JP2519104B2 - Image editing / creating apparatus and image editing / creating method - Google Patents

Description

TECHNICAL FIELD The present invention relates to improvements in an image editing / creating apparatus and an image editing / creating method, and adjusts the thickness of a stylus pen according to the writing pressure and responds to the thickness. By performing anti-aliasing processing called soft edge processing in real time,
The present invention relates to an image editing / creating apparatus and an image editing / creating method capable of creating high-quality drawing at high speed.

(Prior Art) Generally, a conventional image editing / creating apparatus includes an input device including a stylus pen, a bullet, a keyboard, and the like, and an arithmetic processing device that processes various data signals from the input device.
It is composed of a display device and the like, and an image drawn on the tablet by the operator with the stylus pen is displayed on the display in real time.

However, in this type of image editing / creating apparatus, the operator usually has to select a pen having an appropriate thickness from the designated stylus pens and draw with this. However, since the number of stylus pens that can be used is small, it is difficult to obtain a desired delicate pen touch and it is difficult to perform fine correction work accurately and smoothly.

On the other hand, the outer peripheral portion of the drawing drawn by an actual brush forms a natural soft boundary (hereinafter referred to as a soft edge) due to a slight mixture of the color of the normal brush and the color of the paper. In the image editing / creating device using the stylus pen, in order to realize the soft edge of the brush as described above,
It is essential to apply so-called soft edge processing to the video signal.

By the way, as a soft edge processing method in this kind of image editing / creating apparatus, a technique has been developed in which the degree of the soft edge processing itself is changed by the writing pressure of the stylus pen and the soft edge processing is fed back. The soft edge processing method disclosed in Japanese Patent Laid-Open No. 62-35980 is capable of completely simulating various existing drawing tools (brush, pen, etc.) to some extent, Various pen touches can be achieved to the extent that they are almost satisfactory, and they have excellent effects.

However, in general, in the process of drawing or modifying a picture, in order to completely realize the delicate pen touch of a drawing tool such as a brush, soft edge processing of It is a more important requirement to change the pen thickness by the pen pressure of the stylus pen, rather than changing the degree itself and feeding this back.

That is, in the real world of painting, even if the same brush and the same color are used, the touch of the brush will be greatly different depending on what is drawn in the painting (for example, when drawing a painting on paper. The brush touch is about twice as different as when drawing on cloth). Therefore, in order to simulate the brush completely,
Not only changing the degree of soft edge processing by writing pressure,
It is necessary to process the changes in the thickness of the writing due to the writing pressure and the texture of the drawing material, etc., and only the degree of soft edge processing is changed according to the writing pressure, and this is fed back. The conventional soft edge processing method has a drawback in that the drawing tool cannot be completely simulated or the delicate brush touch of the drawing tool cannot be better realized.

Also, with the conventional soft edge processing method, it is extremely difficult to perform soft edge processing that follows the high speed movement of the stylus pen, and as a result, the pen movement speed can be kept below a certain speed or expensive electronic The drawback is that it requires a device.

(Problems to be Solved by the Invention) The present invention has the above-mentioned problem in the conventional image editing and creation, that is, the number of stylus pens that can be selectively used is limited, and it is difficult to obtain a desired pen touch. , It is difficult to make small corrections smoothly, it is difficult to completely simulate drawing tools and brush strokes, and it is difficult to speed up soft edge processing, so it follows the movement speed of the stylus pen. This is an image editing / creating apparatus that solves problems such as difficulty in realizing the above-mentioned soft edge, and can form high-quality drawing on the display in real time without using a lot of expensive devices. In addition, the present invention provides an image editing / creating method.

(Means for Solving the Problems) The inventor carefully observes the painter's drawing work and painting correction work, and even from this, in drawing and correction using actual drawing materials (paper and brush). It was learned that the painter skillfully draws and corrects fine and thick parts by variously using the direction of the brush and the strength (writing pressure) of the brush. In particular, there are many cases in which drawing and correction are performed by changing the strength (writing pressure) of the brush, so even in editing and creating an electronic image, soft edge processing (density) from drawing pressure to drawing Rather than directly determining the degree, determining the thickness of the brush (the thickness of the line of the drawn image) from the writing pressure,
It turns out that it should be done first. In other words, how a natural drawn image can be realized on an electronic device depends on how the pen thickness is adjusted by keeping the soft edge of the brush tip in a way that follows the movement speed of the stylus pen. It turned out to vary or depend on.

