JP2012160120A - Image processing device, image processing method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform drawing without eliminating a line while securing a depth feeling.SOLUTION: A normal transformation matrix drawing processing unit 113 applies inverse affine transformation to a second pixel group to thereby calculate a first pixel group before the affine transformation corresponding to the second pixel group, and draws the second pixel group based on data of the first pixel group. An inverse transformation matrix drawing processing unit 112 applies the affine transformation to a first pixel corresponding to data not used in drawing processing among the first pixel group to thereby calculate the second pixel group corresponding to the first pixel. Then, the inverse transformation matrix drawing processing unit 112 draws the calculated second pixel group based on data of the first pixel.

Description

  The present invention relates to a technique for drawing a second pixel group by performing affine transformation on the first pixel group.

  In order to draw two-dimensional graphics data with three-dimensional deformation, generally, the two-dimensional graphics data is drawn on a texture, and the drawn texture data is three-dimensionally deformed and projected onto a screen. A general method of projecting texture data by three-dimensional transformation is to calculate a pixel (reference pixel) referred to in the texture data by multiplying each pixel of the screen by the inverse matrix of the three-dimensional transformation, and to obtain reference pixel data. Draw with. However, in this method, pixels that are not referred to in the texture data may occur, which causes the disappearance of lines and the like.

  In order to solve such a problem, when two-dimensional graphics data is three-dimensionally deformed and drawn, it is determined whether or not the two-dimensional graphics data is a line. Now, what draws on a screen is known (see, for example, Patent Document 1).

JP 2002-203256 A

  However, the conventional method of drawing lines on the screen with a constant thickness has a problem that the depth of three-dimensional deformation cannot be obtained. Also, when projecting, it is necessary to recognize an object that is a line.

  Therefore, an object of the present invention is to draw a line without disappearing while ensuring a sense of depth.

  An image processing apparatus according to the present invention is an image processing apparatus that draws a second pixel group by performing affine transformation on the first pixel group, and performs inverse affine transformation on the second pixel group. By applying, a first calculation unit that calculates the first pixel group before the affine transformation corresponding to the second pixel group, and the first pixel group calculated by the first calculation unit First drawing means for drawing the second pixel group based on data, and first data corresponding to data not used for drawing processing by the first drawing means among the first pixel group. Second calculation means for calculating the second pixel group corresponding to the first pixel by performing affine transformation on the pixel, and the second calculation based on the data of the first pixel; And having a second drawing means for drawing the second group of pixels calculated by the stage.

  According to the present invention, it is possible to draw without losing a line while ensuring a sense of depth.

It is a figure which shows the structure of the graphics drawing apparatus which concerns on embodiment of this invention. It is a flowchart which shows the flow of the drawing process by reverse affine transformation. It is a figure for demonstrating the rectangular area | region before and behind an affine transformation. It is a figure for demonstrating the drawing result by reverse affine transformation. It is a figure which shows the correspondence of the reference pixel in the rectangular area calculated by performing an affine transformation to an original image, and the reference source pixel obtained by performing a reverse affine transformation with respect to the said rectangular area. It is a flowchart which shows the drawing process in embodiment of this invention. It is a figure which shows the initial state of a reference flag buffer, and the state after a drawing process. It is a figure for demonstrating the drawing result by the drawing process in embodiment of this invention. It is a figure which shows the correspondence of a reference source pixel and a reference destination pixel.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments to which the invention is applied will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a diagram showing a configuration of a graphics drawing apparatus according to an embodiment of the present invention. In FIG. 1, reference numeral 100 denotes a graphics drawing apparatus, which includes a memory 110 and a CPU 120. The graphics drawing device 100 is connected to the display 200 and the input device 300. The memory 110 stores a program for causing the CPU 120 to function as the reference flag buffer management unit 111, the inverse transformation matrix drawing processing unit 112, and the normal transformation matrix drawing processing unit 113. The graphics drawing apparatus 100 is a configuration that is an application example of an image processing apparatus.

  First, drawing processing by inverse affine transformation will be described with reference to FIGS. FIG. 2 is a flowchart showing a flow of drawing processing by inverse affine transformation. In step S2001, the CPU 120 calculates a rectangular area after affine transformation. Here, a case is considered in which affine transformation is performed on the rectangular area shown in FIG. 3A to convert it into the rectangular area shown in FIG. The affine transformation matrix at this time is assumed to be a matrix shown in Equation 1. In addition, the pixel (x, y) before conversion is converted to the pixel (x1, y1) after conversion using the affine transformation matrix of Expression 1 as shown in Expression 2. Each rectangular portion in the rectangular area shown in FIG. 3 corresponds to a pixel.

