JP2019168670A - Image processing apparatus, image processing method, and display unit - Google Patents

Abstract

To make it possible to perform processing of rotating an image, while preventing an increase in cost and improving the efficiency of use of a memory access band.SOLUTION: A projector comprises: a first rotation processing unit 251 that executes processing of rotating an input image input at a specified angle to output a first processed image; and a second rotation processing unit 252 that executes processing of rotating the first processed image output from the first rotation processing unit 251 at an angle specified by a 90-degree unit to output a second processed image.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an image processing device, an image processing method, and a display device.

  2. Description of the Related Art Conventionally, an apparatus that performs image processing for rotating an image is known (see, for example, Patent Document 1). Patent Document 1 stores an image before rotation in a buffer, reads out necessary pixel data from the buffer, and generates pixel data of each pixel constituting the image after rotation, thereby performing image processing for rotating the image. An apparatus is disclosed.

Japanese Patent Laying-Open No. 2015-201677

However, since Patent Document 1 executes a process of reading a plurality of pixel data from a memory and generating one pixel data for a large number of pixels, there is a problem that a memory access band may be tight.
SUMMARY OF THE INVENTION An object of the present invention is to enable processing for rotating an image while improving the use efficiency of a memory access band.

In order to solve the above-described problem, an image processing apparatus according to the present invention executes a process of rotating an input image input at a specified angle and outputs a first image, and the first processor A second processing unit that executes a process of rotating the first image output by the processing unit at an angle specified in units of 90 ° and outputs a second image.
According to the present invention, since the image is rotated using the first processing unit and the second processing unit that rotates the image in units of 90 °, the first processing unit rotates the input image at an angle of 90 ° or less. Just do it. For this reason, the image can be rotated within a range of 360 ° without increasing the buffer of the first processing unit, so that an increase in cost can be suppressed. Further, since the image is rotated in two stages by the first processing unit and the second processing unit, the data read from the memory does not increase, and the use efficiency of the memory access band can be improved in the process of rotating the image. it can. Therefore, it is possible to perform the process of rotating the image while suppressing the cost increase and improving the use efficiency of the memory access band.

  In addition, the present invention may include a memory, and the second processing unit may execute a process of rotating the first image stored in the memory.

In addition, the present invention may include a memory, and the second processing unit may store the second image, which has been subjected to the process of rotating the first image, in the memory.
According to this configuration, since the second processing unit can output the rotated second image simply by reading from the memory, the data read from the memory does not increase, and the use efficiency of the memory access band can be further improved. Can be planned.

In the present invention, the first processing unit can execute a process of rotating the input image in a forward direction and in a reverse direction opposite to the forward direction, and 45 ° or less in the forward direction and in the reverse direction. Further, the input image may be rotated at an angle specified within a range of 45 ° or less.
According to this configuration, since the angle difference between the input image and the first image is small, the buffer of the first processing unit can be reduced.

The first processing unit may be configured to rotate the input image with a point in the input image as a rotation center.
According to this configuration, since the input image is rotated with the point in the input image as the rotation center, the processing load can be significantly reduced by limiting the angle at which the first processing unit rotates the image. For this reason, it is possible to improve the processing efficiency of the first processing unit.

In the present invention, the second processing unit may output the second image having the same size as the input image.
According to this configuration, when outputting an image having the same size as the input image, the second processing unit that rotates the image in units of 90 ° adjusts the size of the second image to the same size as the input image. be able to. For this reason, the load of rotation processing can be further reduced.

In addition, the present invention includes a control unit that controls the first processing unit and the second processing unit, and the first processing unit has a rectangular first image when the input image is a rectangular image. The control unit outputs the ratio of the size of the long side to the size of the short side by the first processing unit corresponding to the angle at which the second processing unit rotates the first image. The first image different from the image may be output.
According to this configuration, the first processing unit can output an image having a size corresponding to the angle at which the second processing unit rotates the first image, and the processing efficiency of the second processing unit can be improved. it can.

Further, according to the present invention, when the second processing unit rotates the first image to 90 ° or 270 °, the first processing unit sets the size of the long side and the size of the short side. The first image having a ratio inverted from the input image is output.
According to the present invention, when the input image is rotated by 90 ° or 270 ° and a second image having the same size and shape as the input image is output, the second processing unit determines the size of the long side and the size of the short side. Can reduce the processing load.

In the present invention, the first processing unit sets a predetermined pixel value to a pixel that constitutes the first image and does not correspond to the input image, and outputs the first image.
According to the present invention, the first image of the designated size can be output by the first processing unit without significantly increasing the processing load of the first processing unit.

In order to solve the above problem, the image processing method of the present invention executes a process of rotating the input image input at a specified angle, outputs the first image, and outputs the first image output. A process of rotating the image at an angle specified in units of 90 ° is executed and a second image is output.
According to the present invention, by combining the process of rotating an image in units of 90 ° and the process of rotating an input image at an angle of 90 ° or less, 360 is used without increasing the buffer used for the process of rotating the image. Since it is possible to cope with the process of rotating the image at an angle, the cost increase can be suppressed. Further, since the image is rotated in two stages, the data read from the memory does not increase, and the use efficiency of the memory access band can be improved in the process of rotating the image. Therefore, it is possible to perform the process of rotating the image while suppressing the cost increase and improving the use efficiency of the memory access band.

In order to solve the above problem, the display device of the present invention performs a process of rotating an input image that has been input by a specified angle, and outputs a first image; A second processing unit that executes a process of rotating the first image output by one processing unit at an angle specified in units of 90 ° and outputs a second image; a display unit that displays the second image; Is provided.
According to the present invention, by combining the process of rotating an image in units of 90 ° and the process of rotating an input image at an angle of 90 ° or less, 360 is used without increasing the buffer used for the process of rotating the image. Because it can handle the process of rotating the image at an angle, the cost increase can be suppressed. Further, since the image is rotated in two stages, the data read from the memory does not increase, and the use efficiency of the memory access band can be improved in the process of rotating the image. Therefore, it is possible to perform the process of rotating the image while suppressing the cost increase and improving the use efficiency of the memory access band.

The block diagram which shows the structure of a projector. The block diagram of an image processing part. The figure for demonstrating rotation of an input image. The figure which shows an example of an input image. The figure which shows the relationship between an input image and the area | region output as a 1st process image. The figure which shows an example of a 1st process image. The figure which shows the relationship between an input image and the area | region output as a 1st process image. The figure which shows an example of a 1st process image. The figure for demonstrating the read-out order of pixel data. The figure for demonstrating the output order of pixel data. The figure which shows an example of a 2nd process image. The figure for demonstrating the read-out order of pixel data. The figure for demonstrating the output order of pixel data. The figure which shows an example of a 2nd process image. The flowchart which shows operation | movement of a projector. The block diagram which shows the structure of the 2nd rotation process part which concerns on 2nd Embodiment. The figure for demonstrating the division | segmentation of block image data. The figure for demonstrating rotation of division | segmentation block image data. The figure for demonstrating writing and reading with respect to a frame memory. The figure for demonstrating shaping of block image data.

[First Embodiment]
First, the first embodiment will be described.
FIG. 1 is a block diagram showing a configuration of a projector 1 (image processing apparatus, display apparatus) according to a first embodiment to which the present invention is applied.
An image supply device 2 is connected to the projector 1 as an external device. The image supply device 2 outputs input image data D1 to the projector 1, and the projector 1 projects a projection image on the screen SC based on the input image data D1 input from the image supply device 2. Projection of a projected image by the projector 1 is an example of displaying an image by a display device.

  The input image data D1 input from the image supply device 2 is image data that conforms to a predetermined standard. The content of the input image data D1 may be a still image or a moving image, and may be accompanied by an audio signal or audio data.

  The image supply device 2 is a so-called image source that outputs the input image data D1 to the projector 1, and may be any device that can be connected to the projector 1 and can output the input image data D1 to the projector 1. For example, a disk-type recording medium playback device, a television tuner device, or a personal computer may be used.

  The screen SC (projection surface) may be a curtain-shaped screen, or a wall surface of a building or a plane of an installation may be used as the screen SC. The screen SC is not limited to a flat surface, and may be a curved surface or a surface having irregularities.