The present invention was developed based on the above observations and analysis results, and the pen writing pressure from the stylus pen is fed back to the arithmetic processing unit to follow the speed of the stylus pen operated by the operator. The basic contents are to smoothly change the thickness and to apply the drawing size variable type anti-aliasing process to the drawing data signal.

The present invention represents a stylus pen that generates a signal that represents a writing pressure value in response to an operator's operation, a position input unit that generates a signal that represents the coordinate value of the stylus pen, and a drawing tool simulated by the stylus pen. An image editing / creating apparatus comprising: a drawing data storage device for storing a drawing pattern; a frame storage device for storing image data to be displayed; and an image display device for displaying image data stored in the frame storage device. The position input device includes a digitizer that represents a coordinate value corresponding to the position of the stylus pen with a finer resolution than the coordinate value that represents a pixel in the image area displayed by the image display device, and the stylus pen and the position input device. Area corresponding to the pen thickness of the drawing pattern based on the pen pressure value and the coordinate value in response to the signal from The drawing front-end processor that calculates the center of the circle and the circle radius b, and the calculation value Z for performing the anti-aliasing process corresponding to the drawing tool simulated by the stylus pen are calculated from the circumference of the circle. Z value table stored in advance as a one-dimensional array corresponding to the distance c, and the area of the circle in the frame storage device in response to the center of the circle and the circle radius b from the circle drawing front-end processor. A drawing address processor that calculates a drawing address that represents a storage area corresponding to pixels in a range calculated for each circle area, a distance a from the calculated drawing address to the center of the circle, and the distance a And the radius c of the circle, the distance c is calculated, and the calculated value c is used to refer to the Z value table. A Z operation processor for deriving an operation value Z for each corresponding pixel; original image data from a storage location in the frame storage device designated by the drawing address according to the operation value Z from the Z operation processor; An anti-aliasing processing device that performs anti-aliasing processing with drawing data from a data storage device and stores image data representing a processing result in a storage location in the frame storage device. An image editing / creating device.

Further, in the present invention, the stylus pen and the position input device generate signals representing a writing pressure value and a coordinate value of the stylus pen at regular intervals, respectively, and the drawing front-end processor continuously outputs from the position input device. It is characterized in that each interpolation value is calculated between the pen pressure value and the coordinate value that are input by inputting, and a calculation value having a circle radius b and a center coordinate of the circle corresponding to the interpolation value is derived.

Furthermore, the present invention corresponds to a drawing pattern expressed by a drawing tool simulated by a stylus pen,
Prepare a Z value table that records the calculated value Z for anti-aliasing processing as a one-dimensional array corresponding to the distance c, and operate a stylus pen equipped with a mechanism for detecting pen writing pressure on the digitizer, A signal representing the writing pressure value from the stylus pen and a signal representing the coordinate value indicated by the tip of the stylus pen from the digitizer are generated, and the writing pressure value and the coordinate value are arithmetically processed to correspond to the writing thickness. The center of the circle indicating the area and the circle radius b are respectively calculated, and in the storage area corresponding to the pixels in the range including the area of the circle and calculated for each circle area, the center coordinates of the circle from each pixel The distance a to the position and the distance c as the difference between the distance a and the circle radius b are respectively calculated, and the Z value table is referred using the distance c, and the calculated value Z corresponding to the distance c is used. Is being displayed For the original image data,
An image editing / creating method is characterized in that, when a drawing pattern expressed by a drawing tool simulated by a stylus pen is overwritten, anti-aliasing processing is applied to a circular edge portion of the circle.

(Operation) According to the present invention, based on the writing pressure value from the stylus pen and the coordinate value from the position input means, the drawing front-end processor indicates a circle corresponding to the writing thickness based on the writing pressure value. The center and the circle radius b are calculated respectively. Corresponding to the drawing address derived from the drawing address processor, the Z arithmetic processor calculates the distance a from each pixel to the center of the circle, and uses the distance c between the distance a and the circle radius b to calculate the Z value. The calculated value Z is derived by referring to the table. In the Z value table, a calculated value Z for performing anti-aliasing processing corresponding to each drawing tool simulated by the stylus pen is recorded in advance as a one-dimensional array corresponding to the distance c. For example, like a hard pencil,
The slope of the change of the calculated value Z with the increase of the distance c is different from the case of a soft brush. Depending on the writing pressure, the state of change of the calculated value Z does not change, but the position where the change starts changes. The anti-aliasing processing device performs the anti-aliasing process between the original image data and the drawing data according to the calculated value Z, and stores the image data representing the result in the storage location specified by the drawing address in the frame storage device. Remember.

