JPH07239937A - Iron print making device - Google Patents

Abstract

PURPOSE:To generate a beautiful iron print with less noise by using an image scanner to read original image such as character graphic, extracting a profile, approximating line segments between adjacent link points with a proper function, generating character graphic data and outputting the data to a cutting plotter to allow the plotter to draw the data on a transfer sheet. CONSTITUTION:A profile point series extract device B obtains profile of read characters and symbols, a curvature arithmetic mechanism E obtains an approximate function for all profile point series groups to obtain a curvature at each point, a data approximation mechanism AD obtains a high curvature in the profile point series to acquire a link point. A data approximation mechanism BN approximates blocks divided by the link points. The profile of the characters and symbols is classified into a straight line, a circle, a circular-arc and a free curve, they have a start point and an end point respectively and parameters such as a tilt, a center, and a radius and they are stored in a compression data storage device P. A thermal transfer sheet is cut off by moving a blade according to a reproduced data output mechanism T being a cutting plotter to cut off the thermal transfer sheet.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an iron print. Iron-on printing is a thermal transfer sheet that represents the original design of figures and characters.
It is transferred by pressing it on the surface of a shirt or the like with an iron. Heat it with an iron to transfer the figure of the sheet. It's easy because it sticks to the surface of the shirt just by pressing and heating it with an iron. Numbers and names can also be printed easily. Since I need sheets of letters and symbols, I'm currently asking a specialty store to iron-print.

However, since it is possible to perform heat transfer with an iron for home use, if a sheet showing characters or the like can be easily obtained, it can be easily printed at home. It is a thermal transfer sheet showing figures and characters, but in the case of fixed characters and symbols, it can be used because specialized stores prepare thermal transfer sheets of various sizes of characters and symbols. Since this is a fixed character or symbol, it is beautiful enough to be transcribed as it is.

[0003]

2. Description of the Related Art Arbitrary figures and handwritten designs can be printed. When the original drawing is brought to a specialty store, the original drawing is read by an image scanner, the contour line is obtained, and the thermal transfer sheet is cut along the contour line by the cutting plotter.

The term "heat transfer sheet" is used herein in a broad sense, and means that characters and the like on the sheet are transferred onto the shirt by applying heat and pressure. Actually, the base sheet and the transfer sheet are attached to each other easily for peeling. The base sheet and the transfer sheet are thin plastic sheets. The cutting plotter cuts only the transfer sheet so that the left and right sides of letters and figures are reversed. The seat is not cut. Although only the transfer sheet is cut, unnecessary portions of the transfer sheet are peeled off and removed. Then, a thermal transfer sheet in which desired characters, figures, etc. are displayed in the opposite directions is obtained.

The transfer sheet is applied to the shirt (the backing sheet is on the upper side), and the iron is pressed from above.
The transfer sheet is melted by heat and adheres to the shirt cloth. The base sheet does not melt and maintains its original shape. Then, when the base sheet is peeled off, a character figure by the transfer sheet remains on the shirt. A small device that can easily manufacture such a thermal transfer sheet is already on the market. Although the size of the original image is limited to a small size, this is a device in which an image scanner and a cutting plotter are integrated. Since the figure as it is read is cut out, there is no correction function. Techniques for easily printing fixed characters, figures, numbers and handwritten characters / symbols on T-shirts already exist.

[0006]

However, the current iron-printing has the following drawbacks. The fixed characters and numbers are beautifully transferred because the heat transfer sheet that is cut nicely in advance is prepared in a specialty store. This cannot be easily manufactured even at a specialty store, so you must always stock it so that you will not run out of stock. Since the size and typeface of letters and numbers are diverse, it is necessary to prepare various sizes and typefaces to meet the demand. This is a burden for specialty stores because of the large number of letters. Moreover, it is actually difficult to have many types of size fonts. Then, the range of selection becomes narrow.

On the other hand, printing the original characters / symbols has a more serious drawback. Noise is generated when the original image is optically read by an image scanner. Since it is an optical means, stains on the surface of the paper will appear, and the lines will be jagged due to the dots being read, and the diagonal lines and curves will not be smooth. There are too many black areas and too many white areas. Since there is no correction function in a simple iron-on-line printing machine currently on the market, there are such drawbacks, and it is difficult to print neatly.

There is nothing that cannot be done only by providing a correction function. The image read by the image scanner is displayed on the screen of the display, and the image is corrected using the mouse. It is also possible to perform curve approximation using a Bezier curve or the like, as is done in normal image processing. However, this correction is time-consuming because a person corrects it while looking at the screen, and he must be familiar with the operation. Also, in the case of an original picture of free letters and symbols, if the person who wrote the original picture and the person who corrects it are different,
There is a possibility that it will hurt. For this reason, there is currently no simple ironing machine with a correction function. If an iron-printing machine has a correction function, it must be able to automatically and quickly correct the original image.

