JPS59231636A - Partial erasure system of handwritten graphic information - Google Patents

Abstract

PURPOSE:To perform partial erasure accurately even in a system equipped with plural graphic input devices by deciding on whether the partial erasure is carried out or not on the basis of input starting-point information and input ending-point information in coordinate value information on a figure. CONSTITUTION:The system is actuated and coordinate value information on a figure inputted on the pen input surface 103 of a graphic input device 100 is extracted and sent out to the arithmetic circuit 105 of a processor 101 through a signal line 107. Then, the circuit 105 stores coordinate value information on an input starting point in a video memory 106 with a partial erasure indication signal, and coordinate value information on a point which is determined as an input ending point because the pressure decreases below a threshold value is inputted in an exclusive-use address of the memory 106. Then, the circuit 105 reads the pieces of coordinate value information on the input starting point and input ending point out of the memory 106 to calculate the distance L between those two points, and decides on whether the partial erasure is performed or not on the basis of the distance. Thus, the system equipped with plural devices performs the partial erasure accurately.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to a system for displaying handwritten figures (including characters and symbols), in which a certain part (including the entire part) of an image of an input figure is erased. This is related to the erasure method.

[Technical background of the invention]

The handwritten figure display system, as shown in Fig. 1,
A graphic input device 1 that extracts the coordinate value information of a graphic including handwritten characters and symbols, a processing device 2 that processes the coordinate value information of the graphic input from the graphic input device 1, and a processor that processes the image of the graphic. 2, and a graphic output device 3 that displays based on the output of 2.

In such a system, the input portion of the graphic input device 10 is, for example, a writing input surface configured so that when pressure is applied, the coordinate values of the point to which the pressure is applied are input. The writing implement for this writing input surface is a ballpoint pen, pencil, or the like.

For example, if you place the paper 5 as shown in Figure 2A on the writing input surface mentioned above and write rXJ with a ballpoint pen, the figure rXJ
The coordinate value information reaches from the graphic input device 1 to the processing device 2,
Appropriate processing is performed by the processing device 2, and the processing results are sent to the graphic output device 3. As a result, the characters rXJ are displayed on the CRT inner surface 6 of the graphic output device 3, for example, as shown in FIG. 2B.

Here, in order to perform partial erasure, for example, if a curve 7 is drawn on the paper 5' on the writing input surface of the graphic input device 1 with a ballpoint pen as shown in FIG. 3A, the input start point S and the input end point The partial erase command for the area surrounded by the straight line t (FIG. 3B) connecting the curve 7 and the curve 7 is confirmed. Of course, in this case, the processing device 2 is notified by, for example, a switch provided in the graphic input device 1 that the input is for partial deletion. If you do this, CR1 as shown in Figure 3B
The figure in the area 8 (actually, the dashed line is not displayed) on the screen 6', which corresponds to the area surrounded by the curve 7 drawn on the paper 5' and the straight line t, is erased.

In this way, in a system in which handwritten figures are displayed on input from one figure input device 1, and partial erasure is also performed from the same figure input device 1, it is difficult to display handwritten figures on the handwritten input surface. There is no problem because the paper is placed on the paper and you can check the part you want to partially erase on the paper.

[Problems with background technology]

However, as shown in FIG. 4, there is a system in which a graphic input device 1 and a graphic input device 1' are connected to the processing device 2, and display can be performed from either of them to a single graphic output device 3. This causes the following problems.

That is, on the paper 9 on the writing input surface of the graphic input device 1, < rXYJ is written as shown in FIG. Assume that B is written as <rZJ with a ballpoint pen. Then, on the CRT image 1nI11 of the graphic output device 3, a display such as <, rXYZJ as shown in FIG. 5C is performed.

Now, assume that a request to partially erase rYJ is generated from the graphical human power device 1'. However, the paper 10 shown in FIG. 5B appears on the writing input surface of the graphic input device 1'.
is placed on the paper 10, it is difficult to know which part of the paper 10 should be surrounded by a curved line.