Although the thickness of the brush of the drawing tool to be simulated changes due to the change of the writing pressure value, the antialiasing process of the peripheral portion is similarly performed according to the Z value table. That is, the writing tool does not change the characteristics of the drawing tool.

Further, according to the invention, the drawing front-end processor calculates the interpolation value for the writing pressure value and the coordinate value, and also calculates the center of the circle and the circle radius b for the interpolation value. This allows a smooth simulation of the drawing tool.

Furthermore, according to the present invention, by referring to the one-dimensional Z value table using the distance c, the anti-aliasing process can be quickly performed, and the drawing tool can be effectively simulated.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 6.

FIG. 1 is a block diagram showing a configuration of an image editing / creating apparatus according to the present invention. The image editing / creating apparatus includes an input device (digitizer) 1 such as a stylus pen, a keyboard, a tacky tablet, a main processor 2 and a drawing front. It is composed of an end processor 3, a drawing address calculation processor 4, a Z calculation processor 5, a frame storage device 6, an anti-aliasing processing device 7, a drawing data storage device 8, an image display device 9, and the like.

The pen coordinate value and pen writing pressure value of the stylus pen operated by the operator are continuously output from the digitizer 1 at regular intervals, and the output data is the main processor 2
Is input to the drawing front-end processor 3, respectively.

The main processor 2 processes the pen coordinate value from the digitizer 1, determines a command from the contents of the menu, and sets the data corresponding to the command in each processor 3 and 4. When executing a command relating to pen drawing, the pen coordinate value is processed in the drawing front-end processor 3 described later in order to realize high speed. Further, in the main processor 2, processing such as cursor display and keyboard sensing is performed.

As described above, the drawing front-end processor 3 processes the pen coordinate values X and Y and the pen writing pressure value Z at the time of executing a command relating to pen drawing.

If the stylus pen moves quickly by the operator, it becomes difficult to trace the pen trajectory sufficiently by the coordinate output of the digitizer 1 due to the processing speed of the digitizer 1, and the output coordinate data is continuous. However, it will be discretized.

In order to avoid the above-mentioned inconvenience, the processor 3 performs so-called interpolation processing of the input data. FIG. 2 shows an example of the interpolation processing. Pen coordinate value data (Xo · Yo) and (X ₁ ·
Since Y ₁₎ and a pen brush pressure value data (Zo) and (Z _1), the interpolation value (Xi · Yi · Zi) are calculated. By performing the interpolation process, the coordinate data can be continuously generated from the digitizer 1, and the smooth movement of the stylus pen can be simulated.

The calculated interpolation values (Xi, Yi, Zi) have the contents corresponding to the center coordinate value of the circle drawing unit and the radius of the circle, and the drawing address calculation processor 4 and the Z value calculation processor for each circle drawing unit. 5 is transferred.

The drawing address processor 4 supplies a so-called DMA address to the frame storage device 6 corresponding to the coordinate value data of the digitizer 1. Further, the processor 4 calculates the address integer data Pn for each circle drawing unit and inputs this to the Z calculation processor 5.

As shown in FIG. 3, the Z operation processor 5 calculates the center coordinate value of the circle drawing unit relatively corresponding in the digitizer coordinates from the address integer data Pn value input from the drawing address operation processor 4. , The Pn
The center coordinate value of the circle drawing unit corresponding relatively to the value point and the digitizer coordinate is calculated, and the distance a to the circle center designated by the digitizer coordinate is calculated at the Pn value point, and further the distance a And the drawing radius b
Calculate ab. Further, the Z arithmetic processor 5 corresponds to the drawing radius by referring to the table as shown in FIG. 5A from the calculated c value (that is, the value corresponding to the pen thickness proportional to the pen writing pressure). The Z value is obtained and the calculated value Z is output to the anti-aliasing processing device 7.

The arithmetic unit of the Z arithmetic processor 5 is configured by so-called pipeline formation, and a real-time operation with no practical problems is performed.

It should be noted that the reference table is prepared in 3 to 5 types in which the c value has a practically necessary width (for example, c = ± 100), and the type of the reference table to be applied depends on the operator at the command level. It is selected appropriately, and this changes the degree of soft edge processing.

In the present invention, as described above, the Z arithmetic processor 5
Since the c value in Fig. 3 is calculated and the Z value corresponding to the c value is calculated by referring to the table, the Z value for the c value within the practically necessary width (for example, c = ± 100). It is only necessary to prepare one set of table of, and by creating one set of reference tables, the pen thickness and brush soft edge processing calculation that follows the moving speed of the stylus pen, which could not be realized in the past, can be performed. , Can be realized without using expensive parts.

