JP2009282307A - Image signal output device and image signal output method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image signal output device capable of updating an image with excellent appearance, while suppressing an increase in a processing load. <P>SOLUTION: A first map image signal output device outputs an image signal for displaying a combined image of a map image displayed by an image signal which is already output, and a map image displayed an image signal to be output next, three times after the image signal based on map image signal data is output, till the image signal based on updated map image data is output. In the combined image, the mixing ratio of the map image displayed by the image signal which is already output, and the map image displayed by the image signal which is to be output next is set 3-to-1, 1-to-1 and 1-to-3, in the order sequentially from the combined image data which are generated first. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  When performing a route guidance or the like, the navigation device generates a map image around the current location of the host vehicle based on map data stored in a storage medium such as a DVD-ROM or HDD, and displays the map image on a display. At this time, the navigation device periodically updates the displayed map image with the movement of the host vehicle. For example, when the moving speed of the host vehicle is high, the navigation device may change the traveling direction of the host vehicle or the current location. Accordingly, the map image cannot be changed smoothly, and the appearance may deteriorate. In order to solve this problem, it is only necessary to increase the update frequency of the map image displayed on the display. However, this increases the processing load on the CPU, graphic controller, etc., bus traffic, etc. Will become bigger. In particular, if the processing load on the CPU, bus traffic, etc. increase, there is a risk that processes other than the drawing process will be delayed. Therefore, the update frequency of the map image cannot be increased unless hardware with high processing capability is used.

  Here, Patent Document 1 and Patent Document 2 describe a map drawing method and the like for rotating a map image in accordance with a change in the traveling direction of the host vehicle. In the map drawing method described in Patent Literature 1, while the vehicle orientation is changing, a simple image, which is a map image composed only of roads, place names, map symbols, and the like, is drawn according to the vehicle orientation. Further, in the map drawing method described in Patent Document 2, when the traveling direction of the host vehicle changes, the road on which the host vehicle is traveling or a road in the vicinity of the road is preferentially drawn and displayed on the screen. By doing so, it is possible to reduce the processing load on the CPU and the like when rotating the map image.

Further, in the map display method described in Patent Document 3, the map image is rotated only when the traveling direction of the host vehicle changes by a predetermined angle. By doing so, it is possible to reduce the frequency of rotating the map image in accordance with the change in the traveling direction of the host vehicle, so that the processing load on the CPU or the like can be reduced.
Japanese Unexamined Patent Publication No. 6-139494 Japanese Patent Laid-Open No. 6-195023 JP-A-6-331374

  However, in Patent Document 1, a simple image is displayed while the vehicle orientation is changing. However, since this simple image is a map image made up of roads, place names, map symbols, etc., it looks bad. . Moreover, in patent document 2, when the advancing direction of the own vehicle changes, since only the road etc. in which the own vehicle is traveling are drawn and other roads are not drawn, the appearance is deteriorated.

  In addition, in the map display method described in Patent Document 3, the map image is rotated only when the traveling direction of the host vehicle changes by a predetermined angle. When the traveling direction changes greatly, the map image must be rotated, and the processing load on the CPU or the like cannot be reduced.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide an image signal output device capable of updating an image with good appearance while suppressing an increase in processing load.

  In the invention according to claim 1 made to solve the above-described problem, the image signal output device includes first storage means for storing first original image data indicating the first original image, and second A second storage means for storing the second original image data indicating the original image; the first original image data is generated and stored in the first storage means; and the second original image data is generated. First generation means to be stored in the second storage means and first original image data stored in the first storage means are read, and then the second original image data is replaced with the second original image data. Read control means for reading the second original image data stored in the storage means. Further, the image signal output apparatus is configured such that after the first original image data is read from the first storage means by the read control means, the second original image data is read from the second storage means. Based on the first original image data stored in the first storage means and the second original image data stored in the second storage means. First composite image data generating means for generating composite image data indicating a composite image that is an image combined with an image according to a predetermined mixing ratio is provided. The image signal output device outputs an image signal based on the original image data read by the read control means, and when the composite image data is generated by the composite image data generation means, Instead, first output means for newly outputting an image signal based on the composite image data is provided.

The first storage unit and the second storage unit may be, for example, a VRAM.
Also known is a function called alpha blend that synthesizes two images according to a predetermined mixing ratio. The first composite image data generation means may generate composite image data based on the first image data and the second image data by this alpha blending.

  For example, in the case where the display image is switched at a predetermined update cycle, such as when the navigation device updates the map image being displayed as the host vehicle moves, the image before switching and the image after switching When the difference is large, it looks bad. Therefore, in the image signal output device according to claim 1, after outputting the image signal based on the first image data and before outputting the image signal based on the second image data, An image signal based on synthesized image data indicating a synthesized image that is an image obtained by synthesizing the second image with a predetermined mixing ratio is output. By doing so, the switching from the first image to the second image can be performed with good appearance. The composite image data is an image generated based on the first image data and the second image data that have already been generated. For this reason, the processing load when combining the first image data and the second image data according to a predetermined mixing ratio is smaller than the processing load when generating the first image data and the second image data. In this case, the processing load can be reduced as compared with the case where the image update frequency is increased. Therefore, the image signal output apparatus according to the first aspect can update the screen with a good appearance while suppressing an increase in processing load.

Further, the first composite image data generation means provided in the image signal output device may have the following configuration.
That is, as described in claim 2, the first composite image data generation means may be constituted by a dedicated circuit for the means.

By having such a configuration, it is possible to generate composite image data without increasing the processing load of the CPU, for example.
Further, the image signal output device may have the following configuration.

  That is, as described in claim 3, the reading control means includes the first original image data stored in the first storage means and the second original image data stored in the second storage means. The first composite image data generation means reads the second original image data from the second storage means by the read control means and then reads the first composite image data from the first storage means. Based on the first original image data stored in the first storage means and the second original image data stored in the second storage means until the original image data is read out, Image data may be newly generated. The first generation means starts generation of composite image data by the first composite image data generation means after the read control means reads the first original image data from the first storage means. Until the newly generated second original image data is stored in the second storage means, and after the second original image data is read from the second storage means by the read control means, The newly generated first original image data may be stored in the first storage unit until the generation of the composite image data is started by one composite image data generation unit.