Attention was then directed to the CRT screen,
Unfortunately, the pressure of the ballpoint pen pressing against the writing input surface of the graphic input device [1] falls below a threshold value at which the graphic input device 1 considers it to be an input pad. For this reason,
An input point below the threshold is regarded as an input end point, and the interior of the closed curve connecting the input start point and this input end point is erased. However, the area erased here does not necessarily match the area that the operator intended to erase.
According to the area surrounded by the straight line t and the curve 7 shown in Figure 3, part of the "X" may be left unerased, and the area may have been misplaced due to focusing on the CRT screen. There was an inconvenience that even if you surrounded the area and raised the pen in the middle, that area would always be erased. Furthermore, r as above
When a more complex figure than an XYZJ figure is displayed, it becomes even more difficult to erase the desired portion.

In this situation, as shown in FIG. 6, the graphic input device 11
A handwritten figure display system consisting of a processing device 2 and a figure output device 3 and a handwritten figure display system consisting of a figure input device 1', a processing device 2' and a figure output device 3' are separated and Contact! It also occurs when

In other words, in this case, the image of the figure input from the figure human input device 1 is transmitted to the figure output device 3 and the figure output device 3.
', and the graphic image input from the graphic input device R1' is also displayed on the graphic output device 3' and the graphic output device 3, so the problem explained using FIG. 5 similarly occurs. .

[Purpose of the invention]

The present invention has been made in view of the above-described drawbacks. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a partial erasure method for handwritten graphic information that can perform accurate partial erasure even in a system where a plurality of graphic input devices are present.

[Summary of the invention]

Therefore, in the present invention, when performing partial erasure in which the coordinate value information of a figure inputted from the figure input device is processed by the processing device as partial erasure area information, input start point information in the coordinate value information of the figure and input end point information are provided. Based on the positional relationship between these two points obtained from the point information, it is determined whether or not to perform partial erasure.

[Embodiments of the invention]

Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 7 is a block diagram showing the handwritten figure display system in some detail. In the same figure, l■ is a graphic input device, 10
1 represents a processing device, and 102 represents a graphic output device. The graphic input device ftxoo is provided with a writing input surface 103,
Further, in this example, a partial erase instruction signal output circuit 104 is added. The processing unit @101 includes an arithmetic circuit 105.
and an image memory 106. Then, the system is activated and the writing input surface 103 of the graphic input device 100 is activated.
The coordinate value information of the figure input from is extracted and sent to signal line 1.
07 to the arithmetic circuit 105 of the processing device 101, and the arithmetic circuit 105 performs calculations to interpolate, for example, between the coordinate values and the coordinate area 11, and the coordinate values resulting from these calculations are stored in the image memo IJ 106. is stored in On the other hand, the graphic output device 102 constantly reads data in the image memory 106 via the signal line 108 and displays it on the CRT screen 109.

Furthermore, a partial erase instruction signal is sent to the arithmetic circuit 105 from the partial erase instruction signal output circuit 104 via a signal line 110. When this partial erase instruction signal is activated, the arithmetic circuit 105 outputs the signal #1.
The coordinate value information input via 07 is treated as partial erasure area information.

That is, the coordinates (x, y) of the chain input surface 103 are as shown in FIG.
Assume that there are up to (am-a + n-1) as shown in FIG.
Assuming that an area is prepared in which mn addresses exist and each address has a bits as shown in FIG.
05 stores coordinate value information in correspondence with each address of one image memory 106, with each a pit in the X-axis direction as one detail.

For example, a coordinate point whose X coordinate is q and whose X coordinate is the rth coordinate of the p group is stored by the arithmetic circuit 105 in association with the rth bit of the qm+p address in the image memory 106. At this time, if the partial erasure instruction signal is active, the arithmetic circuit 105 executes the input starting point sent by the graphic input device 100, as shown in steps 201 to 203 of chart 70 in FIG. The coordinate value information is stored in a dedicated address in the image memory 106, and the input point of the figure (the input point on the way from the input start point to the input end point) is stored in the dedicated address in the image memory 106.
For example, the coordinate value information corresponding to is stored in the image memory 106 as is (or after being thinned out), and the coordinate value information of the point where the pressure has fallen below the threshold and is regarded as the input end point is stored @ The data is stored at a dedicated address in the image memory 106.

