KR100657102B1 - How to remove staircases in shapes on mobile devices - Google Patents

Abstract

A method for eliminating a stair state of a diagram in a mobile terminal is provided to control a color in order to meet the size of the pixel area occupied by the diagram. The power of 2 are multiplied by the coordinates of pixel areas of a diagram by means of a shift calculation(S101). The diagram is divided by straight lines(S103). When the start and end points of the diagram are divided by each straight line, the intersections of each straight lines relating to the virtual scan lines are added into an edge table(S105). The accumulation buffers relating to boundary points stored in the edge table and each scan line are filled(S107). The grade of the color intensity is calculated on the basis of the number of virtual lower pixels filled with the accumulated buffers(S109).

Description

How to remove staircase of figure in mobile device {ELIMINATION METHOD OF STAIR STATE OF THE OBJECT IN THE MOBILE TERMINAL}

1 is a flowchart illustrating a method of removing a step phenomenon of a figure in a mobile terminal according to an exemplary embodiment of the present invention.

2 is a view showing the boundary surface of the figure is not removed step phenomenon for the present invention.

3 (a) and 3 (b) are conceptual diagrams illustrating density levels accumulated per pixel in a cumulative buffer according to the present invention, and color intensity of pixels.

4 is a conceptual diagram of a virtual scanline divided into four for each pixel according to the present invention.

5 is a conceptual diagram of cumulative buffer filling for each scan line according to the present invention;

Figure 6 (a) (b) is a view before and after removing the step phenomenon of the figure in the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing a step phenomenon of a figure in a portable terminal, in particular, so that the step of aliasing generated when drawing a figure on a screen can be removed.

In general, computer graphics necessarily have aliasing in the structure of a display composed of pixels. This step phenomenon is difficult to see the step shape on a computer monitor or the like the display screen is large enough than the size of the pixel. In addition, using a fast computational processor or additional hardware to remove the staircase step to remove the step effect.

This step shape is an unavoidable phenomenon due to the display structure drawn in pixels. This may be more noticeable, especially when trying to display a clear image on a small screen. In other words, when a small screen is used, such as a mobile terminal, the screen is small, so that the user may relatively close to the screen, thereby easily detecting a step phenomenon. For this reason, there is a need for an effective method of eliminating the step phenomenon when drawing a figure in a mobile terminal.

The present invention provides a method of removing a step phenomenon of a figure in a mobile terminal in which a step is not easily seen by adjusting a color according to the size of an area occupying a pixel.

In the portable terminal according to the present invention for achieving the above object, the step removal method of the figure,

Dividing each pixel area constituting the screen into a plurality of virtual lower pixels;

Accumulating and counting the number of the virtual lower pixels corresponding to an area occupied by the figure on the screen;

And determining the color intensity of each pixel in proportion to the number of the virtual subpixels of the accumulated pixels and displaying the color.

Preferably, an integer operation is performed by using a power of 2 for the coordinate values of the figure.

Preferably, each pixel is divided into as many virtual subpixels as the square of a power of 2 multiplied by the coordinate values of the figure.

Preferably, the virtual subpixels of each scan line are accumulated by using virtual scan lines corresponding to powers of two multiplied by the coordinate values of the figure.

Preferably, the accumulated virtual subpixels calculate a first intersection point in the Y-axis direction using a boundary line having a constant slope with the virtual scan line, and accumulate the number of virtual subpixels from the calculated intersection points of each scan line. It is characterized by.

Preferably, the color intensity of each pixel adjacent to the boundary line is specified in proportion to the number of the virtual lower pixels of the pixels for each virtual scan line.

Referring to the accompanying drawings, a method of removing a step phenomenon of a figure in a mobile terminal according to an embodiment of the present invention configured as described above is as follows.

First, in a mobile terminal, since an image display element (for example, an LCD) is formed of a plurality of pixels, colors are filled in pixels when drawing figures such as circles or polygons, and thus pixels filled with colors and pixels not filled with colors are used. The difference in color intensity between the two causes a step phenomenon.

In order to remove such a step phenomenon, the color is adjusted according to the size of the image that the actual figure occupies the pixel so that the step phenomenon is difficult to see.

