display screen in a state that is easy for the user to see, the user must adjust the display magnification by repeatedly pressing the operation button and repeatedly performing enlargement / reduction. There is a problem of being.

For example, when displaying a rectangular image with a large aspect ratio on a small display screen of a portable information device, it is desirable to display the image using the display screen without waste.
Furthermore, when displaying an image including characters on the display screen, the operation magnification is repeatedly performed by pressing an operation button or the like so that the characters are easy to see on the display screen, and the display magnification is increased. It is also complicated to adjust.

  Also, there is a known technique for searching and selecting an image to be processed by displaying index images created by reducing image data on the display screen and switching the index images one after another. It has been. FIGS. 14A and 14B are diagrams for explaining index display in a conventional image display device, and FIG. 14A is a diagram for explaining a method of operating an index image switching key. 14B is a diagram illustrating an example of an index image displayed on the display screen.

In the conventional image display apparatus, the user selects the left / right direction with the index image switching key as shown in FIG. 14 (a) while the index image is displayed on the display screen as shown in FIG. 14 (b). By doing so, the index image displayed on the display screen is switched, and another index image is displayed.
In the conventional image display device, the index image is displayed in a small size on the display screen so that the content of the image can be identified. While viewing the index image displayed on the display screen, the user presses the index image switching key one after another to switch, and when the index image of the desired image is displayed on the display screen, the user selects a selection button (not shown). By pressing and selecting, the image can be viewed in detail.

It is also desired to improve convenience when displaying such an index image on the display screen.
The present invention was devised in view of such a situation, and when displaying an image on a display screen, by applying a device that automatically displays an image with an optimum scaling factor on the display screen, An object of the present invention is to provide an image display control apparatus that can use a display screen without waste and can display an image on the display screen in an easy-to-view state.

  For this reason, the image display control device of the present invention is an image display control device that displays an image on a display screen, a character size detection unit that acquires the size of characters in the image, and a character detected by the character size detection unit Based on the size, a calculation unit that calculates a scaling factor of the image so that characters in the image are displayed at a predetermined size on the display screen, and a display that displays the image on the display screen at the scaling factor calculated by the calculation unit And a control unit (claim 1).

Thereby, the characters in the image can be displayed in a predetermined size on the display screen.
A scroll processing unit for scrolling the image on the display screen may be provided (Claim 2), or an index image created by reducing the original image may be displayed as an image on the display screen (Claim 3). ).

  Thereby, the image can be scrolled on the display screen, and the index image can be displayed on the display screen. Furthermore, the index image can be scrolled when the index image is displayed on the display screen.

As described above in detail, the image display control device of the present invention has the following effects or advantages.
(1) Based on the detected character size, the image magnification is calculated so that the characters in the image are displayed at a predetermined size on the display screen, and the image is displayed on the display screen at the calculated magnification. The characters in the image are displayed in a predetermined size on the display screen, the visibility of the characters on the display screen is improved, and the convenience is improved (claim 1).

(2) The image magnification is calculated so that the angle of view in the character height direction is a predetermined size (for example, about 0.38 to 0.95 (0.19 to 0.475) degrees). By displaying an image on the display screen at a variable magnification, it is possible to display characters in a size that is easy for the user to see on the display screen regardless of the distance between the display screen and the user.
(3) By storing the calculated zoom ratio in association with the image, it is possible to display the image using the held zoom ratio without calculating the zoom ratio again, and to reduce the processing speed. Can be improved.

(4) By holding the display position information of the image displayed on the display screen in association with the image, the display position can be preferentially displayed when the image is displayed, and the user can display the display position. This eliminates the need to perform an operation to display and improves convenience.
(5) By holding the display magnification of the image displayed on the display screen in association with the image, the image can be displayed at the variable magnification when the image is displayed, and the variable magnification is calculated again. In addition, an image can be displayed using the held scaling factor, and the processing speed can be improved.

(6) By scrolling the image on the display screen, the image can be viewed quickly and easily, and convenience is improved (claim 2).
(7) By displaying the index image created by reducing the original image as an image on the display screen, the index image can be displayed on the display screen even when the index image is displayed on the display screen. The index image displayed on the screen is easy to see and convenience is improved (claim 3).

  (8) When the index image is displayed, the position information of the image to be displayed is held in association with the original image, so that the display position can be preferentially displayed when the index image is displayed. However, it is not necessary to perform an operation to display the display position, and convenience is improved.

(A) Description of First Embodiment FIG. 1 is a block diagram showing a functional configuration of an image display device 50a provided with an image display control device 1a as a first embodiment of the present invention, and FIG. 2 shows the image display control device 1a. It is a block diagram which shows the hardware constitutions.
An image display device 50a including the image display control device 1a according to the first embodiment of the present invention is, for example, a portable personal computer, a viewer, or the like, and is a small-sized liquid crystal display (LCD) or the like. A display (display screen) 11 is provided. The image display control device 1a controls the display of images on the display 11.

  As shown in FIG. 2, the image display control apparatus 1a is configured to include an MPU 20, a nonvolatile memory 23, and a RAM 24. The MPU 20 stores programs stored in the nonvolatile memory 23 and a hard disk (not shown). By executing, the display of the image on the display 11 is controlled. The MPU 20, the nonvolatile memory 23, the RAM 24 and the display 11 are connected to each other via a data bus 25 so that various kinds of information can be exchanged with each other via the data bus 25. ing.

  The MPU 20 includes an MPU core 21 and an I / O control unit 22. The MPU core 21 performs various arithmetic processes, and the I / O control unit 22 processes operations performed by a user using a keyboard, buttons, or the like (not shown). Note that the hardware configuration of the MPU 20 is not limited to this, and may include other circuits such as an arithmetic circuit, and can be variously changed without departing from the spirit of the present invention.

Then, the MPU 20 executes a program (an image display control program) stored in a recording medium such as a hard disk or a ROM, so that an operation detection unit 3, a display information writing unit 4, and a display information reading unit 6 described later. The display control unit 7 and the image processing unit 8a function.
The nonvolatile memory 23 stores various information based on instructions from the MPU 20. The non-volatile memory 23 is configured by a storage medium such as a flash memory, a battery-backed CMOS memory, a hard disk, and the like, so that stored information is not lost even when power supply to the apparatus is stopped. ing. The RAM 24 is for temporarily expanding data when the MPU 20 performs arithmetic processing.

