JP5292701B2 - Image display device - Google Patents

Description

  The present invention relates to a technique for combining a character image with an image provided from an external device and selectively displaying it on a plurality of types of display devices.

  Some electronic devices such as photo printers and digital cameras are provided with relatively small display means such as a liquid crystal display for displaying images. In these devices, an external display device having a larger screen, For example, there is a user request to display an image on a television receiver. In order to meet such a demand, for example, in the technology described in Patent Document 1, a video signal corresponding to a thumbnail image, a function selection image, or the like is output from an external output port of a stand-alone printer that is one of the electronic devices described above. The enlarged image is displayed on the external display device connected to the port.

Japanese Patent Application Laid-Open No. 2003-201557

  However, the display means provided in the electronic device main body and the external display device generally have different image sizes and the number of pixels, and the hardware configuration and image processing content required to obtain good image quality for each. Are also very different. For example, if the image data to be displayed on the display means of the apparatus main body is simply enlarged and displayed on the external display device, the image becomes coarse and the significance of displaying it on a large screen is lost. On the other hand, large memory resources are required to perform processing assuming a large screen in advance, and image data thinning-out processing is required to display the processed image on the display means of the device body. The image quality will deteriorate. In order to avoid this and obtain good image quality in any display device, it is necessary to provide an image processing unit corresponding to each.

  In the above prior art, although the point of switching the image display subject is described, how to process the image data to enable switching has not been studied in detail.

  The present invention has been made in view of the above problems, and in a technique for selectively displaying images on a plurality of types of display devices, an image can be displayed with good image quality on any display device while efficiently performing image processing. An object is to provide a technique that can be displayed.

In order to achieve the above object, an image display device according to the present invention provides image generation means for generating character image data in which at least one character is arranged in a character image layer having a predetermined number of pixels, and is provided from an external device. Image compositing means for creating composite image data corresponding to an image obtained by superimposing the external image layer created on the basis of the external image data and the character image layer, and display means for displaying an image corresponding to the composite image data A video signal output means for outputting a video signal corresponding to the composite image data to an external display device having a pixel number different from that of the display means, and a display subject of an image corresponding to the composite image data. Setting means for selectively setting whether to use the display means or the external display device, and the character image The number of pixels of the ear corresponds to the number of pixels of the display unit regardless of the setting contents of the setting unit, and the image synthesizing unit is configured such that the setting unit sets the display unit as a display subject. The external image data is developed on the external image layer having the number of pixels corresponding to the number of pixels of the display means and superimposed on the character image layer, while the setting means creates the composite image data. When the external display device is set as a display subject, the external image data is developed on the external image layer having the number of pixels corresponding to the number of pixels of the external display device, and the display means and the external display The character image layer is enlarged or reduced with the rearrangement of the character according to the ratio of the number of pixels to the display device, and the external image layer Wherein to create the composite image data by superimposing the serial character image layer, said video signal output means, when outputting the video signal to the external display device, capable of outputting a plurality of different signal formats from each other And a control unit for determining whether the signal format of the video signal output from the video signal output means is necessary, and when the signal format is determined to be necessary by the control unit. The image data for operation explanation explaining the setting operation of the signal format as a kind of the character image data is created in the character image layer, and the image data for operation explanation is sent to the display means, The operation explanation image data is sent to the video signal output means and the operation explanation is transmitted. The video signal corresponding to the image data for light is output from the video signal output means to the external display device, and corresponds to the image data for operation explanation when the signal format is compatible with the external display device. Although an image is displayed on the display means and the external display device, and the signal format is not compatible with the external display device, an image corresponding to the operation explanation image data is displayed on the display means. It is characterized by not being displayed on an external display device .

  Here, enlarging or reducing the character image layer means enlarging or reducing the size of the character placed in the layer and the distance from the reference position. The image layer created by placing a character in the image plane can be enlarged or reduced by interpolating or thinning out pixels in the image layer after creation, or in the image plane after enlargement or reduction. This can also be achieved by recalculating the position of the character placed at the position and rearranging the character at that position.

