JP2008116812A - Display apparatus, projector, and display method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector or the like capable of displaying an image appropriately while suppressing a memory capacity and a processing load when displaying an input image with a resolution of the input image expanded or reduced. <P>SOLUTION: The projector 100 is comprised of: a determination part 120 which determines a scaling method based on a resolution of a projection part 190 and the resolution of the input image; a scaling part 130-1 which performs first scaling to the input image based on the scaling method and also writes the image data after the scaling in a memory 140; a read-out part 150 which reads the image data out of the memory 140; a scaling part 130-2 which performs second scaling to the read-out image data based on the scaling method; and a projection part 190 which projects the image based on the image data after the second scaling. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a display device, a projector, and a display method for displaying an input image with an enlarged or reduced resolution.

  A display device such as a projector continuously inputs image information and continuously displays images based on the image information. Since such a display device has different resolutions and transfer speeds of input and output images, a scaler for changing the resolution and a memory for temporarily storing image data are required.

  In such a memory, the amount of data (memory bandwidth) that can be read and written per predetermined time is determined. For this reason, the display device cannot accurately read and write the memo at a speed higher than the memory bandwidth, and cannot perform normal display.

  In the first conventional display device, input image data is written in a memory, and the resolution is adjusted by a scaler for display.

  Such a configuration is easy to apply when the resolution of the input image is small, but when the resolution of the input image is large, a large amount of memory is required and the scaler reduces the resolution when outputting. The memory bandwidth of will be greatly pressed.

  Specifically, for example, when the resolution is reduced by half, the first display device needs to output image data for two pixels from the memory in order to perform display for one pixel. Press the band.

  Further, the conventional second display device writes the input image data to the memory after adjusting the resolution with a scaler, and reads and displays the image data from the memory.

  Such a configuration is easy to apply when the resolution of the input image is large, but when the resolution of the input image is smaller than the resolution of the display device, the memory used when the resolution is reduced by the scaler and written to the memory The band will be greatly squeezed.

  Specifically, for example, when the resolution is reduced by half, the second display device needs to convert image data for one pixel of the input image into image data for two pixels and write it to the memory. Yes, it is necessary to write to the memory at twice the image input speed, which puts pressure on the memory bandwidth.

It is also conceivable to arrange scalers before and after the memory by combining such a first display device and a second display device. For example, Japanese Patent Application Laid-Open No. 2003-309783 describes a display device in which a preprocessing scaler unit for reducing pixels is provided in front of a scaler unit for the purpose of avoiding limitations on the performance of the scaler.
JP 2003-309783 A

  However, the processing load becomes large in the method of performing scaling twice as in the method of Japanese Patent Application Laid-Open No. 2003-309783.

  An object of the present invention is to provide a display device, a projector, and a display method capable of appropriately displaying an image while suppressing memory capacity and processing load when displaying an input image with an enlarged or reduced resolution. There is.

In order to solve the above-described problems, a display device according to the present invention includes:
A determining unit that determines a scaling method based on the resolution of the display unit and the resolution of the input image;
A first scaling unit that performs first scaling on an input image based on the scaling method and writes the scaled image data in a memory;
A reading unit for reading out the image data written by the first scaling unit from the memory;
A second scaling unit that performs second scaling on the image data read by the reading unit based on the scaling method;
Based on the image data after the second scaling, the display unit that displays an image;
Including
If the scaling technique indicates to enlarge the input image,
The first scaling unit writes the image data in the memory with the resolution of the input image,
The second scaling unit performs the second scaling so that the resolution is enlarged with respect to the image data read by the reading unit,
If the scaling technique indicates to reduce the input image,
The first scaling unit performs the first scaling so that the resolution of the image data of the input image is reduced,
The second scaling unit outputs the image data read by the reading unit without changing the resolution.

  In addition, a projector according to the present invention includes the display device.

