JP2013250765A - Image display processing method and image display processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve image quality in addition to filter processing in interpolation processing by a triangulation method.SOLUTION: A noise suppression filter processing unit 14 performs noise suppression processing of expanded image data PD. An edge enhancement filter processing unit 15 performs edge enhancement processing of the expanded image data PD. A triangulation evaluation unit 1311 recognizes a lattice including an attentional interpolation pixel. Next, the triangulation evaluation unit 1311 determines one division pattern among a plurality of division patterns on the basis of values of peripheral pixels including the lattice, being image data after noise suppression processing by the noise suppression filter processing unit 14 about the recognized lattice. An interpolation unit 1312 calculates a value of an interpolation pixel on the basis of a value of a pixel necessary to interpolation determined by the division pattern determined for the lattice, being image data after edge enhancement processing by the edge enhancement filter processing unit 15.

Description

  The present invention relates to an image display processing method and an image display processing device, and more particularly, to an image display processing method and an image display processing device that perform pixel interpolation processing based on a triangulation method for displaying an enlarged image.

  As a method for interpolating pixels to convert a low-resolution image into a high-resolution image, or a method for determining a new pixel value using an original pixel value in image rotation / deformation processing, various methods have been conventionally used. Proposed. For example, the bilinear method is a method of determining an interpolation pixel (also referred to as a small number of pixels) value by linearly interpolating these pixel values according to the distance from four pixels surrounding the interpolation point. Further, the bicubic method is a method of determining an interpolation pixel value by calculating a value of a predetermined three-dimensional function using pixel values of 16 pixels around the interpolation point.

  However, in each of the above-described methods, there is a problem that so-called jaggy occurs on an edge in an oblique direction or the entire image is blurred.

  Therefore, as a high-quality enlargement method, a triangulation method that divides an image area into triangles and interpolates pixels according to the cost function, edge direction, etc. has been proposed. (For example, refer nonpatent literature 1). This is because the sampling (reference) pixel points at the time of calculating the value of the pixel to be interpolated by dividing each region into triangles based on the cost function over each lattice-shaped region having each pixel as a vertex. It is a method to decide.

  According to this triangulation method, the occurrence of jaggies can be suppressed and the problem of blurring can be overcome with respect to the edge in the oblique direction.

X.Yu, B. S. Morse, and T. W. Sederberg, “Image Reconstruction Using Data-Dependent Triangulation”, IEEE Computer Graphics and Applications, Vol. 21, No. 3, pp. 62-68 May / Jun. (2001)

  By the way, in image processing, it is very common to perform various types of filter processing on image data in accordance with the purpose. For example, a noise removal (smoothing) filter is used to remove noise contained in image data, that is, high-frequency components. An edge enhancement (sharpening) filter is used to sharpen the boundaries between individual images included in the image.

  However, at present, filter processing is not employed in the interpolation processing by the triangulation method.

  The present invention has been made for the above-described circumstances, and an object of the present invention is to provide an image display processing method and an image display process capable of improving image quality by combining filter processing in interpolation processing using a triangulation method. To provide an apparatus.

  In order to achieve the above object, an image display processing method according to the present invention is an image display processing method for performing pixel interpolation processing based on a triangulation method in order to enlarge and display an image. Performing noise suppression filter processing on the data, and based on the image data after the noise suppression filter processing, one division pattern of the plurality of division patterns in the triangulation method for a grid including pixels to be obtained by interpolation And determining pixel values to be obtained by the interpolation with reference to image data constituting the image based on the determined division pattern.

  In order to achieve the above object, an image display processing method according to the present invention is an image display processing method that performs pixel interpolation processing based on a triangulation method in order to enlarge and display an image. An edge enhancement filter is determined for the image data constituting the image by determining one division pattern of the plurality of division patterns in the triangulation method for a grid including pixels to be obtained by interpolation based on the image data to be obtained The gist of the present invention is to perform processing and obtain the pixel value to be obtained by the interpolation with reference to the image data after the edge enhancement filter processing based on the determined one division pattern.

