JP2980770B2 - Position data approximation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position data approximation method for approximating position data of a point sequence using a function.

[0002]

2. Description of the Related Art In general, the shapes of characters, figures, etc. are read by an image scanner, and these are taken into a computer or the like as image data, reproduced by an output device such as a CRT or a printer, or recorded on a storage medium such as an FD. To do that is done actively.

In this case, an outline font is called,
2. Description of the Related Art Position data of only a contour portion such as a character or a figure is read, and a portion surrounded by the contour portion is reproduced as a character or a figure.

In such graphic processing using an outline font, outlines of characters, figures, and the like are taken as a row of dots, and these are read or reproduced. Not
Approximate position data obtained by approximating this using an arbitrary function is used. This is because the position data of the original figure generally requires a large capacity when stored in a memory because the position data is largely changed, and a long time is required for various data processing and a long time is required for reproduction. By approximating this using, for example, an arbitrary cubic function, the position data can be compressed, the storage capacity can be reduced, various data processing can be speeded up, and the reproduction time can be shortened. Can be reproduced.

In the conventional position data approximation method,
For example, when approximating the flipped-up portion at the lower left corner of the original graphic "i" shown in FIG. 3A, as shown in FIG. 4, the points of the contour of the original graphic are equally divided for each desired number of points. An approximate section is formed, and position data is approximated to each of the divided sections using an arbitrary function.

[0006]

However, in the above-described conventional method of approximating position data, when determining a section to be approximated by using a function, the points of the contour of the original figure are determined for each desired number of points. Because it was performed by dividing equally, straight sections and curved sections are mixed in the section,
When the approximated position data is reproduced, as shown in the approximate reproduced figure of FIG. 3C, the degree of joining at the connection points of the adjacent sections is not theoretically smooth, and the reproduction quality of the position data is much higher than that of the original figure. There was a disadvantage that it was inferior.

[0007] The present invention has been made in view of these points, and overcomes the above-mentioned problems in the conventional art.
An object of the present invention is to provide a position data approximation method that can smoothly join approximate position data of adjacent sections.

[0008]

In order to achieve the above object, a position data approximation method according to the present invention is directed to a position data approximation method for dividing a point sequence shape position data into sections and approximating the position data using a function. , among the points which the value of the put that cosine in each point of the position data is equal to or less than preset value, and the position data of the column-shaped consecutive points less than the number of preset parameter values and a straight section, said straight section Are divided into two approximation sections as curve sections for approximation.

[0009]

SUMMARY OF According to approximation of the position data of the present invention having the structure described above, when delimiting the section of the point at which the cosine value that put on each point of the contour with respect to the position data is less than or equal to a preset value Since the position data in the form of a point sequence that is continuous over the number of parameter values set in advance is defined as a straight section, and other than the straight section is divided into two approximate sections as a curved section, the data is divided based on this. The approximated approximate position data is joined very smoothly,
The accuracy of the approximate position data reproduced with respect to the position data of the original figure can be set to a desired content.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a flowchart showing a position data approximation method according to the present invention, FIG. 2 is a diagram showing a case where a contour point is divided by the position data approximation method according to the present invention, and FIG. FIG. 4 is a diagram showing an original graphic as an example of an object and approximate reproduced graphics according to the method of the present invention and the conventional method.

[0012] As shown in FIG. 1, the approximation of the position data is started, in step ST10, computes the value of the cosine that put on each point of the contour <br/>.

Next, in step ST11, the value of the cosine is equal to or less than a preset value, and in this embodiment, -0.9.
Look for points below 9. This point is the starting point of the straight line.

Next, in step ST12, it is determined whether or not the value of the cosine of the point following the start point of the straight line (end point of the straight line) is equal to or less than -0.99, and if the determination in step ST12 is YES, the process proceeds to step ST12. Proceeding to ST13, the end point of the straight line is extended (the next point after the start point of the straight line), and the process returns to step ST12. The end point of the straight line is sequentially extended and repeated until the determination in step ST12 becomes NO.

[0015] If the judgment in step ST12 is NO, proceeds to Step ST1 4.