For this purpose, referring to FIG. 1, in the present invention, the coordinates of the figure pixel area are multiplied by a power of two (2 ⁿ , n = 1,2,3 ...) using a shift operation. That is, in order to preserve information below the decimal point while using integer arithmetic, the number obtained by multiplying the coordinate values of the figure by a power of two (for example, 2, 4, 8, ...) is used (S101).

Here, the power of 2 is calculated more accurately as the power of 2 to be multiplied increases, but one of the powers of 2 is selected in consideration of the amount of computing and the memory environment of the terminal. The reason for multiplying a power of 2 rather than a power of 10 is that multiplication and division to return to the coordinate values of the original order can be changed to bitwise operations.

In the present invention, in order to calculate the size of a pixel region, floating point and division operations are conventionally required, resulting in a large amount of computation and a decrease in speed. However, the present invention uses integer and shift operations. Therefore, it is possible to produce a more effective step removal effect than the conventional.

2 is a diagram illustrating a boundary surface of a figure without the step phenomenon, and each grid represents the actual pixel 110. As shown, a step phenomenon occurs from the pixels 110 of the figure which are filled inward with respect to the boundary line 100 connecting the start point and the end point of the figure.

And, it is divided into the straight lines of the figure (S103), which is a boundary line of the figure, and fills the horizontal lines of the screen called scan lines one by one like when drawing a figure in computer graphics. That is, all figures can be decomposed into successive straight lines, and especially a figure made of a curved line can produce an effect that looks like a curve when the length of the straight lines is sufficiently small. In this way, when divided into respective straight lines connecting the start point and the end point of the figure, the intersection point with the virtual scan lines for each straight line is added to the edge table (S107).

Here, when there is a straight line which is a boundary line of the figure, the square of the power of 2 multiplied by the pixel coordinates of the figure to estimate the area occupied by the figure (eg, 2 ² , 4 ² , 8 ² ,. The figure is divided into straight lines by dividing into virtual subpixels. For example, when divided into 16 virtual lower pixels, as shown in (a) of FIG.

FIG. 3A illustrates a case in which each pixel illustrated in FIG. 2 is divided into 16 virtual subpixels 4 * 4 (110), and accordingly, the virtual lower pixel (close to the actual boundary line 100) 111) is filled. In addition, since the number of lower pixels corresponding to the area occupied by the figure is stored in an accumulation buffer (not shown), color intensity is adjusted using the number stored in the accumulation buffer.

Here, the intensity level is the same as the area occupied by the figure, and the grid in the actual pixel represents the virtual lower pixel.

3B shows the number of virtual subpixels in the pixel, and the number of subpixels represents the color intensity level of the actual pixel. Here, when 16 is 100%, 15 means that 15 subpixels are included in the boundary line within the pixel, and 1 means that 1 subpixel is included inside the boundary line in the pixel. It means.

The process of calculating the number of lower pixels of each pixel is shown in FIG. 4.

4 is a conceptual diagram of a virtual scan line divided into four in 16 divided pixels, the intersection of the first virtual scan line with the Y axis (X1), the intersection of the second virtual scan line with the Y axis (X2), and the third virtual image. The intersection X3 of the scan line and the Y-axis and the intersection X4 of the fourth virtual scan line and the Y-axis are obtained, respectively. When the Y-axis point intersecting the four virtual scan lines is referred to as the intersections X1, X2, X3, and X4, the number of lower pixels is calculated from the intersection to the right.

For example, the number of lower pixels occupying a mode figure from the first virtual scan line and the first intersection X1 of the Y axis descending from the top to the boundary line is the number of lower pixels (6), and the first virtual scan line. The second intersection of and Y axis is not calculated (Polygon method). In this way, the number of lower pixels is eight from the intersection X2, the number of lower pixels is 11 from the intersection X3, and the number of the lower pixels is 13 from the intersection X3. In this way, the lower pixel for the region inside the boundary line of the figure is filled.

Then, in FIG. 4, the number of lower pixels in the figure may be one, the second pixel is seven, the third pixel is fourteen, and the fourth number may be sixteen lower pixels.

Here, the intersection X1 with the virtual scan line 1 = (dx / dy) * (Yy) + x, the intersection X2 with the virtual scan line 2 is X1 + (dx / dy), and the intersection X3 with the virtual scan line 3 is X2 +. (dx / dy), and the intersection point X4 with the virtual scan line 4 is obtained as X3 + (dx / dy). Accordingly, each intersection is calculated by adding only an increase amount using a constant slope. The dx / dy is calculated only once per straight line.