Next, in step 204, the arithmetic circuit 105 reads out the coordinate value information of the input start point and the coordinate value information of the input end point in the image memo I7106, and calculates the distance between these two points. That is, the coordinate value of the input start point is (XI + y
x ), and the coordinate value of the input end point is (X2 + 72), the arithmetic circuit 105 calculates L=(xl-xl)2+(V@-3'2)''. In step 205, the arithmetic operation The circuit 105 compares this distance ML with a predetermined 1iFj i, and if L≧i, returns to step 201; otherwise, returns to step 2.
Proceed to 06. Here, the predetermined value i is a value determined by factors such as the number of extraction points mna and system requirements. For example, if the area of the Chinese input surface 1030 is constant, if the number of extraction points mna is large, In this case, if r9 I have no choice but to. Furthermore, if the predetermined value i is fixed, problems may occur due to variations in the area of the erased region. However, if the area of the erase area is narrow, the distance between the two points mentioned above will inevitably become shorter, so if the predetermined value i is not made small, all input will be erased no matter what. In particular, when the area of the erase area is large, the distance mL between the two points mentioned above is often increased, so unless the 191 constant value i is increased, all inputs other than partial erase will be invalid. Become.

Therefore, considering such a case, the erase area (curve 7 in FIG. 3B and the straight line M
The area S or l'S of the area (the area surrounded by It) is calculated. A publicly known method is used for this calculation.

Next, as shown in parentheses in step 205, the obtained S or box is given a constant ε that takes into account the above-mentioned extraction/score m na a, etc.
εS or an ε function multiplied by is used as the predetermined value i.

If the comparison result in step 205 is that L is smaller than the predetermined value i, the process proceeds to step 20G, and in step 206, the arithmetic circuit 105 erases the figure in the erase area using a predetermined erase algorithm. conduct.

As a result, the corresponding image on the OCRT screen 109 of the graphic output device 102 is erased, and more accurate partial erasure is achieved.

〔Effect of the invention〕

As explained above, according to the present invention, when performing partial erasure, the processing device determines the validity or invalidity of the input, so graphics are input using a large number of graphic input devices, and the user input You can erase figures other than those written (other than those written on the paper on your Chinese input surface) according to your intention. In other words, even if the user's attention is taken away by the CRT screen and the input is unintentionally deemed to have ended, the data will not be erased, making it effective for partially erasing complex figures by redoing the steps □.

Further, if the present invention is applied to a system in which a line indicating a partial erasure area (dotted chain 1!lj in FIG. 3B) is displayed on a CRT screen of a graphic output device, partial erasure can be performed more effectively.

[Brief explanation of the drawing]

Figures 1, 4, and 6 are block diagrams of the handwritten figure display system, Figures 2 and 3 are conceptual diagrams for explaining the erasing method by the system in Figure 1, and Figure 5 is a block diagram of the handwritten figure display system. A conceptual diagram for explaining the erasing method by the system of FIG. 4,
FIG. 7 is a block diagram of a system using the method of the present invention,
FIG. 8 is a diagram showing the correspondence between the coordinates of the compost input surface in FIG. 7 and the image memory, and FIG. 9 is a flowchart showing the processing according to the embodiment of the present invention. 100... Graphic input device ioi... Processing device 1
02... Graphic output device 104... Partial erasure instruction signal output circuit agent patent attorney
Book 1) Takashi Figure 7 Figure 8 Figure 9

Claims (4)

[Claims] (1) A graphic input device that extracts coordinate value information of a graphic including handwritten characters and symbols; a processing device that processes the coordinate value information of a graphic input from the graphic input device; In a handwritten figure display system comprising a figure output device that displays a figure based on the output of a processing device, coordinate value information of a figure inputted from the figure input device is used as partial erasure area information for partial erasure processing in the processing device. Upon execution, it is determined whether or not to perform partial erasure based on the positional relationship between these two points, which is obtained from input start point information and input end point information in the coordinate value information of the figure. A method for partially erasing handwritten graphic information. (2) The distance between these two points is determined from the input start point information and the input end point information, and partial deletion is performed only when the distance is smaller than a predetermined value. (Partial erasure method of handwritten figure information described in Section 1. (3) The predetermined value is a value obtained by multiplying the square root of the area formed by the curve from the input start point to the input end point of the figure by a certain value.
) Partial erasure method of handwritten figure information described in section 2. (4) The predetermined value is a value obtained by multiplying the area formed by the curve from the input start point to the input end point by a certain value.
) Partial erasure method of handwritten figure information described in section 2.