On the other hand, for each circle drawing unit, the radius b and the center coordinate value thereof are all made into a table, the Z value is previously written in the memory as image data, and the processing by the Z arithmetic processor 5 of the present invention is performed by referring to the table. In order to realize the same function, as will be described later, the required Z-value pattern image data becomes enormous, which makes practical use impossible.

That is, suppose now that the entire radius range from 1 to 512 is prepared as a pattern, and if a resolution of 0.25 is set as the accuracy required for practical use, 512 / 0.25 = Z corresponding to 2047 kinds of radii. A value pattern is needed. Also,
Regarding the coordinates of the center point, a resolution of 0.25 must be taken for each of X and Y, and the pattern image data of the Z value must be prepared independently for the designation of a decimal point or less. Therefore, the resolution is 0.25 in X and Y coordinates.
Then, the number of possible center point coordinates is 16 as shown in FIG. 4, and pattern image data with 2047 types of radii are required for each center point coordinate.

As a result, the total number of required pattern image data is 2047 × 16 = 32752 patterns, and if five types of Z value distribution patterns are prepared for this, a total of 32752 × 5 = 1
63760 types of Z-value pattern image data are required.

As described above, in the case of the system in which all of them are referred to the table for each circle drawing unit, the required Z value pattern image data becomes too large, and it cannot be realized at all.

The frame storage device 6 is a RAM having a multi-port access structure, and at the same time when the image display data is output to the image display device 9, the image data is read from and written to the anti-aliasing processing device 7.

The anti-aliasing processing device 7 is composed of two sets of multipliers and adders, and the original image data A from the frame storage device 6 has a (1-Z) value based on the Z value from the Z arithmetic processor 5. And the drawing data B from the drawing data storage 8 is multiplied by Z, and the image display data D appropriately soft-edged by the Z value corresponding to the thickness of the brush is input to the frame storage device 6. It

That is, the pig cell data A corresponding to the address from the drawing address arithmetic processor 4 is read from the frame storage device 6, and at the same time, the Z arithmetic processor 5 calculates the Z value corresponding to the address. ,
The calculated value is input to the anti-aliasing processing device 7. The result of the arithmetic processing in the processing device 7 is output to the frame storage device 6 and written as the pig cell data D at the same address as the above address.

FIG. 5B shows the anti-aliasing processing device 7.
FIG. 5C shows the state of the soft edge processing in FIG. 5C. The original image data A and the drawing data B are soft edge processed into data corresponding to the Z value reference table T.
As shown in, the anti-aliasing process is performed on the boundary of the drawing range E in the range according to the c value of the Z value reference table T.

The above-described operation is performed for the entire area designated by the drawing points (that is, the entire area of the circle drawing unit), and the result is overwritten for each drawing point interpolated by the drawing front-end processor 3. And is output from the frame storage device 6 to the image display device 9.

FIG. 6 shows the state of the three-dimensional distribution of Z values under continuous drawing processing, in which the drawing data B and the original image data A are soft edge processed along a smooth Z value distribution, A smooth drawing expression from a thin line to a thick line, which is a characteristic of drawing with a brush, is electronically realized.

(Effect of the Invention) As described above, according to the present invention, a circle indicating a region corresponding to a writing thickness based on a writing pressure value based on the writing pressure value from the stylus pen and the coordinate value from the position input means. And the radius b of the circle are calculated. The distance a from each pixel to the center of the circle is calculated corresponding to the drawing address derived from the drawing address processor, and the Z value table is referred using the distance c which is the difference between the distance a and the circle radius b. The calculated value Z is derived. In the Z value table, a calculated value Z for performing antialiasing processing corresponding to each drawing tool simulated by the stylus pen is recorded in advance as a one-dimensional array corresponding to the distance c. For example, between a hard pencil and a soft brush,
The inclination state of the change of the calculated value Z with the increase of the distance c is different. Depending on the writing pressure, the state of change of the calculated value Z does not change, but the position where the change starts changes. Although the thickness of the brush of the drawing tool to be simulated changes due to the change of the writing pressure value, the antialiasing process of the peripheral portion is similarly performed according to the Z value table. That is, the writing tool does not change the characteristics of the drawing tool.

Further, according to the present invention, the interpolation value for the writing pressure value and the coordinate value is calculated, and the center of the circle and the circle radius b are calculated for the interpolation value.
And are calculated. This makes it possible to simulate a drawing tool whose thickness changes smoothly.

Further, according to the present invention, by referring to the one-dimensional Z value table using the distance c, the anti-aliasing process can be quickly performed, and the drawing tool can be effectively simulated.