As described above, since the slope is constant when calculating the intersection point with the straight line serving as the boundary point of each scan line, only the amount of change can be added or subtracted efficiently.

The cumulative buffer is filled for each boundary point and scan line stored in the edge table (S107). Since the number of lower pixels filled in the pixels belonging to the inside of the figure is constant, the number of loops is maintained as many as the actual number of pixels, and the coordinate value of the actual pixel is found by dividing by the power of two using a shift operation. Here, since the number of loops is divided into virtual subpixels, there are more than two virtual scan lines, which are larger than the actual scan lines. In this case, the number of vertical loops increases, which increases the computational amount, but only changes the amount of change. Can be performed.

In addition, the number of loops may increase because the coordinate value of the figure is multiplied by a power of 2 when filling the horizontal direction from the start point to the end point of the scan line, but the number of subpixels of the pixel of the inner part of the figure that does not pass the boundary point Using the constant does not increase the number of loops.

FIG. 4 is a conceptual diagram of cumulative buffer filling for each scan line. By calculating a value to be added to a cumulative buffer of pixels including both end points (X1, Xn), the pixel corresponding to the inside of the figure is filled with 4 without calculation. As a result, the number of loops does not increase. Here, the line on the left side is the starting point, and at this time, the right side is filled with 3 (= 4-1), 4, 4 centering on the intersection point of the scan line, and since the right intersection point is the end point, the slope is reversed. Will be counted and 2 will be filled to the left.

A color intensity grade is obtained by using the number of virtual subpixels filled in the accumulation buffer, wherein the color intensity grade has a grade corresponding to the number of subpixels, and proportionally increases the color intensity level of the pixel. It is determined (S109).

The color of the actual pixel is filled using the color intensity level filled in the accumulation buffer. For example, when looking at the boundary line of FIG. 2A, color intensities corresponding to the number of lower pixels are displayed. Here, when 16 is regarded as 100% of color, the color intensity corresponding to the number of lower pixels is displayed as the center of the boundary line.

By doing in this way, the color of the pixel adjacent to a boundary line does not differ greatly, and a step phenomenon is practically eliminated. This can be seen by comparing (a) and (b) of FIG. FIG. 6A is a view before the step phenomenon is removed, and FIG. 6B is a view showing a state in which the step phenomenon is removed by the present invention.

So far, the present invention has been described with reference to the preferred embodiments, and those skilled in the art to which the present invention pertains to the detailed description of the present invention and other forms of embodiments within the essential technical scope of the present invention. Could be implemented. Here, the essential technical scope of the present invention is shown in the claims, and all differences within the equivalent range will be construed as being included in the present invention.

According to the method of removing the staircase of a figure in a mobile terminal according to an embodiment of the present invention, it is possible to achieve the effect of removing a calculation phenomenon when drawing a figure on a screen, and to improve the graphic quality by making the user hardly feel it. have.

It also has the effect of eliminating floating point calculations and division and reducing the amount of computation and speeding up the graphics using only integer calculation.

It also has an effect that can be applied to a computer environment.

Claims (6)

Dividing each pixel area constituting the screen into a plurality of virtual lower pixels; Accumulating and counting the number of the virtual lower pixels corresponding to an area occupied by the figure on the screen; And deciding a color intensity of each pixel in proportion to the number of virtual subpixels of the accumulated pixels and displaying a color. The method of claim 1, The method of removing the stair phenomenon of a figure in a mobile terminal, characterized in that to perform an integer operation by using a power of 2 on the coordinate values of the figure to adjust the color according to the size of the area occupying the pixel. The method of claim 2, And dividing each pixel into virtual subpixels equal to a power of 2 multiplied by the coordinate values of the figure. The method of claim 3, wherein And accumulating virtual subpixels of each scan line using virtual scan lines equal to a power of two multiplied by the coordinate values of the figure. The method of claim 3, wherein The cumulative virtual subpixel calculates a first intersection point in the Y-axis direction by using a boundary line having a constant slope with the virtual scan line, and accumulates the number of virtual subpixels from the calculated intersection points of each scan line. How to remove the stair phenomenon of the shape in the mobile terminal. The method of claim 5, And a color intensity for each pixel adjacent to a boundary line in proportion to the number of virtual subpixels of the pixels for each virtual scan line.

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