  In order to achieve the above object, an image display processing method according to the present invention is an image display processing method that performs pixel interpolation processing based on a triangulation method in order to enlarge and display an image. Noise suppression filter processing is performed on the image data to be processed, and based on the image data after the noise suppression filter processing, one of a plurality of division patterns in the triangulation method for a grid including pixels to be obtained by interpolation A division pattern is determined, edge enhancement filter processing is performed on the image data constituting the image, and the interpolation is performed with reference to the image data after the edge enhancement filter processing based on the determined one division pattern The gist is to obtain the pixel value to be obtained by

  Here, it is preferable that the noise suppression process is performed by a Gaussian filter, and the edge enhancement process is performed by a Laplacian filter.

  Alternatively, it is preferable that the noise suppression processing and the edge enhancement processing are each performed by LOG filters having different convolution coefficients.

  In order to achieve the above object, an image display processing device of the present invention is an image display processing device that performs pixel interpolation processing based on a triangulation method in order to enlarge and display an image. A noise suppression filter processing unit that performs noise suppression filter processing on data, and a plurality of division patterns in the triangulation method for a grid including pixels to be obtained by interpolation based on image data that has passed through the noise suppression filter processing unit And a pixel to be obtained by interpolation with reference to image data constituting the image based on the one division pattern determined by the triangle division evaluation unit The gist of the present invention is to include an interpolation unit for obtaining the value of.

  In order to achieve the above object, an image display processing device according to the present invention is an image display processing device that performs pixel interpolation processing based on a triangulation method in order to enlarge and display an image. A triangulation evaluation unit that determines one division pattern among a plurality of division patterns in the triangulation method for a grid including pixels to be obtained by interpolation based on image data to be obtained, and image data constituting the image An edge enhancement filter processing unit for performing edge enhancement filter processing on the basis of the one division pattern determined by the triangulation evaluation unit is obtained by the interpolation with reference to image data that has passed through the edge enhancement filter processing unit. The gist of the present invention is to include an interpolation unit that obtains the value of a power pixel.

  In order to achieve the above object, an image display processing device according to the present invention is an image display processing device that performs pixel interpolation processing based on a triangulation method in order to enlarge and display an image. A noise suppression filter processing unit that performs noise suppression filter processing on image data to be processed, and a grid that includes pixels to be obtained by interpolation based on the image data that has passed through the noise suppression filter processing unit, a plurality of in the triangulation method Triangulation division evaluation unit that determines one division pattern among division patterns, an edge enhancement filter processing unit that performs edge enhancement filter processing on the image data constituting the image, and the triangle division evaluation unit Based on one division pattern, the interpolation is performed by referring to the image data that has passed through the edge enhancement filter processing unit. An interpolation unit for obtaining a value of the pixel to be obtained, and summarized in that comprises a.

  According to the image display processing method and the image display processing apparatus of the present invention, it is possible to improve the image quality by combining the filter processing in the interpolation processing by the triangulation method.

1 is a configuration block diagram of an image processing apparatus including a first embodiment of an image display processing apparatus of the present invention. 4 is a flowchart showing a processing procedure of a drawing circuit 13 in the image display processor 1. It is a figure for demonstrating the grid | lattice containing the interpolation pixel to which attention is paid. It is a figure which shows the kind of division | segmentation pattern of the lattice unit by the division | segmentation based on the triangulation method. It is a figure for demonstrating the interpolation of the pixel based on the triangulation method. It is a block diagram of the configuration of an image processing apparatus including a second embodiment of the image display processing apparatus of the present invention. It is a block diagram of the configuration of an image processing apparatus including a third embodiment of the image display processing apparatus of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In view of this, it is considered that the interpolation processing is performed after improving the quality of the image data by providing various filter processing units before the interpolation processing by the triangulation method. For example, in order to perform interpolation processing after performing noise suppression processing on original image data, a noise suppression filter processing unit is placed as it is before the interpolation processing by the triangulation method. Alternatively, in order to perform interpolation processing after performing edge enhancement processing on the original image data, the edge enhancement filter processing unit is placed as it is before the interpolation processing by the triangulation method. However, according to experiments, in any case, the image after the interpolation processing has deteriorated rather than the expected effect of the filter processing.