[0016] The value of the cosine Te this step ST1 4 smell -
Of the points 0.99 or less, it is determined whether or not there are consecutively more than the preset number of parameter values, and in this embodiment, more than 33 points. If the determination in step 14 is YES, the process proceeds to step ST15. Proceed and extract as a straight section,
The process proceeds to the next step ST16.

If the determination in step ST14 is NO, the process proceeds to step ST17, and proceeds to the next step ST16 as a curved section.

Next, in step ST16, it is determined whether or not the determination has been completed for all points of the contour.
If the determination in step ST16 is NO, step ST16
Returning to step 11, the process is repeated until the determination in step ST16 becomes YES.

If the determination in step ST16 is YES, the process proceeds to the next step ST18, where all sections other than the straight section are extracted as curved sections, and the next step ST18 is performed.
The process proceeds to step 19, where the attribute of the start point of each section, that is, whether it is a straight line or a curve, is determined, and a series of processing is completed.

[0020] Thus, in the present embodiment, the value of the cosine of the points of the contour is the starting point of the straight line the points -0.99 or less in the step ST11, the value of the starting point or et cosine of the straight line -
When 33 or less points that are 0.99 or less continue, they are extracted as straight sections, and the remaining sections are extracted as curved sections.

FIG. 2 shows an example in which the contour points are divided using the cosine . This FIG. 2 is similar to the related art in FIG.
The present invention is applied to the original graphic shown in FIG.

In this embodiment, when a cosine value of -0.99 or less continues for 33 points or more, a straight section is defined. However , the cosine value and the number of continuous points may be determined by a design concept. In particular, the present invention is not limited to this embodiment.

After the contour points are divided into straight sections and curved sections as described above, each section is approximated with a predetermined function in the same manner as in the prior art to obtain approximate position data.

Next, shown in detail the method for calculating the cosine values that put on each point of the contour.

In general, the shape of binary data can be held by a closed loop of one or a plurality of aligned point sequences. .., Pn on the contour correspond to coordinates (X1, Y1), (X2, Y2)... (Xn, Yn), respectively, and a point Pi (Xi, Yi) (N
= 1,2, ..., the value of the cosine that put the points n) may include any number
k For example, two points Pi-k (Xi-k, Yi-k
), Pi + k (Xi + k, Yi + k), and the two vectors formed by these three points Pi, Pi-k, Pi + k are obtained.
It can be obtained from the following equation 1 using Pi Pi-k and Pi Pi + k.

[0026] The value of the arbitrary number k may be determined according to the design concept, and is not particularly limited to the present embodiment.

As described above, according to the present embodiment, the point of the contour
Calculates the value of cosine, since so as to approximate with approximation interval delimited on the straight section and a curved section with respect less than a predetermined value among the cosine of this value, the reproduced approximate figure is a straight line The connection between the curve and the curve becomes extremely smooth, and the approximation accuracy in each approximation section can be improved.

FIG. 3 shows a specific example according to the method of the present invention. The figure of FIG. B obtained by approximating the original figure of FIG. A based on the method of the present invention is approximate reproduced by the conventional method. It can be seen that the reproduction accuracy is extremely excellent as compared with the figure shown in FIG.

It should be noted that the present invention is not limited to the above-described embodiment, and can be modified as needed.

[0030]

As described above, according to the position data approximation method of the present invention, the reconstructed approximate figure has an extremely smooth connection state between adjacent approximate sections and the approximate figure within each approximate section. It has an extremely excellent effect of improving accuracy.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating a position data approximation method according to the present invention.

FIG. 2 is a diagram showing a case where a contour point is divided by the position data approximation method of the present invention.

3A is an original graphic to be approximate-reproduced, b is an approximate reproduced graphic according to the method of the present invention, and c is an approximate reproduced graphic according to the conventional method.

FIG. 4 is a diagram showing a case where a contour point is divided by a conventional method.

Claims (1)

(57) [Claims] With 1. A point separates the position data of a column shape to the section, the approximation method of position data to be approximated using a function, the value of the put that cosine in each point of the position data is less than or equal to a preset value Of the points, the position data in the form of a point sequence that is continuous over the number of preset parameter values is defined as a straight section,
A method for approximating position data, comprising dividing a portion other than the straight line section into a curved section into two approximate sections and performing approximation.