As shown in FIG. 1, the image display device 50a includes an image display control device 1a, an operation unit 2, an image storage unit 9, a display 11, and a display memory 10. Further, the image display control device 1a of the present embodiment includes an image information storage unit 5a, an operation detection unit 3, a display information writing unit 4, a display information reading unit 6, a display control unit 7, and an image processing unit 8a. Has been.
The operation unit 2 includes, for example, a keyboard, a mouse, a button, and the like, and is used by the user to perform various input operations.

  The operation detection unit 3 detects an operation performed by the operation unit 2 and is realized by the I / O control unit 23. The operation detection unit 3 determines whether or not the operation content performed on the operation unit 2 is an operation for changing the display state of the image on the display 11, and an operation for changing the display state on the display 11 is performed. When input, the display information writing unit 4 is notified of a signal (detection signal) to that effect.

The display information writing unit 4 writes predetermined display information (described later) in the image information storage unit 5a. The display information writing unit 4 converts the display information into an image based on a detection signal from the operation detection unit 3. It is determined whether or not the information is stored in the information storage unit 5a. When it is determined that the display information is stored, the display information is stored in the image information storage unit 5a.
The display information reading unit 6 reads predetermined information written in the image information storage unit 5 a and transmits it to the display control unit 7. The display information reading unit 6 refers to the image information storage unit 5a when the power is turned on or when the page is switched. When display information about an image to be displayed on the display 11 is stored in the image information storage unit 5a, This display information is read out.

The image storage unit 9 is configured by a storage medium such as a hard disk or a nonvolatile memory, and stores an image to be displayed on the display 11 in association with a page number. Hereinafter, an unprocessed image stored in the image storage unit 9 is referred to as an original image.
The display control unit 7 performs control for displaying an image on the display 11, and includes a scaling factor (details will be described later) calculated by the calculation unit 14 a and an image read by the display information reading unit 6. The image is enlarged or reduced using a scaling factor (details will be described later) stored in the information storage unit 5a and transferred to the display memory 10.

The display control unit 7 generates a display image to be displayed on the display 11 based on the display information received from the display information reading unit 6, and writes the generated display image in the display memory 10.
When the display image is stored in the image information storage unit 5 a, the display control unit 7 reads out the image and writes it in the display memory 10. On the other hand, when the display image is not stored in the image information storage unit 5a, the display control unit 7 notifies the image processing unit 8a of the page number of the image and acquires an image corresponding to the page number. The image processing unit 8a (calculating unit 14a) calculates an enlargement ratio or a reduction ratio (hereinafter referred to as a variable magnification), and generates a display image using the calculated variable magnification.

  Further, the display control unit 7 writes the display information (see FIGS. 3 and 4) about the generated display image into the image information storage unit 5a via the display memory 10 and the display information writing unit 4. Yes. When the “original image” is stored in the image information storage unit 5a, the position (coordinate value) in the original image of the image displayed on the display 11 is specified and stored as the “display position”. Thereby, the image of the coordinate position stored in the “display position” can be displayed on the display 11.

The image information storage unit 5a is, for example, a storage medium such as a non-volatile memory (flash memory, battery-backed CMOS memory, etc.) or a hard disk, and is stored even when power supply is interrupted in the image display device 50a. There is no loss of information.
3 and 4 are diagrams schematically showing the data structure of display information stored in the image information storage unit 5a. FIG. 3 shows image information for one page from the image information for a plurality of pages shown in FIG. FIGS. 4A and 4B are diagrams illustrating the data structure of display information related to an image (i = 1 to N) of an i-th page, and FIG. 4 is a diagram illustrating the data structure of display information related to an image of a plurality of pages.

As shown in FIG. 3, the image information storage unit 5 a stores “display page number i”, “magnification”, “display position”, and “original image” in association with each other with respect to the image displayed on the display 11. Such display information is written by the display information writing unit 4.
Here, the “display page number i” is a number for specifying the image and indicates the page number of the image to be displayed on the display 11 and is stored as a natural number. Thereby, for example, an image to be displayed when the power is turned on is specified. “Variation ratio” indicates the ratio of the size of the image to be displayed on the display 11 to the size of the original image, and the value calculated by the calculation unit 14a or the last change on the display 11 is displayed. The magnification is memorized.

  “Display position” refers to the position of an image (hereinafter also referred to as a display image) formed by being enlarged or reduced in accordance with the display size of the display 11 for display on the display 11 according to a predetermined reference in the original image. The position (for example, the upper left position) is indicated as a coordinate position indicating the origin. The “original image” is an image formed by copying an image stored in the image storage unit 9, for example, a bitmap image, an image formed in various formats such as TIFF, JPEG, and GIF. .

Further, when an original image is not recorded in the image information storage unit 5a, information to that effect is stored in the "original image" area.
Further, when the display information as described above is stored for a plurality of pages, the image information storage unit 5a, as shown in FIG. 4, for each page, the “magnification”, “display position”, and “original” The “image” is stored in association with each other.

That is, the image information storage unit 5a functions as a first storage unit that holds the scaling factor calculated by the calculation unit 14a in association with the image, and further, the display position of the image displayed on the display 11 It also functions as a second storage unit that stores information in association with images.
The display memory 10 temporarily holds the image transferred by the display control unit 7, and the display 11 displays the image held in the display memory 10.

  The image processing unit 8a performs processing on an image stored in the image storage unit 9, and the display control unit 7 stores an image of a page displayed on the display 11 in the image information storage unit 5a. If it is determined that it is not, the original image of the designated page is read from the image storage unit 9 based on the page number of the image, and further, a scaling factor that matches the size of the display 11 is calculated and displayed. The control unit 7 is notified.

The image processing unit 8a includes a screen size information acquisition unit 12, an image information acquisition unit 13, and a calculation unit 14a.
The screen size information acquisition unit 12 acquires information related to the displayable size of the display 11. For example, the screen size information acquisition unit 12 acquires the vertical size H1 and the horizontal size W1 of the display 11 stored in advance in a hard disk or the like. The size is stored in the image information storage unit 5 or the like.

Note that the screen size information acquisition unit 12 may acquire information relating to the displayable size directly from the display 11, and in response to a request from the screen size information acquisition unit 12, the screen size information acquisition unit 12 may relate to the displayable size. Information may be input using the operation unit 2.
The image information acquisition unit 13 acquires information about the original image stored in the image storage unit 9, and acquires the vertical size H2 and the horizontal size W2 of the original image.

  In the bitmap (BMP) format, TIFF format, and the like that are generally used as image data formats, information about the size of the image is stored in the header portion of the data. 13 can acquire the vertical size H2 and the horizontal size W2 of the image from the information stored in the header portion using a generally known algorithm.