  That is, when the noise suppression filter is applied, the image is blurred as a whole, so that the final output image is also blurred, and the subjective image quality is considered to be deteriorated. In addition, when the edge enhancement filter is applied, the subjective image quality of the edge portion is improved, but in the determination process of the triangulation pattern, the probability that the noise component is erroneously determined as an edge and divided into erroneous triangles increases, It is thought that pattern-like distortion occurred and the subjective image quality was reduced.

  As a result, the present inventor has that each of the so-called “triangulation pattern determination process” and “interpolation process” included in the interpolation process by the triangulation method has an affinity / non-affinity for a specific filter process. I found Specifically, in the interpolation process by the triangulation method, if the image data after the noise suppression process is used for the process of determining the so-called division pattern type, and the image data after the edge enhancement process is used for the interpolation process It was found that the effects of both noise suppression and edge enhancement appear in the finally obtained interpolated image without canceling each other.

  That is, in the present invention, the final image is obtained by combining the triangulation pattern determined from the image subjected to the noise suppression filter and the image not subjected to the noise suppression filter, and calculating the pixel value to be obtained by interpolation. Suppress blurring. In addition, by combining the triangulation pattern determined from the image that has not been subjected to the edge enhancement filter and the image that has been subjected to the edge enhancement filter, calculating the pixel value to be obtained by interpolation, while suppressing the influence of noise Also, improve the subjective image quality of the edge part. In addition, the image with the noise suppression filter is supplied to the decision processing of the triangulation pattern, and the value of the pixel to be obtained by interpolation is calculated by combining the triangulation pattern determined thereby and the image with the edge enhancement filter By doing so, an image with enhanced edges is output while suppressing noise, and the subjective image quality is improved.

<First Embodiment>
FIG. 1 is a block diagram showing the configuration of an image processing apparatus including the first embodiment of the image display processing apparatus of the present invention. The image processing apparatus shown in FIG. 1 generally includes an image display processor 1, an image data ROM (Read Only Memory) 2, and a display unit 3. Note that a CPU (Central Processing Unit) is further connected to the image display processor 1, and a program ROM is typically connected to the CPU. In addition, this image processing apparatus is typically mounted on a gaming machine such as a pachinko machine or a game machine in which a variety of effects such as images, particularly moving images, are performed on the display screen of the display unit 3.

  The image display processor 1 reads the compressed image data from the image data ROM 2 and performs an expansion process, a VRAM (Video Random Access Memory) 12 in which the expanded image data PD is stored, and the expanded image data A noise suppression filter processing unit 14 that performs noise suppression (smoothing) processing on the image data PD, and an edge enhancement filter processing unit 15 that performs edge enhancement (sharpening) processing on the expanded image data PD; A drawing circuit 13 that performs various drawing processes including an interpolation process with reference to the image data processed by the noise suppression filter processing unit 14 and the edge enhancement filter processing unit 15. Typically, the noise suppression filter processing unit 14 can be realized by a Gaussian filter, while the edge enhancement filter processing unit 15 can be realized by a Laplacian filter. Further, both can be realized by employing a LOG (Laplacian of Gaussian) filter and setting different convolution coefficients.

  The drawing circuit 13 includes at least a triangulation interpolation circuit 131. The triangulation interpolation circuit 131 further includes a plurality of divisions in a triangulation method described later with respect to a grid (four original pixels as vertices) including pixels to be obtained by interpolation. Triangulation division evaluation unit 1311 for determining one division pattern among the patterns, and image data processed by edge enhancement filter processing unit 15 based on information DPI of one division pattern determined by triangle division evaluation unit 1311 Referring to FIG. 4, an interpolation unit 1312 that obtains the pixel value to be obtained by interpolation is included.

Next, a processing procedure in the image processing apparatus shown in FIG. 1 will be described.
First, when there is an enlargement display instruction for a specific image from a CPU (not shown), the image display processor 1 reads the compressed image data of the designated image from the image data ROM 2 and performs decompression processing. And stored in the VRAM 12.