By doing so, it is possible to continuously update the image with good appearance while suppressing an increase in processing load.
Further, the image signal output apparatus may change the mixing ratio of the composite image as follows.

  In other words, as described in claim 4, the first composite image data generating means is either one of the first storage means and the second storage means by the read control means. After the original image data is read out from the other storage means, a plurality of composite image data is generated during the period until the original image data is read out from the other storage means. You may increase the ratio of the original image which the original image data read out from a memory | storage means later in the mixing ratio which concerns on the synthesized image which the synthesized image data to produce | generate shows.

By doing this, when updating the image, the image can be changed more smoothly, and the image can be updated with better appearance.
The image signal output device may update the map image.

  That is, as described in claim 5, the first original image indicated by the first original image data generated by the first generation means and the second original image generated by the first generation means. The second original image indicated by the image data may be an image showing a map.

  For example, map images such as urban areas have many components, and the processing load during drawing may be heavy. Therefore, unless hardware with high processing capability is used, the map image update cycle is shortened. It is difficult. Therefore, it is difficult to update the map image with good appearance unless hardware with high processing capability is used. However, by using the image signal output device according to the fifth aspect, it is possible to update the map image with good appearance while suppressing the processing load. Therefore, it is possible to update the map image with good appearance without using hardware with high processing capability.

  The image signal output method according to claim 6 generates the first original image data and stores it in the first storage means, and also generates the second original image data and stores it in the second storage means. The first generation procedure to be stored and the first original image data stored in the first storage means are read out and then stored in the second storage means instead of the first original image data. A read control procedure for reading out the second original image data. In addition, this image signal output method is performed until the second original image data is read from the second storage means after the first original image data is read from the first storage means in the read control procedure. In between, based on the first original image data stored in the first storage means and the second original image data stored in the second storage means, the first original image and the second A first synthesized image data generation procedure for generating synthesized image data indicating a synthesized image that is an image synthesized with the original image according to a predetermined mixing ratio; Also, this image signal output method outputs an image signal based on the original image data read in the read control procedure, and when the synthesized image data is generated by the synthesized image data generating means, Instead of this, a first output procedure for newly outputting an image signal based on the composite image data is provided.

  By using this method, the switching from the first image to the second image can be performed with good appearance. The composite image data is an image generated based on the first image data and the second image data that have already been generated. For this reason, when the processing load at the time of generating the first image data and the second image data is large, the processing load can be reduced as compared with the case of increasing the image update frequency. Therefore, according to the image signal output method of the sixth aspect, it is possible to update the screen with good appearance while suppressing an increase in processing load.

  According to the seventh aspect of the invention, the image signal output device includes a third storage means for storing various data, a fourth storage means for storing image data, and a first original. First generation image data indicating an image and second original image data indicating a second original image are generated, stored in a third storage unit, and stored in a third storage unit The stored first original image data is stored in the fourth storage means, and then the second original image data stored in the third storage means is newly stored in the fourth storage means. Storage control means. Further, the image signal output device is provided until the second original image data is stored in the fourth storage means after the storage control means stores the first original image data in the fourth storage means. In the meantime, based on the first original image data and the second original image data stored in the third storage means, the first original image and the second original image are synthesized according to a predetermined mixing ratio. A second composite image data generating means for generating composite image data representing a composite image that is an image and storing the composite image data in the fourth storage means; and an image signal based on the image data stored in the fourth storage means. Second output means for generating and outputting to the outside.

The fourth storage means may be a VRAM, for example.
Also known is a function called alpha blend that synthesizes two images according to a predetermined mixing ratio. The second composite image data generation means may generate composite image data based on the first image data and the second image data by this alpha blending.

  By doing so, the switching from the first image to the second image can be performed with good appearance. The composite image data is an image generated based on the first image data and the second image data that have already been generated. For this reason, the processing load when combining the first image data and the second image data according to a predetermined mixing ratio is smaller than the processing load when generating the first image data and the second image data. In this case, the processing load can be reduced as compared with the case where the image update frequency is increased. Therefore, the image signal output device according to the seventh aspect can update the screen with a good appearance while suppressing an increase in processing load.

Further, the second composite image data generation means provided in the image signal output device may have the following configuration.
That is, as described in claim 8, the second composite image data generation means may be constituted by a dedicated circuit for the means.

By having such a configuration, it is possible to generate composite image data without increasing the processing load of the CPU, for example.
Further, the image signal output device may have the following configuration.

  That is, as described in claim 9, the storage control means alternately stores the first original image data and the second original image data stored in the third storage means in the fourth storage means. The second composite image data generating means stores the first original image data in the fourth storage means after the storage control means stores the second original image data in the fourth storage means. Until it is stored, composite image data is newly generated based on the first original image data and the second original image data stored in the third storage means, and stored in the fourth storage means. You may let them. In addition, the second generation means stores the first original image data stored in the third storage means in the fourth storage means by the storage control means, and then uses the second composite image data generation means. The second original image data newly generated is stored in the third storage unit and the second original image stored in the third storage unit until the generation of the composite image data is started. After the data is stored in the fourth storage unit by the storage control unit, the newly generated first original image data is generated until the generation of the composite image data is started by the second composite image data generation unit. May be stored in a third storage means.

By doing so, it is possible to continuously update the image with good appearance while suppressing an increase in processing load.
Further, the image signal output apparatus may change the mixing ratio of the composite image as follows.

  That is, as described in claim 10, the second composite image data generation unit is configured to store the first original image data stored in the third storage unit or the second composite image data by the storage control unit. After any one of the original image data is stored in the fourth storage means, the other original image data stored in the third storage means is stored in the fourth storage means. A plurality of composite image data is generated during the period up to this time, and each time composite image data is generated during this period, the fourth storage means later in the mixing ratio of the composite image indicated by the newly generated composite image data The ratio of the original image indicated by the stored original image data may be increased.

By doing this, when updating the image, the image can be changed more smoothly, and the image can be updated with better appearance.
The image signal output device may update the map image.