Moreover, the display method according to the present invention includes:
In a method for displaying an image by a display device,
Determine the scaling method based on the resolution of the display unit and the resolution of the input image,
If the scaling technique indicates to enlarge the input image,
Write the image data to the memory with the resolution of the input image,
Reading the image data from the memory;
The read image data is scaled so that the resolution is enlarged, and the image data is output.
Display the image based on the output image data,
If the scaling technique indicates to reduce the input image,
The image data of the input image is scaled so that the resolution is reduced,
Reading the image data from the memory;
Output the read image data without changing the resolution,
An image is displayed based on the output image data.

  According to the present invention, when enlarging an input image, the display device or the like writes the image data to the memory at the same magnification and then enlarges it after reading. When reducing the input image, the display device or the like reduces the image data. By writing to the same size and then reading at the same magnification, double scaling as in the technique of Japanese Patent Laid-Open No. 2003-309783 is not performed, so that scaling can be performed while suppressing the processing load.

  In addition, according to the present invention, the display device or the like can suppress the amount of memory bandwidth used and the memory capacity by suppressing scaling during reading and writing to the memory.

In addition, it includes an input unit for inputting the display resolution specified by the user,
The determining unit may determine the scaling method according to the designation of the display resolution.

  According to this, even when the display resolution is designated by the user, the display device or the like can appropriately display an image while suppressing the memory capacity and the processing load.

Further, when the input image is an interlaced image, the determining unit determines that the scaling method is to be converted into a progressive image,
If the scaling technique indicates to convert to the progressive image,
The first scaling unit writes the image data in the memory with the resolution of the input image,
The second scaling unit may perform scaling for increasing the resolution as the second scaling so that the image data read by the reading unit becomes the progressive image.

  Accordingly, even when the display method is changed to the progressive method, the display device or the like can appropriately display an image while suppressing the memory capacity and the processing load.

The first and second scaling units are
A sampling unit for determining a sampling position in an image based on the scaling method;
An image signal value of a plurality of pixels adjacent to the sampling position, and an image signal value based on the input image or the image data read by the reading unit, and a coefficient corresponding to the sampling position A filter processing unit that calculates an output image signal value and outputs the output image signal value as the image data;
May be included.

  According to this, a display apparatus etc. can display an image more appropriately.

  Hereinafter, an example in which the present invention is applied to a projector will be described with reference to the drawings. In addition, the Example shown below does not limit the content of the invention described in the claim at all. In addition, all of the configurations shown in the following embodiments are not necessarily essential as means for solving the problems described in the claims.

  FIG. 1 is a functional block diagram of the projector 100 according to the present embodiment.

  A projector 100 that is a type of display device includes a projection unit 190 that is a type of display unit, an input unit 110 that inputs designation of a display resolution by a user, and an image information input unit 112 that inputs image information indicating an input image. And a determination unit 120 that determines a scaling method based on the resolution of the display area of the projection unit 190 and the resolution of the input image.

  In addition, the projector 100 performs the first scaling on the input image based on the memory 140 and the scaling method, and also writes the scaled image data to the memory 140 (first scaling unit) 130-. 1, a reading unit 150 that reads image data from the memory 140, and a scaling unit (second scaling unit) 130- that performs second scaling on the image data read by the reading unit 150 based on a scaling method 2 and an image processing unit 160 that performs image synthesis, keystone distortion correction, and the like on the second scaled image data.

  FIG. 2 is a functional block diagram of the scaling unit 130 of the present embodiment.

  More specifically, the scaling unit 130 includes a sampling processing unit 132 that determines a sampling position in an image, and a filter processing unit 134 that executes a filtering process according to the sampling position.

  Here, the sampling process and the filter process will be described.

  FIG. 3A is a schematic diagram showing the relationship between the input pixel and the sampling position when the image is reduced, and FIG. 3B shows the relationship between the input pixel and the sampling position when the image is enlarged. It is a schematic diagram shown.