  The projector 1 includes a control unit 3 that controls each unit of the projector 1 and a projection unit 10 that projects a projection image. The control unit 3 includes a CPU 30, a storage unit 35, and the like. The storage unit 35 is a storage device that stores the control program 36 and data executed by the CPU 30 in a nonvolatile manner, and includes a semiconductor storage element such as a flash ROM. The storage unit 35 may include a RAM that forms a work area of the CPU 30.

  The CPU 30 functions as the projection control unit 31 and the image processing control unit 32 by executing the control program 36 of the projector 1 stored in the storage unit 35. That is, these functional blocks are realized by the cooperation of software and hardware by the CPU 30 executing the control program 36.

  The storage unit 35 stores setting data 37 in addition to the control program 36. The setting data 37 includes setting values related to the operation of the projector 1. The setting values included in the setting data 37 are, for example, processing contents executed by the image processing unit 25, parameters used for processing of the image processing unit 25, and the like. The storage unit 35 may store other programs and data.

  The projection unit 10 includes a light source unit 11, a light modulation device 12, and a projection optical system 13. The light source unit 11 includes a lamp such as a halogen lamp, a xenon lamp, or an ultrahigh pressure mercury lamp, or a solid light source such as an LED or a laser light source. The light source unit 11 is turned on by the electric power supplied from the light source driving unit 22 and emits light toward the light modulation device 12.

  The light source drive unit 22 supplies a drive current and a pulse to the light source unit 11 under the control of the control unit 3 to cause the light source unit 11 to emit light.

  The light modulation device 12 includes an image forming unit such as a liquid crystal panel that is driven by the light modulation device driving unit 23 to form an image. The light modulation device 12 modulates the light emitted from the light source unit 11 with the image formed on the image forming unit, generates image light, and projects the image light toward the projection optical system 13. The image forming unit includes a transmissive liquid crystal panel, a reflective liquid crystal panel, a digital mirror device (DMD: Digital Mirror Device), and the like.

  The light modulation device driving unit 23 receives output image data D4 of an image to be drawn on the light modulation device 12 from the image processing unit 25, drives the light modulation device 12 in accordance with the output image data D4, and sets each pixel of the image forming unit. Set gradation and draw an image in frame units.

  The projection optical system 13 includes optical elements such as a lens and a mirror, forms an image of the light modulated by the light modulation device 12 on the screen SC, and projects a projection image.

The projector 1 includes an interface unit 24, an image processing unit 25, a frame memory 27 (memory), an input processing unit 53, an operation panel 51, a remote control light receiving unit 52, and a wireless communication unit 55. These units are connected to the control unit 3 via the bus 29 so that data communication is possible.
The image processing unit 25 will be described later with reference to FIG.

  The interface (I / F) unit 24 is a wired interface for data communication, and includes a connector (not shown), an interface circuit (not shown), and the like. The interface unit 24 is connected to the image supply device 2 via a cable, and transmits / receives image data, control data, and the like to / from an external device under the control of the control unit 3. As the interface unit 24, various communication interfaces and image input interfaces can be employed.

  The frame memory 27 includes a plurality of banks. Each bank has a storage capacity capable of writing one frame of image data. The frame memory 27 is configured by, for example, an SDRAM (Synchronous Dynamic Random Access Memory).

The input processing unit 53 is connected to the operation panel 51 and the remote control light receiving unit 52. The input processing unit 53 generates operation data corresponding to the received operation and outputs the operation data to the control unit 3 when the operation is received by the operation panel 51 or the remote control light receiving unit 52.
The operation panel 51 is provided in the housing of the projector 1 and includes various switches that can be operated by the user. The input processing unit 53 detects the operation of each switch on the operation panel 51.
The remote control light receiving unit 52 receives an infrared signal transmitted from the remote control 50. The input processing unit 53 decodes the signal received by the remote control light receiving unit 52, generates operation data, and outputs it to the control unit 3.

  The wireless communication unit 55 includes an antenna, an RF circuit (not shown), and the like, and performs wireless data communication with an external device under the control of the control unit 3. The wireless communication unit 55 performs wireless communication such as a wireless LAN (including Wi-Fi (registered trademark)), Bluetooth (registered trademark), and the like.

Next, functional blocks of the CPU 30 will be described.
The projection control unit 31 controls the light source driving unit 22 and the light modulation device driving unit 23 to turn on the light source unit 11, drive the light modulation device 12 by the light modulation device driving unit 23, and project by the projection unit 10. Project an image. Further, the projection control unit 31 controls the image processing unit 25 to execute image processing on the input image data D1 input to the interface unit 24, and causes the light modulation device driving unit 23 to output image data D4 after image processing. Is output.

The image processing control unit 32 controls image processing on the input image data D1 by the image processing unit 25. When the rotation angle of the input image NG (refer to FIG. 3 etc.) indicated by the input image data D1 is set by the operation of the operation panel 51 or the remote controller 50, the image processing control unit 32 sets the input image NG to the set angle. The image processing unit 25 is caused to perform image processing to be rotated. Note that the rotation of the input image NG includes rotation of an image including the input image NG.
Hereinafter, the rotation angle of the input image NG set by the operation panel 51, the remote controller 50, or the like is referred to as a set rotation angle.

  FIG. 2 is a block diagram of the image processing unit 25. For convenience of understanding, the frame memory 27 and the image processing control unit 32 are illustrated.

  The image processing unit 25 includes a first rotation processing unit 251 (first processing unit) and a second rotation processing unit 252 (second processing unit). The image processing unit 25 performs image processing in each of the first rotation processing unit 251 and the second rotation processing unit 252, and performs image processing for rotating the input image NG to a set rotation angle. The first rotation processing unit 251 and the second rotation processing unit 252 perform image processing for rotating the input image NG at an angle calculated by the image processing control unit 32.

  Based on the set rotation angle, the image processing control unit 32 calculates an angle at which the first rotation processing unit 251 rotates the input image NG and an angle at which the second rotation processing unit 252 rotates the input image NG.

  Hereinafter, the angle at which the first rotation processing unit 251 rotates the input image NG is referred to as a first rotation angle, and the angle at which the second rotation processing unit 252 rotates the input image NG is referred to as a second rotation angle.

Here, before describing the calculation of the image processing control unit 32, the rotation of the input image NG in the present embodiment will be described.
FIG. 3 is a diagram for explaining the rotation of the input image NG.

In the present embodiment, an example in which the input image NG is a horizontally long rectangular image is shown.
In the example described below, the image processing unit 25 executes a process of rotating the input image NG about a point in the input image NG as the rotation center. In the example of FIG. 3, the center of gravity G of the input image NG is set as the rotation center.

  The input image NG can rotate in the clockwise (CW) direction (reverse direction) indicated by the arrow B and the counterclockwise (CCW) direction (forward direction) indicated by the arrow A with the center of gravity G as the rotation center. is there.

  The rotation angle of the input image NG is an angle that is parallel to the long side LH of the input image NG and shows a positive value counterclockwise with a parallel line HS passing through the center of gravity G being 0 °, and is negative in the clockwise direction. An angle indicating a value.

  The first rotation processing unit 251 executes image processing for rotating the input image NG at an angle designated by the image processing control unit 32 in a range of + 45 ° or less and −45 ° or more. The second rotation processing unit 252 executes image processing for rotating the input image NG by an angle designated by the image processing control unit 32 in units of 90 °.

For example, when the set rotation angle is + 60 °, the image processing control unit 32 calculates the first rotation angle as −30 ° and the second rotation angle as + 90 °. As the first rotation processing unit 251 and the second rotation processing unit 252 perform image processing at the angle calculated by the image processing control unit 32, the input image NG is rotated by + 60 °.
For example, when the set rotation angle is + 30 °, the image processing unit 25 calculates the first rotation angle as + 30 ° and the second rotation angle as 0 °. The 0 ° rotation is the same process as the 360 ° rotation. When the first rotation processing unit 251 and the second rotation processing unit 252 perform image processing at an angle calculated by the image processing control unit 32, the input image NG is rotated by + 30 °.

  As described above, the image processing control unit 32 calculates an angle by which each processing unit rotates the input image NG so that the sum of the first rotation angle and the second rotation angle becomes the set rotation angle. The image processing control unit 32 calculates so that the first rotation angle is in a range of −45 ° or more and +45 or less, and the second rotation angle is in units of 90 °. More specifically, the range of the first rotation angle includes at least a range greater than −45 ° and less than or equal to + 45 °, or greater than or equal to −45 ° and less than + 45 °.