  Then, the noise suppression filter processing unit 14 performs noise suppression filter processing by collectively applying an arbitrary filter for noise suppression to the expanded image data PD, and the obtained image data is illustrated in FIG. Do not store in internal local memory. On the other hand, the edge enhancement filter processing unit 15 performs edge enhancement filter processing by collectively applying an arbitrary filter for edge enhancement to the decompressed image data PD, and the obtained image data is illustrated in FIG. Do not store in internal local memory.

  Next, the triangulation interpolation circuit 131 in the drawing circuit 13 performs interpolation processing with reference to the image data processed by the noise suppression filter processing unit 14 and the edge enhancement filter processing unit 15. FIGS. 2A and 2B are flowcharts showing the processing procedure of the drawing circuit 13 in the image display processor 1.

  Therefore, the triangulation interpolation circuit 131 in the drawing circuit 13 causes the noise suppression filter processing unit 14 and the edge enhancement filter processing unit when a pixel to be obtained by interpolation (hereinafter referred to as “interpolation pixel”) occurs due to enlargement. The value of the interpolation pixel is determined based on the triangulation method with reference to the image data processed by 15 (step S1).

  Specifically, the following processing is performed for each interpolation pixel of interest. That is, first, the triangulation evaluation unit 1311 in the triangulation interpolation circuit 131 recognizes a grid (four original pixels as vertices) including the interpolation pixel of interest as shown in FIG. 3 (step S11).

  Next, the triangulation division evaluation unit 1311 is the image data after the noise suppression processing by the noise suppression filter processing unit 14 for the recognized grid, and a plurality of division patterns based on the values of the surrounding pixels including the grid. One division pattern is determined from among them (step S12). That is, the pixel shown in FIG. 3 is image data after noise suppression processing.

  Here, with reference to FIG. 4, the division | segmentation pattern in a triangulation method is demonstrated. FIG. 4 is a diagram showing types of division patterns in units of lattices by division based on the triangulation method. Here, a case will be described in which the inclination of the pixel value is approximated to an accuracy of 360 degrees / 16, that is, an accuracy of 22.5 degrees. When the gradient of the pixel value is approximated to an accuracy of 22.5 degrees, there are 15 division patterns determined as the lattice of interest as shown in FIG. At this time, in order to determine noise resistance and to ensure the continuity of the division pattern of each grid, as shown in FIG. 3, the surrounding 36 pixels or more including 4 pixels at each vertex of the grid Need to refer.

  Next, the interpolation unit 1312 in the triangulation interpolation circuit 131 is the image data after the edge enhancement processing by the edge enhancement filter processing unit 15 and the pixel values necessary for the interpolation determined by the division pattern determined for the grid. Based on the above, the value of the interpolated pixel is obtained (step S13).

  Here, pixels (reference pixels) necessary for interpolation in each case of each division pattern will be described. FIGS. 5A to 5H are diagrams showing examples of division patterns showing how to take reference pixels. Each pixel shown in the figure is image data after edge enhancement processing by the edge enhancement filter processing unit 15. For example, as shown in FIG. 6A, in the case of a pattern without division, the pixels p (ul), p (ur), p (dl), and p (dr) (a, b, The value of the pixel ip to be interpolated is calculated by linear interpolation (same as c and d). Further, in the case of the two divisions in FIG. 5B, in the case of the pixel ip to be interpolated at the position shown in the same figure, based on the values of the pixels p (ul), p (ur), and p (dl), The value of the pixel ip to be interpolated is calculated. Further, in the case of the pixel ip to be interpolated at the position shown in the figure, which is one pattern of three divisions shown in FIG. 10C, the values of the pixels p (ur), p (dl), and p (dll) are set. Based on this, the value of the pixel id to be interpolated is calculated. Further, in the case of the pixel ip to be interpolated at the position shown in the figure, which is one pattern of three divisions shown in FIG. 10D, the values of the pixels p (ur), p (dl), and p (urr) are set. Based on this, the value of the pixel id to be interpolated is calculated. Further, in the case of the pixel ip to be interpolated at the position shown in the figure, which is one pattern of three divisions shown in FIG. 9E, the values of the pixels p (ur), p (dl), and p (uru) are set. Based on this, the value of the pixel id to be interpolated is calculated. Further, in the case of the pixel ip to be interpolated at the position shown in the figure, which is one pattern of three divisions shown in FIG. 8F, the values of the pixels p (ur), p (dl), and p (dld) are set. Based on this, the value of the pixel id to be interpolated is calculated. The same applies to each of the four divided patterns shown in (g) and (h) of FIG. The same applies to the other seven division patterns not illustrated in the figure.

