JPH031688B2 - - Google Patents

Description

[Detailed Description of the Invention] (1) Description of the field to which the invention pertains The present invention provides a method for partially erasing a drawn image, particularly in a modification operation which is one of the drawing data input operations. The present invention relates to an erasing method that partially erases drawing data by setting an erasing area based on an erasing curve specified by an operator.

(2) Description of conventional technology An erasing curve is drawn over the drawing data to indicate a part of the drawing to be erased, and the part of the drawing is erased based on this curve. In the conventional method, the erasing curve was constructed on the assumption that it included the drawing data to be erased, so if an erasing curve was input in the form of, for example, erasing a character with two straight lines, That is, if the erasing curve does not cover the entire area of the drawing data to be erased, there is a drawback that unerased areas may be left behind.

(3) Purpose of the Invention In order to eliminate this drawback, the present invention searches the surrounding drawing data after determining the erasing area from the erasing curve, and creates a polygon by connecting the critical points of the remaining drawing data. The purpose is to eliminate any unerased material by erasing the inside of the image. The drawings will be described in detail below.

(4) Description of structure and operation of the invention FIG. 1 shows an example of the structure of a device according to the invention, in which 1 is a digitizer, 2 is a control section, 3 is a screen image buffer, and 4 is a CRT monitor. The coordinate data input from the digitizer 1 is converted into image information by the control unit 2, and the screen image buffer 3
This image is displayed on the CRT monitor 4. Processing on the CRT monitor is performed on the screen image buffer 3.

The control unit 2 performs processing as shown in the illustrated implementation flow. That is, the erasure area is set based on the erasure curve input by the operator (processing A). Check the width of this erased area and if it is less than the given length,
A search for image data points around the erased area is performed (processing B). To search for an image data point, first, dots on the screen image buffer that are at a given distance from the existing erasing area and parallel to the erasing area are sequentially searched for the image data point.
If there is an image data point, an area outside of it is searched in a similar manner. A search for image data points is performed between the position where the image data points disappear and the existing erasure area, and the outermost point is determined as a critical point (processing C). A polygonal area formed by sequentially connecting these critical points is erased as a new erasure area (processing D).

FIG. 2 is an example of searching for image data points, where 5 is an existing erase area, 6 to 8 are data areas of the screen image buffer 3 to be searched, and 9 to 11 and 12' are critical point images. - Data point 12 is simply an image data point because the coordinates of the line segment connected to the point are directed upward. A search is made for an image data point in the data area 6 of the screen image buffer 3 to be searched, which is located at a given distance from the existing erase area 5. In this figure, since image data point 9 and image data point 12 are present, the image data point in data area 7 of screen image buffer 3 which is further outside by a given distance is searched. In this figure, since the image data point does not exist after searching, the data area 8, which is one dot away from the outermost data area 7 where the image data point does not exist, is set as the data area to be searched. Set and search for image data points. Repeat this search operation up to the erase area and
Search for an image data point that should be a critical point such as 2'.

FIG. 3 is an example of setting the boundary of a polygon that connects critical points to form an erasure area, where 13 is the search direction of the critical point, 14 is the existing erasure area, and 15 to 20 and 21 to 24 are the numbers. The critical points are numbered in ascending order. First, the existing erase area 14
The critical points 15 to 20 and 21 to 24 on both sides of are connected in ascending order, respectively. Thereafter, points 15 and 21, which are the starting points of the critical point search direction 13, and points 20 and 24, which are the ending points, are respectively connected to form a polygon. This constructed polygon provides the boundary of the erasure area. When actually erasing, the drawing existing inside this area is erased. That is, the drawings such as "Aiu" shown in FIG. 2 are erased.

(5) Explanation of Effects As explained above, according to the present invention, when performing partial erasure to erase a part of drawing data, a primary erasure area is set based on the coordinate data of the erasure curve inputted from the digitizer. , when this erasing area is less than a given width, the erasing area is expanded to obtain a true erasing area, so when erasing characters etc., two or one There is an advantage that even when a drawing erasing portion is designated by an erasing curve such as a straight line, erasing within the area can be easily performed.

[Brief explanation of the drawing]

FIG. 1 is an example of the device configuration of the present invention, FIG. 2 is an explanatory diagram illustrating a mode of setting a critical point according to the present invention,
FIG. 3 shows an example of setting a polygon according to the present invention. In the figure, 1 is a digitizer, 2 is a control unit, 3 is a screen image buffer, 4 is a CRT monitor, 9,
10, 11, 12', 15, 16, 17, 18,
19, 20, 21, 22, 23, and 24 represent critical points, respectively.

Claims (1)

[Scope of Claims] 1. At least a digitizer that can digitally encode and input handwritten characters, figures, pictures, etc., a display section that displays this input digital signal, and a screen image buffer that develops and temporarily stores display data as image information. , represents a handwritten input figure that specifies an area to be erased when partially correcting a drawing displayed on the display unit by handwritten input in a device having a control unit that processes digital signals and data. For drawing an image related to the drawing data to be erased specified by the erasure curve, the drawing around the image of the erasure curve developed on the screen image buffer is searched, and the critical point on the drawing corresponding to the erasure area is found. A partial erasing method for a drawn image characterized by determining an erasing area by finding multiple points and connecting them in order. 2 The above critical point is an image data point representing a line drawing that constitutes drawing data parallel to the erasing area at a given processing location from the image of the screen image buffer when the erasing area does not have a given width. If there is an image data point, search the area outside of it using the same operation, and search for image data points from the position where the image data point disappears to the existing erase area. conduct,
2. The method for partially erasing a drawn image according to claim 1, wherein the outermost shell point is determined as the critical point.