  That is, as described in claim 11, the first original image indicated by the first original image data generated by the second generation unit and the second original image generated by the second generation unit. The second original image indicated by the image data may be an image showing a map.

  For example, a map image of an urban area or the like has many components, and there are cases where the processing load when drawing is heavy. For this reason, it is difficult to shorten the update period of the map image without using hardware with high processing capability. Therefore, it is difficult to update the map image with good appearance unless hardware with high processing capability is used. However, by using the image signal output device according to the eleventh aspect, it is possible to update the map image with good appearance while suppressing the processing load. Therefore, it is possible to update the map image with good appearance without using hardware with high processing capability.

  An image signal output method according to claim 12 generates first original image data indicating a first original image and second original image data indicating a second original image, and various data A second generation procedure for storing in the third storage means for storing the first original image data stored in the third storage means, and a fourth storage means for storing the image data And a storage control procedure for newly storing the second original image data stored in the third storage unit in the fourth storage unit. In addition, this image signal output method is performed after the first original image data is stored in the fourth storage means in the storage control procedure until the second original image data is stored in the fourth storage means. Based on the first original image data and the second original image data stored in the third storage means, the first original image and the second original image are synthesized according to a predetermined mixing ratio. Image data based on the second composite image data generation procedure for generating the composite image data indicating the composite image that is the generated image and storing the composite image data in the fourth storage means, and the image data stored in the fourth storage means And a second output procedure for outputting to the outside.

  By using this method, the switching from the first image to the second image can be performed with good appearance. The composite image data is an image generated based on the first image data and the second image data that have already been generated. For this reason, when the processing load at the time of generating the first image data and the second image data is large, the processing load can be reduced as compared with the case of increasing the image update frequency. Therefore, according to the image signal output method of the twelfth aspect, it is possible to update the screen with good appearance while suppressing an increase in processing load.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments of the present invention are not limited to the following embodiments, and various forms can be adopted as long as they belong to the technical scope of the present invention.

[First embodiment]
First, the first image signal output device 10 in the first embodiment will be described.
[Description of configuration]
FIG. 1 is a block diagram showing the configuration of the first image signal output device 10. The first image signal output device 10 is connected to the CPU 20 and the memory 30 via a bus. The first image signal output device 10, the CPU 20, and the memory 30 are mounted on a known navigation device that performs route guidance and the like.

The CPU 20 is a well-known CPU that performs various processes in accordance with a ROM (not shown) or a program stored in the memory 30.
The memory 30 includes a RAM and the like, and is a part that stores map data read from a storage medium (not shown) such as a DVD-ROM, data used for generating image data, and the like.

  The first image signal output device 10 includes a first drawing unit 11, a first VRAM 12, a second VRAM 13, a third VRAM 14, a reading unit 15, and a first image signal generation unit. 16 is a dedicated circuit.

  The first drawing unit 11 generates image data using data stored in the memory 30 based on an instruction from the CPU 20, and generates the generated image data as a first VRAM 12, a second VRAM 13, and a third VRAM 14. It is a part memorize | stored in either. The first drawing unit 11 uses the map data stored in the memory 30 in about 200 ms cycle (12 VSYNC cycle, 1 VSYNC cycle is 16.7 ms) based on an instruction from the CPU 20 to determine the current location of the host vehicle. Map image data or the like indicating a map image in a predetermined range as a reference is generated and stored alternately in the first VRAM 12 and the second VRAM 13. The map image indicated by the map image data is an image obtained by overwriting various information such as a host vehicle icon indicating the position of the host vehicle on a map image in a predetermined range. Further, the first drawing unit 11 displays a screen (hereinafter also referred to as an operation screen) on which various information such as an icon for accepting an operation from the user based on an instruction from the CPU 20 and a scale of the map image is arranged. Operation screen image data for display is generated and stored in the third VRAM 14.

  The first VRAM 12, the second VRAM 13, and the third VRAM 14 are parts that store image data for displaying an image for one screen of the display device. These VRAMs may be constituted by a dual port RAM or the like.

  The reading unit 15 reads image data from the first VRAM 12, the second VRAM 13, and the third VRAM 14, generates new image data based on the read image data, and generates the generated image data as the first image signal. This is a part to be output to the generation unit 16. The reading unit 15 includes a reading control unit 15a and a first combining unit 15b.

  The read control unit 15a displays the image indicated by the image data read from the first VRAM 12 or the like based on the image data read from the first VRAM 12 or the second VRAM 13 and the operation screen image data read from the third VRAM 14. This is a part that generates image data for displaying an image obtained by superimposing the operation screen and the operation screen, and outputs the generated image data to the first image signal generation unit 16.

  In addition, the first combining unit 15b uses the alpha blend function to display the image indicated by these image data based on the image data stored in the first VRAM 12 and the image data stored in the second VRAM 13. Is generated at a predetermined mixing ratio. Further, based on the generated composite image data and the operation screen image data read from the third VRAM 14, the composite image data for displaying the composite image obtained by superimposing the composite image and the operation screen is generated and generated. This is a part for outputting the composite image data to the first image signal generator 16.

  The first image signal generation unit 16 is a part that generates an image signal based on the image data input from the reading unit 15 and outputs the generated image signal to a connected display device or the like.

[Description of operation]
Next, a process in which the first image signal output device 10 outputs an image signal will be described.
FIG. 2 shows a first image signal output process showing the timing of processes performed at each part constituting the first image signal output apparatus 10 when the first image signal output apparatus 10 outputs an image signal. It is a timing chart. The first image signal output processing timing chart includes a first drawing unit 11, a read control unit 15 a, a first synthesis unit 15 b, and a first image signal generation unit 16 in the first image signal output device 10. The timing of each process executed in is described.