The calculation unit 14a is configured so that at least one of the vertical and horizontal directions of the image matches or substantially matches the displayable sizes H1 and W1 of at least one of the vertical and horizontal directions of the display 11. A variable magnification is calculated.
Specifically, the computing unit 14a matches the vertical direction of the image with the displayable size H1 in the vertical direction of the display 11 and the horizontal direction of the image to the displayable size W1 in the horizontal direction of the display 11. The scaling factor of the image in both cases of matching or nearly matching is calculated, and the larger scaling factor in the vertical or horizontal direction of the image is selected and output to the display control unit 7. Yes. Therefore, the magnification of the image calculated by the calculation unit 14a is
Scaling factor = max [Horizontal scaling factor (W1 / W2) of image, vertical scaling factor of image (H1 / H2)]
Can be expressed as

  In the present embodiment, the vertical size H1 and the horizontal size W1 of the display 11 are directly used as displayable sizes of the display 11. However, the present invention is not limited to this. For example, the vertical size of the display 11 is used. A value obtained by excluding a predetermined margin from H1 and the horizontal size W1 may be used as the displayable size, or a value preset by the user may be used as the displayable size. Various modifications can be made without departing from the scope of the invention.

Also, the vertical magnification of the image = the displayable size of the display 11 in the vertical direction / the vertical size of the image = H1 / H2, the horizontal scaling factor of the image = the displayable size of the display 11 in the horizontal direction / the size of the image. The horizontal size can be expressed as W1 / W2.
Control when the image (original image) is displayed on the display 11 by the image display control device 1a according to the first embodiment of the present invention configured as described above will be described according to the flowchart (step A10 to step A60) shown in FIG. To do.

First, the screen size information acquisition unit 12 acquires the vertical size H2 and the horizontal size W2 of the original image recorded in the image storage unit 9, temporarily stores them in the nonvolatile memory 23, and displays the screen size information. The acquisition unit 12 acquires the vertical size H1 and the horizontal size W1 of the display 11 and stores them in the nonvolatile memory 23 (step A10).
Then, the calculation unit 14a calculates an image scaling factor (enlargement / reduction ratio) W1 / W2 when the horizontal direction of the original image matches or substantially matches the displayable size W1 in the horizontal direction of the display 11 (step A20). ) When the vertical direction of the image matches or substantially matches the displayable size H1 in the vertical direction of the display 11, an image scaling factor (enlargement / reduction ratio) H1 / H2 is calculated (step A30).

  The computing unit 14a compares the vertical scaling factor H1 / H2 of the image with the horizontal scaling factor W1 / W2 of the image (step A40), and the horizontal scaling factor W1 / W2 of the image is the vertical scaling factor. If it is larger than the magnification H1 / H2 (see YES route at step A40), the horizontal scaling factor W1 / W2 is selected and output to the display controller 7 (step A50). On the other hand, when the vertical scaling factor H1 / H2 of the image is larger than the horizontal scaling factor W1 / W2 (see NO route in step A40), the vertical scaling factor H1 / H2 is selected and displayed. To the unit 7 (step A60).

Then, the display control unit 7 outputs the original image stored in the image storage unit 9 to the display memory 10 at the scaling factor selected by the calculation unit 14a in this way. The display 11 displays an image stored in the display memory 10.
Here, when the user inputs an instruction to temporarily store the image displayed on the display 11 via the operation unit 2, the operation detection unit 3 detects the input, and the display information writing unit 4 is notified. Then, the display information writing unit 4 stores the magnification ratio calculated by the calculation unit 14a and the coordinate information of the display position from the display control unit 7 in a predetermined area of the image information storage unit 5a together with the original image.

Thereafter, when the image stored in the image information storage unit 5 a is displayed on the display 11, the display control unit 7 acquires display information from the image information storage unit 5 a and displays it on the display 11.
Thus, according to the image display control device 1a and the image display device 50a as the first embodiment of the present invention, the calculation unit 14a has at least one of the vertical direction and the horizontal direction of the image in the vertical direction of the display 11. The image scaling factor is calculated so that it matches or substantially matches at least one of the displayable size H1 or W1 in the horizontal direction or the horizontal direction, and the display control unit 7 uses the scaling factor thus calculated. Since the image is displayed on the display 11, the display 11 can be used efficiently, and the image can be displayed on the display 11 in a large size, so that the displayed image is easy to see and the convenience is improved. For example, even on a small display 11 such as a portable information device, an image is easy to see.

At this time, since the image is displayed on the display 11 at the larger magnification ratio of the vertical direction or the horizontal direction of the image, when the image is displayed on the rectangular display 11, the image can be displayed at the largest size. The image displayed on the display 11 is easy to see and the convenience is improved.
Further, when image information is stored in the image information storage unit 5a and the image stored in the image information storage unit 5a is displayed on the display 11, the image stored in the image information storage unit 5a is Since the image is displayed on the display 11 at a magnification that is stored in association with the image, it is not necessary to calculate the magnification again by the image processing unit 8a, and the processing speed can be improved.

  Further, the image information storage unit 5a always stores the position (coordinate value) last displayed on the display 11 in the image in association with the scaling factor used when the display is performed. Therefore, the display position can be displayed, and the image of the part that the user most desires can be quickly displayed on the display 11. Further, when this image is displayed on the display 11, it can be quickly displayed at a variable magnification that the user desires, so that, for example, the user does not have to adjust the display magnification by operating the operation unit 2. , Improve convenience.

(B) Description of Second Embodiment FIG. 6 is a block diagram showing a functional configuration of an image display device 50b provided with an image display control device 1b as a second embodiment of the present invention. As shown in FIG. Similarly to the image display device 50a shown in FIG. 1, the image display device 50b including the image display control device 1b as the second embodiment of the present invention is, for example, a portable personal computer or a viewer. A small display (display screen) 11 such as a liquid crystal display is provided.

Note that the image display control apparatus 1b as the second embodiment of the present invention also has almost the same hardware configuration as the image display control apparatus 1a as the first embodiment shown in FIG. The detailed description about is omitted. In the drawing, the same reference numerals as those already described indicate the same or substantially the same parts, and the description thereof is omitted.
The image display control device 1b of the second embodiment is configured in substantially the same manner as the image display control device 1a of the first embodiment. However, in the image display control device 1b, an image processing unit is used instead of the image processing unit 8a. 8b is provided.

