JP2015011130A - Image processing apparatus, electrophoretic display device, image processing method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an afterimage from being generated, while preventing a user from feeling discomfort, in rewriting an image.SOLUTION: An image processing apparatus includes: a display unit 110 formed of a plurality of pixels having electrophoretic elements including electrophoretic particles; a contour extraction unit 132 which extracts a contour component from a first image to be displayed on the display unit 110; and a display control unit 140 which displays, on the display unit 110, an image obtained by subtracting a value formed by multiplying brightness of the pixels in an image of the contour component extracted by the contour extraction unit by a predetermined coefficient, from brightness of pixels of a predetermined image.

Description

  The present invention relates to an electrophoretic display device, an image processing device that processes an image displayed on the electrophoretic display device, an image processing method, and a program.

  In recent years, an electrophoretic display device (EPD: Electrophoretic Display) is known as an electronic paper (see, for example, Patent Documents 1 to 3 and Non-Patent Documents 1 and 2). The electrophoretic display device forms an image on a display unit by moving a colored electrophoretic particle by applying a voltage between a pixel electrode and a common electrode facing each other with an electrophoretic element interposed therebetween. The electrophoretic element is composed of a microcapsule containing electrophoretic particles, and the microcapsule is fixed between the pixel electrode and the common electrode by an adhesive.

US Pat. No. 6,538,801 US Patent Application Publication No. 2006/0017659 US Patent Application Publication No. 2012/0026106

Wen-Chung Kao et al., “Image quality improvement for electrophoretic displays by combining contensing enhancement and halftoning techniques. 55, no. 1, pp. 15-19 Johnson M.C. T. T. et al. Et al., "High-quality images on electrophoretic displays", Journal of the Society for Information Display, 2006.

However, the electrophoretic display device has a problem that an afterimage is generated along the contour portion of the previously displayed image when the image is rewritten. This is because even when the distance between the electrophoretic elements is extremely close and the voltage value of a certain electrophoretic element does not change, movement of the electrophoretic particles of the electrophoretic element occurs due to voltage application of the adjacent electrophoretic element. It is. On the other hand, a method has been proposed in which a white image and a black image are displayed and the afterimage is reset when the image is rewritten. However, when this method is used, there is a problem that it takes time to rewrite an image and makes the user feel uncomfortable.
An object of the present invention is to provide a display control device, an electrophoretic display device, a display control method, and a program that solve the above-described problems.

  The present invention has been made to solve the above-described problem, and includes a contour extraction unit that extracts a contour component from a first image that is an image to be displayed on an electrophoretic display device, and the brightness of each pixel of the predetermined image. And a difference calculation unit that generates an image obtained by subtracting a value obtained by multiplying the brightness of each pixel of the image of the contour component extracted by the contour extraction unit by a predetermined coefficient. It is.

  In the present invention, it is preferable that the difference calculation unit generates an image obtained by subtracting the brightness of each pixel of the contour component image extracted by the contour extraction unit from the first image.

  Further, in the present invention, the difference calculation unit includes each of the contour component images extracted by the contour extraction unit from a second image that is displayed on the electrophoretic display device after the first image. It is preferable to generate an image obtained by subtracting the brightness of the pixel.

  In the present invention, it is preferable that the contour extraction unit extracts the contour component by applying a Laplacian filter to the first image.

  In addition, the present invention provides a display unit including a plurality of pixels each provided with an electrophoretic element including electrophoretic particles, and a contour extraction unit that extracts a contour component from a first image that is an image displayed on the display unit. And an image obtained by subtracting a value obtained by multiplying the brightness of each pixel of the contour component image extracted by the contour extraction unit by a predetermined coefficient from the brightness of each pixel of the predetermined image on the display unit. An electrophoretic display device comprising: a display control unit for controlling the display.

  The present invention also provides a step of extracting a contour component from a first image that is an image to be displayed on an electrophoretic display device, and an image of the contour component extracted by the contour extraction unit from the brightness of each pixel of the predetermined image. Generating an image obtained by subtracting a value obtained by multiplying the brightness of each pixel by a predetermined coefficient.