  The first image signal generator 16 outputs a new image signal at each timing of T41, T41a to T41c, T42, T42a to T42c, and T43 in the first image signal output processing timing chart. To FIG. 7 are explanatory diagrams showing map images displayed based on image signals newly output at these timings. A map image 100 to I map image 180 described in FIGS. 3 to 7 show a state in which the A map image 100 rotates, and are displayed in order from the A map image 100 at a time interval of 3 VSYNC. The first image signal output device 10 outputs an image signal based on the newly generated map image data in the 12VSYNC cycle. The A map image 100, the E map image 140, and the I map image 180 are the image signals. The map image displayed by is shown. Further, the B map image 110 to the D map image 130 are composite images of the A map image 100 and the E map image 140 generated by the alpha blend function of the first combining unit 15b. In the B map image 110 to the D map image 130, it is shown that the mixing ratio of the E map image 140 is gradually increased. Further, the F map image 150 to the H map image 170 are a composite image of the E map image 140 and the I map image 180 generated by the alpha blend function of the first composition unit 15b. In the F map image 150 to the H map image 170, it is shown that the mixing ratio of the I map image 180 gradually increases.

  The process in which the first image signal output device 10 updates the map image will be described with reference to the first image signal output processing timing chart shown in FIG. 2 and the explanatory diagrams shown in FIGS. . Incidentally, at the timing of T21 in the first image signal output processing timing chart, the map image data is already stored in the second VRAM 13 (hereinafter, the map image data stored in the second VRAM 13 is Also described as second map image data). At the above timing, the map image data generated after the second map image data is generated is already stored in the first VRAM 12 (hereinafter, the map image stored in the first VRAM 12). The data is also referred to as first map image data). Moreover, the map image displayed by 1st map image data is also described as a 1st map image, and the map image displayed by 2nd map image data is also described as a 2nd map image.

  At the timing T21, the reading control unit 15a reads the first map image data stored in the first VRAM 12, and also reads the operation screen image data from the third VRAM 14, and the first map image and the operation screen. Image data for displaying an image obtained by superimposing and.

  At T41, which is a timing immediately after T21, the first image signal generation unit 16 outputs an image signal based on the image data generated by the read control unit 15a at the timing of T21. A map image 100 shown in FIG. 3A is displayed based on the image signal output at the timing of T41.

  At T11, which is the timing after T41, the first drawing unit 11 uses the map data read from the DVD-ROM or the like by the CPU 20 according to the instruction from the CPU 20, and the surrounding map image at the current location of the host vehicle. Data is newly generated and stored in the second VRAM 13.

  At each timing of T31a, T31b, and T31c, the first synthesizing unit 15b uses the alpha blend function to perform the first map image data stored in the first VRAM 12 and the first map image data stored in the second VRAM 13. Composite image data is generated by combining the two map image data. The mixing ratio of the first map image and the second map image in the composite image data generated at each timing is 3 to 1 for T31a, 1 to 1 for T31b, and 1 to 3 for T31c. T31a is a timing immediately after T11.

  At T41c, which is the timing immediately after T31a, T31b, which is the timing immediately after T31a, and T41b, which is the timing immediately after T31b, the first image signal generation unit 16 sets the first timing at each timing of T31a, T31b, T31c. An image signal is output based on the image data generated by the combining unit 15b. Also, the B map image 110 shown in FIG. 3B is based on the image signal output at the timing of T41a, and the C map image 120 shown in FIG. 4A is based on the image signal output at the timing of T41b. However, the D map image 130 shown in FIG. 4B is displayed based on the image signal output at the timing of T41c. The timings T41, T41a, T41b, and T41c are timings separated by a time interval of 3VSYNC.

  At T22, which is the timing after T41c, the read control unit 15a reads the second map image data stored in the second VRAM 13, and also reads the operation screen image data from the third VRAM 14, Image data for displaying an image obtained by superimposing the map image and the operation screen is generated.

  At T42, which is a timing immediately after T22, the first image signal generation unit 16 outputs an image signal based on the image data generated by the read control unit 15a at the timing of T22. T42 is a timing that is separated from T41c by a time interval of 3VSYNC. Further, the E map image 140 shown in FIG. 5A is displayed based on the image signal output at the timing of T42.

  At T12, which is the timing after T42, the first drawing unit 11 uses the map data read from the DVD-ROM or the like by the CPU 20 according to the instruction from the CPU 20, and the surrounding map image at the current location of the host vehicle. Data is newly generated and stored in the first VRAM 12.

  At each timing of T32a, T32b, and T32c, the first synthesizing unit 15b uses the alpha blend function to perform the first map image data stored in the first VRAM 12 and the second map image stored in the second VRAM 13. Composite image data is generated by combining the two map image data. The mixing ratio of the first map image and the second map image in the composite image data generated at each timing is 1 to 3 for T32a, 1 to 1 for T32b, and 3 to 1 for T32c. T32a is the timing immediately after T12.

  In T42c, which is the timing immediately after T42a and T32b, which is the timing immediately after T32a, and T42b, which is the timing immediately after T32b, the first image signal generation unit 16 sets the first timing at each timing of T32a, T32b, and T32c. An image signal is output based on the image data generated by the combining unit 15b. 5B is based on the image signal output at the timing T42a, and the G map image 160 illustrated in FIG. 6A is based on the image signal output at the timing T42b. However, the H map image 170 shown in FIG. 6B is displayed based on the image signal output at the timing of T42c. The timings T42, T42a, T42b, and T42c are timings separated by a time interval of 3VSYNC.

  At T23, which is the timing after T42c, the read controller 15a reads the first map image data stored in the first VRAM 12, and also reads the operation screen image data from the third VRAM 14, Image data for displaying an image obtained by superimposing the map image and the operation screen is generated.

  At T43, which is a timing immediately after T23, the first image signal generation unit 16 outputs an image signal based on the image data generated by the read control unit 15a at the timing of T23. Note that an I map image 180 shown in FIG. 7A is displayed based on the image signal output at the timing of T43.

  The processing executed at each timing of T23 and T43 is the same processing as the processing executed at each timing of T21 and T41. After T23, processing similar to the processing executed in the period from T21 to T42c is continuously executed.

[effect]
In the first image signal output device 10 in the first embodiment, the first map image data and the second map image data are alternately generated by the CPU 20 and the first drawing unit 11, and the first map image data And the image signal based on the second map image data are alternately output at a time interval of 12 VSYNC. Then, in this time interval, composite image data indicating a composite image that is an image obtained by combining the first map image and the second map image according to a predetermined mixing ratio is generated by the first combining unit 15b. An image signal based on the image data is output. Therefore, the first image signal output device 10 can continuously update the map image with good appearance.