  For example, a case where input pixels having pixel numbers 0 to 5 (input image information from the image information input unit 112 or image data read by the reading unit 150) is used will be described as an example. For example, when the input image is reduced to 3/5, the sampling positions indicating the positions of the pixels to be used are 0, 1.667, 3.334, and 5 as shown in FIG.

  For example, when the input image is enlarged three times, the sampling positions are 0, 0.333, 0.666, 1, 1.333, 1.666, 2, 2 as shown in FIG. .333, 2.666, 3, 3.333, 3.666, 4, 4.333, 4.666, and 5.

  Note that the scaling method indicating such reduction and enlargement is determined by the determination unit 120, and the sampling processing unit 132 determines the sampling position based on the scaling method.

  Next, filter processing will be described.

  The filter processing unit 134 determines a pixel to be used from the integer part of the sampling position determined by the sampling processing unit 132, and determines a filter coefficient to be used from the decimal part of the sampling position.

  FIG. 4 is a schematic diagram of the filter coefficient data of this embodiment. FIG. 5 is a schematic diagram showing processing for determining an output value based on the sampling position of the present embodiment.

  For example, it is assumed that the application range of the filter processing is 4 pixels adjacent to the target pixel position, and that there are 8 interpolation positions between the pixels.

  In this case, as shown in FIG. 4, eight interpolation positions are set for each of the four pixel positions, and a filter coefficient Coef (interpolation position, pixel position) is set for each pixel position and interpolation position. In addition, the specific numerical value of a filter coefficient is calculated | required by experiment etc., for example.

  For example, when the filter processing unit 134 outputs image data with a sampling position of 1.667 when reducing the input image to 3/5, the integer part is 1, and the decimal part is a numerical value (0.667). Is multiplied by 8 and its integer value (5) is determined as the interpolation position.

  In this case, as shown in FIG. 5, the filter processing unit 134 multiplies the image signal value (RGB value, alpha value indicating transparency, etc.) of pixel number 0 and Coef (5, −1), pixel number 1 A value obtained by multiplying the image signal value of Coef (5, 0), a value obtained by multiplying the image signal value of pixel number 2 and Coef (5, +1), and an image signal value of pixel number 3 and Coef (5, +2). An image signal value obtained by summing the multiplied values is output.

  Through the above procedure, the scaling unit 130 determines the sampling position in the image based on the scaling method, and outputs the output image based on the image signal values of a plurality of pixels adjacent to the sampling position and the coefficient corresponding to the sampling position. While calculating the signal value, the output image signal value can be output as image data.

  Note that each unit of the projector 100 may be mounted using, for example, the following hardware. For example, the input unit 110 is a button, an infrared receiving unit that receives operation information from a remote controller, the image information input unit 112 is an input terminal, the determination unit 120 is a CPU, the scaling unit 130 is a scaler, and the like. The memory 140 may be a RAM, the reading unit 150, the image processing unit 160 may be an image processing circuit, and the projection unit 190 may be a liquid crystal panel, a liquid crystal driving circuit, a lamp, a projection lens, or the like.

  Next, the flow of processing using the determination unit 120 will be described.

  FIG. 6 is a flowchart showing the flow of processing of this embodiment.

  The image information input unit 112 inputs image information (for example, RGB values) from a PC (Personal Computer) or the like (step S1).

  The determination unit 120 determines the scaling method based on the resolution of the display area of the projection unit 190 (for example, the display area of the liquid crystal panel) and the resolution of the input image indicated by the image information input by the image information input unit 112. (Step S2).

  For example, when the number of horizontal pixels in the display area of the projection unit 190 is 1152 and the number of horizontal pixels in the input image is 1920, the determination unit 120 reduces the horizontal direction of the input image to 3/5. Determine the scaling method shown. For example, when the number of horizontal pixels of the display area of the projection unit 190 is 1920 and the number of horizontal pixels of the input image is 640, the determination unit 120 indicates that the horizontal direction of the input image is expanded three times. Determine the scaling method.

  Note that the determination unit 120 determines the scaling method for the vertical direction as well as the horizontal direction.