  After calculating the first rotation angle, the image processing control unit 32 outputs angle information indicating the calculated angle to the first rotation processing unit 251, and sets an angle for rotating the input image NG with respect to the first rotation processing unit 251. specify. Further, the image processing control unit 32 also outputs angle information indicating the second rotation angle to the first rotation processing unit 251. Similarly, the image processing control unit 32 outputs angle information for the second rotation processing unit 252 as well. Note that the second rotation processing unit 252 may not output angle information including the first rotation angle.

The first rotation processing unit 251 and the second rotation processing unit 252 will be described in detail with reference to FIG.
The first rotation processing unit 251 includes a line buffer 253, a correspondence table 254, an image output unit 255, and a filter table 256. The image output unit 255 includes a line buffer 257.

The line buffer 253 includes line buffers 253A, 253B, 253C, and 253D. Each line buffer 253A, 253B, 253C, 253D stores image data for one line in the horizontal direction. That is, the line buffer 253 of this embodiment stores image data for four horizontal lines. Hereinafter, image data for a plurality of horizontal lines input from the I / F unit 24 and stored in the line buffer 253 will be referred to as image data D2. The line buffer 253 is a dedicated buffer for storing the image data D2 before image processing.
The image data D2 includes pixel data of each pixel constituting the image data D2. The pixel data includes pixel position information indicating the position of the pixel and a pixel value of the pixel.
Although FIG. 2 shows the line buffer 253 including the four line buffers 253A, 253B, 253C, and 253D, the number of line buffers 253 is not limited to four.

The image output unit 255 of the first rotation processing unit 251 refers to the pixel correspondence information stored in the correspondence table 254 based on the angle specified by the image processing control unit 32, and stores the image stored in the line buffer 253. Image processing for rotating the input image NG using the data D2 is executed. Then, the first rotation processing unit 251 outputs an image including the rotated input image NG to the second rotation processing unit 252.
In the following description, an image output from the first rotation processing unit 251 to the second rotation processing unit 252 is referred to as a first processed image SG1 (first image) (see FIG. 5 and the like).

  The correspondence table 254 stores a plurality of pieces of pixel correspondence information corresponding to the first rotation angle and the second rotation angle. The pixel correspondence information indicates, for each pixel constituting the first processed image SG1, pixel position information in the first processed image SG1 and a position on the input image NG corresponding to the pixel position indicated by the pixel position information. This is information associated with position information.

The process of the first rotation processing unit 251 will be described in detail with reference to FIGS. 4, 5, and 6. 4, 5, and 6 show processing of the first rotation processing unit 251 when the set rotation angle is −30 °.
FIG. 4 is a diagram illustrating an example of the input image NG. FIG. 4 shows an enlarged view of a part of the pixels constituting the input image NG. FIG. 5 is a diagram illustrating a correspondence relationship between the region of the input image NG rotated by −30 ° and the region AA output to the second rotation processing unit 252 as the first processed image SG1. FIG. 6 is a diagram illustrating an example of the first processed image SG1.

  When the set rotation angle is −30 °, the image processing control unit 32 designates −30 ° as the first rotation angle to the first rotation processing unit 251 and 0 ° as the second rotation angle. 252 is specified.

  When the image output unit 255 of the first rotation processing unit 251 receives angle information indicating −30 ° and angle information indicating 0 ° from the image processing control unit 32, the first rotation angle is obtained from the correspondence table 254. Pixel correspondence information corresponding to −30 ° and a second rotation angle of 0 ° is acquired. The pixel correspondence information acquired here is pixel correspondence information related to the horizontally long first processed image SG1 having the same size as the input image NG.

  Image data D2 indicating the input image NG-1 in the input image NG of FIG. 4 is stored in the line buffer 253. Using this image data D2, the pixels GS1 and GS2 constituting the first processed image SG1 are stored. A case where pixel data is generated will be described.

The pixel correspondence information includes pixel position information of the pixel GS1 in the first processed image SG1 and position information indicating a position on the input image NG rotated by −30 ° corresponding to the position of the pixel GS1 in the first processed image SG1. With correspondence.
For convenience, FIG. 4 shows the position on the input image NG rotated by −30 ° corresponding to the position of the pixel GS1 as the position of the pixel GS1 ′. FIG. 4 also shows an example of the input image NG and the pixels constituting the input image NG located around the positions of the pixels GS1 ′ and GS2 ′.

  The image output unit 255 has one pixel constituting the input image NG at the position of the pixel GS1 ′ based on the pixel correspondence information and the image data D2 indicating the input image NG-1 stored in the line buffer 253. It is determined whether or not. When it is determined that there is no image output unit 255, the image output unit 255 performs an interpolation process based on a plurality of pixels located around the position of the pixel GS1 ′ to obtain a pixel value of the pixel GS1. The line buffer 253 stores data of each pixel constituting the input image NG. Therefore, the image output unit 255 can determine whether or not there is one pixel constituting the input image NG at the position of the pixel GS1 ′ by referring to the data stored in the line buffer 253. When 2 × 2 pixels are used in the interpolation processing, the image output unit 255 calculates the pixel value of the pixel GS1 using the pixels GSa, GSb, GSc, and GSd located around the position of the pixel GS1 ′. The image output unit 255 calculates the pixel value of the pixel GS1 by performing a convolution operation with the filter coefficients registered in the filter table 256 at the time of calculation and the pixel values of the pixels GSa, GSb, GSC, and GSd. The filter coefficient is a coefficient for obtaining a pixel value by interpolation processing.

  When the pixel value of the pixel GS1 is calculated, the image output unit 255 causes the line buffer 257 to store pixel data in which the calculated pixel value and the pixel position information in the first processed image SG1 are associated with each other for the pixel GS1. When there is one pixel constituting the input image NG at the position of the pixel GS1 ′, the image output unit 255 uses the pixel value of the one pixel as the pixel value of the pixel GS1, and sends the pixel data to the line buffer 257. Remember.

  The line buffer 257 includes line buffers 257A, 257B, and 257C. Each line buffer 257A, 257B, 257C stores image data for one line in the horizontal direction. The line buffer 257 is a dedicated buffer for storing pixel data after image processing. 2 shows the line buffer 257 including the three line buffers 257A, 257B, and 257C, the number of line buffers 257 is not limited to three.

  The image output unit 255 burst-transfers the pixel data stored in the line buffer 257 to the second rotation processing unit 252 in units of blocks. This is because the pixel data of the pixels constituting the first processed image SG1 is efficiently transferred to the second rotation processing unit 252. A block is a storage area per unit obtained by dividing the line buffer 257 according to a predetermined standard. When the pixel data of the pixel GS1 is stored in the line buffer 257, the image output unit 255 outputs the pixel data of the pixel GS1 to the second rotation processing unit 252 in units of blocks.

  The image output unit 255 calculates the pixel value of the pixel GS2 in the same manner as the pixel GS1. The pixel correspondence information includes pixel position information of the pixel GS2 in the first processed image SG1 and position information indicating a position on the input image NG rotated by −30 ° corresponding to the position of the pixel GS2 indicated by the pixel position information. With correspondence. For convenience, FIG. 4 shows the position on the input image NG rotated by −30 ° corresponding to the position of the pixel GS2 as the position of the pixel GS2 ′. The image output unit 255 calculates the pixel value of the pixel GS2 using the pixels GSc, GSe, GSf, and GSg located around the position of the pixel GS2 ′. When the pixel value of the pixel GS2 is calculated, the image output unit 255 stores the pixel data associated with the calculated pixel value and pixel position information in the line buffer 257 for the pixel GS2, and the second rotation processing unit in units of blocks. Output to.

  Note that when there is one pixel constituting the input image NG at the position of the pixel GS2 ′, the image output unit 255 uses the pixel value of the one pixel as the pixel value of the pixel GS2, and sends the pixel data to the line buffer 257. Remember.

  The image output unit 255 stores the pixel data in the line buffer 257 in a manner in which the input image NG is rotated. For example, when the pixel GS1 and the pixel GS2 are adjacent and located on the same horizontal line in the first processed image SG1, the image output unit 255 causes the pixel GS1 and the pixel GS2 to be adjacent in the horizontal direction. Store in the line buffer 257.

  As described above, the first rotation processing unit 251 refers to the pixel correspondence information, and for each of the pixels constituting the first processed image SG1, the position of the pixel on the first processed image SG1 and the rotated input image NG A pixel value is calculated based on the correspondence with the position. Then, the first rotation processing unit 251 passes, through the line buffer 257, pixel data in which the pixel value and the pixel position information on the first processed image SG1 correspond to each of the pixels constituting the first processed image SG1. The data is output to the second rotation processing unit 252. As a result, the first rotation processing unit 251 outputs the first processed image SG1 including the input image NG rotated by −30 ° to the second rotation processing unit 252 as shown in FIG.

  In FIG. 5, a rectangular area AA indicated by a one-dot chain line is an area output to the second rotation processing unit 252 as the first processed image SG1. As shown in FIG. 5, the pixels GS1 and GS2 constituting the first processed image SG1 are pixels corresponding to the input image NG rotated by −30 °, but the pixel GS3 is an input image NG rotated by −30 °. Pixels that do not correspond to the top. The image output unit 255 sets, for example, a black pixel value for such a pixel. The pixel correspondence information is associated with pixel position information of the pixel GS3 and information indicating that the position corresponding to the position of the pixel GS3 does not correspond to the input image NG rotated by −30 °. The image output unit 255 outputs, to the second rotation processing unit 252 via the line buffer 257, pixel data in which the set predetermined pixel value and the pixel position information in the first processed image SG1 are associated with each other for the pixel GS3. .

  In this way, the image output unit 255 refers to the pixel correspondence information for rotating the input image NG by −30 ° from the correspondence table 254, and based on the image data D2 stored in the line buffer 253, the first The pixel data of each pixel constituting the processed image SG1 is output to the second rotation processing unit 252. As a result, the first rotation processing unit 251 includes the first processed image SG1 including the input image NG rotated by −30 ° as shown in FIG. 6 and filling the area other than the input image NG with a predetermined color. Output to the second rotation processing unit 252.

  Next, the process of the first rotation processing unit 251 when the set rotation angle is + 60 ° will be described with reference to FIGS. 7 and 8. FIG. 7 is a diagram illustrating a correspondence relationship between the region of the input image NG rotated by −30 ° and the region AB output to the second rotation processing unit 252 as the first processed image SG1. FIG. 8 is a diagram illustrating an example of the first processed image SG1.

  When the set rotation angle is + 60 °, the image processing control unit 32 specifies −30 ° as the first rotation angle and + 90 ° as the second rotation angle.

  When the angle information indicating −30 ° and the angle information indicating + 90 ° are input from the image processing control unit 32, the image output unit 255 of the first rotation processing unit 251 receives the first rotation angle from the correspondence table 254. Pixel correspondence information corresponding to the fact that is −30 ° and the second rotation angle is + 90 °. The pixel correspondence information acquired in this case is pixel correspondence information related to the first processed image SG1 in which the ratio of the size of the long side LH to the size of the short side TH is inverted from the input image NG.

  The image output unit 255 refers to the pixel correspondence information about the vertically long first processed image SG1 as shown in FIG. 7 from the correspondence table 254, and the pixel data of each pixel constituting the first processed image SG1 is described above. And generated and output to the second rotation processing unit 252. As a result, the first rotation processing unit 251 outputs the vertically long first processed image SG1 including the input image NG rotated by −30 ° to the second rotation processing unit 252 as shown in FIG.

  As described above, the first rotation processing unit 251 outputs the first processed image SG1 in which the ratio between the size of the long side LH and the size of the short side TH is different according to the second rotation angle. More specifically, when the second rotation angle is 90 ° or 270 °, a vertically long first processed image SG1 obtained by inverting the ratio of the size of the long side LH to the size of the short side TH from the horizontally long input image NG. Is output to the second rotation processing unit 252. In addition, when the angle at which the second rotation processing unit 252 rotates the first processed image SG1 is 0 ° (360 °) or 180 °, the first rotation processing unit 251 has the same size and the same shape as the input image NG. The first processed image SG1 is output to the second rotation processing unit 252. The effect of this will be described later.

Next, the process of the second rotation processing unit 252 will be described.
The second rotation processing unit 252 writes the image data D3 indicating the first processed image SG1 output from the first rotation processing unit 251 in the frame memory 27.

The second rotation processing unit 252 performs image processing for rotating the first processed image SG1 stored in the frame memory 27 based on the angle designated by the image processing control unit 32, and shows an image subjected to image processing. The image data is output to the light modulator driving unit 23. The image data output to the light modulator driving unit 23 is the output image data D4 described above.
In the following description, the image output by the second rotation processing unit 252 is referred to as a second processed image SG2 (second image) (see FIG. 11 and the like).

  The second rotation processing unit 252 rotates the first processed image SG1 by reading each pixel data of the first processed image SG1 on the frame memory 27 in the reading order corresponding to the rotation angle specified in units of 90 °. The processed second processed image SG2 is output.

  9, 10 and 11 are diagrams for explaining the processing of the second rotation processing unit 252 when the first processed image SG1 is rotated at 0 °. FIG. 9 is a diagram illustrating the order in which the pixel data of the pixels constituting the first processed image SG1 stored in the frame memory 27 is read. FIG. 10 is a diagram illustrating an order in which pixel data read from the frame memory 27 is output to the second rotation processing unit 252. FIG. 11 shows an example of the second processed image SG2 when the process of rotating the first processed image SG1 shown in FIG. 6 at 0 ° is executed.

  The first processed image SG1 illustrated in FIG. 9 is an image in which n pixel rows in which pixels are arranged in the horizontal direction are arranged in an orthogonal direction orthogonal to the horizontal direction. When the first processed image SG1 is rotated at 0 °, the second rotation processing unit 252 is arranged in the order of the first row, the second row, the (n−1) th row, and the nth row as shown in FIG. Pixel data of one pixel is read out from the left to the right for one pixel column.

  The second processed image SG2 illustrated in FIG. 10 is an image in which n pixel rows in which pixels are arranged in the horizontal direction are arranged in the orthogonal direction. When the second rotation processing unit 252 outputs the second processed image SG2, according to the order in which the pixel data is read from the first processed image SG1, the second rotation processing unit 252 converts the read pixel data into the first row, the second row, as shown in FIG. Rows... Are output one by one from the left to the right for one pixel column in the order of the (n−1) th row and the nth row.

  For example, when pixel data is read from the first pixel column of the first processed image SG1 from the left to the right, the second rotation processing unit 252 reads the read pixel column to the first row of the second processed image SG2. As the pixel column, pixel data is output from left to right in the readout order.

  The second rotation processing unit 252 outputs the second processed image SG2 illustrated in FIG. 11 by performing the above-described reading and output on the first processed image SG1 illustrated in FIG. That is, the second rotation processing unit 252 outputs the second processed image SG2 including the input image NG rotated by −30 °.

  When the first processed image SG1 is rotated by 180 °, the second rotation processing unit 252 has one pixel column in the order of the nth row, the n−1th row,. The pixel data is read one by one in the direction opposite to the arrow shown in FIG. Then, the second rotation processing unit 252 reads the read pixel data from the left to the right for one pixel column in the order of the first row, the second row,..., The n−1th row, the nth row. Pixel data is output one by one. For example, when the pixel data is read from the right to the left in the nth pixel column of the first processed image SG1, the second rotation processing unit 252 uses the read pixel column as the first row of the second processed image SG2. Output from left to right. By performing this reading and output, the second rotation processing unit 252 outputs the second processed image SG2 obtained by rotating the first processed image SG1 by 180 °.

  FIGS. 12, 13, and 14 are diagrams for explaining the processing of the second rotation processing unit 252 when the first processed image SG1 is rotated by 90 °. FIG. 12 shows the order in which the pixel data of the pixels constituting the first processed image SG1 stored in the frame memory 27 is read. FIG. 13 shows the order in which the second rotation processing unit 252 outputs the pixel data read from the frame memory 27. FIG. 14 illustrates an example of the second processed image SG2 output by the second rotation processing unit 252 that has performed image processing for rotating the first processed image SG1 illustrated in FIG. 8 at 90 °.

  As described above, when the second rotation processing unit 252 rotates the first processed image SG1 at 90 ° or 270 °, the frame memory 27 stores the size of the long side LH and the short side TH as shown in FIG. A first processed image SG1 obtained by inverting the ratio with the size from the input image NG is stored.

  The first processed image SG1 shown in FIG. 12 is an image in which n pixel rows in which pixels are arranged in the orthogonal direction are arranged in the horizontal direction. When the first processed image SG1 is rotated by 90 °, as shown in FIG. 12, the second rotation processing unit 252 is arranged in the order of the first column, the second column, the n−1th column, and the nth column. Pixel data is read out one pixel row at a time from top to bottom.

  The second processed image SG2 illustrated in FIG. 13 is an image in which n pixel rows in which pixels are arranged in the horizontal direction are arranged in the orthogonal direction. When the second rotation processing unit 252 outputs the second processed image SG2, the read pixel data in the first row, the second row, as shown in FIG. 13, according to the order in which the pixel data is read from the first processed image SG1. The pixel data of the pixels are output one by one from the left to the right for one pixel column in the order of the row... N-1 and n.

  For example, when pixel data is read from top to bottom for the first pixel column from the first processed image SG1, the second rotation processing unit 252 uses the read pixel column as the first row of the second processed image SG2. As the pixel column, pixel data is output from left to right in the readout order.

  The second rotation processing unit 252 outputs the second processed image SG2 illustrated in FIG. 14 by performing the above-described reading and output on the first processed image SG1 illustrated in FIG. That is, the second rotation processing unit 252 outputs the second processed image SG2 including the input image NG rotated by + 60 °.

  When the first processed image SG1 is rotated at 270 °, the second rotation processing unit 252 has one pixel column in the order of the nth column, the n−1th column,. The pixel data is read one by one in the direction opposite to the arrow shown in FIG. Then, the second rotation processing unit 252 reads the read pixel data from the left to the right for one pixel column in the order of the first row, the second row,..., The n−1th row, the nth row. Pixel data is output one by one. For example, when pixel data is read from the bottom to the top of the n-th pixel column of the first processed image SG1, the second rotation processing unit 252 uses the read pixel column as the first row of the second processed image SG2. Output from left to right. By performing this reading and output, the second rotation processing unit 252 outputs the second processed image SG2 obtained by rotating the first processed image SG1 by 270 °.

  As described above, the first rotation processing unit 251 performs the image processing for rotating the input image NG at an angle specified in the range of + 45 ° or less and −45 ° or more, and performs the second rotation processing on the first processed image SG1. To the unit 252. And the 2nd rotation process part 252 performs the image process which rotates 1st process image SG1 by the angle designated by the 90 degree unit, and outputs 2nd process image SG2. When the second rotation processing unit 252 rotates the first processed image SG1 by an angle specified in units of 90 °, it is only necessary to change the order of the pixel data read from the frame memory 27 according to the angle. Therefore, the second rotation processing unit 252 does not need to read a plurality of pixel data from the frame memory 27 when outputting one pixel data for each of the pixels constituting the second processed image SG2. Therefore, it is possible to perform a process of rotating the input image NG while improving the use efficiency of the access band for the frame memory 27.

  When the second rotation processing unit 252 rotates the first processed image SG1 to 90 ° or 270 °, the first rotation processing unit 251 determines that the ratio between the size of the long side LH and the size of the short side TH is an input image. A first processed image SG1 inverted from NG is output. Accordingly, the second rotation processing unit 252 can output the second processed image SG2 having the same size and the same size as the input image NG by rotating the first processed image SG1 by 90 ° or 270 °. Therefore, the angle of view of the projected image does not change according to the rotation of the input image NG. In addition, when the second processed image SG2 having the same size and shape as the input image NG is output, the processing load of the second rotation processing unit 252 changing the size of the long side LH and the size of the short side TH can be reduced. .

The first rotation processing unit 251 rotates the input image NG at an angle designated by the image processing control unit 32 within a range of + 45 ° or less and −45 ° or more. Accordingly, the image processing unit 25 can perform image processing that suppresses the cost increase of the projector 1 and rotates the input image NG at all angles of 360 °.
As described above, the line buffer 257 stores pixel data in a manner in which the input image NG is rotated by a predetermined angle. For this reason, the pixel data stored in the line buffer 257 increases in a direction orthogonal to the horizontal direction on the line buffer 257 as the rotation angle of the input image NG approaches + 90 ° or −90 °. Therefore, if the first rotation processing unit 251 can rotate the input image NG over a wide range of angles, the first rotation processing unit 251 needs a large number of line buffers 257. This leads to an increase in the cost of the projector 1. Therefore, it is desirable that the range of the angle at which the first rotation processing unit 251 rotates the input image NG is as narrow as possible. However, if the range is less than +45 or less and −45 or more, the rotation angle combined with the second rotation processing unit 252 is Cannot cover all 360 ° angles.
Therefore, the first rotation processing unit 251 is configured to rotate the input image NG at an angle specified by the image processing control unit 32 within a range of + 45 ° or less and −45 ° or more, thereby achieving the above-described effect. it can.
Further, the image processing unit 25 can rotate the input image NG because the first rotation processing unit 251 can rotate the input image NG with a small angle difference between the input image NG and the first processing image SG1. The line buffer 257 can be reduced.

  In addition, the first rotation processing unit 251 sets a predetermined pixel value to pixels that constitute the first processed image SG1 and does not correspond to the input image NG, and outputs the first processed image SG1. In the projector 1, unless a predetermined pixel value is set in an area other than the input image NG, the area other than the input image NG projected on the screen SC becomes unnaturally bright, which causes a reduction in image quality of the projected image. Therefore, since a predetermined pixel value is set to a pixel that constitutes the first processed image SG1 and does not correspond to the input image NG, it is possible to suppress deterioration in the image quality of the projection image including the rotated input image NG. .

Next, the operation of the projector 1 will be described.
FIG. 15 is a flowchart showing the operation of the projector 1.

  Based on the output from the input processing unit 53, the image processing control unit 32 of the projector 1 determines whether or not an angle for rotating the input image NG is set by operating the operation panel 51, the remote controller 50, or the like (step). S1).

  When it is determined that the angle for rotating the input image NG is set (step S1: YES), the image processing control unit 32 determines whether the set rotation angle is −45 ° or more and + 45 ° or less (step S2). ).

  When determining that the set rotation angle is not less than −45 ° and not more than + 45 ° (step S2: YES), the image processing control unit 32 designates the first rotation angle in the range of not less than −45 ° and not more than + 45 °. The 2 rotation angle is designated as 0 ° (step S3).

  On the other hand, if the image processing control unit 32 determines that the set rotation angle is not −45 ° or more and + 45 ° or less (step S2: NO), the first rotation angle is specified in the range of −45 ° or more and + 45 ° or less. The second turn angle is designated as an angle in units of 90 ° (step S4).

Step S4 will be described in more detail.
When the set rotation angle is greater than + 45 ° and less than + 135 °, the image processing control unit 32 designates the first rotation angle in the range of −45 ° to + 45 ° and designates the second rotation angle to + 90 °. . Even when the set rotation angle is larger than −225 ° and smaller than −315 °, the image processing control unit 32 designates similarly.
When the set rotation angle is greater than + 135 ° and less than + 225 °, the image processing control unit 32 designates the first rotation angle in a range of −45 ° to + 45 ° and sets the second rotation angle to + 1800 °. Set. Even when the set rotation angle is greater than −135 ° and less than or equal to −225 °, the image processing control unit 32 similarly designates.
When the set rotation angle is larger than +225 and smaller than + 315 °, the image processing control unit 32 designates the first rotation angle in the range of −45 ° to + 45 ° and sets the second rotation angle to + 270 °. . Even when the set rotation angle is greater than −45 ° and less than or equal to −135 °, the image processing control unit 32 specifies the same.

As described above, the projector 1 according to the embodiment to which the present invention is applied executes the process of rotating the input image NG that has been input at a specified angle to perform the first process image SG1 (first image). The first rotation processing unit 251 (first processing unit) that outputs the first processed image SG1 output by the first rotation processing unit 251 and a process of rotating the first processing image SG1 by an angle specified in units of 90 ° are executed. A second rotation processing unit 252 that outputs a two-process image SG2.
According to the image processing apparatus and the projector 1 to which the image processing method of the present invention is applied, the first rotation processing unit 251 and the second rotation processing unit 252 that rotates the first processed image SG1 in units of 90 ° are used. Therefore, the first rotation processing unit 251 may rotate the input image NG at an angle of 90 ° or less. For this reason, the input image NG can be rotated within a range of 360 ° without increasing the line buffer 257 of the first rotation processing unit 251, so that an increase in cost can be suppressed. In addition, since the input image NG is rotated in two stages by the first rotation processing unit 251 and the second rotation processing unit 252, the data read in the rotation processing of the input image NG does not increase, and in the processing of rotating the input image NG. The use efficiency of the access band to the memory including the frame memory 27 can be improved. Therefore, it is possible to perform the process of rotating the input image NG while improving the utilization efficiency of the memory access band while suppressing the cost increase.

In addition, a frame memory 27 (memory) that stores the first processed image SG1 is provided, and the second rotation processing unit 252 executes a process of rotating the first processed image SG1 stored in the frame memory 27.
According to this configuration, when the second rotation processing unit 252 rotates the first processed image SG1 by an angle specified in units of 90 °, the second rotation processing unit 252 only changes the order of the pixel data read from the frame memory 27 according to the angle. It's okay. Therefore, the second rotation processing unit 252 does not need to read a plurality of pixel data from the frame memory 27 when outputting one pixel data for each of the pixels constituting the second processed image SG2. For this reason, it is possible to improve the use efficiency of the access band to the frame memory 27 and to improve the efficiency of the process of rotating the input image NG.

  Further, the first rotation processing unit 251 can execute a process of rotating the input image NG in the counterclockwise direction (forward direction) and the clockwise direction (reverse direction), and in the counterclockwise direction. The input image NG is rotated at an angle specified within a range of 45 ° or less and 45 ° or less in the clockwise direction.

  According to this configuration, since the angle at which the first rotation processing unit 251 rotates the input image NG is in a range of 45 ° or less in the forward direction and 45 ° or less in the reverse direction, the cost increase of the projector 1 is suppressed, In addition, image processing for rotating the input image NG at all angles of 360 ° can be performed.

  In addition, the first rotation processing unit 251 may be configured to rotate the input image NG with a point in the input image NG as the rotation center. In the present embodiment, the point in the input image NG is the center of gravity G of the input image NG.

  According to this configuration, since the input image NG is rotated with the center of gravity G of the input image NG as the rotation center, the processing load is significantly reduced by limiting the angle at which the first rotation processing unit 251 rotates the input image NG. it can. As a result, the projector 1 can further improve the processing efficiency of rotating the input image NG.

  The second rotation processing unit 252 may be configured to output the second processed image SG2 having the same size as the input image NG.

  According to this configuration, when outputting the second processed image SG2 having the same size as the input image NG, the second rotation processing unit 252 adjusts the size of the second processed image SG2 to the same size as the input image NG. can do. Therefore, the second rotation processing unit 252 can further reduce the processing load on the first rotation processing unit 251.

  The projector 1 also includes an image processing control unit 32 (control unit) that controls the first rotation processing unit 251 and the second rotation processing unit 252. The first rotation processing unit 251 outputs a rectangular first processed image SG1 when the input image NG is a rectangular image. The image processing control unit 32 corresponds to the angle at which the second rotation processing unit 252 rotates the first processed image SG1, and the first rotation processing unit 251 uses the ratio between the size of the long side LH and the size of the short side TH. Outputs a first processed image SG1 different from the input image NG.

  According to this configuration, the ratio of the size of the long side LH to the short side TH is determined by the first rotation processing unit 251 corresponding to the angle at which the second rotation processing unit 252 rotates the first processed image SG1. Since the first processed image SG1 different from NG is output, the second processed image SG2 having a size corresponding to the angle at which the first processed image SG1 is rotated can be output.

  Further, when the second rotation processing unit 252 rotates the first processed image SG1 to 90 ° or 270 °, the image processing control unit 32 causes the first rotation processing unit 251 to set the size of the long side LH and the short side TH. The first processed image SG1 in which the ratio to the size is inverted from the input image NG is output.

  According to this configuration, when the first processed image SG1 is rotated by 90 ° or 270 °, the first processed image SG1 in which the ratio of the size of the long side LH to the short side TH is inverted from the input image NG is output. The second processed image SG2 having the same size and the same shape as the input image NG can be output. In addition, the second rotation processing unit 252 can output the second processed image SG2 having the same size and the same shape as the input image NG by changing the reading order of the pixel data. Therefore, the processing efficiency of the second processed image SG2 can be improved.

  In addition, the first rotation processing unit 251 sets a predetermined pixel value to pixels that constitute the first processed image SG1 and does not correspond to the input image NG, and outputs the first processed image SG1.

  According to this configuration, since a predetermined pixel value is set to a pixel that constitutes the first processed image SG1 and does not correspond to the input image NG, the image quality of the first processed image SG1 after rotation is degraded. Can be suppressed. Furthermore, it can suppress that the image quality of the projection image containing the rotated input image NG falls. In addition, since the first rotation processing unit 251 sets predetermined pixel values for pixels that do not correspond to the input image NG, the first processing image SG1 is not significantly increased in processing load for pixels that do not correspond to the input image NG. Can output.

  The projector 1 (display device) includes a projection unit 10 (display unit) that projects the second processed image SG2.

  According to this configuration, the second processed image SG2 including the input image NG rotated at the set rotation angle can be projected on the screen SC as a projection image.

[Second Embodiment]
Next, a second embodiment will be described.
The projector 1 according to the second embodiment is different from the projector 1 according to the first embodiment in the rotation processing of the input image NG in the second rotation processing unit 252 of the image processing unit 25. In the description of the second embodiment, the same components as those of the projector 1 shown in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 16 is a block diagram showing a configuration of the second rotation processing unit 252 according to the second embodiment, and also shows a frame memory 27 for convenience of understanding.

  As shown in FIG. 16, the second rotation processing unit 252 includes a data dividing unit 2521, a data rotating unit 2522, a data writing unit 2523, a data reading unit 2524, and a data shaping unit 2525.

  The data dividing unit 2521 includes a buffer 25A1. The buffer 25A1 stores image data D3 for one block that is burst-transferred by the image output unit 255 of the first rotation processing unit 251. The storage area of the buffer 25A1 may be image data D3 for at least one block. In the following, the image data D3 for one block that has been burst transferred by the image output unit 255 will be referred to as “block image data” and will be labeled “D31”. The data dividing unit 2521 divides the block image data D31 stored in the buffer 25A1 into a plurality of image data, and outputs the divided image data to the data rotating unit 2522.

  FIG. 17 is a diagram for explaining division of the block image data D31.

  FIG. 17 illustrates a first processed image SG1 including an input image NG that has a set rotation angle of + 60 ° and has been subjected to a rotation process of −30 ° by the first rotation processing unit 251. Further, since the first processed image SG1 shown in FIG. 17 is rotated by + 90 ° in the second rotation processing unit 252, the ratio of the size of the long side LH to the size of the short side TH is set to the horizontally long input image NG. It is the vertically long first processed image SG1 reversed from the above.

  The first processed image SG1 shown in FIG. 17 is an image that is finally divided into 15 image data by the data dividing unit 2521. In FIG. 17, in order to easily identify the divided image data, alphabets “A to O” are attached to the divided image data for convenience.

  The image output unit 255 of the first rotation processing unit 251 indicates 5 indicated by “C”, “F”, “I”, “L”, “O” among the image data indicating the first processed image SG1 of FIG. Assume that block image data D31 including two pieces of image data is output. In this case, the data dividing unit 2521 stores block image data D31 including five image data indicated by “C”, “F”, “I”, “L”, and “O” in the buffer 25A1. The data dividing unit 2521 divides the block image data D31 stored in the buffer 25A1 into five image data of “C”, “F”, “I”, “L”, and “O”. For example, when the block image data D31 is 8 × 40 pixel image data, the data dividing unit 2521 divides one divided block image data D32 into 8 × 8 pixel image data. The division method is appropriately determined in advance by a prior test or simulation. When the data dividing unit 2521 divides the block image data D31 into five image data of “C”, “F”, “I”, “L”, and “O”, the divided data is sent to the data rotating unit 2522. Output.

  In the following description, one piece of image data divided by the data dividing unit 2521 is referred to as “divided block image data”, and is denoted by “D32”.

  The data rotation unit 2522 performs a rotation process of rotating the divided block image data D32 input from the data division unit 2521 based on an angle designated by the image processing control unit 32. The data rotation unit 2522 includes a buffer 25A2. The buffer 25A2 is composed of, for example, a plurality of flip-flops, and stores one divided block image data D32. The storage area of the buffer 25A2 may be an area that can store at least one divided block image data D32. The data rotation unit 2522 rotates the divided block image data D32 at an angle specified by the image processing control unit 32 by changing the reading order of the pixel data constituting the divided block image data D32 stored in the buffer 25A2. Let As will be described later, the data shaping unit 2525 shapes the divided block image data D32 in the order in which the data rotation unit 2522 reads the pixel data from the buffer 25A2. Therefore, the data rotation unit 2522 can change the arrangement of the pixel data constituting the divided block image data D32 shaped by the data shaping unit 2525 by changing the order of reading the pixel data from the buffer 25A2, and the divided block The image data D32 can be rotated at a specified angle. Therefore, reading the pixel data by changing the reading order of the data rotation unit 2522 corresponds to a process of rotating the first processed image SG1 in units of 90 °.

  FIG. 18 is a diagram for explaining the rotation of the divided block image data D32.

  In the description using FIG. 18, a case where the divided block image data D <b> 32 marked with “C” in FIG. 17 is stored in the buffer 25 </ b> A <b> 2 capable of storing 64 pixel data is illustrated.

  The numbers shown in FIG. 18 indicate the order in which the pixel data constituting the divided block image data D32 is written in the buffer 25A2. That is, FIG. 18 shows the divided block image data D32 in which eight pixel data are sequentially written from the left to the right in the order of the first row, the second row,..., The seventh row, the eighth row. The case where 25A2 is stored is shown.

  When the angle specified by the image processing control unit 32 is 0 °, the data rotation unit 2522 reads the pixel data in the order in which the pixel data constituting the divided block image data D32 is written in the buffer 25A2. That is, the data rotation unit 2522 reads pixel data in the order of 0, 1... 62, 63.

  Further, when the angle specified by the image processing control unit 32 is 90 °, the data rotation unit 2522 is in the order from the top to the bottom with respect to one column, and in the eighth column, the seventh column,. Read pixel data in the order of the second column and the first column. That is, the data rotation unit 2522 reads pixel data in the order of numbers 7, 15,... 63, 6,.

  In addition, when the angle designated by the image processing control unit 32 is 180 °, the data rotation unit 2522 is in the order from the right to the left with respect to one row, and in the eighth row, the seventh row,. Read pixel data in the order of the second row and the first row. That is, the data rotation unit 2522 reads the pixel data in the order of the numbers 63... 56, 55,.

  In addition, when the angle specified by the image processing control unit 32 is 270 °, the data rotation unit 2522 is in order from the bottom to the top with respect to one column, and in the first column, the second column,. ... Read out pixel data in the order of the seventh and eighth columns. That is, the data rotation unit 2522 reads pixel data in the order of numbers 56, 48,..., 0, 57,.

  The data rotation unit 2522 sequentially outputs the pixel data read from the buffer 25A2 to the data writing unit 2523 in the reading order corresponding to the angle specified by the image processing control unit 32, thereby performing a rotation process in units of 90 °. The divided block image data D32 subjected to is output to the data writing unit 2523. The data rotation unit 2522 can rotate the first processed image SG1 in units of 90 ° by reading the pixel data in the same reading order with respect to each of the divided block image data D32 constituting the first processed image SG1. it can.

  Returning to the description of FIG. 16, when the divided block image data D32 subjected to the rotation process is input from the data rotation unit 2522, the data writing unit 2523 writes the input divided block image data D32 into the frame memory 27. When writing the pixel data constituting the input divided block image data D32 into the frame memory 27, the data writing unit 2523 writes the input pixel data in a line in the order in which the pixel data is input.

  FIG. 19 is a diagram for explaining writing and reading of the divided block image data D32 with respect to the frame memory 27.

  FIG. 19 shows the divided block image data D32 written to the frame memory 27 when the second rotation processing unit 252 performs + 90 ° rotation processing. Further, FIG. 19 shows a case where the 15 divided block image data D32 shown in FIG. For convenience of understanding, the alphabet “A to O” shown in FIG. 19 is attached to the same divided block image data D32 as the divided block image data D32 to which the alphabet “A to O” shown in FIG. ing.

  In the description of FIG. 19, it is assumed that one divided block image data D32 before being stored in the frame memory 27 is composed of pixel data of 8 × 8 pixels.

  In the data writing unit 2523, for the divided block image data D32 indicated by "C", the data rotating unit 2522 has numbers 7, 15, ... 63, 6 ... 57, 0 ... 56 shown in FIG. When the pixel data are read in order, the read pixel data are arranged in one row in this order and written to the frame memory 27. In the case of FIG. 19, the data writing unit 2523 writes the 64 pixel data in a line from the left to the right according to the reading order of the data rotation unit 2522. That is, the data writing unit 2523 shapes the 8 × 8 pixel divided block image data into 64 × 1 pixel divided block image data and writes it into the frame memory 27. Further, when the pixel data is read by the data rotation unit 2522 for the divided block image data D32 indicated by “F”, the data writing unit 2523 is in the same column as the divided block image data D32 indicated by “C”. Similarly, the pixel data is written in a line from the side next to the divided block image data D32. When the divided block image data D32 in which the divided block image data D32 and the block image data D31 that have already been written are input from the data rotation unit 2522, the data writing unit 2523 inputs the divided block images that are input in different columns. Data D32 is written. In the case of FIG. 19, after writing the block image data D31 including the divided block image data D32 indicated by “C”, “F”, “I”, “L”, “O”, “B”, “E”, It is assumed that the divided block image data D32 indicated by “B” is input among the block image data D31 including the divided block image data D32 indicated by “H”, “K”, and “N”. In this case, the data writing unit 2523 has a column different from the column in which the block image data D31 including the divided block image data D32 indicated by “C”, “F”, “I”, “L”, and “O” is written. Similarly, the divided block image data D32 indicated by “B” is written.

  The data writing unit 2523 performs rotation processing by the data rotation unit 2522 by writing pixel data to the frame memory 27 in a line for each of the divided block image data D32 constituting the image data of the first processed image SG1. The image data of the first processed image SG1 is written into the frame memory 27. Since the data writing unit 2523 arranges the pixel data constituting the divided block image data D32 in a line and writes it in the frame memory 27, it is not necessary to designate an address for each pixel data to be written, and burst writing can be performed. Therefore, the data writing unit 2523 can write the first processed image SG1 rotated by the data rotating unit 2522 to the frame memory 27 at high speed.

  Returning to the description of FIG. 16, the data reading unit 2524 reads the divided block image data D32 written in the frame memory 27 in units of block image data D31. The data reading unit 2524 reads the written one block image data D31 at the timing when the one block image data D31 is written in the frame memory 27. Note that the reading timing of the data reading unit 2524 is arbitrary, and may be a timing at which all the pixel data constituting the first processed image SG1 is written in the frame memory 27. The data reading unit 2524 reads the pixel data constituting one block image data D31 in the order of the pixel data written by the data writing unit 2523 to the frame memory 27. For example, when reading block image data D31 composed of divided block image data D32 indicated by “C”, “F”, “I”, “L”, and “O” shown in FIG. Pixel data is sequentially read from left to right in the order of “C”, “F”, “I”, “L”, and “O”. When reading out the block image data D31, the data reading unit 2524 only needs to read out the pixel data arranged in a line in the frame memory 27. Therefore, the data reading unit 2524 can perform burst-like reading without specifying an address for each pixel data to be read out. Therefore, the data reading unit 2524 can read the block image data D31 from the frame memory 27 at high speed.

  The data reading unit 2524 outputs the read block image data D31 to the data shaping unit 2525 in the order of the read pixel data.

  The data shaping unit 2525 includes a line buffer 25A3. The storage area of the line buffer 25A3 may be an area that can store at least one block image data D31. The data shaping unit 2525 shapes the block image data D31 while storing the pixel data constituting the block image data D31 sequentially read out by the data reading unit 2524 in the line buffer 25A3.

  FIG. 20 is a diagram for explaining shaping of the block image data D31.

  In FIG. 20, the set rotation angle is + 60 °, the first rotation processing unit 251 performs the rotation process of −30 °, and the second rotation processing unit 252 includes the input image NG including the + 90 ° rotation process. A two-process image SG2 is shown.

  The second processed image SG2 illustrated in FIG. 20 is an image obtained by performing + 90 ° rotation processing on the first processed image SG1 illustrated in FIG. 17 for convenience of understanding. In FIG. 20, the same alphabet is attached | subjected for convenience about the same divided block image data D32 as the divided block image data D32 shown in FIG. The alphabets “A to O” shown in FIG. 20 are illustrated in a mode rotated to + 90 ° to clearly indicate that the first processed image SG1 has been rotated by + 90 °.

  When the block image data D31 including the divided block image data D32 indicated by “C”, “F”, “I”, “L”, and “O” is input from the data reading unit 2524, the data shaping unit 2525, respectively. The pixel data is stored in the line buffer 25A3 so that the divided block image data D32 becomes the divided block image data D32 of 8 × 8 pixels. For example, the data rotation unit 2522 reads out the pixel data in the order of the numbers 7, 15... 63, 6... 57, 0. Thus, it is assumed that the data reading unit 2524 reads pixel data. In this case, the data shaping unit 2525 stores the pixel data read by the data rotation unit 2522 in the order of the numbers “7,..., 63” in the first row of 8 × 8 pixels in this order. ,..., 62 ”in the order of numbers, the pixel data read by the data rotation unit 2522 is stored in the second row in this order, and the third and subsequent rows are similarly read by the data rotation unit 2522 by 8 pixels. To store the pixel data.

  As a result, the data shaping unit 2525 shapes the divided block image data D32 indicated by “C” in which the pixel data is arranged in a line and written in the frame memory 27 into the rectangular divided block image data D32. By storing the pixel data in the line buffer 25A3 in this way, the data shaping unit 2525 can shape the rectangular divided block image data D32 that has been subjected to the + 90 ° rotation process. The data shaping unit 2525 similarly shapes each of the divided block image data D32 indicated by “F”, “I”, “L”, and “O”, and performs “C”, “F”, “I”, “ Block image data D31 in which the shaped divided block image data D32 is arranged in the order of “L” and “O” is generated.

  The data shaping unit 2525 outputs the generated block image data D31 as output image data D4 to the light modulation device driving unit 23. Similarly, the data shaping unit 2525 shapes the divided block image data D32 indicated by “B”, “E”, “H”, “K”, and “N” shown in FIG. When block image data D31 including is generated, it is output as output image data D4. The same applies to the divided block image data D32 indicated by “A”, “D”, “G”, “J”, and “M”. Thereby, as shown in FIG. 20, the second rotation processing unit 252 outputs the second processed image SG2 in which the first processed image SG1 is rotated by + 90 °.

  As described above, in the second embodiment, the second rotation processing unit 252 stores the second processed image SG2 in which the processing for rotating the first processed image SG1 is performed in the frame memory 27.

  According to this configuration, the second rotation processing unit 252 only needs to read out pixel data that has already been subjected to rotation processing when rotating the first processed image SG1 by an angle specified in units of 90 °. Therefore, the second rotation processing unit 252 does not need to read a plurality of pixel data from the frame memory 27 when outputting one pixel data for each of the pixels constituting the second processed image SG2. Therefore, it is possible to perform a process of rotating the input image NG while improving the use efficiency of the access band for the frame memory 27.

  The above-described embodiment is a preferred embodiment of the present invention. However, the present invention is not limited to this, and various modifications can be made without departing from the scope of the present invention.

  For example, in the first embodiment described above, the configuration in which the second rotation processing unit 252 stores the first processed image SG1 in the frame memory 27 has been described. However, the first rotation processing unit 251 stores the first processed image SG1 in the frame memory. 27 may be stored.

  For example, in the above-described embodiment, the rotation about the center of gravity G in the input image NG is described as the rotation of the input image NG. However, the center of rotation does not have to be the center of gravity G. It does not have to be a point in NG. Further, for example, in the above-described embodiment, the input image NG indicated by the input image data D1 and the second processed image SG2 indicated by the output image data D4 have been described as having the same size, but may be different sizes.

  Further, the processing unit of the flowchart shown in FIG. 15 is divided according to the main processing contents in order to facilitate understanding of the processing of the image processing control unit 32 of the projector 1. The present invention is not limited by the way of dividing the processing units and the names shown in the flowchart of FIG. Further, the processing of the image processing control unit 32 can be divided into more processing units according to the processing content, or can be divided so that one processing unit includes more processing. Further, the processing order of the above flowchart is not limited to the illustrated example.

  The display device of the present invention is not limited to the projector 1 that projects an image on the screen SC. For example, a liquid crystal display having a liquid crystal display panel may be used. Further, for example, a display having a PDP (plasma display panel) or an organic EL display panel may be used, and the present invention can be applied to various other display devices.

  In addition, at least a part of each functional block shown in the block diagram in the above embodiment may be realized by hardware, or may be realized by cooperation of hardware and software. Therefore, the present invention is not limited to a configuration in which independent hardware resources are arranged as shown in the block diagram. The program executed by the control unit may be stored in a storage unit or other storage device (not shown). In addition, the control unit may acquire and execute a program stored in an external device. In addition, the specific detailed configuration of each other part can be arbitrarily changed without departing from the gist of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Projector (image processing apparatus, display apparatus), 10 ... Projection part (display part), 25 ... Image processing part, 27 ... Frame memory (memory), 32 ... Image processing control part (control part), 251 ... 1st Rotation processing unit (first processing unit), 252 ... second rotation processing unit (second processing unit), 253, 253A, 253B, 253C, 253D ... line buffer, 254 ... correspondence table, 255 ... image output unit, 256 ... Filter table, 257, 257A, 257B, 257C ... line buffer, G ... gravity center (point in input image), LH ... long side, NG ... input image, SG1 ... first processed image (first image), SG2 ... first 2-processed image (second image), TH ... short side.

Claims (11)

A first processing unit that executes a process of rotating the input image input at a specified angle and outputs a first image;
A second processing unit that executes a process of rotating the first image output by the first processing unit at an angle specified in units of 90 ° and outputs a second image.
Image processing device. With memory,
The second processing unit executes a process of rotating the first image stored in the memory;
The image processing apparatus according to claim 1. With memory,
The second processing unit stores the second image, which has been subjected to the process of rotating the first image, in the memory.
The image processing apparatus according to claim 1. The first processing unit can execute a process of rotating the input image in the forward direction and in the opposite direction opposite to the forward direction, and is in a range of 45 ° or less in the forward direction and 45 ° or less in the reverse direction. Rotate the input image at an angle specified by
The image processing apparatus according to claim 1. The first processing unit rotates the input image with a point in the input image as a rotation center.
The image processing apparatus according to claim 1. The second processing unit outputs the second image having the same size as the input image.
The image processing apparatus according to claim 1. A control unit for controlling the first processing unit and the second processing unit;
The first processing unit outputs the rectangular first image when the input image is a rectangular image;
The control unit corresponds to an angle at which the second processing unit rotates the first image, and the ratio of the size of the long side to the size of the short side is different from the input image by the first processing unit. Outputting the first image;
The image processing apparatus according to claim 1. When the second processing unit rotates the first image to 90 ° or 270 °, the control unit causes the first processing unit to determine a ratio of a long side size to a short side size from the input image. Outputting the inverted first image;
The image processing apparatus according to claim 7. The first processing unit sets a predetermined pixel value to a pixel that constitutes the first image and does not correspond to the input image, and outputs the first image.
The image processing apparatus according to claim 1. Execute the process of rotating the input image input at a specified angle to output the first image,
Executing a process of rotating the output first image at an angle specified in units of 90 ° to output a second image;
Image processing method. A first processing unit that executes a process of rotating the input image input at a specified angle and outputs a first image;
A second processing unit that executes a process of rotating the first image output by the first processing unit at an angle specified in units of 90 ° and outputs a second image;
A display unit for displaying the second image,
Display device.

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