  Note that when the grid including the interpolation pixel of interest recognized in step S11 is the same as the grid related to the already processed interpolation pixel, the process of step S12 and the process of determining the division pattern need not be performed.

  When the values are obtained for all the pixels to be interpolated, the process of step S1 ends (steps S14 and S15). Returning to FIG. 2A, the drawing circuit 13 performs other necessary drawing processing, and displays an image on the display unit 3 based on the value of the pixel including the interpolation pixel (step S2).

  In the above-described embodiment, the noise suppression filter processing unit 14 and the edge enhancement filter processing unit 15 collectively perform noise suppression filter processing and edge enhancement filter processing on the decompressed image data PD, respectively. The triangulation evaluation unit 1311 and the interpolation unit 1312 determine a division pattern and perform interpolation by referring to necessary pixels from the image data. However, regardless of this configuration, every time the triangulation evaluation unit 1311 determines a division pattern based on the reference pixels determined for the recognized grid, the noise suppression filter processing unit 14 assigns the reference pixels (36 pixels) to the VRAM 12. Each time the interpolation unit 1312 obtains the value of the interpolation pixel based on the reference pixel determined by the determined division pattern, the edge enhancement filter processing unit 15 converts the reference pixel to the VRAM 12. The edge emphasis filter processing may be performed by reading out from.

  As described above, according to the above-described embodiment, image data after noise suppression processing is used for processing for determining a so-called division pattern type in interpolation processing using a triangulation method, and edge enhancement processing is used for interpolation processing. Since the later image data is used, the effects of both noise suppression and edge enhancement appear in the finally obtained interpolated image without canceling each other. Therefore, in the interpolation process using the triangulation method, the image quality can be improved by combining the filter process.

Second Embodiment
Next, the second embodiment will be described. The same components and processes as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted. FIG. 6 is a configuration block diagram of an image processing apparatus including the second embodiment of the image display processing apparatus of the present invention.

  As shown in FIG. 6, the image processing apparatus according to the second embodiment is an image display processor having a configuration in which the edge enhancement filter processing unit 15 is removed from the image display processor 1 according to the first embodiment shown in FIG. 1B is provided. As described above, even if only the noise suppression filter processing unit 14 is used, if the image data after the noise suppression process is appropriately input only to the triangulation evaluation unit 1311 as in the first embodiment, the final result is obtained. The effect of noise suppression appears effectively in the image after a typical interpolation. Therefore, also in the second embodiment, the image quality can be improved by combining the filter processing in the interpolation processing by the triangulation method.

<Third Embodiment>
Next, the third embodiment will be described. The same components and processes as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted. FIG. 7 is a configuration block diagram of an image processing apparatus including the third embodiment of the image display processing apparatus of the present invention.

  As shown in FIG. 7, the image processing apparatus according to the third embodiment is an image display processor having a configuration in which the noise suppression filter processing unit 14 is removed from the image display processor 1 according to the first embodiment shown in FIG. 1C is provided. As described above, even if only the edge enhancement filter processing unit 15 is used, if the image data after the edge enhancement processing thereby is appropriately input only to the interpolation unit 1312 as in the first embodiment, the final image data is finally obtained. The effect of edge enhancement appears effectively in the interpolated image. Therefore, also in the third embodiment, the image quality can be improved by combining the filter processing in the interpolation processing by the triangulation method.

  In each of the above-described embodiments, the case where image data is read from the image data ROM and stored in the VRAM has been described. However, the present invention is not limited to this, for example, via a network (for example, an IP network). The same applies when processing such as enlargement is performed on the sent compressed image data. As such an example, for example, there is distribution of electronic book information.