It is an object of the present invention to enable an iron print making machine to quickly and automatically correct an original image and output it to a cutting plotter in a clean form to achieve a clean iron print with less noise. Also, an iron-printing machine which can store an original image with a small amount of data and output it at an arbitrary time is provided. Further, the present invention provides an iron-print maker which can be freely scaled up and down so that noise does not occur due to scaling up or down. Since fixed characters and symbols can be stored with a small amount of data and can be output instantly, there is no need to prepare ready-made transfer sheets of various types and sizes, which reduces the burden on specialty stores. It is also an object of the invention to provide.

[0010]

SUMMARY OF THE INVENTION An iron-printing producing apparatus according to the present invention reads an original image of a desired character or figure with an image scanner, stores it for each pixel, extracts a contour line, and draws a contour line. The joint points are found from the line segment between the adjacent joint points by an appropriate function, the contour line and the function are stored, and the character / graphic data corresponding to the original drawing is generated from the stored information. Then, it is output to a cutting plotter and the figure created by correcting the original drawing is drawn on the transfer sheet. Extraction of joint points and function approximation are performed automatically.

In order to obtain the junction point and perform the function approximation, the reading error and noise by the image scanner are removed,
The image is beautifully corrected. Therefore, the character graphic drawn on the transfer sheet can faithfully reproduce the characteristics of the original image. In the case of fixed characters and numbers, the original character font is read by an image scanner and stored in the storage device in the form of data after contour point string extraction, joint point extraction, and function approximation. This should be prepared from the beginning as common data.

That is, the iron-print making apparatus of the present invention optically reads a desired character or symbol, optically reads character or symbol data, and stores the character or symbol corresponding to a finite number of vertical and horizontal pixels. A symbol reading device, a contour point sequence extraction device that extracts a contour line of a character / symbol read in association with pixels arranged vertically and horizontally as a point sequence, and two-dimensional coordinates (X, Y) of the extracted contour line. A contour point sequence storage device that stores t as an independent variable and X and Y as dependent variables for each continuous group; a curvature calculation mechanism that obtains the curvature at each point of the point sequence for each group in the x and y spaces; A perfect circle extraction mechanism that extracts a perfect circle from each curvature data, a joint point position extraction mechanism that extracts a point that cannot be spatially differentiated as a joint point from the curvature data of a point sequence, and the same point sequence Approximate between the adjacent junction points in the group in the order of straight line and arc When a predetermined approximation accuracy is not obtained t
Is an independent variable, and x and y are dependent variables, and the least squares approximation is repeated while increasing the number of dimensions of the piecewise polynomial until the approximation accuracy falls within a predetermined value. A data approximation mechanism for approximating with a circular arc, a piecewise polynomial, and a compression data for storing the coordinates of the above-mentioned joint points and the parameters of the function approximating between adjacent joint points for each group of point sequences.
A data storage device and a function parameter for inputting the stored compression data and approximating the coordinates of the junction points for each group of point sequences and the adjacent junction points.
And a contour playback mechanism that plays back the contour line to the left and right,
And a cutting mechanism for cutting the thermal transfer sheet along the contour of the reproduced character / symbol.

[0013]

FIG. 1 shows an outline of a method for making an iron print. In, a manuscript is created using characters and symbols. This may be created on paper by any method such as handwriting or cad. When using cad, the image reading work can be omitted. This original is processed by the apparatus of the present invention. The thermal transfer sheet is cut along the pattern of the original by the cutting plotter which is the output mechanism. Remove unnecessary parts from the mount.

The sheet cut by the cutting plotter is placed inside out on the fabric to be printed. Press the iron from the back. The heat causes the sheet to adhere to the fabric. Peel off the mount. The apparatus of the present invention can automatically read the original document and cut the sheet to the left and right by the cutting plotter.

FIG. 2 shows a list of the entire structure. All mechanisms are described here in advance. A. Image storage device B. Contour point sequence extraction device C. Contour point sequence storage device D. Data approximation mechanism A E. Curvature calculation mechanism E '. Approximate curvature storage device F. Perfect circle extraction mechanism G. Perfect circle memory device Joint position extraction mechanism I. Junction point storage device N. Data approximation mechanism B O. Compressed data output mechanism P. Compressed data storage device R. Contour reproduction mechanism Reproduction data output mechanism

Characters and symbols desired to be iron-printed vary depending on the person. The present invention is
It can also be handled as a symbol. For example, the procedure will be briefly described for the symbol of the diode shown in FIG.

First, the figure of the diode written on the paper is read by an image scanner (image reading device). This is the optical reading of characters and symbols. When a contour point string, which is a set of contour lines, is extracted, white characters and symbols are obtained. This is shown in (b). The horizontal direction is the X axis and the vertical direction is the Y axis. Each point of the contour line can be represented by two-dimensional coordinates. There are many continuous contour point sequences. These are treated independently.

The X and Y coordinates of the contour point are defined as a function of t using the parametric display. Since the sequence of contour points is continuous, X
(T) and Y (t) are almost continuous functions with respect to t. Approximate with a piecewise polynomial over the entire contour point sequence group. In the first approximation, one contour point string is approximated by one piecewise polynomial. This is to find the curvature. The accuracy of the approximation may be low. Since it is a continuous function with a piecewise polynomial, the second-order differentiation is performed on each contour point sequence to obtain the curvature. A contour point sequence having a constant curvature is a perfect circle. This is separated as a perfect circle. The junction has a large curvature. In FIG. 3, cross marks, intersections, and the like of the contour point sequence are marked with x. This is the junction.