  The normal transformation matrix drawing processing unit 113 calculates a rectangular area after affine transformation by performing affine transformation on each of the four vertices before affine transformation. Next, the processing of steps S2002 to S2004 described below is repeatedly executed for each pixel in the rectangular area after the affine transformation. Hereinafter, each pixel in the rectangular area after the affine transformation is referred to as a reference pixel. In step S2002, the inverse transformation matrix drawing processing unit 112 performs inverse affine transformation on each reference destination pixel in the converted rectangular area, as shown in Expression 3, thereby corresponding to each reference destination pixel. Pixels in the area before conversion are calculated. In step S2003, the inverse transformation matrix drawing processing unit 112 obtains a pixel referred to by the nearest neighbor method (hereinafter referred to as a reference source pixel) from the pixel calculated in step S2002, and refers to the value of the reference source pixel on each screen. Draw on the destination pixel. In the present embodiment, the reference source pixel is obtained by the nearest neighbor method, but may be obtained by another method such as a linear interpolation method.

  Consider an example in which an affine transformation is applied to an original image that is bitmap data as shown in FIG. The original image is binary bitmap data. As shown in FIG. 4D, the value of a pixel painted black is set to 1, and the values of other pixels are set to 0. Here, binary bitmap data is taken as an example, but multi-value bitmap data or color bitmap data may be used. FIG. 5 shows a reference pixel (FIG. 5A) in a rectangular area calculated by performing affine transformation on the original image shown in FIG. 4A and inverse affine transformation on the rectangular area. It is a figure which shows the correspondence with the reference source pixel (FIG.5 (B)) obtained by (5). That is, when affine transformation is performed on the original image shown in FIG. 4A according to the correspondence shown in FIG. 5, the drawing result shown in FIG. 4B is obtained. As shown in FIG. 4B, since the rectangular area becomes smaller after the affine transformation, a non-reference pixel (FIG. 4E) that is a pixel that is not referred to in the original image as shown in FIG. 4C. Has occurred. For this reason, the values of all pixels of the original image are not reflected in the drawing result, and horizontal lines may be lost as shown in FIG. Note that the rectangular area illustrated in FIG. 4A is an example of the first pixel group, and the rectangular area illustrated in FIG. 4B is an example of the second pixel group.

  Next, drawing processing according to the embodiment of the present invention will be described with reference to FIGS. In step S6001, the reference flag buffer management unit 111 secures a buffer for storing a flag indicating whether or not each pixel of the original image has been referred to by inverse affine transformation and initializes the buffer. Hereinafter, the buffer is referred to as a reference flag buffer. That is, as shown in FIG. 7A, the reference flag buffer management unit 111 secures a reference flag buffer having the same size as the original image and initializes all reference flag buffers to 0. In step S6002, the positive transformation matrix drawing processing unit 113 calculates a rectangular area after affine transformation.

  Steps S6003 to S6005 are repeatedly executed for all reference destination pixels in the rectangular area calculated in step S6002. In step S6003, the inverse transformation matrix drawing processing unit 112 performs inverse affine transformation on the reference pixel after the affine transformation to calculate a reference source pixel of the original image. In step S6004, the inverse transformation matrix drawing processing unit 112 draws the value of the reference source pixel (color information) on the reference destination pixel on the screen. In step S6005, the reference flag buffer management unit 111 updates the value of the reference flag buffer at the same position as the reference source pixel calculated in step S6003 to 1. When the processing up to step S6005 is completed, the drawing result is the same as the drawing result by inverse affine transformation. Further, the reference flag buffer is updated as shown in FIG. FIG. 7B shows that the pixel that is 0 has not been referenced. Step S6003 is a processing example of the first calculation unit, and step S6004 is a processing example of the first drawing unit.

  Subsequent to the above processing, the processing in steps S6006 to S6008 is repeatedly executed for all pixels in which the color information of the original image is valid. In this embodiment, the pixel having effective color information is a pixel having a pixel value of 1, but in the case of multi-value bitmap data or color bitmap data, the pixel value is All pixels other than 0. In step S6006, the reference flag buffer management unit 111 determines whether the value of the reference flag buffer corresponding to a pixel for which color information is valid is zero. If the value of the reference flag buffer is 0, the process proceeds to step S6007. On the other hand, if the value of the reference flag buffer is 1, not 0, steps S6007 and S6008 are skipped.

  In step S6007, the positive transformation matrix drawing processing unit 113 performs affine transformation on the current pixel and calculates a corresponding pixel on the screen. In step S6008, the positive transformation matrix drawing processing unit 113 draws the pixel calculated in step S6007 with the color information of the current pixel in the original image. Step S6007 is a processing example of the second calculation unit, and step S6008 is a processing example of the second drawing unit.