  The image display control device 1b controls display of images on the display 11 when the MPU 20 executes a program stored in the nonvolatile memory 23 or a hard disk (not shown). At this time, the MPU 20 executes a program (image display control program) stored in a recording medium such as a hard disk or a ROM, whereby an operation detection unit 3, a display information writing unit 4, a display information reading unit 6, a display It functions as the control unit 7 and the image processing unit 8b.

The image processing unit 8b processes the image stored in the image storage unit 9, and includes a screen size information acquisition unit 12, a character size detection unit 15, and a calculation unit 14b. .
The character size detection unit 15 detects the size of characters in the image, and detects the most frequently used character size in the image.

  As described above, the reason for detecting the most frequently used character size in the image is that the text composed of the character size with the largest number of characters in the image including characters is considered to be the body part. Is to be surely read on the display 11. Specifically, as will be described later, the character size detection unit 15 totals the first and second histograms for each image formed by dividing the original image into 16 parts, and the text character size (in pixel units). Ask for. Thereafter, the calculator 14b calculates the scaling factor using the character size obtained in this way.

  FIGS. 7A to 7C are diagrams for explaining a character size detection method. FIG. 7A shows a second histogram, and FIG. 7B shows a first histogram. FIG. 7C is a diagram illustrating an example of an image including characters. Note that the image shown in FIG. 7C is configured by arranging black characters on a white background, and a character having 12 pixels in the character height direction (“text body...”). And a 48-pixel character (“headline”).

The character size detection unit 15 divides the input image into a predetermined number of images (in this embodiment, 16 divisions of 4 (vertical direction) × 4 (horizontal direction)), and each image configured by dividing these images. For the above, the number of black pixels in the horizontal direction is summed in units of pixels in the vertical direction, and a histogram (first histogram) as shown in FIG. 7B is created.
In addition, by dividing the input image into a plurality of images, it is possible to avoid erroneous recognition due to a heading portion, a photograph portion, or the like in the image. In the second embodiment, the original image is divided into 16 parts, but the present invention is not limited to this, and the original image may be divided into a number other than 16, and various kinds may be used without departing from the spirit of the present invention. Can be deformed.

Thereafter, the character size detection unit 15 measures the width of each column constituting the histogram (vertical size in FIG. 7B: number of pixels) for the first histogram, and the number of pixels for the number of these columns. The second histogram (see FIG. 7A) is created by accumulating the frequency for each.
Then, the character size detection unit 15 obtains the most frequently appearing pixel number in the second histogram. Further, the character size detection unit 15 performs the same processing on each image formed by dividing the original image into 16 parts, and transmits the image to the calculation unit 14b as the size of the character most frequently used in the formed image. It is like that.

The calculation unit 14b calculates the magnification of the image based on the character size detected by the character size detection unit 15 so that the characters in the image are displayed at a predetermined size on the display 11. The calculating unit 14b calculates the scaling factor by calculating the following expression.
For example, when the “detected character size” is 40 pixels and the “preferable character size” is 5 pixels, the original image is converted to 5 / By displaying at a scaling factor (reduction ratio) of 40, the most frequently used characters in the original image are displayed on the display 11 with 5 pixels, and can be displayed in a state that is easy for the user to see.

Here, an example of a method for calculating a character size (preferable character size) to be displayed on the display 11 will be described with reference to FIG.
FIG. 10 is a diagram for explaining the relationship between the size of the character displayed on the display 11 and the angle of view. As shown in FIG. 10, when calculating the magnification of an image, the calculation unit 14b specifies the angle of view in the character height direction on the surface of the eyeball when the user looks at the character displayed on the display 11. The zoom ratio may be calculated such that the angle of view becomes approximately 0.19 to 0.475 °, for example.

Specifically, the calculation unit 14b assumes an interval between the display 11 and the user's eyes in use in advance, and according to the distance, the angle of view in the character height direction on the user's eyeball surface is, for example, The character size (character height) is set to be about 0.19 to 0.475 °.
That is, as shown in FIG. 10, when the distance between the user's eyes and the display 11 is short (for example, about 20 cm) during use, such as a portable viewer, the size of characters displayed on the display 11 is large. The scaling factor is set so that the height (character height) is small. Further, when the interval between the user and the display 11 is large during use, a scaling factor is set such that the size of the character (character height) displayed on the display 11 is increased.

  Further, even when the image display control device 1b of the second embodiment is applied to a large display or the like installed on the assumption that the image display control device 1b is viewed from a relatively distant position, according to the distance from the user to the display, By applying a scaling factor such that the size in the height direction of the character is about 0.19 to 0.475 ° in the angle of view of the user's eyeball, the character is displayed on the display at the optimum size for the user. An image is displayed at a variable magnification.

Thereby, regardless of the distance between the user's eyes and the display 11, it is possible to display characters on the display 11 in a size that is easy for the user to see.
An image display control method in the image display control device 1b according to the second embodiment of the present invention configured as described above will be described with reference to a flowchart (step B10 to step B80) shown in FIG.

  The character size detection unit 15 divides the original image acquired from the image storage unit 9 into 16 (step B10) and clears the histogram table and the image counter (steps B20 and B30). Then, for one of the images formed by dividing the original image, the character size in the image is extracted (step B40). A specific method for detecting the character size in step B40 will be described later.

Then, the character size detection unit 15 creates or updates a histogram according to the extracted character size (step B50), and increments the image counter (step B60).
Further, the character size detection unit 15 determines whether or not the character size has been extracted for all images formed by dividing the original image, that is, whether or not the value of the image counter is 16 (step S1). B70) If character size extraction has not been completed for all images, that is, if the value of the image counter is less than 16 (see NO route of step B70), the process returns to step B40.

When character size extraction has been completed for all 16 images (see YES route in step B70), the character size detection unit 15 uses the most frequently used character size in the histogram table for the entire image. The character size (character height) is transferred to the calculation unit 14b (step B80).
Next, a more specific character size detection method of the character size detection unit 15 will be described according to the flowchart (step C10 to step C140) shown in FIG. 9 with reference to FIGS. 7 (a) to 7 (c). .
First, the character size detection unit 15 sets the Y position counter to 0 (step C10). Here, the Y position indicates the position in the vertical direction in the image, and is indicated in units of pixels. In the second embodiment, the numerical value of the Y position counter increases downward with the upper left position being 0 in the image shown in FIG.

Next, the character size detection unit 15 clears the pixel count table (first histogram table) (step C20), and then the number of black pixels in the horizontal direction at the vertical position of the image indicated by the Y position counter. (Step C30), and the count result is stored in the pixel count table [Y position counter] (step C40).
Thereafter, the character size detection unit 15 increments the Y position counter (step C50), and then determines whether or not the Y position has reached the lower end of the image (step C60). If the Y position is not the lower end of the image (see NO route in step C60), the process returns to step C30.