As described above, the present invention can realize an extremely high-quality drawn image in real time without using an expensive device, and has excellent practical utility.

[Brief description of drawings]

FIG. 1 is a block diagram showing the basic configuration of the image editing / creating apparatus according to the present invention. FIG. 2 is a schematic explanatory diagram of interpolation processing in the rendering front-end processor. FIG. 3 is an explanatory diagram of the arithmetic processing contents of the z arithmetic processor. FIG. 4 is an explanatory diagram showing coordinate points in a real number calculation. FIG. 5 (a) shows an example of a Z value reference table in the z arithmetic processor, and FIG. 5 (b) and FIG.
FIG. 6C is an explanatory diagram showing the data distribution and the anti-aliasing processing range in the anti-aliasing processing. FIG. 6 is a drawing showing the distribution of Z values in the continuous drawing process. DESCRIPTION OF SYMBOLS 1 ... Input device (digitizer) 2 ... Main processor 3 ... Drawing front-end processor 4 ... Drawing address arithmetic processor 5 ... Z arithmetic processor 6 ... Frame storage device 7 ... Anti-aliasing processing device 8 ... Drawing data storage device 9 ... Image display apparatus

Claims (3)

(57) [Claims] 1. A stylus pen for generating a signal indicating a writing pressure value in response to an operator's operation, a position input means for generating a signal indicating a coordinate value of the stylus pen, and a drawing tool simulated by the stylus pen. In an image editing / creating apparatus including a drawing data storage device that stores a drawing pattern to be stored, a frame storage device that stores image data to be displayed, and an image display device that displays the image data stored in the frame storage device, The position input device includes a digitizer that represents a coordinate value corresponding to the position of the stylus pen with a resolution that is finer than the coordinate value that represents the pixel in the image area displayed by the image display device, and the stylus pen and the position input device. A region that responds to the signal from the device and corresponds to the writing thickness of the drawing pattern based on the writing pressure value and the coordinate value. Corresponding to the drawing front-end processor that calculates the center of the circle indicating the circle and the circle radius b, and the drawing tool simulated by the stylus pen. A Z value table stored in advance as a one-dimensional array corresponding to the distance c from the circle drawing area, and the area of the circle in the frame storage device in response to the circle center and the circle radius b from the circle drawing front-end processor. A drawing address processor for calculating a drawing address representing a storage area corresponding to pixels in a range calculated for each circle area, a distance a from the calculated drawing address to the center of the circle, and the distance The distance c is calculated as the difference between a and the radius b of the circle, and the calculated value c is used to calculate the Z
A Z arithmetic processor for deriving an arithmetic value Z for each pixel corresponding to the drawing address by referring to a value table, and a Z arithmetic processor in the frame storage device designated by the drawing address according to the arithmetic value Z from the Z arithmetic processor. Anti-aliasing for performing anti-aliasing processing between the original image data from the storage location and the drawing data from the drawing data storage apparatus, and storing the image data representing the processing result in the storage location in the frame storage apparatus. An image editing / creating apparatus including a processing apparatus. 2. The stylus pen and the position input device generate signals representing a pen pressure value and a coordinate value of the stylus pen, respectively, at regular intervals, and the drawing front-end processor continuously outputs from the position input device. The interpolation value is calculated between the pen pressure value and the coordinate value that are input by calculating the center of the circle and the circle radius b corresponding to the interpolation value, respectively.
The described image editing / creating apparatus. 3. A calculated value Z for anti-aliasing processing corresponding to a distance c corresponding to a drawing pattern expressed by a drawing tool simulated by a stylus pen.
Prepare a Z value table to be recorded as an array of dimensions, operate a stylus pen equipped with a mechanism for detecting pen writing pressure on the digitizer, and output a signal indicating the writing pressure value from the stylus pen and the stylus pen from the digitizer. Generates a signal representing the coordinate value indicated by the tip of the, and calculates the writing pressure value and the coordinate value to calculate the center of the circle indicating the area corresponding to the writing thickness and the circle radius b, respectively. A distance a from each pixel to the position of the center coordinates of the circle, and the distance a and the circle radius b in the storage area corresponding to the pixels in the range calculated for each circle area including the circle area. The distance c as the difference between the two is calculated, the Z value table is referenced using the distance c, and the calculated value Z corresponding to the distance c is used to simulate the original image data being displayed with the stylus pen. An image editing / creating method, characterized in that an antialiasing process is applied to a peripheral portion of the circle when the drawing pattern expressed by the drawing tool is overwritten.