  FIG. 8A shows a pixel in which the pixel value of the original image is 1 and the value of the reference flag buffer is 0 when the processing up to step S6005 is completed. FIG. 9 is a diagram illustrating a correspondence relationship between the reference source pixel and the reference destination pixel illustrated in FIG. Here, it is assumed that the same alphabet is converted from a reference source pixel indicated by lowercase letters to a reference destination pixel indicated by uppercase letters. Some of the reference pixels represented by the uppercase alphabet corresponding to the reference pixels represented by the lowercase alphabet are partly because they have been converted from different reference pixels to the same reference pixel. The drawing result of the entire process of FIG. 6 is as shown in FIG. In addition, among the processes in FIG. 6, the drawing result by the processes in steps S6006 to S6008 is as shown in FIG. The final drawing result shown in FIG. 8C is the drawing result (FIG. 8B) obtained by the drawing process added in this embodiment to the drawing result (FIG. 4B) obtained by the drawing process based on the inverse affine transformation reference. ) Is added.

  As described above, according to the present embodiment, even when a figure such as a character including a thin line is three-dimensionally deformed, drawing without losing the line while ensuring a sense of depth by the three-dimensional deformation. It becomes possible to do.

  In the present embodiment, an example in which affine transformation is performed on bitmap data has been described. However, similar processing can be applied to bitmap data obtained by rasterizing vector data. In the present embodiment, an example of a 3 × 3 affine matrix is shown, but two-dimensional deformation or three-dimensional deformation can be performed by 3 × 3.

  In this embodiment, the nearest neighbor method is used as a method for obtaining a reference destination pixel by affine transformation from a reference source pixel, but a linear interpolation method may be used. Further, in consideration of the size of the reference source pixel after affine transformation, the reference destination pixel may be obtained from the reference source pixel by affine transformation. For example, when the size of the reference pixel is increased by affine transformation, the plurality of reference pixels after affine transformation are affected. On the other hand, when the size of the reference pixel is reduced by affine transformation, a part of the reference pixel after affine transformation is affected, and therefore transparency may be added. Furthermore, in the present embodiment, the reference flag buffer is secured in an area different from the bitmap data, but may be shared and processed.

  The present invention can also be realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, or the like) of the system or apparatus reads the program. It is a process to be executed.

  DESCRIPTION OF SYMBOLS 100: Graphics drawing apparatus, 110: Memory, 111: Reference flag buffer management part, 112: Inverse transformation matrix drawing process part, 113: Positive transformation matrix drawing process part, 200: Display, 300: Input device

Claims (9)

An image processing apparatus that draws a second pixel group by performing an affine transformation on the first pixel group,
First calculating means for calculating the first pixel group before affine transformation corresponding to the second pixel group by performing inverse affine transformation on the second pixel group;
First drawing means for drawing the second pixel group based on the data of the first pixel group calculated by the first calculating means;
The second pixel corresponding to the first pixel is subjected to affine transformation on the first pixel corresponding to the data not used in the drawing process by the first drawing unit in the first pixel group. Second calculating means for calculating a pixel group of:
An image processing apparatus comprising: second drawing means for drawing the second pixel group calculated by the second calculation means based on the data of the first pixel.   The image processing apparatus according to claim 1, wherein the affine transformation includes at least one of two-dimensional deformation and three-dimensional deformation.   The image processing apparatus according to claim 1, wherein affine transformation is performed from the first pixel group to the second pixel group using a nearest neighbor method.   The image processing apparatus according to claim 1, wherein an affine transformation is performed from the first pixel group to the second pixel group using a linear interpolation method.   3. The image processing according to claim 1, wherein affine transformation is performed from the first pixel group to the second pixel group based on a size of the second pixel group after affine transformation. apparatus.   The image processing apparatus according to claim 1, wherein the data includes bitmap data obtained by rasterizing vector data.   A storage area for storing information for managing a first pixel corresponding to data not used in the drawing process by the first drawing unit in the first pixel group, and the data are stored. The image processing apparatus according to claim 1, wherein the image processing apparatus shares an area. An image processing method executed by an image processing apparatus that draws a second pixel group by performing an affine transformation on the first pixel group,
A first calculation step of calculating the first pixel group before the affine transformation corresponding to the second pixel group by performing inverse affine transformation on the second pixel group;
A first drawing step of drawing the second pixel group based on the data of the first pixel group calculated by the first calculation step;
The second pixel corresponding to the first pixel is subjected to affine transformation on the first pixel corresponding to the data not used in the drawing process in the first drawing step in the first pixel group. A second calculation step of calculating a pixel group of
And a second drawing step of drawing the second pixel group calculated in the second calculation step based on the data of the first pixel. A program for causing a computer to execute an image processing method executed by an image processing apparatus that draws a second pixel group by performing affine transformation on the first pixel group,
A first calculation step of calculating the first pixel group before the affine transformation corresponding to the second pixel group by performing inverse affine transformation on the second pixel group;
A first drawing step of drawing the second pixel group based on the data of the first pixel group calculated by the first calculation step;
The second pixel corresponding to the first pixel is subjected to affine transformation on the first pixel corresponding to the data not used in the drawing process in the first drawing step in the first pixel group. A second calculation step of calculating a pixel group of
A program for causing a computer to execute a second drawing step of drawing the second pixel group calculated in the second calculation step based on data of the first pixel.

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