JPH0434791B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a drawn image display device. In particular, it relates to means for partially erasing a drawn image.

〔overview〕

The present invention provides a drawing image display device in which a drawing trajectory caused by contact is displayed as an image, which provides an erasure area of the image by a drawing trajectory caused by contact,
By approximating this erasing area with a rectangular collection area surrounded by a straight line circumscribing this drawing locus and a straight line perpendicular to this line, and erasing the image within this approximated area, the displayed image can be This is a simplified configuration of a device that can erase a desired area of an image.

[Conventional technology]

A conventional graphic image display device that displays a graphic image corresponding to a contact trajectory on a flat plate must be equipped with correspondingly large-scale software in order to partially erase a graphic image that has already been displayed.

[Problem that the invention seeks to solve]

In such a conventional device, the device becomes expensive and the processing time becomes long in order to correct a drawn image that has already been displayed. In particular, software for accurately capturing a drawn image of a designated area has the drawback of becoming complicated.

The present invention aims to eliminate such drawbacks, and aims to simplify the construction of a drawn image display device that can partially erase a drawn image that has already been displayed in order to modify it.

[Principle of the invention]

The principle of the present invention will be explained based on FIGS. 3 and 4.

First, the image storage device 15 stores the locus coordinates of the drawn image input from the contact position detection device 1, and the display device 6 visually displays them.

Now, the trajectory coordinates of the drawn image are input to the contact position coordinate detection device 10, the zone determination means 11 determines the coordinates to which this trajectory coordinate belongs, and the zone maximum and minimum coordinate determination means 12 determines whether this trajectory coordinate is within this zone. If the coordinates are the largest or smallest than the previously detected coordinates, the maximum or minimum coordinates within the zone are stored in the storage device 13.
is memorized. After all the coordinates of the locus indicating the erased position have been detected, an image is stored corresponding to a rectangular area surrounded by the zone boundary line and the maximum and minimum coordinates in this zone stored in the zone maximum and minimum coordinate storage device 13. The drawn image of the area within the device 15 is erased by the rectangular area eraser 14.

Next, the principle of the process of erasing an area within the image storage device 15 will be explained based on FIG. As shown in FIG. 4, the input position is represented by coordinates (x, y) on a two-dimensional plane indicated by the X-axis and Y-axis. First, the Y axis is n
zone 100. Next, a zone z _i where z _il ≦y<z _ih is determined for the input position coordinates (x, y). However, z _il and z _ih are the y-coordinate values of the lower and upper boundaries of zone z _i , respectively.

For the obtained z _i , the maximum value x _inax and minimum value x _inio corresponding to z _i in the zone maximum and minimum value storage device 13 are compared with the input coordinate x, and when x>x _inax , x _inax , and when x<x _inio , x is made x _inio .

After the trajectory surrounding the erased area is completed, x _nio and
For the zone where both x _nax exist, z _il , z _ih ,
The area in the image storage device 15 corresponding to the rectangular portion consisting of the four sides x _inio and x _inax is erased. Fourth
In the figure, a closed curve 50 is a figure that provides input position coordinates, and a hatched area surrounded by a concave polygon 75 is an area to be erased.

[Means for solving problems]

The present invention provides a position coordinate detection device that detects a two-dimensional position signal from a contact position coordinate specifying means that specifies two-dimensional coordinates on a flat plate by contact, and a drawing of the position signal according to the movement of the position signal. The apparatus includes a calculation means for calculating a trajectory, and a display means for displaying the drawing trajectory, and the calculation means is surrounded by the drawing trajectory of the position signal input to the position coordinate detection device when an erase mode is specified. A drawing image display device including means for erasing a portion, and as a means for solving the above-mentioned problem, the erasing means is an area defined by a straight line perpendicular to one coordinate axis of the two-dimensional coordinates of the position signal. A region identification means for identifying the region, and a region identified by the region identification means,
an area defining means for approximately defining an area as an area defined by a straight line passing through a point indicating the maximum value and minimum value of the other coordinate of the position signal included in this area and parallel to one coordinate axis; and means for erasing the displayed image within the area defined by the defining means.

[Effect]

When the region of the drawn image to be erased is given as a locus due to contact, this locus is cut by a straight line perpendicular to one of the coordinate axes, and a segmented figure is generated. Furthermore, passing through the point that takes the maximum and minimum values of the other coordinates among the points on the periphery of the divided figure,
A straight line parallel to one coordinate axis is found.

The drawn image on the area within the figure, which is a collection of rectangles surrounded by these four straight lines, is erased by the drawn image erasing means.

This erasing means does not have a shape that exactly corresponds to the specified area, but by making this approximation,
The software is significantly simplified and the execution processing time is reduced. Depending on the intended use of the device, the approximation can be set to a level that poses no problem in practice.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS A device according to an embodiment of the present invention will be explained below based on the drawings.

FIG. 1 is a block diagram showing the structure of this embodiment of the apparatus. FIG. 2 is a flowchart showing the operation of this embodiment apparatus.

First, the configuration of this embodiment device will be explained based on FIG. This embodiment device includes a contact position coordinate detection device 1 and an analog-to-digital converter (hereinafter referred to as
It is called an A/D converter. )2, CPU31, RAM
32 and ROM 33, an image storage device 4, and a display device 5. The output of the contact position coordinate detection device 1 is connected to the input of the A/D converter 2, and the output of the A/D converter 2 is
It is connected to the first input of the CPU 31. CPU31
The second input/output of the CPU 31 is connected to the input/output of the RAM 32, the third input/output of the CPU 31 is connected to the input/output of the RAM 33, and the fourth input/output of the CPU 31 is connected to the first input/output of the image storage device 4. The output of the image storage device 4 is connected to the input of the display device 5.

Next, the operation of this embodiment device will be explained based on FIGS. 1 and 2. ROM33 has CPU3
A program is written to control 1.
In accordance with this program, the CPU 31 imports the X and Y coordinates from the A/D converter 2 and stores them in the RAM.
32, arithmetic processing is executed, and data is written to the image storage device 4 as necessary. In addition, the contact position coordinates detection position 1
Then, an analog electrical signal having a magnitude corresponding to the contact position coordinates is generated and supplied to the A/D converter 2.

Next, the program written in the ROM 33 will be explained based on the flowchart of FIG.

First, "0" is written into all of the zone maximum and minimum value storage table on the RAM 32 (step). Next, from the A/D converter 2, x, y
Coordinates are read (step). Continuing,
Zone number i is obtained by calculating i=y/Z ₀ (step). However, Z ₀ is the width of the zone i
is an integer value. Next, from the in-zone maximum and minimum value storage table on the RAM 32,
x _inio and x _inax are read (step). In the process from step to step, it is compared with x, and x
When <x _inio or x _inio = 0, x is assigned to x _inio , and when x>x _inax , x is assigned to x _inax . This updates the maximum and minimum values within the zone. Continuing on, the end of inputting the locus coordinates is determined (step), and in step x _inio and x _inax are taken out from the zone maximum and minimum value table for all zones, and the zone boundaries and
All data in the image storage device 4 corresponding to the area surrounded by x _inio and x _inax are set to 0 (step).

〔Effect of the invention〕

According to the present invention, a shape substantially close to the shape surrounded by the drawn image is reproduced within a reasonable execution time, and a portion of the drawn image within the range of this shape is erased. As a result, although the part to be erased is not strictly specified,
A practically useful device capable of partially erasing a displayed drawn image is obtained.

[Brief explanation of drawings]

FIG. 1 is a block configuration diagram showing the configuration of an apparatus according to an embodiment of the present invention. FIG. 2 is a flowchart showing the operation of the apparatus according to the embodiment of the present invention. FIG. 3 is a block diagram showing the principle of the present invention. FIG. 4 is a schematic diagram showing an erase area realized by the present invention. 1, 10...Touch position coordinate detection device, 2...A/D
Converter, 3... Microcomputer, 4, 15...
Image storage device, 5, 16...Display device, 11...Zone determination means, 12...Zone maximum and minimum coordinate determination means, 13...Zone maximum and minimum coordinate storage means, 14
...Rectangular area eraser.

Claims (1)

[Scope of Claims] 1. A position coordinate detection device that detects a two-dimensional position signal from a contact position coordinate specifying means that specifies two-dimensional coordinates on a flat plate by contact; The calculation means calculates the drawing locus of the signal, and the display means displays the drawing locus, and when the erase mode is specified, the computing means calculates the drawing locus of the position signal input to the position coordinate detection device. In the drawing image display device, the erasing means includes a region identifying means for identifying a region defined by a straight line perpendicular to one coordinate axis of the two-dimensional coordinates of the position signal; The area identified by this area identification means is approximated as an area defined by a straight line that passes through the points indicating the maximum and minimum values of the other coordinate of the position signal included in this area and is parallel to one coordinate axis. What is claimed is: 1. A drawn image display device comprising: a region defining means for defining a region; and a means for erasing a display image within the region defined by the region defining means.