  When the scaling method indicates that the input image is enlarged (step S3), the scaling unit 130-1 writes the input image information as it is into the memory 140 as image data (step S4).

  Then, the reading unit 150 reads the image data from the memory 140 (step S5), and the scaling unit 130-2 executes the sampling process and the filter process described above when the scaling method indicates that the input image is enlarged. As a result, the resolution of the read image data is enlarged (step S6).

  The image processing unit 160 performs distortion correction processing or the like on the image data from the scaling unit 130-2 to generate an image (step S11), and the projection unit 190 projects an image (step S12).

  On the other hand, when the scaling method indicates that the input image is to be reduced (step S7), the scaling unit 130-1 performs the sampling process and the filter process described above on the image data of the input image, thereby The resolution is reduced and written in the memory 140 (step S8).

  Then, the reading unit 150 reads the image data from the memory 140 (step S9), the scaling unit 130-2 transfers the image data as it is to the image processing unit 160, and the image processing unit 160 includes the scaling unit 130- The image data from 2 is subjected to distortion correction processing or the like to generate an image (step S11), and the projection unit 190 projects the image (step S12).

  When the scaling method indicates that neither enlargement nor reduction is performed, the scaling unit 130-1 writes the image data in the memory 140 with the resolution of the input image (step S10), and the reading unit 150 reads the image data from the memory 140. (Step S9), the scaling unit 130-2 transfers the image data as it is to the image processing unit 160, and the image processing unit 160 performs distortion correction processing on the image data from the scaling unit 130-2. Then, an image is generated (step S11), and the projection unit 190 projects the image (step S12).

  As described above, according to the present embodiment, when the input image is enlarged, the projector 100 writes the image data in the memory 140 at the same magnification and then enlarges it after reading, and when the input image is reduced, the image is displayed. By reducing the data and writing it to the memory 140 and then reading it at the same magnification, double scaling as in the technique of Japanese Patent Application Laid-Open No. 2003-309783 is not performed. Therefore, scaling can be performed while suppressing the processing load. it can.

  Further, according to the present embodiment, the projector 100 can suppress the amount of memory bandwidth used and the memory capacity by suppressing scaling at the time of reading and writing to the memory 140.

  Further, according to the present embodiment, the projector 100 performs sampling processing and filter processing when performing scaling, thereby making blurring and edge enhancement more effective, and simply performing pixel thinning and compensation. Compared with the case where it performs, an image can be displayed more appropriately.

  In addition, application of this invention is not limited to the Example mentioned above, A various deformation | transformation is possible.

  For example, the aspect ratio of the display area of the projection unit 190 may be 4: 3 or 16: 9.

  FIG. 7A is a schematic diagram illustrating an outline of processing when the aspect ratio of the display area 300 is 4: 3, and FIG. 7B illustrates a case where the aspect ratio of the display area 302 is 16: 9. It is a schematic diagram which shows the outline | summary of a process.

  For example, as shown in FIG. 7A, when the aspect ratio of the display area 300 is 4: 3, when an input image with an aspect ratio of 16: 9 is enlarged in the vertical direction (case C1), the aspect ratio is The present invention is also effective when a 4: 3 input image is reduced in the vertical direction (case C2).

  Also, for example, as shown in FIG. 7B, when the aspect ratio of the display area 300 is 16: 9, when an input image having an aspect ratio of 4: 3 is enlarged in the horizontal direction (case C3), the aspect ratio The present invention is also effective when an input image having a ratio of 16: 9 is reduced in the horizontal direction (case C4).

  In addition, when an interlaced input image is displayed by a progressive method, it corresponds to case C1, and the present invention is also effective in such a case.

  Furthermore, the determination unit 120 may determine a scaling method according to the display resolution designation by the user from the input unit 110.

  According to this, the projector 100 can appropriately display an image while suppressing the memory capacity and the processing load even when the display resolution is designated by the user.