Then, the first histogram is formed by repeating Step C30 to Step C60.
When the Y position has reached the lower end of the image (see YES route in step C60), the character size detection unit 15 then sets a value obtained by dividing the horizontal size of the image by 20 as a threshold (step C70). ).

The threshold is not limited to the value obtained by dividing the horizontal size of the image by 20 as described above, and can be implemented with various modifications without departing from the spirit of the present invention.
Thereafter, the character size detector 15 once clears the second histogram (step C80) and then clears the Y position counter again (step C90) in order to create the second histogram table.

Then, in the first histogram, the character size detection unit 15 counts the column width (character height; vertical direction in FIG. 7B) of the columns that are equal to or higher than the threshold set in step C70 as the number of pixels. At the same time, the interval between the pillar and the pillar adjacent to the pillar (the width of the white space) is counted as the number of pixels (step C100).
Next, the character size detection unit 15 adds 1 to the value (frequency) corresponding to the pixel value (character height) of the pillar width obtained by counting in step C100 in the second histogram (step C110). ). Thereafter, the character size detection unit 15 adds “character height + white space width” to the value of the Y position counter (step C120), and then determines whether the Y position has reached the lower end of the image. However (step C130), if the Y position is not the lower end of the image (see NO route of step C130), the process returns to step C100.

In step C120, by adding “character height + white column width” to the value of the Y position counter, the Y position moves to the next column in the first histogram. Then, the second histogram is formed by repeating Step C100 to Step C130.
When the Y position reaches the lower end of the image (see YES route in step C100), the character size detection unit 15 determines the character height (number of pixels) at which the frequency value is the highest value in the second histogram. The size of the character most frequently used in the image is set (step C140).

For example, in the image shown in FIG. 7C, as shown in FIG. 7A, the frequency of characters having a character height of 12 pixels is 6, and the frequency of characters having a character height of 48 is 1. Therefore, the character size detection unit 15 has a character size (character height) of 12 pixels.
As described above, when the character size detection unit 15 detects the character size of the most used character in the image (original image), the calculation unit 14b then uses the above formula based on the character size. A scaling factor of an image to be displayed on the display 11 is calculated, and the scaling factor is transferred to the display control unit 7.

  Then, the display control unit 7 applies the scaling factor calculated by the calculation unit 14 b to the image stored in the image storage unit 9 and stores it in the display memory 10. The display 11 displays an image stored in the display memory 10, whereby the character size used most frequently in the image is enlarged on the display 11 so as to be the optimum size for the user. / The reduced image is displayed.

Further, the display control unit 7 writes display information (see FIGS. 3 and 4) about the generated display image in the image information storage unit 5a. When the image to be displayed on the display 11 is already stored in the image information storage unit 5a, the display control unit 7 uses the scaling factor stored in the image information storage unit 5a. To be displayed on the display 11.
As described above, according to the image display control device 1b and the image display device 50b as the second embodiment of the present invention, the calculation unit 14b displays the characters in the image based on the character size detected by the character size detection unit 15. 11, the image scaling factor is calculated so that the image is displayed at a predetermined size, and the image is displayed on the display screen at the calculated scaling factor. Therefore, characters on the image are displayed at a predetermined size on the display 11. The visibility of characters on the display 11 is improved, and convenience can be improved.

  The character size detecting unit 15 detects the most frequently used character size in the image, and the calculating unit 14b displays the most frequently used character in the image based on the detected character size. 11, the display 11 is displayed at the magnification of the image calculated so as to be displayed at a predetermined size, so that the character size used most frequently in the image is in a state that is most easily seen by the user. An image can be displayed on the screen, and convenience can be improved.

  Further, when the user looks at the character displayed on the display 11 by the calculation unit 14b, the most frequently used character in the image has an angle of view in the character height direction on the surface of the user's eyeball. For example, since the scaling factor is calculated so as to be about 0.19 to 0.475 °, the most in the image regardless of the size of the display 11 or the distance between the display 11 and the user. An image can be displayed on the display 11 so that the character size used is most visible to the user, and convenience can be improved.

In the second embodiment, the calculation unit 14b calculates the magnification of the image, and when the user views the character displayed on the display 11, the character height direction on the surface of the user's eyes. The zoom ratio is calculated so that the angle of view is, for example, about 0.19 to 0.475 °, but is not limited thereto.
For example, in the second embodiment, display control of a display in an information terminal that is held and used by a user is assumed. In such a case, the computing unit 14b may display the dimension in the character height direction on the display 11 to be, for example, about 2 mm to 5 mm when calculating the scaling factor of the image.

  Here, the reason why the size in the character height direction on the display 11 is set to about 2 mm to 5 mm is that the character size on the display 11 of the portable information terminal is subjected to subjective evaluation and is displayed on the display 11. This is because it has been found that readability is secured when the height of the characters is 2 mm to 5 mm. Thereby, the number of characters that can be displayed on the display 11 and the readability of the characters can be balanced.

Further, when calculating the magnification of the image, the number of pixels in the character height direction on the display 11 may be displayed to be, for example, about 5 to 13 pixels. These also make it easier for the user to see the characters displayed on the display 11.
Here, the reason why the number of pixels in the character height direction on the display 11 is about 5 to 13 pixels is that, for example, even when displaying the same size character according to the resolution of the LCD, the pixels used for displaying the character This is because if the number is different and if the character has a size larger than a certain size, it has been experimentally found that the readability depends on the number of pixels contributing to the display of the character.

As a result, in the case of an image having characters, when it is displayed so as to have a character size (character height) of 5 to 13 pixels, the number of characters that can be displayed on the display 11 and the readability of the characters are balanced. be able to.
Further, in the second embodiment described above, by calculating the scaling factor of an image based on the most frequently used character size in the image, the most commonly used character size in the image is most easily seen by the user. However, the present invention is not limited to this.

  For example, the character size detecting unit 15 detects the size of the smallest character in the image, and the computing unit 14b detects the smallest character in the image with a predetermined size (for example, a size that the user can visually recognize on the display 11). ) May be calculated, and an image may be displayed at this magnification. Thereby, it is not necessary for the user to operate the operation unit 2 in order to enlarge and display a small character, and convenience can be improved.