  Further, in the first image signal output device 10, composite image data having different mixing ratios is generated three times by the first combining unit 15 b in the time interval of 12 VSYNC, and image signals based on the respective composite image data are generated. It is output at a time interval of 3VSYNC. In these composite image data, the mixture ratio of the map image displayed by the image signal output earlier and the map image displayed by the image signal output later is the composite image data generated earlier. The order is set to 3: 1, 1: 1, 1/3. By doing so, in the composite image displayed three times, the mixture ratio of the map image displayed later can be gradually increased, and the map image can be changed more smoothly. Therefore, the map image can be updated with good appearance.

  Further, the first image signal output device 10 continuously updates the map image, but the map image such as the city area has many components, and the processing when generating such map image data is performed. The load may increase. For this reason, it is difficult to shorten the update period of the map image without using hardware with high processing capability. On the other hand, the first synthesizing unit 15b of the first image signal output device 10 generates a map image generated in advance three times before new map image data is generated by the CPU 20 and the first drawing unit 11. Composite image data is generated based on the data. Then, the first image signal generation unit 16 outputs the image signal based on the combined image data three times at a time interval of 3VSYNC before outputting the image signal based on the new map image data. Therefore, when the processing load when the first combining unit 15b generates the composite image data is smaller than the processing load when the CPU 20 and the first drawing unit 11 generate the map image data, the 3VSYNC cycle As compared with the case of outputting an image signal based on new map image data, the processing load can be reduced. Therefore, the first image signal output device 10 can update the screen with good appearance while suppressing an increase in processing load, and can update the map image with good appearance without using hardware with high processing capability. It becomes possible.

  Further, the first image signal output device 10 includes a first combining unit 15b which is a dedicated circuit for generating the combined image data. For this reason, it is possible to update the screen with good appearance without increasing the processing load of the CPU 20, the first drawing unit 11, and the like.

[Second Embodiment]
Next, the second image signal output device 210 in the second embodiment will be described.
[Description of configuration]
FIG. 8 is a block diagram showing a configuration of the second image signal output device 210. The second image signal output device 210 is connected to the CPU 220 and the memory 230 via a bus. The second image signal output device 210, the CPU 220, and the memory 230 are mounted on a known navigation device that performs route guidance and the like.

The CPU 220 is a well-known CPU that performs various processes in accordance with a ROM (not shown) or a program stored in the memory 230.
The memory 230 includes a RAM and the like, and is a part that stores map data read from a storage medium (not shown) such as a DVD-ROM, data used for generating image data, and the like.

  The second image signal output device 210 includes a second drawing unit 211, a storage control unit 212, a second synthesis unit 213, a VRAM 214, and a second image signal generation unit 215. It is a dedicated circuit.

  The second drawing unit 211 generates image data using data stored in the memory 230 based on an instruction from the CPU 220, and generates the generated image data in the first area 231 and the second area 232 in the memory 230. , And a region stored in any one of the third regions 233. The second drawing unit 211 uses the map data stored in the memory 230 at about 200 ms period (12 VSYNC period, 1 VSYNC period is 16.7 ms) based on an instruction from the CPU 220 to determine the current location of the host vehicle. Map image data or the like indicating a map image in a predetermined range as a reference is generated and stored alternately in the first area 231 and the second area 232. The map image indicated by the map image data is an image obtained by overwriting various information such as a host vehicle icon indicating the position of the host vehicle on a map image in a predetermined range. Further, the second drawing unit 211 displays a screen (hereinafter also referred to as an operation screen) on which various information such as an icon for accepting an operation from a user based on an instruction from the CPU 220, a scale of a map image, and the like are arranged. Operation screen image data for display is generated and stored in the third area 233.

  The storage control unit 212 reads the image read from the first area 231 or the like based on the image data read from the first area 231 or the second area 232 and the operation screen image data read from the third area 233. This is a part that generates image data for displaying an image obtained by superimposing an image indicated by data and an operation screen, and stores the generated image data in the VRAM 214.

  The second synthesizing unit 213 uses the alpha blending function, based on the image data stored in the first area 231 and the image data stored in the second area 232, the images indicated by these image data Is generated at a predetermined mixing ratio. Further, based on the generated composite image data and the operation screen image data read from the third area 233, composite image data for displaying a composite image in which the composite image and the operation screen are superimposed is generated and generated. This is a part for storing the synthesized image data in the VRAM 214.

The VRAM 214 is a part that stores image data for displaying an image for one screen of the display device. The VRAM 214 may be configured by a dual port RAM or the like.
The second image signal generation unit 215 is a part that generates an image signal based on the image data stored in the VRAM 214 and outputs the generated image signal to a connected display device or the like.

[Description of operation]
Next, a process in which the second image signal output device 210 outputs an image signal will be described.
FIG. 9 shows a second image signal output process showing the timing of processing performed at each part of the second image signal output device 210 when the second image signal output device 210 outputs an image signal. It is a timing chart. The second image signal output processing timing chart includes a second drawing unit 211, a storage control unit 212, a second synthesis unit 213, and a second image signal generation unit 215 in the second image signal output device 210. The timing of each process executed in is described.

  The second image signal generation unit 215 outputs a new image signal at each timing of T81, T81a to T81c, T82, T82a to T82c, and T83 in the second image signal output processing timing chart. To FIG. 7 are explanatory diagrams showing map images displayed based on image signals newly output at these timings. A map image 100 to I map image 180 described in FIGS. 3 to 7 show a state in which the A map image 100 rotates, and are displayed in order from the A map image 100 at a time interval of 3 VSYNC. The second image signal output device 210 outputs an image signal based on the newly generated map image data in the 12VSYNC cycle. The A map image 100, the E map image 140, and the I map image 180 The map image displayed by is shown. Further, the B map image 110 to the D map image 130 are composite images of the A map image 100 and the E map image 140 generated by the alpha blend function of the second combining unit 213. In the B map image 110 to the D map image 130, it is shown that the mixing ratio of the E map image 140 is gradually increased. Further, the F map image 150 to the H map image 170 are a composite image of the E map image 140 and the I map image 180 generated by the alpha blend function of the second combining unit 213. In the F map image 150 to the H map image 170, it is shown that the mixing ratio of the I map image 180 gradually increases.