  In the invention configured as described above, the external image data is developed into an image layer corresponding to the number of pixels of the display subject set by the setting unit. Therefore, regardless of which of the display means provided in the apparatus main body and the external display device is selected as the display subject, image data corresponding to the display subject can be created and displayed with good image quality. On the other hand, the character image data is always created as image data on only one type of image layer corresponding to the number of pixels of the display means of the apparatus main body, so that the processing contents are the same regardless of the display subject and the processing is simple. It becomes. And when displaying an image on the display means provided in the apparatus main body, the character image layer and the external image layer may be superimposed as they are. On the other hand, when displaying on an external display device, the character image layer is enlarged or reduced in accordance with the number of pixels of the external display device at the stage of overlapping with the external image layer, but the character originally requires high resolution. In particular, degradation of image quality hardly poses a problem when enlargement / reduction is performed not by simple enlargement / reduction of image data that has been developed, but by rearrangement of characters in the image layer.

  Then, by displaying an image corresponding to the combined image data on the selected display main body, in the present invention, the image processing can be performed efficiently even if the image is displayed on any of the different display main bodies. It is possible to display an image with good image quality. In addition, since it is not necessary to provide a means for performing image processing separately according to the display subject, the apparatus configuration is simplified.

  The present invention further comprises storage means for individually storing the character image data generated by the image generation means and image data obtained by developing the external image data according to the number of pixels of the display main body, The image composition means is particularly effective in an apparatus configured to create the composite image data based on the image data read from the storage means. This is because according to the present invention, the amount of data to be stored for both the character image data and the external image data is one layer, and the data capacity can be reduced.

  In particular, the effect of the present invention is remarkable when the video signal output means is configured to output the video signal to an external display device having a larger number of pixels than the display means. This is because when the number of pixels of the character image layer is matched with that of the external display device, the number of pixels of the character image layer increases according to the number of pixels of the external display device and the data capacity increases. This is because such a problem does not occur because the number of pixels of the display means is adjusted.

  In the image display device configured as described above, for example, when the setting unit sets the external display device as a display subject, the video signal output unit outputs a video signal corresponding to the composite image data. On the other hand, the display by the display means may not be performed. By doing so, it is possible to prevent an image with inferior image quality from being displayed on the display means that does not match the composite image data.

  Further, for example, when the setting means sets the external display device as a display subject, the video signal output means outputs a video signal corresponding to the synthesized image data, while the display means outputs the character image data. An image corresponding to may be displayed. This is because the character image data is originally generated according to the number of pixels of the display means and can be displayed without degrading the image quality.

  The technical idea of the present invention is not limited to that having the display means in the apparatus body as described above, and an apparatus having a function of selectively displaying images on at least a plurality of types of display apparatuses having different pixel numbers. Is applicable.

  FIG. 1 is a perspective view showing a photo printer which is an embodiment of the image display apparatus of the present invention. FIG. 2 is a diagram showing an outline of the internal configuration of the photo printer. In this photo printer 10, a printing mechanism 50 (see FIG. 2) is built in the printer main body 12, and in response to an operation command from a controller 70 (see FIG. 2) that controls the entire photo printer 10. Printing on the paper P is executed. Then, the printed paper is discharged to the front surface of the printer main body 12.

  As shown in FIG. 1, a front door 14 is attached to the front surface of the printer main body 12 so as to be freely opened and closed. The front door 14 is a lid for opening and closing the front surface of the printer main body 12. In the open state, it functions as a paper discharge tray for receiving the paper P discharged from the print mechanism 50. In addition, various memory card slots 16 provided on the front surface of the printer main body 12 can be used by the user. That is, in this state, the user can insert the memory card M storing the image file to be printed into the memory card slot 16. The external medium for storing the image file data is not limited to the memory card, but may be another one such as a USB memory or a disk medium. Further, an electronic device such as a digital camera or a mobile phone that stores images may be connected to the photo printer 10 by communication using a cable or infrared rays so as to function as an external medium.

  An operation panel 20 is provided on the upper surface of the printer main body 12, and a cover 30 is attached to an inner side of the upper surface of the printer main body 12 so as to be freely opened and closed. The cover 30 is a resin plate formed in a size that can cover the upper surface of the printer main body 12, and exposes the surface of the operation panel 20 to the outside in the open state (see FIG. 1). On the other hand, when the cover 30 is closed, the entire operation panel 20 is covered.