  Similarly, the character size detecting unit 15 detects the size of the largest character in the image, and the computing unit 14b ensures that the largest character in the image fits within a predetermined size (for example, within the display 11). (Magnification) may be calculated, and an image may be displayed at this magnification. Thereby, it is not necessary for the user to operate the operation unit 2 in order to display a large character in a reduced size, and convenience can be improved.

Further, the character size detection method by the character size detection unit 15 is not limited to the above-described method, and can be implemented in various modifications without departing from the spirit of the present invention. The character size may be detected using various methods such as character recognition.
(C) Description of Third Embodiment FIG. 11 is a block diagram showing a functional configuration of an image display device 50c provided with an image display control device 1c as a third embodiment of the present invention. As shown in FIG. 11, an image display device 50c provided with an image display control device 1c as a third embodiment of the present invention is also an image display device 50a (see FIG. 1) and an image display device 50b (see FIG. 6). Similarly to, for example, a portable personal computer, a viewer, or the like, which includes a small display (display screen) 11 such as a liquid crystal display.

The image display control device 1c as the third embodiment of the present invention also has almost the same hardware configuration as the image display control device 1a (1b) as the first embodiment shown in FIG. A detailed description of the hardware configuration is omitted. In the drawing, the same reference numerals as those already described indicate the same or substantially the same parts, and the description thereof is omitted.
The image display control device 1c according to the third embodiment is configured in substantially the same manner as the image display control device 1a according to the first embodiment. However, in the image display control device 1c, the image information storage unit 5a is replaced with image information. A storage unit 5b is provided, and a scroll processing unit 16 is newly added.

  The image display control device 1c controls display of images on the display 11 when the MPU 20 executes a program stored in the nonvolatile memory 23 or a hard disk (not shown). At this time, the MPU 20 executes a program (image display control program) stored in a recording medium such as a hard disk or a ROM, whereby an operation detection unit 3, a display information writing unit 4, a display information reading unit 6, a display It functions as the control unit 7, the image processing unit 8 a, and the scroll processing unit 16.

  The scroll processing unit 16 scrolls the image on the display 11, and scrolls the image vertically and horizontally on the display 11 in accordance with an instruction from the operation detection unit 3. That is, when the user instructs the operation unit 2 to scroll the image, the operation detection unit 3 detects the scroll operation, causes the scroll processing unit 16 to perform the scroll process, and the display control unit 7 displays the image in the scrolled state. Are formed and displayed on the display 11.

In this image display device 50c, in order to select an image to be displayed on the display 11 from a plurality of images, an index image created by reducing the original image can be displayed on the display 11. . Hereinafter, the display of the index image on the display 11 may be referred to as an index display.
FIGS. 12A and 12B are views for explaining the display of the index image performed by the image display control apparatus 1c according to the third embodiment of the present invention. FIG. FIG. 12B is a diagram for explaining a key operation method, and FIG. 12B is a diagram illustrating an example of an index image displayed on the display 11.

  In the image display control apparatus 1c according to the third embodiment, as shown in FIG. 12B, at the time of index display, the image processing unit 8a causes at least one of the vertical direction and the horizontal direction of the index image to be displayed. The display 11 can be displayed so as to match or substantially match the displayable size of at least one of the vertical and horizontal directions.

As a result, as shown in FIG. 12B, the index image is displayed in the full displayable range of the display 11, and the user can recognize the content of the image even in the index display created by reducing the original image. For example, characters in an image can be read.
In the example shown in FIGS. 12A and 12B, the index image is displayed so that the horizontal direction of the index image matches or substantially matches the horizontal direction of the display 11. Further, the index image switching key shown in FIG. 12A functions as an index image switching key in the left-right direction and functions as a scroll key in the up-down direction.

In the third embodiment, the index image switching key corresponds to the operation unit 2, and an operation input by the index image switching key is transmitted from the operation detection unit 3 to the scroll processing unit 16. The image displayed on the display 11 is scrolled by the scroll processing unit 16.
Then, while the index is being displayed, as shown in FIG. 12A, the index image is scrolled using a scroll key (up and down direction of the index image switching key in FIG. 12A). Thus, the contents of the image can be grasped with the index image, and the convenience is improved.

The image information storage unit 5b has the same function as the image information storage unit 5a in the image display control device 1a of the first embodiment and the image display control device 1b of the second embodiment, and is displayed when displaying an index image. It also functions as a third storage unit that holds the position information of the image to be associated with the original image.
FIG. 13 is a diagram schematically showing a data structure of display information stored in the image information storage unit 5b, and is a diagram showing a data structure of display information related to images for a plurality of pages.

As shown in FIG. 13, the image information storage unit 5 b relates to an image to be displayed on the display 11, for each “display page number”, “magnification”, “first display position”, “second display position”, and “ The “original image” is stored in association with each other, and the display information writing unit 4 writes the display information.
Here, the “display page number” indicates the number of pages of an image to be displayed on the display 11 and specifies, for example, an image to be displayed when the power is turned on, and is stored as a natural number. “Variation ratio” indicates the ratio of the size of the image to be displayed on the display 11 to the size of the original image, and the value calculated by the calculation unit 14a or the last change on the display 11 is displayed. The magnification is memorized.

The “first display position” refers to a position of an image (hereinafter also referred to as a display image) formed by being enlarged or reduced in accordance with the display size of the display 11 for display on the display 11. The reference position (for example, the upper left position) is indicated as a coordinate position indicating the origin.
The “second display position” indicates the position of an image to be displayed on the display 11 when performing index display, as a coordinate position indicating a predetermined reference position (for example, the upper left position) in the original image as an origin.

The “original image” is an image formed by copying an image stored in the image storage unit 9, for example, a bitmap image, an image formed in various formats such as TIFF, JPEG, and GIF. .
Further, when an original image is not recorded in the image information storage unit 5b, information to that effect is stored in the “original image” area.

In the image display control device 1c according to the third embodiment, the image information storage unit 5b holds the “second display position” in association with the original image, thereby enlarging / reducing the thumbnail display. A position different from when an image is displayed on the display 11 can be displayed on the display 11.
For example, for a part of an image that needs to be enlarged and displayed in order to perform processing such as editing, the position information (coordinate value) is stored in the “first display position” of the image information storage unit 5b. When the index is displayed, position information (coordinate values) of a portion convenient for identifying the image (for example, a title portion) is stored in the “second display position” of the image information storage unit 5b. By doing so, the place to be displayed on the display 11 can be changed between the case of performing the enlarged / reduced display and the case of performing the index display, and the convenience is improved.