  The process in which the second image signal output device 210 updates the map image will be described with reference to the second image signal output processing timing chart shown in FIG. 9 and the explanatory diagrams shown in FIGS. . Incidentally, at the timing of T61 in the second image signal output processing timing chart, the map image data is already stored in the second area 232 in the memory 230 (hereinafter, stored in the second area 232). The map image data is also referred to as second map image data). At the above timing, the map image data generated after the second map image data is generated is already stored in the first region 231 of the memory 230 (hereinafter, stored in the first region 231). This map image data is also referred to as first map image data). Moreover, the map image displayed by 1st map image data is also described as a 1st map image, and the map image displayed by 2nd map image data is also described as a 2nd map image.

  At the timing of T61, the storage control unit 212 reads the first map image data stored in the first area 231 and also reads the operation screen image data from the third area 233, Image data for displaying an image superimposed on the operation screen is generated.

  At T81, which is a timing immediately after T61, the second image signal generation unit 215 outputs an image signal based on the image data generated by the storage control unit 212 at the timing of T61. A map image 100 shown in FIG. 3A is displayed based on the image signal output at the timing of T81.

  At T51, which is the timing after T81, the second drawing unit 211 uses the map data read from the DVD-ROM or the like by the CPU 220 according to the instruction from the CPU 220, and the surrounding map image at the current location of the host vehicle. Data is newly generated and stored in the second area 232.

  At each timing of T71a, T71b, and T71c, the second combining unit 213 stores the first map image data stored in the first area 231 and the second area 232 by the alpha blend function. Composite image data is generated by combining the second map image data. The mixing ratio of the first map image and the second map image in the composite image data generated at each timing is 3 to 1 for T71a, 1 to 1 for T71b, and 1 to 3 for T71c. Note that T71a is the timing immediately after T51.

  In T81c, which is timing immediately after T81a, T71b, which is timing immediately after T71a, and T81b, which is timing immediately after T71b, the second image signal generation unit 215 performs second timing at each timing of T71a, T71b, T71c. Based on the image data generated by the combining unit 213, an image signal is output. Further, the B map image 110 shown in FIG. 3B is based on the image signal output at the timing of T81a, and the C map image 120 shown in FIG. 4A is based on the image signal output at the timing of T81b. However, the D map image 130 shown in FIG. 4B is displayed based on the image signal output at the timing of T81c. The timings T81, T81a, T81b, and T81c are timings separated by a time interval of 3VSYNC.

  At T62, which is the timing after T81c, the storage control unit 212 reads out the second map image data stored in the second region 232, and also reads out the operation screen image data from the third region 233. Image data for displaying an image obtained by superimposing the second map image and the operation screen is generated.

  At T82, which is a timing immediately after T62, the second image signal generation unit 215 outputs an image signal based on the image data generated by the storage control unit 212 at the timing of T62. Note that T82 is a timing separated by a time interval of 3VSYNC from T81c. Further, the E map image 140 shown in FIG. 5A is displayed based on the image signal output at the timing of T82.

  At T52, which is the timing after T82, the second drawing unit 211 uses the map data read from the DVD-ROM or the like by the CPU 220 according to the instruction from the CPU 220, and the surrounding map image at the current location of the host vehicle. Data is newly generated and stored in the first area 231.

  At each timing of T72a, T72b, and T72c, the second combining unit 213 stores the first map image data stored in the first area 231 and the second area 232 by the alpha blend function. Composite image data is generated by combining the second map image data. The mixing ratio of the first map image and the second map image in the composite image data generated at each timing is 1 to 3 for T72a, 1 to 1 for T72b, and 3 to 1 for T72c. T72a is the timing immediately after T52.

  At T82c, which is the timing immediately after T82a, T72b, which is the timing immediately after T72a, and T82c, which is the timing immediately after T72b, the second image signal generation unit 215 performs the second timing at each timing of T72a, T72b, T72c. Based on the image data generated by the combining unit 213, an image signal is output. 5B is based on the image signal output at the timing T82a, and the G map image 160 illustrated in FIG. 6A is based on the image signal output at the timing T82b. However, the H map image 170 shown in FIG. 6B is displayed based on the image signal output at the timing of T82c. The timings T82, T82a, T82b, and T82c are timings separated by a time interval of 3VSYNC.

  At T63, which is the timing after T82c, the read control unit 15a reads the first map image data stored in the first area 231 and the operation screen image data from the third area 233, Image data for displaying an image obtained by superimposing one map image and an operation screen is generated.

  At T83, which is a timing immediately after T63, the second image signal generation unit 215 outputs an image signal based on the image data generated by the storage control unit 212 at the timing of T63. Note that the I map image 180 shown in FIG. 7A is displayed based on the image signal output at the timing of T83.

  The process executed at each timing of T63 and T83 is the same process as the process executed at each timing of T61 and T81. After T63, processing similar to the processing executed during the period from T61 to T82c is continuously executed.

[effect]
In the second image signal output device 210 in the second embodiment, the first map image data and the second map image data are alternately generated by the CPU 220 and the second drawing unit 211, and the first map image data And the image signal based on the second map image data are alternately output at a time interval of 12 VSYNC. In this time interval, the second combining unit 213 generates composite image data indicating a composite image that is an image obtained by combining the first map image and the second map image in accordance with a predetermined mixing ratio. An image signal based on the image data is output. Therefore, the second image signal output device 210 can continuously update the map image with good appearance.

  Further, in the second image signal output device 210, the second combining unit 213 generates combined image data having different mixing ratios three times in the time interval of 12VSYNC, and image signals based on the respective combined image data are generated. It is output at a time interval of 3VSYNC. In these composite image data, the mixture ratio of the map image displayed by the image signal output earlier and the map image displayed by the image signal output later is the composite image data generated earlier. The order is set to 3: 1, 1: 1, 1/3. By doing so, in the composite image displayed three times, the mixture ratio of the map image displayed later can be gradually increased, and the map image can be changed more smoothly. Therefore, the map image can be updated with good appearance.