  The operation panel 20 includes a display unit 22 configured by, for example, an LCD display for displaying characters, graphics, symbols, and the like, and a button group 24 arranged around the display unit 22. As shown in FIG. 2, the button group 24 includes a power button 24a for turning on / off the power, a menu button 24b for calling the main menu screen, canceling the operation in the middle, and interrupting the printing on the paper P in the middle. A cancel button 24c for printing, a print button 24d for instructing execution of printing on the paper P, a save button 24e for saving an edited image in the memory card M inserted in the memory card slot 16, a display unit Each of the up / down / left / right arrow buttons 24f to 24i operated when selecting a desired option from the plurality of options displayed on the screen 22 or moving the cursor, and the up / down / left / right arrow buttons 24f to 24i. An OK button for instructing that the option selected by the arrow buttons 24f to 24i arranged in the center is selected. 24j, a display switching button 24k for switching the screen display on the display unit 22, a left guide selection button 24l for selecting the left guide displayed on the display unit 22, and a right for selecting the right guide displayed on the display unit 22. It includes a guide selection button 24m, a paper discharge tray open button 24n for opening the front door 14 having a function as a paper discharge tray, and the like.

  Further, in order to confirm the display content of the display unit 22, the cover 30 is provided with a window 32 having the same size as the display unit 22. That is, when the cover 30 is in the closed state, the user can check the display content of the display unit 22 through the window 32. On the other hand, when the cover 30 is in the open state, the display unit 22 can be adjusted to a desired angle as shown in FIG.

  Thus, when the cover 30 is in the open state, the cover 30 is held while being inclined obliquely rearward with respect to the operation panel 20 and can be used as a tray for supplying the paper P to the print mechanism 50. . Further, at the back of the operation panel 20, a paper feed port 58 of the print mechanism 50 is provided, and a pair of paper guides 59 that are slid in the left-right direction so that the guide width matches the paper width are provided. .

  Then, the paper P is sent to the print mechanism 50 through the paper supply port 58 and printing is executed. As shown in FIG. 2, the carriage 53 is driven by a timing belt 51 spanned in a loop shape in the left-right direction and reciprocates left and right along the guide 52. The carriage 53 is provided with a paper edge detection sensor 57 for detecting the left and right edges and the upper and lower edges of the paper P. In other words, the paper edge detection sensor 57 detects the left and right edges of the paper set in the paper supply port 58 before the printing, and allows the paper width to be recognized by detecting the right and left edges of the paper. Or detecting the trailing edge of the paper during printing to enable recognition of the paper length.

  The carriage 53 is mounted with an ink cartridge 54 that individually accommodates ink of each color such as cyan, magenta, yellow, and black. Each of these ink cartridges 54 is connected to a print head 55. The print head 55 applies pressure to the ink from the ink cartridge 54 and ejects the ink from the nozzle (not shown) toward the paper P. In this embodiment, the print head 55 employs a method in which a voltage is applied to the piezoelectric element to deform the piezoelectric element and pressurize the ink. However, a voltage is applied to the heating resistor (for example, a heater) to apply the ink. You may employ | adopt the system which pressurizes ink with the bubble generated by heating. The printed paper P is sent out to the opened front door (paper discharge tray) 14 by the transport roller 56.

  Although not shown, a battery pack can be attached to the back surface of the printer main body 12, and the printer 10 can be operated by a battery without being connected to a commercial power source. Because of this point and the fact that the printer 10 is a stand-alone printer that can be used without being connected to a host computer, the printer 10 is easy to carry and can be used anywhere.

  FIG. 3 is a block diagram showing the configuration of the controller. As shown in FIG. 3, the controller 70 is configured as a microprocessor centered on a CPU 711, and includes a ROM 72 that stores various processing programs and various data, various programs and various tables, and a RAM 73 that temporarily stores data. And an interface (I / F) 75 that enables communication with the printer mechanism 50, the memory card slot 16, and the like. Further, the controller 70 stores an edited image or the like in the memory card M, and outputs a control signal to the print head 55 of the print mechanism 50 and a control signal to the display 22 of the operation panel.

  In addition, the controller 70 is provided with an image processing module 712 for performing necessary image processing on image data provided from an external storage medium such as a memory card M through the interface 75. The image processing module 712 also has a function of generating image data corresponding to a printer-specific image such as a menu screen to be displayed on the display unit 22. A video RAM (VRAM) 713 for temporarily storing image data is connected to the image processing module 712.