The contour point sequence is divided by the joint points. Approximate a straight line, a circular arc, and a free curve between the joining points. Approximation is performed in the order of straight line, circular arc, and free curve. First, approximate with a straight line. This can be expressed simply by the fact that it is a straight line with the starting point coordinates. Next, it approximates with an arc. This can also be specified by the starting point, radius, and central angle. There is very little data for expressing these. If it cannot be approximated by a straight line or a circular arc, then a free curve approximation is performed. In this case, the joining points are divided into M subsections and approximated by a piecewise polynomial. Since the approximation can be improved by increasing the number of subdivisions, the approximation with desired accuracy can be performed.

In this way, the parameters of the joining point and the straight line, the circular arc and the free curve can be obtained.
Memorize as data. It is stored in a memory element, which requires only a small memory capacity because the data is significantly compressed according to the invention. The time required for reading is also short. Depending on the number of strokes and complexity, there are about 30 per character / symbol.
Data of 0 to 500 bytes is enough. If the image is a black and white image, there is data corresponding to the number of all the pixels that make up the screen. For example, if there are 256 pixels in the vertical and horizontal directions, there are 8 kilobytes (kbytes), but in the present invention, the data can be significantly compressed. On the contrary, this data can be read out to reproduce a straight line, a circular arc or a free curved line with the junction point as a reference. It can be reproduced at any size and at any position by calculation. The reproduction data is output by the cutting plotter. The thermal transfer sheet is cut along the contour.

[0021]

【Example】

[A. Image Storage Device] This is a device for reading characters / symbols written on paper or the like by optical means and storing them as information decomposed into pixels. A commercially available image scanner is used. The character / symbol part is black, and the part that does not form the character / symbol is white to form a binary image, which is stored for each pixel.

For example, by using an image scanner, 256 ×
It is entered with an accuracy of 256 dots. The number of dots is of course arbitrary, and the one with more dots should be stored as characters / symbols with higher quality, but the more dots, the longer the calculation time and storage capacity. The image reading device described above may be used. Each dot (pixel) is temporarily stored by distinguishing whether it is a white pixel or a black pixel. Hereinafter, one pixel may be referred to as a point. A continuous black pixel row is called a dot row. To indicate a point, coordinates (x, y) consisting of a horizontal number x and a vertical number y of the pixel on the screen are used. Different suffixes are added to coordinate variables to distinguish them.

[B. Contour Point Sequence Extraction Device] The contour point sequence extraction device performs an operation for obtaining the contour line of the read character / symbol. Since we know the coordinates of all black pixels,
A contour point sequence can be obtained as a boundary between black pixels and white pixels. ○ Representation of contour point sequence A contour point sequence is a sequence of points that are continuous diagonally to the left, right, up, down, and left and right of the black pixel cluster. In the case of a closed curve element, there are contour point sequences inside as well as outside. One closed point sequence is called a contour point sequence. Let U be the total number of contour point sequences. The U contour point sequences are numbered from 0 to U-1. The total number of contour points in the u-th contour point sequence is N (u)
It is represented by. Number k for consecutive points in one contour point sequence
Attach. k is an integer of 0 to N (u) -1.

The coordinates of the k-th contour point in the u-th contour point sequence are represented by (x _k ^u , y _k ^u ). All contour points are {(x _k ^u , y _k ^u )} _{k = 0} ^{N u -1} _{u = 0} ^U-1 (1)

Is represented by That _{k = 0} ^{N u -1} means that the point sequence number k can take values from 0 to N (u) -1. N (u) -1 includes parentheses, which is 1
When it is a suffix of a variable because it cannot be / 4 corner, parentheses are removed and it is written as Nu-1. N u
−1 = N (u) −1. Since it is a suffix, it should be written above and below, but since this cannot be done, it is attached separately to the lower left and upper right. _{When u = 0} ^U-1 , the number u of the contour point sequence group is _{0 to} ^U -1
Is to take the value of. Also, the number u of the contour point sequence should be shown with parentheses on the right shoulder of the variable, but the parentheses are 1 /
Omit parentheses because it can't be square. Actually, it has brackets as shown in the drawing. It is not the u-th power of the variable.
This is common to the parameter t and the independent variables x and y.
u is a group number and is written on the right shoulder of the variable as it is, but it is actually enclosed in parentheses.

[C. Contour Point Sequence Storage Device] The contour point sequence storage device is a device for storing the contour point sequence obtained in the preceding stage. (X
This is stored in the form of _k ^u , y _k ^u ) _{k = 0} ^{N u -1} _{u = 0} ^U-1 . As described above, U is the number of all points and u is the number given to the points. The number of points in the point sequence u is N (u)
And k is the point number attached to it. Such a thing is expressed by _{k = 0} ^{N u -1} _{u = 0} ^U-1 . (X _k ^u, y _k
^u ) is the x, y coordinate of the kth point of the uth point sequence.
Again, with N (u) -1 as the suffix, N
It is written as u -1.