  The image display processing method and the image display processing apparatus of the present invention can be applied to an image display processor responsible for image display processing in gaming machines such as pachinko machines and game machines.

1 Image display processor 11 Image decoder 12 VRAM
13 Drawing circuit 131 Triangulation interpolation circuit 1311 Triangulation division evaluation unit 1312 Interpolation unit 14 Noise suppression filter processing unit 15 Edge enhancement filter processing unit 2 Image data ROM
3 Display unit DPI Division pattern information p Pixel ip Pixel to be interpolated

Claims (9)

An image display processing method for performing pixel interpolation processing based on a triangulation method to display an enlarged image,
Perform noise suppression filter processing on the image data constituting the image,
Based on the image data after the noise suppression filter processing, for a grid including pixels to be obtained by interpolation, determine one division pattern among a plurality of division patterns in the triangulation method,
An image display processing method characterized in that, based on the determined one division pattern, a pixel value to be obtained by the interpolation is obtained by referring to image data constituting the image. An image display processing method for performing pixel interpolation processing based on a triangulation method to display an enlarged image,
Based on the image data constituting the image, for a grid including pixels to be obtained by interpolation, determine one division pattern among a plurality of division patterns in the triangulation method,
Performing edge enhancement filter processing on image data constituting the image;
An image display processing method, wherein the pixel value to be obtained by the interpolation is obtained by referring to the image data after the edge enhancement filter processing based on the determined one division pattern. An image display processing method for performing pixel interpolation processing based on a triangulation method to display an enlarged image,
Perform noise suppression filter processing on the image data constituting the image,
Based on the image data after the noise suppression filter processing, for a grid including pixels to be obtained by interpolation, determine one division pattern among a plurality of division patterns in the triangulation method,
Performing edge enhancement filter processing on image data constituting the image;
An image display processing method, wherein the pixel value to be obtained by the interpolation is obtained by referring to the image data after the edge enhancement filter processing based on the determined one division pattern.   The image display processing method according to claim 1, wherein the noise suppression process is performed by a Gaussian filter.   4. The image display processing method according to claim 2, wherein the edge enhancement processing is performed by a Laplacian filter.   The image display processing method according to claim 3, wherein the noise suppression process and the edge enhancement process are each performed by a LOG filter having different convolution coefficients. An image display processing device that performs pixel interpolation processing based on a triangulation method to display an enlarged image,
A noise suppression filter processing unit for performing noise suppression filter processing on image data constituting the image;
A triangulation evaluation unit that determines one division pattern among a plurality of division patterns in the triangulation method for a grid including pixels to be obtained by interpolation based on image data that has passed through the noise suppression filter processing unit;
Based on one division pattern determined by the triangulation evaluation unit, referring to image data constituting the image, an interpolation unit for obtaining a pixel value to be obtained by the interpolation;
An image display processing device comprising: An image display processing device that performs pixel interpolation processing based on a triangulation method to display an enlarged image,
A triangulation evaluation unit that determines one division pattern among a plurality of division patterns in the triangulation method for a grid including pixels to be obtained by interpolation based on image data constituting the image;
An edge enhancement filter processing unit that performs edge enhancement filter processing on image data constituting the image;
Based on one division pattern determined by the triangulation evaluation unit, with reference to the image data that has passed through the edge enhancement filter processing unit, an interpolation unit that obtains a pixel value to be obtained by the interpolation;
An image display processing device comprising: An image display processing device that performs pixel interpolation processing based on a triangulation method to display an enlarged image,
A noise suppression filter processing unit for performing noise suppression filter processing on image data constituting the image;
A triangulation evaluation unit that determines one division pattern among a plurality of division patterns in the triangulation method for a grid including pixels to be obtained by interpolation based on image data that has passed through the noise suppression filter processing unit;
An edge enhancement filter processing unit that performs edge enhancement filter processing on image data constituting the image;
Based on one division pattern determined by the triangulation evaluation unit, with reference to the image data that has passed through the edge enhancement filter processing unit, an interpolation unit that obtains a pixel value to be obtained by the interpolation;
An image display processing device comprising:

Images