  The RGB image data output from the image processing module is sent to an LCD controller 771 for controlling the display of the display unit 22 and a video encoder 772 for converting the RGB image data into a video signal compliant with the television broadcasting system. Given in parallel or selectively. In the following, the number of pixels of the display unit 22 constituted by the LCD display is 320 dots × 240 dots in the QVGA (Quarter Video Graphics Array) format, and the number of pixels of the video signal output to an external device such as a television receiver is It is assumed that the size is 640 dots × 480 dots in VGA (Video Graphics Array) format.

  The video encoder 772 has a function of outputting video signals of a plurality of television broadcasting systems having different signal formats, that is, a PAL system, an NTSC system, and a SECAM system, and among these, a format selection signal given from the CPU 711 is used. A video signal conforming to one designated signal format is output. The video signal is output to the output terminal 774 via the video amplifier 773, and the user displays an image on the television screen by connecting an external television receiver TV to the output terminal 774 via the video cable VC. Let me enjoy it. In addition, since a plurality of television broadcasting systems can be supported, the user can carry the photo printer 10 and connect it to a television receiver at a desired location.

  The output terminal 774 is provided with a television connection detection circuit 775. The television connection detection circuit 775 detects whether or not a television receiver serving as a load is connected depending on whether the output terminal 774 is open or terminated with a predetermined impedance (typically 75Ω). More preferably, the television receiver connected to the output terminal 774 may be configured to detect whether or not an image can be displayed.

  When the television receiver TV is connected to the output terminal 774, an image can be displayed on the television receiver TV by outputting a video signal from the printer 10 side. However, a plurality of incompatible video signal formats for the television broadcasting system are used all over the world, and the television receiver TV can accept the images in order to display the images correctly on the television receiver TV. It is necessary to output a video signal conforming to the signal format. Even if the format of the video signal output from the printer can be selected, it is not user-friendly to have the user select and set it in accordance with each television receiver. This is because a user who does not have expertise does not always know the signal format of the television receiver. Also, if the signal format is not compatible, abnormal video will be displayed or nothing will be displayed on the TV screen, but for general users it is due to signal format incompatibility or due to device abnormality It is not easy to judge whether it is a thing.

  Therefore, in the photo printer 10 according to this embodiment, a video signal output adapted to the signal format of the television receiver can be easily and surely performed even by a user having no specialized knowledge by executing the initial operation described below. It is possible to set.

  FIG. 4 is a flowchart showing an initial operation in this photo printer. In the photo printer 10, when the apparatus is turned on, the CPU 70 executes a program stored in advance in the ROM 72 of the controller 70, whereby the initial operation shown in FIG. 4 is executed. Further, even immediately after the power is turned on, for example, when the television connection detection circuit 775 detects that a new television receiver is connected, or when the execution of the initial operation is instructed by a user operation, the initial operation is performed. The action is executed. An instruction for executing an initial operation by a user operation can be selected from a menu screen displayed when the menu button 24b is pressed, for example.

  In the initial operation, it is first determined whether or not the television receiver is connected based on the detection result of the television connection detection circuit 775 (step S101). When a television receiver is connected to output terminal 774 (YES in step S101), it is subsequently determined whether format setting is necessary (step S102). When it is determined that the format setting is necessary, the format determination process (step S103) is subsequently executed to determine the signal format of the output signal. Whether or not format setting is necessary can be determined as follows, for example.

  That is, if the format has never been set in the device, it is determined that the format setting is necessary. In addition, format setting is required even if settings have been made in the past but the prohibition setting operation described later has not been performed by the user, and when the initial operation has been started by a user operation. It is judged that. On the other hand, if the setting has been performed in the past and the prohibition setting operation has been performed by the user at that time, it is determined that the format setting is unnecessary.

  FIG. 5 is a flowchart showing the format determination process. In this process, first, an image for operation explanation to be displayed on the display unit 22 is created on the character image layer which is a virtual layer on the VRAM 713 by the image processing module 712 (step S201). In this operation explanation image, characters preliminarily stored in the ROM 72 such as characters for explaining the operation and cursor symbols are arranged at predetermined positions on a 320 dot × 240 dot plane corresponding to the size (QVGA) of the display unit 22. This is an image.