[D. Data Approximation Mechanism A] There are two data approximation mechanisms. This is the first one, but is added with A for distinction. This is necessary in order to find the point where the curvature of the contour point sequence is large and the joining point. The x and y coordinates of the contour point sequence of each continuous group are approximated by a quadratic piecewise polynomial in which t is an independent variable and x and y are dependent variables, and the least squares method is applied until the approximation accuracy falls within a predetermined range. The approximation is repeated to find an approximate polynomial for each group of contour line point sequences. This is not to obtain the final data, but to find the junction point. The coordinates for each contour point sequence are read from the contour point sequence storage device.

This is decomposed into a parameter display. That is, for each point, a common parameter t is associated with two (x _k ^u , y _k ^u ). This is also subscripted to be t _k ^u . It was two-dimensional information, but to make this a one-dimensional problem, parameters are used. u is the group number of the contour point sequence,
k is a point number in one contour point sequence.

By using the parameters, (t _k ^u ,
A combination of two coordinates of (x _k ^u ) and (t _k ^u , y _k ^u ) corresponds to each point of each contour point sequence. Hereinafter, the same thing will be done for the two variables, so only one will be explained. The function S _{x of} t approximating the contour point sequence (t _k ^u , x _k ^u ) in the group u
(T) is given as a linear combination whose base is a quadratic full-energy-function system {ψ _m }. We approximate x as a function of t in group u by S _x (t). Similarly S _y
Approximate y in group u by (t). The evaluation as to whether or not it is appropriate as an approximate function is made by the method of least squares and whether or not the error is within a predetermined range.

Note that S _x (t), S _y
This means that the entire closed curve of the group of contour point sequences u is approximated at once by (t). Instead of having a junction in the middle, the whole is approximated by one function S _x (t). This is done because the junction has not been decided yet. As mentioned above, there is a simpler method for obtaining the curvature without using approximation. It is the contour point sequence data
This is a method of directly calculating the discrete curvature. Such a discrete curvature may be used for carrying out the present invention. However, this is not explained here, and the approximation function S _x
Generation of (t) and S _y (t) will be described.

S _x (t) is a non-period mth-order full-energy
Expand with the function ψ _k as the basis. S _x (t) = Σ _{k = -m} ^{M + m} C _k ^x ψ _k (t) (2)

The full-energy function is a function name named by the present inventor. The order m corresponds to the order of the polynomial. M is the number of dimensions. Generally, a m-th order full-energy function has a domain of [0, T], a parameter of k,
This parameter is shown as a suffix. C _k ^x
Is the coefficient of the linear linear combination. ψ _k itself is a polynomial whose value is near k.

Ψ_k (T) = 3 (T / M)^-mΣ_{q = 0} ^{m + 1}(-1)^q {T- (k + q) (T / M)} ^m ₊ / {Q! (M + 1-q)! } (3)

However, k = -m, -m + 1, ..., 0, 1, 2, ..., M
+ M

Here, the plus added below the m-th power is 0 when the inside of the parentheses is negative, and the m-th power when it is positive, and is defined as follows.

(T−a) ^m ₊ = (t−a) ^m t> a, (4) 0 t ≦ a (5)

The basis function ψ _k is a mountain-shaped function having a finite value from the division number _{k to k} + m + 1 and having 0 on both sides. This is 0 such as {t- (k + q) (T / M)} ^m ₊
The coordinates of the m-th order function rising from are shifted laterally one by one (increase q by one), and these are superimposed. 0 when t> (k + m + 1) (T / M)
Must. Under this condition, the superposition coefficient is (-1) ^q / {q! (M + 1-q)! } Is decided. The size T of the area is the number N of points in the contour point sequence group.
It is easy to make it equal to (u), but it may be defined as proportional. As described above, the contour point sequence is approximated by using the full-energy function. However, since there are many division points having the intervals of T / M, the contour point sequence can be approximated even if there are no junction points. In order to increase the degree of approximation, the order m of the full-energy function may be increased.

The inventor's argument is that many functions representing the fluctuations of physical quantities in the natural world are expressed as a linear combination of first-order and second-order full-energy functions. The full-ency function is not a complete orthogonal normalization function. If a function up to ∞ is adopted as m and a linear combination of them is adopted, an arbitrary function can be expressed. There is no doubt about this. However, the present inventor does not mean that it is possible to write down the fluctuation of the physical quantity in the natural world by using the full-energy function having a small number of dimensions. Here, only m = 2 is adopted.
As a result, the outlines of characters and symbols can be expressed in just the right amount.

If the most suitable function system is adopted and the fluctuation of the physical quantity is described by the linear combination, the optimum approximation can be obtained with the fewest function. If the function system is not good, we have to expand the equation of linear combination with many functions as the base. With this, a good approximation cannot be obtained, the number of final data is increased, and the load on the storage device is heavy. It is also not easy to read and use this. You should choose the optimal function system. The inventor thinks that m = 2 is optimal.

The present inventor uses a flu-ency function with m = 2 here. This is a quadratic curve over three intervals. The rising and falling edges at both ends are quadratic functions. It is the maximum at the central point, but it is also a quadratic function in this neighborhood.

In general, the m-th order full-ency function is (m +
1) A smooth (m ≧ 2) function that exists over the interval and has a maximum in the central portion. At both ends, it rises and falls with the m-th power. The function form at the center is also the m-th power. Base ψ
_When the parameter _k of k increases by one, it means that the original one is translated to the right one by one.

In the above equation, when m = 2,

S _x (t) = Σ _{k = −2} ^{M + 2} C _k ^x ψ _k (t) (6)

Ψ _k (t) = 3 (T / M) ⁻² Σ _{q = 0} ³ (−1) ^q {t− (k + q) (T / M)} ² ₊ / {q! (3-q)! } (7)

It becomes The basis function is {t- (k + q) (T
/ M)} ² ₊ is a superposition of quadratic functions rising from four 0s which are shifted by T / M in the lateral direction. It is a function whose number of subdivisions has a value from k to k + 3. k + 4
The coefficient of superposition is (-
1) ^q / {q! (3-q)! } Becomes. The number of basis functions is M + 5. M is the number of divisions of the entire section, which is called the approximate number of dimensions. This should not be confused with the order m of the full-ency function.

If the number of dimensions M is increased, any complicated change can be approximated as it is. If the number of dimensions M is large, calculation takes time and the amount of data to be stored also increases. It is desirable to perform approximation with the minimum number of dimensions that gives the required approximation. The degree of approximation can be judged by how close it is to the original contour point sequence (x _k ^u , y _k ^u ).
We evaluate this by the method of least squares, which is

Q = Σ {S _x (t _k ^u ) −x _k ^u } ² + {S _y (t _k ^u ) −y _k ^u } ² (8)

Is to minimize. The range of integration is all the points of the contour point sequence group u. Since only the curvature is obtained here, the accuracy does not have to be so high. The coefficient C _h is determined, and the number of dimensions of this is M. When defining a certain M, equation (6), is uniquely determined coefficient C _h ^x (7). However, this coefficient does not always satisfy the restriction by the least square method. In this case, the number of dimensions M is increased by one. When the desired approximation range is reached, the coefficient C _h in the dimension M is determined.

[E. Curvature calculation mechanism] Since approximate functions have been obtained for all contour point sequence groups, the second order differentiation is performed to obtain the curvature at each contour point sequence group and each point. The curvature K (t _k ^{u at} the k-th point (x _k ^u , y _k ^u ) of the contour point sequence group ^u
) Is

K (t_k ^u ) = {S_x ′ (T_k ^u ) S_y '' (T_k ^u ) -S_x '' (T_k ^u ) S _y ′ (T_k ^u )} / {S_x ′ (T_k ^u )² + S_y ′ (T_k ^u )² }^3/2 (9)

Can be calculated by First u =
The calculation is started from the point of k = 0 in the group of 0 contour points. This calculation is done point by point. That is, if the k-th point can be calculated, then the same calculation is performed for the k + 1-th point. When the calculation is completed for one contour point sequence group, the process moves to the next contour point sequence. Then, the curvature is calculated for all the points of all the contour point sequences.

[E '. Approximate Curvature Storage Device] This is a device that stores the curvature K (t _k ^u ) obtained in the previous stage for each point (contour point group u, point number k).

[F. True Circle Extraction Mechanism] This is to extract a true circle by discriminating whether or not a certain contour point sequence is a perfect circle based on the approximate curvature. A perfect circle means that the curvature at each point in the contour point sequence is all the same.
In reality, since there is noise, the curvature is extracted on the condition that it is within a certain small error range from a certain value. The characters and symbols have a lot of parts that are perfect circles. However, since the true circle here is about the contour line, it means an isolated true circle. If the part of the perfect circle is in contact with another straight line or curve, it is not extracted as a perfect circle.

Extracting a perfect circle has the following advantages. One is that even if what is originally a perfect circle is slightly distorted due to noise, it is converted to a perfect circle and the noise is dropped, so that the shape can be determined more accurately. Further, since the circle can be specified only by the radius and the coordinates of the center, it is extremely effective in terms of data compression.

[G. True circle storage device] The center circle coordinates and radius r obtained in the previous step are stored. Thereby, the data of the group u can be described by three values. Since the target is characters and symbols, all contour point sequences are closed curves. In the case of a single true circle, this is an isolated circle point because the entire interior is a circle filled with black pixels. In the case of a double true circle, the space between the double circles corresponds to a circle filled with black pixels.

[H. Joint Point Position Extraction Mechanism] A joint point is a joint between straight lines, a joint between curves, a joint between curves, or a joint between curves. This is called a junction because lines with different slopes touch. Junction points play an extremely important role in function approximation of characters and symbols. Here is the gist of the present invention. The present invention can minimize the amount of data while maintaining high quality of characters and symbols through accurate and proper determination of the joining points. Find the junction from the curvature given by the previous piecewise polynomial approximation. This is obtained as a point with a large curvature. Joint points are obtained for all contour point sequences.

In the schematic diagram of the diode of FIG. 3, the junction points are indicated by x. There are a total of three contour lines, which are the outer circular contour line Y and the inner contour lines R and S. Although there are eight junction points of the outer contour line, only the upper half is marked. Tsu-ne is a short line segment, ne-na is a half arc, and na-la is a short line segment,
Tuff is a short arc or free curve. Inner contour line
Since Seo is symmetrical, I will explain about Re. Mu-u is a line segment, u- ヰ is a line segment, and ヰ -no is also a line segment, but it is a free curve that bends near No. No-o is a line segment, o-
KU is also a line segment, KU-YA is a line segment, YA-MA is a line segment, and MAM is a semicircular arc. This also has many straight lines. Then there are many arcs. Geometrically, a line segment is fixed at both ends, and a straight line is a figure without both ends. However, in this specification, a line segment or a half line is also called a straight line.

[I. Joining point position storage device] This is the number and coordinates {d _i (x _i ^u , y _{i of} the joining point obtained by the above operation.
^u )} is stored.

[N. Data approximation mechanism B] Then, when the joint points are obtained, the contour point sequence is divided into several sections by the joint points. The section divided by the junction points is approximated by a piecewise polynomial. The approximation of this piecewise polynomial is the same as that described in the data approximation mechanism A, but in the previous one, the approximation interval was over the entire contour point sequence group. This time, instead, a piecewise polynomial approximation is performed for each junction.

The data approximating mechanism B is a mechanism for approximating the data from the data of the contour point sequence, the final joining point, the perfect circle and the like obtained so far. It is the central part of the invention. What is input from each storage device is a contour point sequence storage device ... Contour point sequence {(x _k ^u , y _k ^u )}
_{k = 0} ^{N u -1} _{= 0} ^U-1 Junction point memory ...... Joint point {(x _i ^u , y _i ^u )
_{i = 0} ^I-1 True circle memory device ... Circle Circle (u)

It is A straight line, a circular arc, and a free curve are approximated between two adjacent joint points (between joint points). As in the previous approximation, the parameter t is used to calculate the x component as s _x (t)
Then, the y component is represented by s _y (t).

This means that the entire contour point sequence is first transformed by the parameter t.
It is the same method as described in. But this time the region is between the junctions, so the range of t or t and s _x
The correspondence between (t) and s _x (t) is different from the previous one. Further, it is known when the curvature is obtained at each point whether the section starting from a certain joint is a straight section, an arc section, or a free curve section.

Since the characteristics of the intervals can be distinguished in this way, it is easy to determine the parameters of the approximate calculation. [Approximation of straight line section] The approximation of the section starting from the junction of straight lines will be described. It is determined to be a straight line in the step of extracting the junction point.

The proportional constants of the parameters t and s _x (t) and s _y (t) serve as parameters. However, it is not necessary to store this proportional constant. If it is a straight line section, the starting point (x ₁ , y ₁ )
This is because if the end point (x _n3 , y _n3 ) is known, a straight line can be drawn between them. Since the end point (x _n3 , y _n3 ) is given as the start point of the next section, it is not necessary to store it here. All you have to do is set a flag that is a straight line with the starting point coordinates.

[Approximation of Arc Section] Approximation of a section starting from a junction point of arcs will be described. This section is determined to be a circular arc at the stage of extracting the joining point. Approximate curves s _x (t) and s _y (t) representing arcs are represented by the linear combination of the following trigonometric functions. If the observation interval is t ∈ [0, T],
s _x (t) and s _y (t) are

S_x (T) = A_xcos (2πt / (T / n_arc )) + B_x sin (2πT / (T / n _arc )) + C_x (10)

S_y (T) = A_ycos (2πt / (T / n_arc )) + B_y sin (2πT / (T / n _arc )) + C_y (11)

It is represented by n _arc is the ratio of the arc to the total circle. That is, it is a value obtained by dividing the central angle of the arc by 360 degrees. For example, in the case of a _quadrant , n _arc is 1/4
Is. Therefore, 2πn _arc is the central angle of this arc. The variable 2πt / (T / n _arc ) is the central angle from the starting point of the arc to the point corresponding to the parameter t. (C _x , C
_y ) is the coordinates of the center of the arc. This time,

A _x ² + B _x ² = A _y ² + B _y ² (12)

B _y / A _y = B _x / A _x (13)

If the following is true, the approximation function is a circular arc. In this case, parameter defines an arc - data each coefficient A _x of the function, B _x, is _{C x, A y, B y} , C y, n arc. If it is known from the beginning that this section is a circular arc, such parameters can be uniquely determined from the coordinates of the start and end points and the coordinate of the curvature and one point in the middle.