  In addition, the second image signal output device 210 continuously updates the map image, but the map image such as the city area has many components, and the processing when generating such map image data is performed. The load may increase. For this reason, it is difficult to shorten the update period of the map image without using hardware with high processing capability. On the other hand, the second synthesizing unit 213 of the second image signal output device 210 generates a map generated in advance three times before new map image data is generated by the CPU 220 and the second drawing unit 211. Composite image data is generated based on the image data. Then, the second image signal generation unit 215 outputs the image signal based on the composite image data three times at a time interval of 3VSYNC before outputting the image signal based on the new map image data. For this reason, when the processing load when the second combining unit 213 generates the composite image data is smaller than the processing load when the CPU 220 and the second drawing unit 211 generate the map image data, the 3VSYNC cycle As compared with the case of outputting an image signal based on new map image data, the processing load can be reduced. Therefore, the second image signal output device 210 can update the screen with good appearance while suppressing an increase in processing load, and can update the map image with good appearance without using hardware with high processing capability. It becomes possible.

  In addition, the second image signal output device 210 has a second combining unit 213 which is a dedicated circuit for generating the combined image data. Therefore, it is possible to update the screen with good appearance without increasing the processing load of the CPU 220, the second drawing unit 211, and the like.

[Other Embodiments]
(1) The first image signal output device 10 and the second image signal output device 210 generate composite image data based on the map image data, and output an image signal based on the composite image data, thereby processing load. It is possible to update the map image with good appearance while suppressing the increase in the number of images. However, it goes without saying that the first image signal output device 10 or the like may perform the same processing using image data other than the map data. Even if it has such a structure, the same effect can be acquired when updating the image which other image data shows.

  (2) The first image signal output device 10 and the second image signal output device 210 are configured as dedicated circuits. However, the functions of the first image signal output device 10 and the second image signal output device 210 may be realized by software. Even with such a configuration, it is possible to update the map image with good appearance while suppressing an increase in processing load.

[Correspondence with Claims]
The correspondence between the terms used in the description of the above embodiment and the terms used in the description of the claims is shown.

  In the first embodiment and the second embodiment, the first map image is the first original image, the first map image data is the first original image data, and the second map image is the second original image. The second map image data corresponds to the second original image data.

  The first image signal output device 10 in the first embodiment corresponds to the image signal output device in claim 1. The first VRAM 12 is the first storage means, the second VRAM 13 is the second storage means, the first drawing unit 11 is the first generation means, the read control unit 15a is the read control means, The first combining unit 15b corresponds to a first combined image data generating unit, and the first image signal generating unit 16 corresponds to a first output unit.

  In the first image signal output processing timing chart, processing performed at timings T11 and T12 corresponds to the first generation procedure, and processing performed at timings T21, T22, and T23 corresponds to the reading control procedure. In addition, the processing performed at the timings T31a, T31b, T31c, T32a, T32b, and T32c in the first image signal output processing timing chart is the first composite image data generation procedure, and T41, T41a, T41b, T41c, T42, The processing performed at the timings T42a, T42b, T42c, and T43 corresponds to the first output procedure.

  The second image signal output device 210 and the memory 230 in the second embodiment correspond to the image signal output device in claim 7. Further, the memory 230 is the third storage unit, the VRAM 214 is the fourth storage unit, the second drawing unit 211 is the second generation unit, the storage control unit 212 is the storage control unit, and the second synthesis unit. Reference numeral 213 corresponds to second composite image data generation means, and the second image signal generation unit 215 corresponds to second output means.

  In the second image signal output processing timing chart, processing performed at timings T51 and T52 corresponds to the second generation procedure, and processing performed at timings T61, T62, and T63 corresponds to the storage control procedure. In addition, the processing performed at the timings T71a, T71b, T71c, T72a, T72b, and T72c in the second image signal output processing timing chart is the second composite image data generation procedure, and T81, T81a, T81b, T81c, T82, The processing performed at the timings T82a, T82b, T82c, and T83 corresponds to the second output procedure.

2 is a block diagram for explaining a first image signal output device 10. FIG. It is a timing chart for demonstrating the process at the time of the 1st image signal output device 10 outputting an image signal. It is explanatory drawing which shows A map image 100, and explanatory drawing which shows B map image 110. It is explanatory drawing which shows C map image 120, and explanatory drawing which shows D map image 130. It is explanatory drawing which shows E map image 140, and explanatory drawing which shows F map image 150. It is explanatory drawing which shows G map image 160, and explanatory drawing which shows H map image 170. It is explanatory drawing which shows I map image 180. FIG. 6 is a block diagram for explaining a second image signal output device 210. FIG. It is a timing chart for demonstrating the process at the time of the 2nd image signal output device 210 outputting an image signal.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... 1st image signal output device, 11 ... 1st drawing part, 12 ... 1st VRAM, 13 ... 2nd VRAM, 14 ... 3rd VRAM, 15 ... Reading part, 15a ... Reading control part, 15 ... First synthesis unit, 16 ... First image signal generation unit, 20 ... CPU, 30 ... Memory, 100 ... A map image, 110 ... B map image, 120 ... C map image, 130 ... D map image, 140 ... E map image, 150 ... F map image, 160 ... G map image, 170 ... H map image, 180 ... I map image, 210 ... second image signal output device, 211 ... second drawing unit, 212 ... Storage control unit, 213 ... second synthesis unit, 214 ... VRAM, 215 ... second image signal generation unit, 220 ... CPU, 230 ... memory, 231 ... first region, 232 ... second region, 233 ... Third area.