  Then, the CPU 711 outputs a format selection signal to the video encoder 772 and temporarily sets the signal format of the video signal output from the video encoder 772 to a predetermined initial format (step S202), and the operation description from the image processing module 712. RGB image data corresponding to the work image is sent in parallel to the LCD controller 771 and the video encoder 772 (step S203).

  FIG. 6 is a diagram illustrating an example of an operation explanation image. As shown in FIG. 6, the operation explanation image 22a to be displayed on the display unit 22 is a matter to be confirmed by the user that the output mode setting operation is currently being executed (in this example, “correctly displayed on the TV screen”). Message is displayed? ") And a message to the user such as a description of the button to be operated. Here, the user is guided to press the OK button 24j when a correct image is displayed on the television screen, and to press other buttons when nothing is displayed. In this way, by assigning a button that accepts an operation in the format determination process to a button that is used to realize another function in the normal operation, a special operation input for a format determination process with a low effective frequency is performed. There is no need to provide means.

  The operation image 22 a is displayed on the display unit 22. On the other hand, on the TV receiver TV side, the same image is displayed if the signal format of the video signal sent from the printer side is compatible with that of the TV receiver, but what if the signal format is not compatible? Also not reflected.

  Returning to FIG. 5, the description of the format determination process will be continued. Since the user performs a predetermined button operation in accordance with the operation image displayed on the display unit 22, the user waits for any button operation (step S204), and determines what the pressed button is (step S205). . If the pressed button is other than the OK button, it means that the correct image is not currently displayed on the TV screen, that is, the signal format is not compatible with the TV receiver. Therefore, in this case, the signal format is switched to another one (step S206), and the video signal is transmitted again. As described above, when a button other than the OK button is pressed, the video signal is transmitted while sequentially switching the signal format according to the operation. In this way, a video signal suitable for the television receiver TV is output and a correct image is displayed. In addition, since the signal format is switched according to the user's button operation, even a user who is unfamiliar with the operation can perform the operation without panicking.

  In this embodiment, the operation explanation image displayed on the display unit 22 and the image displayed on the external television receiver TV are the same. However, the present invention is not limited to this, and the images may be different from each other. However, if both images have the same content, the projected image may be output from the printer only by looking at the television screen. It is convenient because it understands. In addition, an image displayed on the television screen has a small QVGA size, but this is not a problem for the purpose of setting the signal format of the video signal. In order to avoid this, it is possible to display an enlarged image without degrading the image quality by performing character rearrangement on the screen by an enlargement operation of a character image layer described later.

  If the button pressed at a certain point in time is an OK button, it means that the currently set signal format is compatible with the TV receiver TV. The signal format is set (step S207). Thereby, since the subsequent video signals are transmitted in the selected signal format, the user can immediately display an image on the television receiver unless the setting is changed.

  Further, in order to use the signal format selected here for the first time when the format determination process is performed next, the current signal format is set as the initial format in the next format determination process (step S208). The television broadcasting system is often fixed for each region, and the frequency of selecting the signal format is not so high, but the next format is decided by setting the previously selected signal format as a new initial format. The probability that the signal format used first in the processing is the desired one becomes high, and it becomes possible to reduce the time and time required for setting by reducing the operation time.

  Further, the user is allowed to select whether or not the subsequent format setting is prohibited (step S209). Unless the device is moved between areas with different broadcasting systems, basically, once the format setting is performed, it is not necessary thereafter. For example, if the format determination process described above is automatically executed each time the power is turned on, the user It is cumbersome for me. Therefore, if the user selects prohibition, the subsequent format determination process is prohibited (step S210), and the format determination process is not executed unless necessary, so that such a problem can be solved. . When it is desired to set the signal format again, it can be selected from the menu screen.

  As described above, in the photo printer 10 of this embodiment, a video signal is output while sequentially switching a plurality of signal formats, and the user presses a predetermined button when an image is displayed on an externally connected television screen. By doing so, the format of the video signal suitable for the television receiver TV is specified. Therefore, the user can easily and surely select an appropriate signal format and display a correct image on the television receiver without knowing the signal format adopted for the television receiver used by the user.