[Approximation of Free Curve] Even at the junction of straight lines,
Approximate the section starting from the joining point that is not the joining point of the circular arc with the free curve. The contour point sequence is (x _i3
^u , y _i3 ^u ), and t is associated with this,
The parameters are represented by (t _i3 ^u , x _i3 ^u ) and (t _i3 ^u , y _i3 ^u ). Up to now, the suffix of the contour point sequence has been k, but since k is used as the section division number here, i3 is used as the contour point sequence number instead of k. The total number of contour point sequences is n3.

Then, s _x (t) and s _y (t) are expanded using the quadratic full-energy function ψ _k3 as the base. This is 3
This function has a value only in one subdivision. The interval is [0,
T], the quadratic full-energy function ψ _k3 is an M-dimensional functional system.

Ψ _k3 (t) = 3 (T / M) ⁻² Σ _{q = 0} ³ (−1) ^q (t−ξ _{k + q} ) ² ₊ / {(q! (3−q)!)} (14) k = -2, -1, 0, 1, 2, ... M + 2

It is With this as the base, s _x (t _i3 ), s
_y (t _i3 ) is _obtained by using the coefficients c _k ^x and c _k ^y ,

S _x (t _i3 ) = Σ _{k = -2} ^{M + 2} c _k ^x ψ _k3 (t _i3 ) (15) s _y (t _i3 ) = Σ _{k = -2} ^{M + 2} _ck ^y ψ _k3 It is expressed as (t _i3 ) (16). here,

When t> ξ _{k + q} (t−ξ _{k + q} ) ² ₊ = (t−ξ _{k + q} ) ² (17) When t ≦ ξ _{k + q} (t−ξ _{k + q} ) ^It is defined as ² ₊ = 0 (18). ξ _{k + q} is a subdivision when the section T is divided into M equal parts.

Ξ _{k + q} = (k + q) T / M (19)

The coefficients c _k ^x and c _k ^y are the values (x _i3
^u , y _i3 ^u ) and the values of s _x (t _i3 ) and s _y (t _i3 ) are determined so as to approximate each other. The value of the coefficient is determined by the method of least squares. Squared error Q is

Q = Σ _{i3 = 1} ⁿ³ | x _i3 ^u −s _x (t _i3 ) | ² −Σ _{i3 = 1} ⁿ³ | y _i3 ^u −s _y (t _i3 ) | ² (20)

Is defined by (15), (16)
The coefficient can be determined by reversing. The squared error is obtained by inserting this coefficient. If this does not fall below a predetermined threshold value, the number of dimensions is increased. The same process is repeated so that the squared error is equal to or less than the predetermined threshold. This determines the number of dimensions and the coefficient.

[O. Compressed data output mechanism] The outlines of characters / symbols are separated into straight lines (line segments), perfect circles, arcs, and free curves by the above procedure. These have start and end points, and have parameters such as inclination, center, and radius. The data to be stored also differs depending on each type.

In the case of straight line data, a flag indicating that the line is a straight line and the start point coordinates of the straight line are stored as data. Since the end point coordinate is given as the start point of the next section, it is not necessary to store it here.

In the case of perfect circle data, the data can be obtained directly from the perfect circle storage device G. This has already been selected by the first data approximation mechanism A. In the case of a perfect circle, the flag indicating the perfect circle, the center coordinates of the circle, and the radius of the circle are deleted.
Stored as a data.

As the arc data, a flag indicating that it is an arc, the starting point coordinates of the arc, the arc division length (arc length / perimeter),
The number of contour points and the coefficient of the function are stored. De of free curve - The data, dimensionality of the function, the contour points, the middle point (μ _x, μ _y) of the variation of the contour point sequence and the coefficient of the function c ^x, stores c ^y.

[P. Compressed data storage device] Stores data such as straight lines, perfect circles, circular arcs, and free curves output from the compressed data output mechanism. This is stored and then output at an appropriate time. Up to this point, the device is for compressing and generating data and storing it. A device for reproducing characters / symbols from the accumulated data will be described below. Table 1 shows the data structure stored in the compressed data storage device P.

[0087]

[Table 1]

The size of the data will be described. If there is a straight line between the junction points, 1 byte for the flag indicating the straight line, 2 bytes for indicating the start point of the line segment (x coordinate and y coordinate)
It requires a total of 3 bytes. If there is an arc between the joining points, 1 byte is the flag that indicates the arc, 2 bytes to indicate the start point of the arc,
4 bytes to represent the central angle of the arc, 1 byte to represent the number of contour point sequences, 1 to represent the coefficients of the approximation function (there are 6)
Two bytes require a total of 20 bytes. If there is a free curve between the connecting points, it is 1 byte to represent the dimension number M of the function, 1 byte to represent the number of contour points, 2 bytes to represent the center of variation of the contour points, and 2M to represent the coefficient of the approximation function. 4 bytes in total
It becomes +2 Mbytes.

A contour reproducing mechanism R and a reproducing data which will be described below.
The data output mechanism T is a mechanism for reproducing characters / symbols in an arbitrary size and outputting them to the cutting plotter.

[R. Contour Reproducing Mechanism] This is a mechanism for reproducing the contour line to be the skeleton of the character / symbol from the stored compression data. The contour line may be a straight line, a perfect circle, an arc, or a free curve.