  Further, according to the present invention, a contour extraction unit that extracts a contour component from a first image that is an image displayed on an electrophoretic display device, and the contour extraction unit extracts the brightness of each pixel of a predetermined image. This is a program for functioning as a difference calculation unit that generates an image obtained by subtracting a value obtained by multiplying the brightness of each pixel of the contour component image by a predetermined coefficient.

  According to the present invention, by displaying an image obtained by subtracting the contour component of the image to be displayed on the display unit, it is possible to prevent the afterimage of the contour component of the image from being accumulated, and to prevent the user from feeling uncomfortable. Switching can be done.

1 is a schematic block diagram illustrating a configuration of an electrophoretic display device according to a first embodiment of the present invention. 3 is a flowchart showing an operation of the electrophoretic display device according to the first embodiment of the present invention. It is a schematic block diagram which shows the structure of the electrophoretic display device which concerns on the 2nd Embodiment of this invention. 6 is a flowchart illustrating an operation of an electrophoretic display device according to a second embodiment of the present invention. It is a schematic block diagram which shows the structure of the electrophoretic display device which concerns on the 3rd Embodiment of this invention. It is a flowchart which shows operation | movement of the electrophoretic display apparatus which concerns on the 3rd Embodiment of this invention.

<< First Embodiment >>
Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic block diagram showing the configuration of the electrophoretic display device 100 according to the first embodiment of the present invention.
The electrophoretic display device 100 includes a display unit 110, a CPU 120, an image processing device 130, and a display control unit 140.
The display unit 110 is obtained by sandwiching a plurality of electrophoretic elements enclosing colored electrophoretic particles between opposing pixel electrodes and a common electrode and fixing them with an adhesive. A plurality of electrophoretic elements constitutes a pixel of the display unit 110, and the display unit 110 forms an image by applying a voltage between the pixel electrode and the common electrode to move the electrophoretic particles.
The CPU 120 generates an image to be displayed on the display unit 110 and outputs it to the image processing device 130.
The image processing device 130 is a GPU (Graphic Processing Unit) of the electrophoretic display device 100, and performs arithmetic processing of an image displayed on the display unit 110.
The display control unit 140 controls the voltage between the pixel electrode and the common electrode of the display unit 110 based on the image generated by the image processing device 130.

The image processing apparatus 130 includes a frame buffer 131, a contour extraction unit 132, a difference calculation unit 133, and a transfer buffer 134.
The frame buffer 131 temporarily stores an image to be displayed on the display unit 110 generated by the CPU 120.
The contour extraction unit 132 extracts the contour of the image (first image) stored in the frame buffer 131. The contour extraction unit 132 can extract the contour of an image using, for example, a 4-neighbor Laplacian filter or an 8-neighbor Laplacian filter. A Laplacian filter is a filter that takes a difference between a pixel of interest and neighboring pixels on both sides above and below.
The difference calculation unit 133 generates an image obtained by subtracting the image extracted by the contour extraction unit 132 from the image (first image) stored in the frame buffer 131 and records the image in the transfer buffer 134.
The transfer buffer 134 temporarily stores the image calculated by the difference calculation unit 133. The display control unit 140 controls the display unit 110 based on the image recorded in the transfer buffer 134.

Next, the operation of the electrophoretic display device 100 according to this embodiment will be described.
FIG. 2 is a flowchart showing the operation of the electrophoretic display device 100 according to the first embodiment of the present invention.
When generating an image to be displayed on the display unit 110, the CPU 120 records the image in the frame buffer 131 (step S101). When an image is recorded in the frame buffer 131, the contour extracting unit 132 reads the image from the frame buffer 131, and applies a Laplacian filter to the image to extract a contour image (step S102).