  Further, simply outputting a video signal for confirming the display does not allow the user to know what is the cause when the image is not displayed on the television screen and what to do to display correctly. On the other hand, in this embodiment, since the operation to be performed by the user is clearly indicated on the display unit 22 provided in the printer main body 12, the user can select the correct signal format without hesitation in the operation. Further, by making the content of the image output to the television receiver the same as the content of the image to be displayed on the display unit 22, the image displayed on the television screen is output from the printer 10 for the user. In addition, since the next operation to be performed is displayed on the television screen, the user can be made to perform the correct operation. In addition, since it is not necessary to individually prepare images to be displayed on the respective screens in the printer 10, the processing is simplified and memory resources are also saved.

  Returning to FIG. 4, the description of the initial operation will be continued. When the television receiver is not connected, when the format setting is unnecessary, and when the format determination process ends, an image corresponding to one of the image files such as a photographic image subsequently stored in the external medium Data (hereinafter referred to as “external image data”) is read out and developed into an external image layer which is a virtual layer on the VRAM 713. The image size at this time is assumed to be equivalent to QVGA (320 × 240 dots) corresponding to the display unit 22 (step S104). In addition, in order to display the operation icons, the remaining battery level, and the like in combination with the image, character image data corresponding to an image in which these icons are arranged in the QVGA size character image layer is separately generated (step S105). This image is formed by arranging characters whose image patterns are stored in advance in the ROM 72 while designating their coordinate positions.

  Subsequently, it is determined whether or not a television receiver is connected to the output terminal 774 (step S106). When the television receiver is not connected, the image is displayed on the display unit 22 provided at the top of the printer. That is, the image processing module 712 creates composite image data by superimposing the image data of the external image layer and the character image layer created in the QVGA size, and outputs them to the LCD controller 771 (step S107). . Thus, the character image generated in the printer is superimposed on the image read from the external medium and displayed on the display unit 22.

  On the other hand, when a television receiver is connected, the following is performed. In order to display an image on a television receiver, image data corresponding to the VGA size must be regenerated. This is because the image to be displayed becomes smaller if the QVGA size is maintained, and the significance of displaying on a large screen is diminished. First, the external image data is re-developed as a VGA size image on the external image layer of the VRAM 713 (step S108). In this case, it is not preferable to enlarge and use the image once developed to the QVGA size in step S104. This is because mere enlargement causes the image to become rough and the image quality to deteriorate significantly. Therefore, it is desirable to use the external image data stored in the external medium again and re-expand the image to obtain a VGA size image.

  On the other hand, character image data is basically a combination of characters and symbols and does not require a high resolution from the start because it is sufficient to ensure a certain level of legibility. In addition to this, the image is created by designating the coordinates on the image plane and arranging the characters. Therefore, by re-designating the coordinates, the image quality is reduced unlike when the image is simply enlarged by interpolation. It is possible to easily enlarge an image without deteriorating.

  Therefore, the character image layer is enlarged to the VGA size by recalculating the coordinate position according to the VGA size and rearranging each character, and is superposed on the previously developed external image layer of the VGA size. Thus, composite image data is obtained (step S109). By sending the composite image data thus obtained to the video encoder 772, a video signal corresponding to a VGA size image is given to the television receiver and the image is displayed.

  FIG. 7 is a conceptual diagram showing a state of image composition. When the display destination of the image is the display unit 22 which is an LCD display, as shown in FIG. 7A, the character image layer and the external image layer both developed in the QVGA size on the VRAM 713 are the image processing module 712. The composite image data obtained in this manner is output to the LCD controller 771 and the composite image is displayed on the display unit 22.

  On the other hand, when the image display destination is an external television receiver TV, as shown in FIG. 7B, the image processing module 712 displays each character on the character image layer created in the QVGA size. By recalculating the coordinate position, it is rearranged on the image plane of VGA size, and this is superimposed on the external image layer developed to VGA size, thereby obtaining VGA size composite image data. The composite image data obtained in this manner is sent to the video encoder 772, and the video encoder 772 outputs the selected signal format video signal, whereby the composite image is displayed on the television receiver TV.