Claims (12)

First storage means for storing first original image data indicating the first original image;
A second storage means for storing second original image data indicating the second original image;
First generating means for generating the first original image data and storing it in the first storage means, and generating the second original image data and storing it in the second storage means;
The first original image data stored in the first storage means is read out, and then the second original stored in the second storage means instead of the first original image data. Read control means for reading original image data;
After the first original image data is read from the first storage means by the read control means, the second original image data is read from the second storage means until the second original image data is read. Based on the first original image data stored in one storage means and the second original image data stored in the second storage means, the first original image and the second original image data First synthesized image data generating means for generating synthesized image data indicating a synthesized image that is an image synthesized with the original image according to a predetermined mixing ratio;
An image signal based on the original image data read by the read control means is output, and when the composite image data is generated by the composite image data generation means, the composite image data is generated instead of the image signal being output. First output means for newly outputting an image signal based on the image data;
An image signal output device comprising: The image signal output device according to claim 1,
The first composite image data generating means is constituted by a dedicated circuit for the means;
An image signal output device. The image signal output device according to claim 1 or 2,
The read control means alternately reads the first original image data stored in the first storage means and the second original image data stored in the second storage means,
The first synthesized image data generating means reads the first original image from the first storage means after the second original image data is read from the second storage means by the read control means. Based on the first original image data stored in the first storage means and the second original image data stored in the second storage means until data is read out. , Newly generating the composite image data,
The first generation means generates the composite image data by the first composite image data generation means after the first original image data is read from the first storage means by the read control means. The second original image data newly generated is stored in the second storage means until the second storage image is started from the second storage means by the read control means. After the data is read, the newly generated first original image data is stored in the first storage until the first composite image data generation means starts generating the composite image data. Memorizing means,
An image signal output device. In the image signal output device according to any one of claims 1 to 3,
The first composite image data generation means includes
After the original image data is read from the storage means of either the first storage means or the second storage means by the read control means, the original storage data is read from the other storage means. In a period until image data is read out, a plurality of the composite image data is generated,
Each time the composite image data is generated in the period, the ratio of the original image indicated by the original image data to be read later from the storage unit in the mixing ratio is increased.
An image signal output device. In the image signal output device according to any one of claims 1 to 4,
The first original image indicated by the first original image data generated by the first generation means, and the second original image data indicated by the second original image data generated by the first generation means. The original image is an image showing a map,
An image signal output device. A first generation procedure for generating first original image data and storing it in the first storage means, and generating second original image data and storing it in the second storage means;
The first original image data stored in the first storage means is read out, and then the second original stored in the second storage means instead of the first original image data. Read control procedure for reading original image data;
After the first original image data is read from the first storage means in the read control procedure, until the second original image data is read from the second storage means, Based on the first original image data stored in the first storage means and the second original image data stored in the second storage means, the first original image and the first A first composite image data generation procedure for generating composite image data indicating a composite image that is an image obtained by combining the two original images according to a predetermined mixing ratio;
While outputting the image signal based on the original image data read in the read control procedure, and when the composite image data is generated in the composite image data generation procedure, instead of the image signal being output, A first output procedure for newly outputting an image signal based on the composite image data;
An image signal output method comprising: A third storage means for storing various data;
A fourth storage means for storing image data;
Second generation means for generating first original image data indicating a first original image and second original image data indicating a second original image, and storing the generated data in the third storage means;
The first original image data stored in the third storage means is stored in the fourth storage means, and then the second original image data stored in the third storage means Storage control means for newly storing in the fourth storage means,
After the first original image data is stored in the fourth storage unit by the storage control unit, the second original image data is stored in the fourth storage unit until the second original image data is stored in the fourth storage unit. Based on the first original image data and the second original image data stored in the third storage means, the first original image and the second original image are synthesized according to a predetermined mixing ratio. A second composite image data generating unit that generates composite image data indicating a composite image that is a generated image and stores the composite image data in the fourth storage unit;
Second output means for generating an image signal based on the image data stored in the fourth storage means and outputting the image signal to the outside;
An image signal output device comprising: The image signal output device according to claim 7,
The second composite image data generating means is constituted by a dedicated circuit for the means;
An image signal output device. In the image signal output device according to claim 7 or 8,
The storage control means stores the first original image data and the second original image data stored in the third storage means alternately in the fourth storage means,
The second composite image data generation means stores the first original image data in the fourth storage after the storage control means stores the second original image data in the fourth storage means. The composite image data is newly generated based on the first original image data and the second original image data stored in the third storage means before being stored in the means, Memorize in the fourth storage means,
The second generation unit is configured to store the second composite image after the first original image data stored in the third storage unit is stored in the fourth storage unit by the storage control unit. The newly generated second original image data is stored in the third storage unit and stored in the third storage unit until the generation of the composite image data is started by the data generation unit. After the second original image data being stored is stored in the fourth storage means by the storage control means, the generation of the composite image data is started by the second composite image data generation means. In the meantime, the newly generated first original image data is stored in the third storage means,
An image signal output device. In the image signal output device according to any one of claims 7 to 9,
The second composite image data generation means includes
Either the first original image data stored in the third storage unit or the second original image data is stored in the fourth control unit by the storage control unit. After being stored in the storage means, a plurality of the composite image data are generated in a period until the other original image data stored in the third storage means is stored in the fourth storage means. ,
Increasing the ratio of the original image indicated by the original image data stored in the fourth storage means later in the mixing ratio each time the composite image data is generated in the period;
An image signal output device. The image signal output device according to any one of claims 7 to 10,
The first original image indicated by the first original image data generated by the second generation means and the second original image data indicated by the second original image data generated by the second generation means An original image is an image showing a map.
An image signal output device. The first original image data indicating the first original image and the second original image data indicating the second original image are generated and stored in the third storage means for storing various data. Two generation procedures;
The first original image data stored in the third storage means is stored in a fourth storage means for storing image data, and thereafter stored in the third storage means. A storage control procedure for newly storing the second original image data in the fourth storage means;
After the first original image data is stored in the fourth storage means in the storage control procedure, until the second original image data is stored in the fourth storage means, Based on the first original image data and the second original image data stored in the third storage means, the first original image and the second original image are in accordance with a predetermined mixing ratio. A second composite image data generation procedure for generating composite image data indicating a composite image that is a composite image and storing the composite image data in the fourth storage unit;
A second output procedure for generating an image signal based on the image data stored in the fourth storage means and outputting the image signal to the outside;
An image signal output method comprising: