JP2010004358A - Image processing device, and image processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processing device and an image processing method, capable of attaining high resolution by suppressing the increase of a processing load to the minimum. <P>SOLUTION: This image processing device is equipped with a sharpening processing part 50 to apply an edge highlighting process to an input video signal, a high resolution processing part 51 to form the interpolated pixel of the video signal to which image processing by the sharpening processing part 50 is applied, and to form a video signal of high resolution, and a smoothing processing part to perform different smoothing processes in accordance with the direction of edges in the image of the video signal to which the image processing by the high resolution processing part 51 is applied. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image encoding technique, an image decoding technique, and an image resolution conversion technique, and more particularly to an image processing apparatus and an image processing method capable of performing optimum image processing.

In general, when an image is displayed using a high-resolution display, the number of pixels may be converted into a high-resolution pixel in accordance with the resolution of the input image. For example, Patent Document 1 discloses a technique for performing high-resolution processing by performing edge enhancement after performing pixel interpolation and finally performing smoothing processing.
JP 2008-54267 A

  However, in the technique described in Patent Document 1, since pixel interpolation is first performed on an input image to increase the resolution, the data amount of subsequent processing increases, and the processing load is increased. Increase.

  SUMMARY An advantage of some aspects of the invention is that it provides an image processing apparatus and an image processing method capable of increasing resolution while minimizing an increase in processing load.

  In order to solve the above-described problem, according to one aspect of the present invention, a first filter that performs edge enhancement processing on an input video signal and the image processing performed by the first filter are performed. A second filter that generates interpolated pixels of the video signal and generates a high-resolution video signal, and smoothing that differs depending on the direction of the edge in the image of the video signal that has undergone image processing by the second filter There is provided an image processing apparatus comprising a third filter for performing the digitization process.

  Further, according to another aspect of the present invention, an edge enhancement process is performed on an input video signal, an interpolation pixel of the video signal subjected to the image process by the edge enhancement process is generated, and a high resolution An image processing method is provided in which a different smoothing process is performed according to an edge direction in an image of the video signal on which the high-resolution video signal is generated. .

  According to the present invention, it is possible to provide an image processing apparatus and an image processing method capable of increasing the resolution while minimizing an increase in processing load.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, the configuration of an image processing apparatus according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. This image processing apparatus is realized as, for example, a notebook personal computer 10.

  FIG. 1 is a perspective view of the notebook personal computer 10 with the display unit opened. The computer 10 includes a computer main body 11 and a display unit 12. The display unit 12 incorporates a display device composed of an LCD (Liquid Crystal Display) 17, and the display screen of the LCD 17 is located substantially at the center of the display unit 12.

  The display unit 12 is attached to the computer main body 11 so as to be rotatable between an open position and a closed position. The computer main body 11 has a thin box-shaped housing, and a keyboard 13, a power button 14 for powering on / off the computer 10, an input operation panel 15, a touch pad 16, and the like are arranged on the upper surface. ing.

  The input operation panel 15 is an input device that inputs an event corresponding to a pressed button to the system, and includes a plurality of buttons for starting a plurality of functions. These buttons include a TV start button 15A and a DVD (Digital Versatile Disc) start button 15B. The TV start button 15A is a button for starting a TV function for reproducing and recording broadcast program data such as a digital TV broadcast program. When the TV start button 15A is pressed by the user, the TV function is executed. The TV application program is activated. The DVD activation button 15B is a button for reproducing video content recorded on the DVD, and when pressed by the user, an application program for reproducing video content is automatically activated.

  Next, the system configuration of the computer 10 will be described with reference to FIG.

  As shown in FIG. 2, the computer 10 includes a CPU 111, a north bridge 112, a main memory 113, a graphics controller 114, a south bridge 119, a BIOS-ROM 120, a hard disk drive (HDD) 121, and an optical disk drive (ODD) 122. , A digital TV broadcast tuner 123, an embedded controller / keyboard controller IC (EC / KBC) 124, a network controller 125, and the like.

  The CPU 111 is a processor provided to control the operation of the computer 10, and various applications such as an operating system (OS) and a video playback application 201 loaded from the hard disk drive (HDD) 121 to the main memory 113. Run the program.

  The CPU 111 also executes a system BIOS (Basic Input Output System) stored in the BIOS-ROM 120. The system BIOS is a program for hardware control.

  The north bridge 112 is a bridge device that connects the local bus of the CPU 111 and the south bridge 119. The north bridge 112 also includes a memory controller that controls access to the main memory 113. The north bridge 112 also has a function of executing communication with the graphics controller 114 via an AGP (Accelerated Graphics Port) bus or the like.

  The graphics controller 114 is a display controller that controls the LCD 17 used as a display monitor of the computer 10. The graphics controller 114 generates a display signal to be sent to the LCD 17 from the image data written in the video memory (VRAM) 114A.

  The south bridge 119 controls each device on an LPC (Low Pin Count) bus and each device on a PCI (Peripheral Component Interconnect) bus. The south bridge 119 incorporates an IDE (Integrated Drive Electronics) controller for controlling the HDD 121 and the ODD 122. Further, the south bridge 119 has a function of controlling the digital TV broadcast tuner 123 and a function of controlling access to the BIOS-ROM 120.

  The HDD 121 is a storage device that stores various software and data. The optical disk drive (ODD) 122 is a drive unit for driving a storage medium such as a DVD in which video content is stored. The digital TV broadcast tuner 123 is a receiving device for receiving broadcast program data such as a digital TV broadcast program from the outside.

  The embedded controller / keyboard controller IC (EC / KBC) 124 is a one-chip microcomputer in which an embedded controller for power management and a keyboard controller for controlling the keyboard (KB) 13 and the touch pad 16 are integrated. . The embedded controller / keyboard controller IC (EC / KBC) 124 has a function of turning on / off the computer 10 in accordance with the operation of the power button 14 by the user. Further, the embedded controller / keyboard controller IC (EC / KBC) 124 can also turn on the computer 10 in accordance with the operation of the TV start button 15A and the DVD start button 15B by the user. The network controller 125 is a communication device that executes communication with an external network such as the Internet.

  The video reproduction application 201 is software for decoding, increasing the resolution, and reproducing the compression-coded moving image data. This video playback application 201 is based on the MPEG-2 standard, H.264, or the like. This is a software decoder corresponding to the H.264 / AVC standard. The video playback application 201 is an H.264 file. A moving image stream (for example, a digital TV broadcast program received by the digital TV broadcast tuner 123, HD read out from the optical disc drive (ODD) 122) is compressed and encoded by the encoding method defined in the H.264 / AVC standard. Definition) standard video content, etc.) for decoding and increasing the resolution.

  For example, as shown in FIG. 3, the video playback application 201 inputs a video signal (low resolution data) such as a DVD disc read by the ODD 122 and converts the low resolution data that is the input video signal into high resolution data. Convert. The video playback application 201 includes a sharpening processing unit 50, a high resolution processing unit 51, and a jaggy reduction processing unit 52. The sharpening processing unit 50 is a first filter that performs edge enhancement processing on an input low-resolution video signal (image data). The first filter performs edge enhancement processing of the video signal by unsharp processing. The high resolution processing unit 51 generates an interpolated pixel of the video signal that has been subjected to image processing by the first filter, and generates a high resolution video signal. The second filter generates an interpolated pixel of the video signal by, for example, a cubic convolution method, and generates a high-resolution video signal. The jaggy reduction processing unit 52 performs different smoothing processing according to the direction of the edge in the image of the video signal subjected to the image processing by the second filter. The third filter uses a predetermined pixel of the image of the video signal as a target pixel, performs a predetermined calculation (described later) on the target pixel and eight pixels around the target pixel, and the target pixel is an edge. It is determined whether or not. Further, the combination of pixels in the smoothing process is changed based on the determination result of determining whether the target pixel is an edge.