  As described above, in this embodiment, since the image read from the external medium is displayed based on the image data developed in accordance with the image size of the display destination, it is good in any display destination. Image quality is obtained. Further, since the character image generated in the printer is enlarged by rearrangement of each character, good image quality can be obtained. This also makes it possible to reduce the required VRAM capacity.

  FIG. 8 is a diagram showing a memory map of the VRAM. The VRAM 713 stores image data corresponding to each of the character image layer and the external image layer. As described above, the character image layer is created in the QVGA size regardless of the display destination of the image. It is sufficient that a data area of 320 × 240 dots is secured. As for the external image layer, when the image display destination is an external television receiver TV, the image is developed in the VGA size, so that a data area of 640 × 480 dots is required. Therefore, as the data capacity of the VRAM 713, it is sufficient that the capacity obtained by adding the QVGA size for one screen to the VGA size for one screen is a minimum. This is greatly reduced compared to the capacity for securing the VGA size data capacity for both image layers and the capacity for individually preparing the screens corresponding to each of the display unit 22 and the television receiver TV. Yes. In particular, the effect is great when there are a plurality of character image layers.

  FIG. 9 is a diagram showing image composition in the case of having a plurality of character image layers. More specifically, FIG. 9A is a conceptual diagram showing a state of image composition when a plurality of character image layers and an external image layer are overlapped to create VGA size composite image data. FIG. 9B is a diagram showing a VRAM map for enabling this. When a plurality of character image layers are provided, frames, characters, decorative parts, and the like to be displayed together with an image given from an external medium can be arranged on individual layers to increase the degree of freedom of image editing. In this case, as shown in FIG. 9A, each character image layer is created in a QVGA size. Then, each character image layer is synthesized while being enlarged to the VGA size by rearranging the characters, and is temporarily stored in a data area corresponding to the synthesized character image layer provided on the VRAM 713, and thus obtained VGA size synthesized character image is obtained. Composite image data is created by superimposing a layer and an external image layer of a VGA size separately developed.

  In this case, as shown in FIG. 9B, a data area of 640 × 480 dots is required on the VRAM 713 in order to save the composite character image layer. Compared with the case where images are individually developed on the VRAM 713, the memory size can be greatly reduced.

  As described above, in this embodiment, a character image layer having no image deterioration caused by enlargement / reduction is created with a small QVGA size regardless of the display destination, while an external image layer in which image quality is important. Develops images according to the size of the display destination, and superimposes them to create composite image data. Therefore, good image quality can be obtained at any display destination. Further, it is not necessary to provide an image processing module for each display destination, and image data processing for displaying an image on a different display destination can be performed efficiently.

  As described above, in the above-described embodiment, the image processing module 712 also functions as the “image generation unit” and “image composition unit” of the present invention. The display unit 22, the video encoder 772, and the CPU 711 function as “display means”, “video signal output means”, and “setting means” of the present invention, respectively. In the above embodiment, the VRAM 713 functions as the “storage unit” of the present invention. In the present embodiment, the memory card M corresponds to the “external device” of the present invention, and the television receiver TV corresponds to the “external display device” of the present invention.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, in the above embodiment, the case where the display unit 22 of the main body of the photo printer 10 is QVGA size and the television receiver TV as an external display device is VGA size has been described. However, the image size is limited to these. Alternatively, at least one of the other sizes may be used. In the above embodiment, the external display device has a larger number of pixels, but the reverse may be possible.

  Further, in the above-described embodiment, although the image is displayed on the television receiver TV, that is, the content of the display on the display unit 22 as the display unit when the external display device is a display main body is not mentioned, For example, it can be as follows. First, it is conceivable to display an image having the same content as that of the external display device. However, in the present embodiment, image processing is not performed separately for the external display device and for the internal display means, so the image displayed on the display unit 22 is a pixel of the image displayed on the external display device. Therefore, the image quality is deteriorated. As a second method for avoiding this, the display unit 22 may not display the image when the image is displayed outside. Thirdly, only the character image layer may be displayed on the display unit 22. In this case, the image data before enlargement may be output to the LCD controller 771, or the image data after enlargement may be thinned out to match the size of the display unit 22. This is because the character image is less deteriorated by thinning.

  The photo printer 10 of the present embodiment is a device that includes the display unit 22 and can output a video signal to an external display device, and corresponds to the “image display device” of the present invention. The application target of the present invention is not limited to this. That is, the present invention is applied to a display control apparatus that does not have display means, and that has an electronic device function of outputting a video signal to a plurality of external display apparatuses having different numbers of pixels. Is possible. In such a display control device, a character image layer may be provided corresponding to the smallest image size among the image sizes that can be handled.

  Further, the present invention is applied not only to the photo printer as in the above embodiment but also to an electronic apparatus configured to output a video signal to an external display device such as a digital camera or a PDA (Personal Digital Assistant) device. be able to. In particular, the present invention is effective in an apparatus configured to superimpose and output image data generated by the apparatus itself on image data given from an external medium. Furthermore, since the image to be displayed is not limited to a still image, the present invention can be applied to a device that outputs a moving image such as a movie camera.

1 is a perspective view showing a photo printer which is an embodiment of an image display device of the present invention. FIG. 2 is a diagram illustrating an outline of an internal configuration of a photo printer. The block diagram which shows the structure of a controller. 3 is a flowchart showing an initial operation in this photo printer. The flowchart which shows a format determination process. The figure which shows an example of the image for operation description. The conceptual diagram which shows the mode of image composition. The figure which shows the memory map of VRAM. The figure which shows the image composition in the case of having a some character image layer.

Explanation of symbols

  22 ... Display unit (display means), 711 ... CPU (setting means), 712 ... Image processing module (image generation means, image composition means), 713 ... VRAM (storage means), 772 ... Video encoder (video signal output means) M ... Memory card (external device) TV ... Television receiver (external display device)

Claims (5)

Image generating means for generating character image data in which at least one character is arranged in a character image layer having a predetermined number of pixels;
Image compositing means for creating composite image data corresponding to an image obtained by superimposing the external image layer created on the basis of external image data given from an external device and the character image layer;
Display means for displaying an image corresponding to the composite image data;
Video signal output means for outputting a video signal corresponding to the composite image data to an external display device having a different number of pixels from the display means;
Setting means for selectively setting whether the display main body of the image corresponding to the composite image data is the display means or the external display device;
The number of pixels of the character image layer corresponds to the number of pixels of the display means regardless of the setting contents of the setting means,
The image composition means includes
When the setting means sets the display means as a display subject, the external image data is developed on the external image layer having the number of pixels corresponding to the number of pixels of the display means, and is superimposed on the character image layer. While creating the composite image data by combining,
When the setting means sets the external display device as a display subject, the external image data is developed on the external image layer having the number of pixels corresponding to the number of pixels of the external display device, and the display The character image layer is enlarged or reduced with the rearrangement of the character in accordance with the ratio of the number of pixels between the means and the external display device, and the external image layer and the character image layer are overlapped to overlap the character image layer. Create composite image data ,
The video signal output means can output the video signal in a plurality of different signal formats when outputting the video signal to the external display device,
A control unit for determining whether or not the signal format of the video signal output from the video signal output unit needs to be set;
When it is determined that the setting of the signal format is necessary by the control unit, operation explanation image data explaining the setting operation of the signal format is created in the character image layer as a kind of the character image data, The operation explanation image data is sent to the display means, and the operation explanation image data is sent to the video signal output means, and the video signal corresponding to the operation explanation image data is output to the video signal. Output from the means to the external display device,
When the signal format is compatible with the external display device, an image corresponding to the operation explanation image data is displayed on the display means and the external display device, and the signal format is compatible with the external display device. If not, an image corresponding to the operation explanation image data is displayed on the display means but not displayed on the external display device. A storage means for individually storing the character image data generated by the image generation means and image data obtained by developing the external image data according to the number of pixels of the display main body;
The image display device according to claim 1 , wherein the image composition unit creates the composite image data based on the image data read from the storage unit. It said video signal output means, an image display apparatus according to claim 1 or 2 is configured to output the video signal to an external display device a large number of pixels than the display unit. 2. The video signal output unit outputs a video signal corresponding to the synthesized image data while the setting unit sets the external display device as a display subject, and does not perform display by the display unit. 4. The image display device according to any one of 3 . When the setting means sets the external display device as a display subject, the video signal output means outputs a video signal corresponding to the synthesized image data, while the display means outputs an image corresponding to the character image data. It claims 1 to display a to the image display apparatus according to any one of the three.

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