  Next, the difference calculation unit 133 reads the image from the frame buffer 131, and the value obtained by multiplying the brightness of each pixel of the contour component image extracted by the contour extraction unit 132 by a predetermined coefficient is used for each pixel of the read image. A difference image is generated by subtracting from the brightness (step S103). Here, the predetermined coefficient is a coefficient in accordance with the afterimage characteristics of the display unit 110 (the relationship between the magnitude of contrast between the target pixel and neighboring pixels and the brightness of the afterimage generated in the target pixel). Next, the difference calculation unit 133 records the generated difference image in the transfer buffer 134 (step S104), and deletes the image from the frame buffer 131 (step S105). As a result, an image in which the contrast of the contour portion is lower than the image generated by the CPU 120 is generated in the transfer buffer 134.

  The display control unit 140 reads an image from the transfer buffer 134, and controls the voltage between the pixel electrode and the common electrode of the display unit 110 based on the image (step S106). Then, when the display control unit 140 displays an image on the display unit 110, the display control unit 140 deletes the image stored in the transfer buffer 134 (step S107).

  Next, the CPU 120 determines whether or not to display a new image on the display unit 110 (step S108). When CPU 120 determines to display a new image on display unit 110 (step S108: YES), CPU 120 returns to step S101 to generate the new image.

  On the other hand, if the CPU 120 determines that no new image is to be displayed on the display unit 110 at the present time (step S108: NO), the CPU 120 has accepted an input of an end request for processing from the outside by an operation or interruption processing by a user or the like. It is determined whether or not (step S109). If the CPU 120 determines that an input of a termination request has not been received from the outside (step S109: NO), the determination in step S108 is continued. On the other hand, when CPU 120 determines that an input of an end request has been received from the outside (step S109: YES), CPU 120 ends the process.

  As described above, according to the present embodiment, since the display unit 110 displays an image having a lower contrast of the contour portion than the image generated by the CPU 120, each electrophoretic element is adjacent to the voltage value of its own element. The difference from the voltage value of the electrophoretic element can be reduced. Thereby, the electrophoretic display device 100 can suppress the movement of the electrophoretic particles due to the voltage value of the adjacent electrophoretic element, and can prevent the occurrence of an afterimage.

<< Second Embodiment >>
Hereinafter, a second embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 3 is a schematic block diagram showing the configuration of the electrophoretic display device 100 according to the second embodiment of the present invention.
In the electrophoretic display device 100 according to the second embodiment, the image processing device 130 includes a contour image buffer 135 in addition to the configuration of the image processing device 130 according to the first embodiment, and each processing of the image processing device 130 is performed. The operation of the part is different.
The contour image buffer 135 temporarily stores the contour image of the image (first image) displayed on the display unit 110. In the initial state where the display unit 110 does not display, the contour image buffer 135 stores an image (black image) in which the brightness of all the pixels is zero.

Next, the operation of the electrophoretic display device 100 according to this embodiment will be described.
FIG. 4 is a flowchart showing the operation of the electrophoretic display device 100 according to the second embodiment of the present invention.
When the CPU 120 generates an image (second image) to be displayed on the display unit 110, the CPU 120 records the image in the frame buffer 131 (step S201). When the image is recorded in the frame buffer 131, the difference calculation unit 133 reads the image from the frame buffer 131, and multiplies the brightness of each pixel of the contour component image stored in the contour image buffer 135 by a predetermined coefficient. Then, a difference image is generated by subtracting from the brightness of each pixel of the image (step S202). Next, the difference calculation unit 133 records the generated difference image in the transfer buffer 134 (step S203), and deletes the image from the contour image buffer 135 (step S204).

  Next, the contour extracting unit 132 reads an image from the frame buffer 131, and applies a Laplacian filter to the image to extract a contour image (step S205). Next, the contour extraction unit 132 records the extracted contour image in the contour image buffer 135 (step S206), and deletes the image from the frame buffer 131 (step S207).

  The display control unit 140 reads an image from the transfer buffer 134, and controls the voltage between the pixel electrode and the common electrode of the display unit 110 based on the image (step S208). When the display control unit 140 displays an image on the display unit 110, the display control unit 140 deletes the image stored in the transfer buffer 134 (step S209).

  Next, the CPU 120 determines whether or not to display a new image on the display unit 110 (step S210). When CPU 120 determines to display a new image on display unit 110 (step S210: YES), CPU 120 returns to step S201 to generate the new image.

  On the other hand, if the CPU 120 determines that a new image is not displayed on the display unit 110 at the present time (step S210: NO), the CPU 120 has received an input of a process end request from the outside by an operation or an interrupt process by a user or the like. It is determined whether or not (step S211). If the CPU 120 determines that an input of a termination request has not been received from the outside (step S211: NO), the determination at step S210 is continued. On the other hand, if CPU 120 determines that an input of an end request has been received from the outside (step S211: YES), it ends the process.

  As described above, according to the present embodiment, the display unit 110 displays an image obtained by subtracting the contour portion of the currently displayed image. Therefore, when the image displayed on the display unit 110 is switched to a new image. The afterimage caused by the currently displayed image can be canceled.

<< Third Embodiment >>
Hereinafter, the third embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 5 is a schematic block diagram showing the configuration of the electrophoretic display device 100 according to the third embodiment of the present invention.
In the electrophoretic display device 100 according to the third embodiment, the image processing device 130 includes a frame transfer unit 136 in addition to the configuration of the image processing device 130 according to the second embodiment, and each processing of the image processing device 130 is performed. The operation of the part is different.
The frame transfer unit 136 records the image stored in the frame buffer 131 in the transfer buffer 134 and deletes the image from the frame buffer 131.

Next, the operation of the electrophoretic display device 100 according to this embodiment will be described.
FIG. 6 is a flowchart showing the operation of the electrophoretic display device 100 according to the third embodiment of the present invention.
When generating an image to be displayed on the display unit 110, the CPU 120 records the image in the frame buffer 131 (step S301). When the image is recorded in the frame buffer 131, the difference calculation unit 133 stores the brightness of each pixel of the image (white image) in which the brightness of all the pixels has the maximum value (for example, 255). A difference image is generated by subtracting a value obtained by multiplying the brightness of each pixel of the contour component image to be multiplied by a predetermined coefficient (step S302). Next, the difference calculation unit 133 records the generated difference image in the transfer buffer 134 (step S303), and deletes the image from the contour image buffer 135 (step S304). As a result, the transfer buffer 134 records an image in which only the outline portion of the image currently displayed on the display unit 110 is dark.

  Next, the contour extraction unit 132 reads an image from the frame buffer 131 and applies a Laplacian filter to the image to extract a contour image (step S305). Next, the contour extracting unit 132 records the extracted contour image in the contour image buffer 135 (step S306). Next, the frame transfer unit 136 records the image stored in the frame buffer 131 in the transfer buffer 134 (step S307), and deletes the image from the frame buffer 131 (step S308). As a result, the image generated by the CPU 120 is recorded in the transfer buffer 134 after the image in which only the outline portion of the image currently displayed on the display unit 110 is darkened.

The display control unit 140 reads the image recorded at the head of the transfer buffer 134, that is, the difference image generated in step S302, and controls the voltage between the pixel electrode and the common electrode of the display unit 110 based on the difference image. (Step S309). Then, when displaying the difference image on the display unit 110, the display control unit 140 deletes the top image stored in the transfer buffer 134 (step S310). Next, the display control unit 140 reads the image recorded at the head of the transfer buffer 134, that is, the image recorded in step S307, and controls the voltage between the pixel electrode and the common electrode of the display unit 110 based on the image. (Step S311). When the display control unit 140 displays an image on the display unit 110, the display control unit 140 deletes the first image stored in the transfer buffer 134 (step S312).
Thereby, the difference image is displayed for a moment on the display unit 110, and the image generated by the CPU 120 is immediately displayed.

  Next, the CPU 120 determines whether or not to display a new image on the display unit 110 (step S313). If the CPU 120 determines to display a new image on the display unit 110 (step S313: YES), the CPU 120 returns to step S301 and generates the new image.

