1. Field of Invention
The invention relates to a stroke data editing device for editing stroke data indicative of one or more strokes of a coordinate input device on an input plane provided in a coordinate reader. The invention also relates to a method for editing the stroke data and to a computer-readable memory medium that stores a stroke data editing program for editing the stroke data.
2. Description of Related Art
Stroke data editing systems comprising stroke data generating devices (such as tablets) and stroke data editing devices are known. The stroke data generating systems ordinarily comprise coordinate input devices for inputting coordinates thereof, coordinate readers for reading the input coordinates of the coordinate input devices, stroke data generators for generating, based on the read coordinates, the stroke data indicating strokes of the coordinate input devices, and stroke data editing devices for editing the stroke data.
The strokes, defined by the coordinates of the coordinate input devices, indicate characters, numerals and/or figures, which may constitute a word and/or a line. The conventional stroke data editing devices manage and edit the stroke data on such a block basis (namely, a character, a word, a line or a figure basis).
For example, U.S. Pat. No. 5,796,866 discloses a stroke data editing system that comprises a tablet and a group management unit for managing group data representative of a plurality of strokes within one group. Each group includes at least one of a character group indicating a handwritten character, a word group indicating a handwritten word, a line group consisting of a plurality of handwritten characters and/or words, and a figure group indicating a handwritten figure.
The stroke data editing devices ordinarily comprise displays that display the strokes based on the stroke data thereon. The conventional stroke data editing devices retrieve and edit the stroke data, when the corresponding strokes are designated by an editing area on the displays.
However, if the editing area includes strokes to be edited (referred to as target strokes) and strokes not to be edited (referred to as non-target strokes), the stroke data editing devices retrieve the stroke data corresponding to both the target strokes and the non-target strokes, regardless of the operators' intentions. (Herein, the stroke data to be edited is referred to as target stroke data, while the stroke data not to be edited is referred to as non-target stroke data.) In other words, the conventional stroke data editing devices can not retrieve the target stroke data while not retrieving the non-target stroke data. The conventional stroke data editing devices result in both the target and the non-target stroke data being edited.
For example, it is assumed that an editing area is set including a black-colored character train and a red-colored character train. Even if it is intended to edit only the stroke data of the black-colored character train, the conventional stroke data editing devices retrieve the stroke data, not only of the black-colored character train, but of the red-colored character train.
It is assumed, as another example, that an editing area is set including character trains handwritten by two people. Even if it is intended to edit only the stroke data of the character train written by one person, the conventional stroke data editing devices will also retrieve the stroke data of the character train written by another person.
It is further assumed that character trains “ABC” and “DEF” are written in two lines: “ABC” in an upper line and “DEF” in a lower line, as shown in FIG. 14. In FIG. 14, an editing area T4 is set including the character trains “ABC” and one stroke of the character “E”. Thus, even if it is intended to edit only the stroke data of the character train “ABC”, the stroke data editing devices retrieve, not only the stroke data of the character train “ABC”, but also the stroke data of the one stroke of the character “E” simultaneously, and can not withdraw the stroke data of the one stroke of the character “E” from editing.
Moreover, the stroke data editing devices store the stroke data in a memory so as to play back the stroke data on the displays at any time, even if the corresponding strokes are erased from the input planes. For example, the strokes written by pens are erased by using erasers, but the stroke data of the erased strokes is stored in the memory. For that purpose, when erasing the strokes of the pens by using the erasers, the stroke data editing devices recognize tracks of the erasers as new strokes, and then, input and store new stroke data indicating the strokes of the erasers. (Herein, the stroke data of the pen is referred to as writing stroke data, while the stroke data of the eraser is referred to as erasing stroke data. Also, the stroke of the pen is referred to as writing stroke, while the stroke of the eraser is referred to as erasing stroke.) The erasing stroke data is input in a background color of the input plane. Both of the writing stroke data and the erasing stroke data on the displays are reproduced at one time, whereby the writing strokes of the pens appear to be erased by being masked by the erasing strokes of the erasers. If new strokes are written by the pens over the erasing strokes, the stroke data editing devices input and store the corresponding new writing stroke data.
However, in that case, the conventional stroke data editing devices retrieve not only the new writing stroke data but also the precedent writing stroke data simultaneously, if the editing area is set to edit the new stroke data. In addition, the conventional stroke data editing devices also retrieves the erasing stroke data.
By way of example, it is assumed that a character train “ABC” is first written on the input plane as shown in FIG. 13A and then erased by wiping the input plane along an erasing stroke E3 tracked by the eraser as shown in FIG. 13B. It is further assumed that another character train “XYZ” is written over the erasing stroke E3 as shown in FIG. 13C. If an editing area T3 is set as shown in FIG. 13D to edit the character train “XYZ”, the conventional stroke data editing devices retrieve not only the writing stroke data of the character train “XYZ” but the writing stroke data of the character train “ABC” and the erasing stroke data of the erasing stroke E3, as shown in FIG. 13E. It is noted that, in FIG. 13E, the writing strokes of the character train “ABC” are shown for convenience for explanation, but are actually masked by the erasing stroke E3.
As described above, the conventional stroke data editing devices can not select and retrieve only the target writing stroke data. Therefore, the conventional stroke data editing devices edits both the target and non-target writing stroke data and the erasing stroke data.