In particular, when displaying an index image, the display position of the image to be displayed is stored in the image information storage unit 5b in association with the original image, so that the display position can be preferentially displayed when the index image is displayed. This eliminates the need for the user to perform an operation for displaying the display position, thereby improving convenience.
In the example shown in FIG. 12A, the index image switching key also functions as a scroll key. However, the present invention is not limited to this, and the index image switching key and the scroll key are not limited thereto. And may be prepared separately.

Further, in the example shown in FIG. 12B, the horizontal direction of the index image is displayed so as to match or substantially match the horizontal direction of the display 11, but the present invention is not limited to this. You may display so that a vertical direction may correspond with the vertical direction of the display 11, or may correspond substantially.
In this case, when the index image switching key and the scroll key are used in common, the index image switching key functions as a scroll key in the left-right direction and functions as the index image switching key in the up-down direction. It is desirable.

That is, when the index image switching key and the scroll key are used in combination, the convenience of index display is improved by using the one not used for selecting the index image as the scroll key.
(D) Others The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

For example, both the functions as the image processing unit 8a in the first embodiment and the function as the image processing unit 8b in the second embodiment are provided, and the user uses the operation unit 2 as necessary. These functions may be selectively switched to display an image.
For example, when displaying the entire image on the display 11, the function as the image processing unit 8 a is used to calculate the magnification of the image, display the image, and display the image on the display 11 to read the characters in the image. In the case of displaying, the function as the image processing unit 8b can be used to calculate the magnification of the image and display the image, thereby displaying the image in an optimal state on the display 11 according to the application. be able to.

Further, the image display control device 1c shown in the third embodiment includes the image processing unit 8a shown in the first embodiment. However, the present invention is not limited to this, and the second embodiment. The image processing unit 8b shown in FIG.
Thus, when an image including characters is displayed on the display 11 as an index image, the index image is displayed on the display 11 so that the most frequently used characters in the image are easy to see for the user. Can be scrolled. Thereby, the information described in the image can be confirmed even in the index display, and the convenience is improved.

Also in this case, the characters included in the index image can be displayed so as to be easy to see on the display 11.
In addition, if each embodiment of this invention is disclosed, it can be manufactured by those skilled in the art.
(E) Appendix (Appendix 1) An image display control device for displaying an image on a display screen,
A screen size information acquisition unit for acquiring information on the display size of the display screen;
An image information acquisition unit for acquiring information related to the vertical size and horizontal size of the image;
The scaling factor of the image is calculated so that at least one of the vertical direction and the horizontal direction of the image matches or substantially matches the displayable size of at least one of the vertical direction and the horizontal direction of the display screen. An arithmetic unit;
An image display control apparatus comprising: a display control unit that displays the image on the display screen at a scaling factor calculated by the calculation unit.

  (Supplementary Note 2) When the arithmetic unit matches or substantially matches the vertical direction of the image with the displayable size in the vertical direction of the display screen, and the displayable size in the horizontal direction of the display screen Calculating the scaling factor of the image in both cases of matching or substantially matching the image, selecting the larger scaling factor in the vertical direction or the horizontal direction of the image, and outputting to the display control unit The image display control device according to appendix 1, which is characterized.

(Supplementary note 3) An image display control device for displaying an image on a display screen,
A character size detector for detecting the size of characters in the image;
An arithmetic unit that calculates a scaling factor of the image based on the character size detected by the character size detection unit so that characters in the image are displayed at a predetermined size on the display screen;
An image display control apparatus comprising: a display control unit that displays the image on the display screen at a scaling factor calculated by the calculation unit.

(Additional remark 4) The said predetermined magnitude | size is given as a dimension (for example, about 2 mm-5 mm) of a character height direction, The image display control apparatus of Additional remark 3 characterized by the above-mentioned.
(Supplementary Note 5) The image display control device according to Supplementary Note 3, wherein the predetermined size is given as the number of pixels in the character height direction (for example, about 5 to 13 pixels).
(Additional remark 6) The said predetermined magnitude | size is given as an angle of view (for example, about 0.19-0.475 degree | times) of this character height direction, The image display control apparatus of Additional remark 3 characterized by the above-mentioned.

(Supplementary note 7) The image display control device according to any one of supplementary notes 1 to 6, further comprising a first storage unit that holds the scaling factor calculated by the calculation unit in association with the image. .
(Supplementary note 8) In any one of Supplementary notes 1 to 7, further comprising a second storage unit that holds display position information of the image displayed on the display screen in association with the image. The image display control device described.

(Supplementary note 9) The image display control device according to supplementary note 8, wherein the second storage unit holds the display magnification of the image displayed on the display screen in association with the image.
(Supplementary note 10) The image display control device according to any one of supplementary notes 1 to 9, further comprising a scroll processing unit that scrolls the image on the display screen.
(Supplementary Note 11) The image display control device according to any one of Supplementary Note 1 to Supplementary Note 10, wherein an index image created by reducing an original image is displayed on the display screen as the image.

(Supplementary note 12) The image display control device according to supplementary note 11, further comprising a third storage unit that holds position information of an image to be displayed in association with the original image when displaying the index image. .
(Supplementary note 13) An image display control method for displaying an image on a display screen of an image display device,
A screen size information acquisition step for acquiring information on the display size of the display screen;
An image information acquisition step of acquiring information related to the vertical size and horizontal size of the image;
The scaling factor of the image is calculated so that at least one of the vertical direction and the horizontal direction of the image matches or substantially matches the displayable size of at least one of the vertical direction and the horizontal direction of the display screen. A computation step;
An image display control method comprising: a display control step for displaying the image on the display screen at a scaling factor calculated in the calculation step.

  (Supplementary Note 14) In the calculation step, the vertical direction of the image matches or substantially matches the displayable size in the vertical direction of the display screen, and the displayable size in the horizontal direction of the display screen 15. The scaling ratio of the image in both the case of matching or substantially matching the image and calculating the scaling ratio of the image, and selecting the larger scaling ratio in the vertical or horizontal direction of the image Image display control method.

(Supplementary Note 15) An image display control method for displaying an image on a display screen of an image display device,
A character size detecting step for detecting a character size in the image;
A calculation step of calculating a scaling factor of the image based on the character size detected by the character size detection step so that characters in the image are displayed at a predetermined size on the display screen;
An image display control method comprising: a display control step for displaying the image on the display screen at a scaling factor calculated in the calculation step.