  On the other hand, if the CPU 120 determines that no new image is to be displayed on the display unit 110 at the present time (step S313: NO), the CPU 120 has accepted an input of a process end request from the outside through an operation by the user or an interrupt process. It is determined whether or not (step S314). If the CPU 120 determines that an input of a termination request is not accepted from the outside (step S314: NO), the determination in step S313 is continued. On the other hand, when CPU 120 determines that an input of an end request has been received from the outside (step S314: YES), CPU 120 ends the process.

  Thus, according to the present embodiment, the display unit 110 displays an image to be displayed next after displaying an image obtained by subtracting the contour portion of the currently displayed image. Thereby, when the image displayed on the display unit 110 is switched to a new image, an afterimage generated by the currently displayed image is canceled, and then the next image to be displayed can be displayed.

Although several embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to that described above, and various designs can be made without departing from the scope of the present invention. It is possible to make changes.
For example, in the above-described embodiment, the case where the contour extracting unit 132 extracts a contour using a Laplacian filter has been described. You may do it.

  In the above-described embodiment, the case has been described in which the electrophoretic display device 100 includes the image processing device 130 that is a GPU, and the image processing device 130 performs the contour component removal calculation. However, the present invention is not limited thereto. For example, the display control unit 140 may have the function of the image processing apparatus 130.

  For example, when the electrophoretic display device 100 does not include the image processing device 130, the CPU 120 and the memory may execute the same processing as the image processing device 130. In this case, the operation of each processing unit described above is stored in a computer-readable recording medium in the form of a program, and the CPU 120 (computer) reads and executes the program to perform the above processing. Here, the computer-readable recording medium means a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like. Alternatively, the computer program may be distributed to a computer via a communication line, and the CPU 120 that has received the distribution may execute the program.

  The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

  DESCRIPTION OF SYMBOLS 100 ... Electrophoretic display apparatus 110 ... Display part 120 ... CPU 130 ... Image processing apparatus 131 ... Frame buffer 132 ... Contour extraction part 133 ... Difference calculating part 134 ... Transfer buffer 135 ... Contour image buffer 136 ... Frame transfer part 140 ... Display control Part

Claims (7)

A contour extraction unit that extracts a contour component from a first image that is an image to be displayed on the electrophoretic display device;
A difference calculation unit that generates an image obtained by subtracting a value obtained by multiplying the brightness of each pixel of the contour component image extracted by the contour extraction unit by a predetermined coefficient from the brightness of each pixel of the predetermined image. An image processing apparatus. The said difference calculating part produces | generates the image obtained by subtracting the brightness of each pixel of the image of the contour component which the said contour extraction part extracted from the said 1st image. Image processing device. The difference calculation unit subtracts the brightness of each pixel of the contour component image extracted by the contour extraction unit from a second image that is displayed on the electrophoretic display device after the first image. The image processing apparatus according to claim 1, wherein an image to be obtained is generated. The image processing according to any one of claims 1 to 3, wherein the contour extracting unit extracts the contour component by applying a Laplacian filter to the first image. apparatus. A display unit composed of a plurality of pixels each provided with an electrophoretic element including electrophoretic particles;
A contour extraction unit that extracts a contour component from a first image that is an image to be displayed on the display unit;
Display that displays on the display unit an image obtained by subtracting a value obtained by multiplying the brightness of each pixel of the image of the contour component extracted by the contour extraction unit by a predetermined coefficient from the brightness of each pixel of the predetermined image An electrophoretic display device comprising: a control unit. Extracting a contour component from a first image that is an image to be displayed on the electrophoretic display device;
Generating an image obtained by subtracting a value obtained by multiplying the brightness of each pixel of the image of the contour component by a predetermined coefficient from the brightness of each pixel of the predetermined image. . Computer
A contour extraction unit that extracts a contour component from a first image that is an image to be displayed on the electrophoretic display device;
A difference calculating unit that generates an image obtained by subtracting a value obtained by multiplying the brightness of each pixel of the contour component image extracted by the contour extraction unit by a predetermined coefficient from the brightness of each pixel of the predetermined image. Program for.

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