[Reproduction of Straight Line] Reproduction of a straight line is performed by connecting a line from the coordinates of the starting point to the coordinates of the junction point of the next section. No data is needed on the slope of the straight line. [Reproduction of Perfect Circle] The reproduction of a perfect circle is performed by drawing a circle having a given radius centered on the center coordinate from the data of the center coordinate and the radius. [Reproduction of arc] Reproduction of arc is performed by storing each data (A _x , B _x , ...
・) Is substituted into the following formula.

S _x (t) = A _x cos {2πt / (T / n _arc )} + B _x sin {2πt / (T / n _arc )} + C _x (21) S _y (t) = A _y cos _{{2πt / (T / n arc} )} + B y sin {2πt / (T / n arc)} + C y (2 2)

By changing the parameter t in the interval of [0 to T], x and y coordinates are obtained from S _x (t) and S _y (t).

[Reproduction of Free Curve] As for the value of the basis ψ _K3 of the approximation function at each sample point t _i , the sample point t _i has the interval [(L
-1) (T / M), L (T / M)] (1≤L
≦ M), p = L−t _i × M / T,

Ψ _k3 (t _i ) = 0.5p ² k = L (23) ψ _k3 (t _i ) = p (1-p) +0.5 k = L + 1 (24) ψ _k3 (t _i ) = 1 −φ _L3 (t _i ) −φ _{L + 13} (t _i ) k = L + 2 (25) φ _k3 (t _i ) = 0 k ≦ L−1, L + 3 ≦ k (26) However, L is a natural number having a dimension number M or less. It should be written as M'because it is a number of the same property, but since 'does not become a quarter angle, it is expressed by L.

Using such a basis ψ _K3 , the approximate function value S (t _i ) at each sample point is S (t _i ) = Σ _{k = L} ^{L + 2} C _k ψ _k3 (t _i ) (27 ).

[T. Reproduction data output mechanism] This is a cutting plotter for cutting the thermal transfer sheet.
Since the contour line is obtained, the blade of the cutting plotter is moved according to the contour line to cut the sheet. For this, for example, a cutting plotter of CAMM-1 series manufactured by ROLAND can be used.

FIG. 4 is a diagram showing an actual mechanism of the present invention. It consists of an image scanner, a personal computer and a cutting plotter. The above-mentioned mechanism is housed in a custom IC fixed to the printed board. It's not just installed on a PC as software. In the present invention, since the original image is stored in the form of the coordinates of the joining point and the coefficient, the original image can be enlarged or reduced to any magnification. In addition, the center of coordinates can be arbitrarily specified. Therefore, it is possible to output any design character / symbol in any size. That is, a sheet having a desired size can be cut out without being limited to the size of the original image.

[0099]

According to the present invention, a character or a symbol, which is an original image such as handwriting, is optically read, stored as a small amount of data, and stored in a cutting plotter. You can easily and quickly create the desired iron print. There is no need to prepare many original drawings of various designs. It is an extremely convenient invention.

[Brief description of drawings]

FIG. 1 is a schematic view illustrating an iron printing method.

FIG. 2 is a configuration diagram showing an entire mechanism of the present invention.

FIG. 3 is a diagram for explaining extraction of a sequence of contour points and extraction of a connection point by taking a figure of a diode as an example.

FIG. 4 is a perspective view showing the actual structure of the device of the present invention.

Front page continuation (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location G06T 3/40 9/20 G06F 15/66 355 K 7459-5L 15/70 335 Z

Claims (1)

[Claims] 1. An apparatus for producing an iron print by cutting a heat transfer sheet along a desired character / symbol,
Character / symbol reading device that optically reads desired characters / symbols, optically reads character / symbol data, and stores them in correspondence with a finite number of vertical and horizontal pixels. A contour point sequence extraction device that extracts the contour lines of the extracted characters / symbols as a point sequence, and t is an independent variable for each continuous group of the two-dimensional coordinates (X, Y) of the extracted contour lines. A contour point sequence storage device for storing as a dependent variable, a curvature calculation mechanism for obtaining a curvature at each point of a point sequence for each group in x, y space, and a true circle for extracting a perfect circle from data of curvature for each group. A circle extraction mechanism, a joint point position extraction mechanism that extracts points that cannot be spatially differentiated from the curvature data of a point sequence as joint points, and a straight line and an arc in the order of adjacent joint points in the same point sequence group. Approximate and if this does not give the desired approximation accuracy, t is an independent variable and x and y are dependent The number of piecewise polynomials is approximated and the least-squares approximation is repeated while increasing the number of dimensions of the piecewise polynomial until the approximation accuracy falls within a predetermined value. A data approximating mechanism, a compression data storage device for storing the coordinates of the joint points and the parameters of a function for approximating adjacent joint points for each group of point sequences, and the stored compression data. , A contour reproducing mechanism for reproducing the contour line by obtaining the function parameter approximating the joint point of each group of point sequences and the adjacent joint point, and the reproduced character
And a cutting mechanism for cutting the heat transfer sheet along the outline of the symbol.