  As shown in FIG. 4, the jaggy reduction processing unit 52 includes a memory 60, an edge determination unit 61, and a smoothing processing unit 62. The memory 60 is, for example, a buffer memory that temporarily stores the video signal input to the jaggy reduction processing unit 52, and holds high-resolution image data for one frame. The edge determination unit 61 determines the edge direction in the image data (video signal) output from the memory 60. The edge determination unit 61 sets a predetermined pixel of the image of the video signal as a target pixel, performs a predetermined calculation (described later) on the target pixel and eight pixels around the target pixel, and determines whether the target pixel is an edge. Determine whether or not. The smoothing processing unit 62 changes the combination of pixels in the smoothing processing based on the determination result obtained by determining whether or not the predetermined target pixel is an edge by the edge determination unit 61.

  A video processing method according to the video processing apparatus of the present invention will be described with reference to FIG.

First, the sharpening processing unit 50 performs edge enhancement processing on the input low resolution image data (video signal) (step S101). In this edge enhancement processing, edge enhancement processing of the video signal is performed by unsharp processing. An interpolated pixel of the video signal that has undergone image processing by edge enhancement processing is generated to generate a high-resolution video signal (step S102). In this high resolution processing, an interpolation pixel of a video signal is generated, and a high resolution video signal is generated. In this high resolution processing, for example, interpolated pixels of a video signal are generated by a cubic convolution method, and a high resolution video signal is generated. Next, a different smoothing process is performed according to the edge direction in the image of the high-resolution video signal (step S103). When performing the smoothing process, first, the smoothing process is performed. As shown in FIG. 6, for example, a predetermined pixel of the image of the video signal, for example, “pixel a” is set as the target pixel, and the target pixel “pixel” 7 is performed on “a” and eight pixels (“pixels b to i”) around the target pixel “pixel a” to determine whether or not the target pixel is an edge. . The luminance value of each pixel is
Y (a), Y (b), Y (c) ...
When any of the following conditions is satisfied, it is determined that the target pixel a corresponds to the edge portion. However, the thresholds th1 to th3 satisfy the following conditions.

th1>th2> th3
For example, an edge (target pixel a) as shown in FIG. Note that the luminance value of the pixel is represented by shades of black to white.

  Further, an edge (target pixel a) as shown in FIG.

  Furthermore, an edge (target pixel a) as shown in FIG.

  Further, according to condition 4, an edge (target pixel a) as shown in FIG. 11 can be determined.

  The smoothing processing unit 62 of the jaggy reduction processing unit 52 receives the determination result from the edge determination unit 61, and performs smoothing processing when it is determined as an edge. Further, the combination of pixels in the smoothing process is changed based on the determination result of determining whether the target pixel is an edge.

  For example, if the edge satisfies the condition 1 or 2, “pixels a, d, g” are used, and the smoothing process is performed by the following calculation.

(m * Y (d) + n * Y (a) + m * Y (g)) / (n + 2 * m) where n and m are integers greater than 0.

  The above calculation result is used as the luminance value of the target pixel.

Furthermore, if the edge satisfies the condition 3 or 4, use "pixels a, b, i"
Let (m * Y (b) + n * Y (a) + m * Y (i)) / (n + 2 * m) be the luminance value of the target pixel.

  These smoothing processes can reduce jaggy.

  In addition, the calculation in the edge determination unit 61 and the smoothing processing unit 62 described above is performed on all the pixels of the image data (video signal) stored in the memory 60 while changing the target pixel.

For example, FIG. 12 shows the luminance values of the pixels in FIG. Here, if th1 = 30, th2 = 10, th3 = 5,
Y (i) -Y (a) = 255-125 = 130> th1
Y (h) -Y (a) = 255-125 = 130> th2
Y (f) -Y (a) = 255-125 = 130> th2
Y (a) -Y (c) = 125-115 = 10> th3
Y (a) -Y (e) = 125-115 = 10> th3
And condition 1 is satisfied. Therefore, smoothing processing is performed using the pixels of the target pixels a, d, and g.