(Supplementary Note 16) a display screen for displaying an image;
A screen size information acquisition unit for acquiring information on the display size of the display screen;
An image information acquisition unit for acquiring information related to the vertical size and horizontal size of the image;
The scaling factor of the image is calculated so that at least one of the vertical direction and the horizontal direction of the image matches or substantially matches the displayable size of at least one of the vertical direction and the horizontal direction of the display screen. An arithmetic unit;
An image display device comprising: a display control unit that displays the image on the display screen at a scaling factor calculated by the calculation unit.

  (Supplementary Note 17) When the arithmetic unit matches or substantially matches the vertical direction of the image with the displayable size in the vertical direction of the display screen, and the displayable size in the horizontal direction of the display screen Calculating the scaling factor of the image in both cases of matching or substantially matching the image, selecting the larger scaling factor in the vertical direction or the horizontal direction of the image, and outputting to the display control unit The image display device according to appendix 16, which is a feature.

(Supplementary note 18) a display screen for displaying an image;
A character size detector for detecting the size of characters in the image;
An arithmetic unit that calculates a scaling factor of the image based on the character size detected by the character size detection unit so that characters in the image are displayed at a predetermined size on the display screen;
An image display device comprising: a display control unit that displays the image on the display screen at a scaling factor calculated by the calculation unit.

(Supplementary note 19) A computer-readable recording medium recording an image display control program for causing a computer to execute an image display control function for displaying an image on a display screen of an image display device,
The image display control program is
A screen size information acquisition unit for acquiring information on the display size of the display screen;
An image information acquisition unit for acquiring information related to the vertical size and horizontal size of the image;
The scaling factor of the image is calculated so that at least one of the vertical direction and the horizontal direction of the image matches or substantially matches the displayable size of at least one of the vertical direction and the horizontal direction of the display screen. An arithmetic unit;
A computer-readable recording medium storing an image display control program, wherein the computer is caused to function as a display control unit that displays the image on the display screen at a scaling factor calculated by the arithmetic unit.

  (Supplementary note 20) When the calculation unit matches or substantially matches the vertical direction of the image with the displayable size in the vertical direction of the display screen, and the displayable size in the horizontal direction of the display screen Calculating the scaling factor of the image in both cases of matching or substantially matching the image, selecting the larger scaling factor in the vertical direction or the horizontal direction of the image, and outputting to the display control unit A computer-readable recording medium on which the image display control program according to appendix 19 is recorded.

(Supplementary note 21) A computer-readable recording medium recording an image display control program for causing a computer to execute an image display control function for displaying an image on a display screen of an image display device,
A character size detector for detecting the size of characters in the image;
An arithmetic unit that calculates a scaling factor of the image based on the character size detected by the character size detection unit so that characters in the image are displayed at a predetermined size on the display screen;
A computer-readable recording medium storing an image display control program, wherein the computer is caused to function as a display control unit that displays the image on the display screen at a scaling factor calculated by the arithmetic unit.

  Note that when the image is displayed on the display screen according to Supplementary Note 1, at least one of the vertical direction or the horizontal direction of the image matches or substantially matches the displayable size of at least one of the vertical direction or the horizontal direction of the display screen. Since the display screens can be matched, the display screen can be used efficiently, and the image can be displayed in a large size on the display screen, making it easier to see the image displayed on the display screen and improving convenience. There are effects or benefits.

  Further, according to Supplementary Note 2, the larger the magnification ratio in the vertical or horizontal direction of the image matches or substantially matches the displayable size in the vertical or horizontal direction of the display screen, and the display screen can be used effectively. it can. That is, when an image is displayed on a rectangular display screen, the image can be displayed most greatly, and the image displayed on the display screen is easy to see and convenience is improved.

  Left and right can be easily selected using a switch attached to the chassis, and by installing a translucent hood on the side edge, it can be applied to applications where high brightness lighting is required and direct viewing of the input position by the operator is essential. .

It is a block diagram which shows the function structure of the image display apparatus provided with the image display control apparatus as 1st Embodiment of this invention. It is a block diagram which shows the hardware constitutions of the image display control apparatus in each embodiment of this invention. It is a figure which extracts and shows the image information for one page from the image information for a plurality of pages shown in FIG. It is a figure which shows the data structure of the display information regarding the image for several pages. It is a flowchart for demonstrating the control at the time of displaying an image on a display by the image display control apparatus as 1st Embodiment of this invention. It is a block diagram which shows the function structure of the image display apparatus provided with the image display control apparatus as 2nd Embodiment of this invention. (A) is a figure which shows a 2nd histogram, (b) is a figure which shows a 1st histogram, (c) is a figure which shows the example of the image containing a character. It is a flowchart for demonstrating the control method of the image display in the image display control apparatus in each embodiment of this invention. It is a flowchart for demonstrating the more concrete character size detection method of a character size detection part. It is a figure for demonstrating the relationship between the magnitude | size of a character displayed on the display, and a field angle. It is a block diagram which shows the function structure of the image display apparatus provided with the image display control apparatus as 3rd Embodiment of this invention. (A) is a figure for demonstrating the operation method of the key for index image switching, (b) is a figure which shows the example of the index image displayed on the display. It is a figure which shows typically the data structure of the display information memorize | stored in the image information storage part of the image display control apparatus as 3rd Embodiment of this invention. (A), (b) is a figure for demonstrating the index display in the conventional image display apparatus.

Explanation of symbols

1a, 1b, 1c Image display control device 2 Operation unit 3 Operation detection unit 4 Display information writing unit 5a Image information storage unit (first storage unit, second storage unit)
5b Image information storage unit (first storage unit, second storage unit, third storage unit)
6 Display Information Reading Unit 7 Display Control Unit 8a, 8b Image Processing Unit 9 Image Storage Unit 10 Display Memory 11 Display (Display Screen)
12 screen size information acquisition unit 13 image information acquisition unit 14a, 14b calculation unit 15 character size detection unit 20 MPU (image display control unit)
21 MPU core 22 I / O control unit 23 Non-volatile memory 24 RAM
25 Data bus 50a, 50b, 50c Image display device

Claims (3)

An image display control device for displaying an image on a display screen,
A character size detection unit for acquiring the size of characters in the image;
An arithmetic unit that calculates a scaling factor of the image based on the character size detected by the character size detection unit so that characters in the image are displayed at a predetermined size on the display screen;
An image display control apparatus comprising: a display control unit that displays the image on the display screen at a scaling factor calculated by the calculation unit.   The image display control apparatus according to claim 1, further comprising a scroll processing unit that scrolls the image on the display screen.   3. The image display control apparatus according to claim 1, wherein an index image created by reducing an original image is displayed on the display screen as the image.

Images