  Projector 100 is not limited to a liquid crystal projector, and may be, for example, a projector using DMD (Digital Micromirror Device) developed by Texas Instruments, Inc., a CRT projector, a projector using organic EL, or the like. .

  The present invention is also effective when a display device such as a liquid crystal display or a TV (Tele Vision) is used instead of the projector 100.

  Further, the functions of the projector 100 described above may be distributed to a plurality of devices (for example, a PC and a projector, a DVD player and a TV, etc.).

It is a functional block diagram of the projector of a present Example. It is a functional block diagram of the scaling part of a present Example. FIG. 3A is a schematic diagram showing the relationship between the input pixel and the sampling position when the image is reduced, and FIG. 3B shows the relationship between the input pixel and the sampling position when the image is enlarged. It is a schematic diagram shown. It is a schematic diagram of the filter coefficient data of a present Example. It is a schematic diagram which shows the process which determines an output value based on the sampling position of a present Example. It is a flowchart which shows the flow of a process of a present Example. FIG. 7A is a schematic diagram illustrating an outline of processing when the aspect ratio of the display area is 4: 3, and FIG. 7B illustrates processing when the aspect ratio of the display area is 16: 9. It is a schematic diagram which shows an outline.

Explanation of symbols

  100 projector (display device), 110 input unit, 112 image information input unit, 120 determination unit, 130-1 scaling unit (first scaling unit), 130-2 scaling unit (second scaling unit), 140 memory, 150 Reading unit, 160 Image processing unit, 190 Projection unit (display unit), 300, 302 Display area

Claims (6)

A determining unit that determines a scaling method based on the resolution of the display unit and the resolution of the input image;
A first scaling unit that performs first scaling on an input image based on the scaling method and writes the scaled image data in a memory;
A reading unit for reading out the image data written by the first scaling unit from the memory;
A second scaling unit that performs second scaling on the image data read by the reading unit based on the scaling method;
Based on the image data after the second scaling, the display unit that displays an image;
Including
If the scaling technique indicates to enlarge the input image,
The first scaling unit writes the image data in the memory with the resolution of the input image,
The second scaling unit performs the second scaling so that the resolution is enlarged with respect to the image data read by the reading unit,
If the scaling technique indicates to reduce the input image,
The first scaling unit performs the first scaling so that the resolution of the image data of the input image is reduced,
The display device, wherein the second scaling unit outputs the image data read by the reading unit without changing a resolution. The display device according to claim 1,
It includes an input part for inputting display resolution specification by the user,
The display device, wherein the determining unit determines the scaling method in accordance with designation of the display resolution. The display device according to any one of claims 1 and 2,
When the input image is an interlaced image, the determining unit determines to convert to a progressive image as the scaling method,
If the scaling technique indicates to convert to the progressive image,
The first scaling unit writes the image data in the memory with the resolution of the input image,
The second scaling unit performs scaling for increasing the resolution as the second scaling so that the image data read by the reading unit becomes an image of the progressive method. Display device. The display device according to any one of claims 1 to 3,
The first and second scaling units are
A sampling unit for determining a sampling position in an image based on the scaling method;
An image signal value of a plurality of pixels adjacent to the sampling position, and an image signal value based on the input image or the image data read by the reading unit, and a coefficient corresponding to the sampling position A filter processing unit that calculates an output image signal value and outputs the output image signal value as the image data;
A display device comprising:   A projector comprising the display device according to claim 1. In a method for displaying an image by a display device,
Determine the scaling method based on the resolution of the display unit and the resolution of the input image,
If the scaling technique indicates to enlarge the input image,
Write the image data to the memory with the resolution of the input image,
Reading the image data from the memory;
The read image data is scaled so that the resolution is enlarged, and the image data is output.
Display the image based on the output image data,
If the scaling technique indicates to reduce the input image,
The image data of the input image is scaled so that the resolution is reduced,
Reading the image data from the memory;
Output the read image data without changing the resolution,
A display method characterized by displaying an image based on output image data.

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