  For example, when calculating with n = 2 and m = 1, the luminance value of the target pixel a after the smoothing process is (1 * 255 + 2 * 125 + 1 * 255) / (2 + 2 * 1) = 190 .

  This completes the smoothing process. The above-described processing is performed using the video playback application 201, but is not limited thereto, and can be performed using hardware such as a dedicated IC.

According to the above-described embodiment, a sharp high-resolution image can be obtained with a small amount of processing. That is, by performing the conversion process from the low resolution to the high resolution of the video signal after the edge enhancement process, it is possible to increase the resolution while minimizing an increase in the load of the image processing. The embodiments described above are not limited to the above. In the implementation stage, the present invention can be embodied by changing the components without departing from the scope of the invention.

  Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above-described embodiments. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

1 is a diagram illustrating an appearance of an image processing apparatus according to an embodiment of the present invention. The figure which shows the structure of the video reproduction application of the image processing apparatus which concerns on the same embodiment. The block diagram which shows the main structures of the fingerprint sensor IC which concerns on the same embodiment. The figure which shows the structure of the jaggy reduction process part of the image processing apparatus which concerns on the same embodiment. 6 is a flowchart for explaining an image processing method of the image processing apparatus according to the same embodiment. The conceptual diagram for demonstrating the object pixel which the image processing apparatus which concerns on the same embodiment handles. The conceptual diagram which showed the conditions of the image processing which the image processing apparatus which concerns on the same embodiment performs. The conceptual diagram which showed the concept of the edge determination process which the image processing apparatus which concerns on the same embodiment performs. The conceptual diagram which showed the concept of the edge determination process which the image processing apparatus which concerns on the same embodiment performs. The conceptual diagram which showed the concept of the edge determination process which the image processing apparatus which concerns on the same embodiment performs. The conceptual diagram which showed the concept of the edge determination process which the image processing apparatus which concerns on the same embodiment performs. The conceptual diagram which showed the luminance value corresponding to FIG. 8 which the image processing apparatus which concerns on the same embodiment performs.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Computer, 12 ... Display unit, 14 ... Power button, 17 ... LCD, 50 ... Sharpening process part, 51 ... High resolution process part, 52 ... Juggy reduction process part, 60 ... Memory, 61 ... Edge determination part, 62: smoothing processing unit 62, 111 ... CPU, 113 ... (main) memory, 114 ... graphics controller, 120 ... BIOS-ROM, 121 ... HDD, 124 ... EC / KBC, 201 ... video playback application

Claims (7)

A first filter that performs edge enhancement processing on an input video signal;
A second filter that generates an interpolated pixel of the video signal that has undergone image processing by the first filter, and generates a high-resolution video signal;
An image processing apparatus comprising: a third filter that performs different smoothing processing according to an edge direction in an image of the video signal that has been subjected to image processing by the second filter. The image processing apparatus according to claim 1.
The third filter sets a predetermined pixel of the image of the video signal as a target pixel, performs a predetermined calculation on the target pixel and eight pixels around the target pixel, and determines whether the target pixel is an edge. An image processing apparatus that determines whether or not. The image processing apparatus according to claim 1.
The image processing apparatus according to claim 3, wherein the third filter changes a combination of pixels in the smoothing process according to a determination result for determining whether or not the target pixel is an edge. The image processing apparatus according to claim 1.
The image processing apparatus according to claim 1, wherein the first filter performs edge enhancement processing of the video signal by unsharp processing. The image processing apparatus according to claim 1.
The image processing apparatus, wherein the second filter generates an interpolated pixel of the video signal by a cubic convolution method and generates a high-resolution video signal. The image processing apparatus according to any one of claims 1 to 5,
An image processing apparatus, further comprising display means for displaying a video signal output from the third filter. Perform edge enhancement processing on the input video signal,
Generating an interpolated pixel of the video signal that has undergone image processing by the edge enhancement processing, and generating a high-resolution video signal;
An image processing method, comprising: performing different smoothing processing according to an edge direction in an image of the video signal on which the high-resolution video signal is generated.

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