JP2787454B2 - Distortion correction method for picture film with characters - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to a method of correcting a distortion of a picture film having a character, and more particularly to a method of correcting a distortion when a character is added to a molded article having a three-dimensional curved surface.

[Related Art] In recent years, a simultaneous injection painting method in which a printing film is put into a mold at the same time as injection molding and only ink is transferred to a molded product has become widespread.

FIG. 1 is a diagram showing a basic configuration of an apparatus for performing such simultaneous injection painting method. A transfer film 2 is wound around the supply roll 1. The transfer film 2 includes a cylinder 3
Is passed through the heater 4 connected to the male die 5 and the female die 6 to be wound by the winding roll 7. On the transfer film 2, a pattern, a character, or the like to be transferred to a molded product is printed in advance. When the pattern, characters, and the like are aligned with the mold, and the male mold 5 is pressed against the female mold 6 or suction is performed from the female mold 6, the transfer film 2 is heated by the heater 4 and easily stretched. , And deforms along the shape of the female mold 6.
Thus, when the resin is injected from the male mold 5, the pattern, characters, and the like of the transfer film are transferred to the molded product during injection molding.

FIG. 2 is a view showing a state where the transfer by the transfer film 2 to the molded article 8 is performed by the above-described method. A printed molded product 9 in which characters are transferred to the upper surface of the three-dimensional molded product is produced, but the printed surface is actually distorted as shown in FIG. This is because the transfer film 2 extends.
In particular, in the case of a pattern having characters, distorted characters are very difficult to read, which is a problem.

Conventionally, in order to correct such a distortion, a print molded article 9 having a distorted pattern, character, or the like as shown in FIG. 3 is produced as a trial, and the amount of print distortion of the prototype is manually determined. I am working on measuring and correcting the composition on which the original patterns, characters, etc. were drawn. A prototype is further created based on the corrected composition, and the work of measuring and correcting the amount of distortion is repeated to obtain a final composition to be used.

[Problems to be solved by the invention]

However, the conventional manual distortion correction requires time and effort, which increases the cost and makes it very difficult to create a good copy. For example, if distortion correction is performed manually on a molded product with a size of 300 x 300 mm using a grid pattern of 1 mm, the number of intersection points of the grid may reach 90,000 points, and this must be input manually. Is very difficult. Although the number of intersections can be reduced by roughening the grid, the accuracy is reduced, so that high-quality correction cannot be performed.

Accordingly, an object of the present invention is to provide a picture film distortion correction method having characters that can perform high-quality correction in a short time.

[Means for solving the problem]

The present invention, when a two-dimensional pattern film formed with a reference pattern having a plurality of reference points is formed into a three-dimensional three-dimensional shape according to the molded product, a distortion pattern obtained by distorting the reference pattern, Inputting a two-dimensional first coordinate system; and inputting a pattern on which a contour figure representing a contour of a character to be given to the molded product is to be corrected into the first coordinate system,
A step of superimposing the distortion pattern on the same coordinate system, a step of defining a reference pattern on the second coordinate system, and a first coordinate system based on the correspondence between the reference point of the reference pattern and the reference point of the distortion pattern. Obtaining a mapping of the above pattern on the second coordinate system, outputting the mapping obtained on the second coordinate system as a correction pattern, and assigning a character based on the distorted contour figure on the correction pattern. And performing the distortion correction of the picture film having characters by the following steps.

(Operation)

According to the present invention, first, a picture film on which a reference pattern is printed is formed according to a formed product. As a result, the pattern on the picture film is distorted. So the first
In the coordinate system, a regular contour figure without distortion is superimposed on the distorted pattern. On the other hand, a regular reference pattern is created on the second coordinate system. Then, a mapping of the contour figure on the first coordinate system is obtained on the second coordinate system based on the positional relationship between the reference points corresponding to the two patterns created in both coordinate systems. The mapping of the contour figure thus obtained is a distorted figure. Characters are assigned based on the distorted outline figure, and a picture film is created. Therefore, characters will be assigned to distorted positions on the picture film, but if this picture film is molded according to the molded product, the letters given instead of the picture film being distorted will be placed at regular positions without distortion. Assigned.

〔Example〕

Hereinafter, the present invention will be described based on the illustrated embodiments.
Here, first, an example in which not only characters but also a general pattern is transferred to a molded product will be described.
In the following, a description will be given of an embodiment of character assignment which is a feature of the present invention.

§1 Basic Configuration of Apparatus FIG. 4A is a block diagram showing a configuration of a transfer film distortion correction apparatus according to the present invention, and FIG. 4B is a detailed view of a distortion correction processing unit. Distortion pattern image reader 11
Is a device for inputting a distortion pattern as an image, and includes a CCD camera, an ITV, and the like. The image-to-be-corrected input device 12 is a device for inputting a pattern to be transferred to a molded product, and may be a device such as a flat scanner. The pattern is input using the composition or original information. Note that a CAD system can also be used as the corrected image input device 12. In this case, the digital data created by the CAD system is directly input as the picture. The arithmetic processing device 13 is a device that corrects a pattern based on data input from these devices, and has an image processing unit 14 and a distortion correction processing unit 15. The image processing unit 14 has a function of extracting the position coordinates of each reference point based on the pattern input from the distortion pattern image reading device 11, and the operation will be described later in detail. The distortion correction processing unit 15 is based on the data supplied from the image processing unit 14,
It has a function to correct the picture input from the user. A storage device 16 such as a magnetic disk or a magnetic tape is externally connected to the distortion correction processing unit 15, and can store data input once, calculated data, and the like. The storage device 16 may be incorporated in the arithmetic processing device 13. Distortion correction processing unit
The corrected picture corrected in 15 is output by the corrected picture output device 17. As the corrected picture output device 17, devices such as a plotter, a dot impact printer, an ink jet printer, a thermal transfer printer, and a film recorder can be used. In addition, data can be temporarily output to a storage medium such as a floppy disk or a magnetic tape, and the data can be transmitted to another output device offline. In this case, the corrected picture output device 17 is a drive device for each storage medium. The distortion correction processing unit 15 includes a first coordinate system 18 and a second coordinate system, as shown in FIG.
19 and a mapping operation device 20, the operation of which will be described later in detail.

§2 Basic operation of the apparatus Here, first, the operation of the entire apparatus shown in FIG. 4 (a) will be described. As shown in FIG. 2, when the transfer film 2 is formed in conformity with the molded product 8, the pattern is distorted as shown in FIG. Therefore, for example, FIG.
As shown in (b), when a square lattice pattern is printed on the transfer film 2 and the transfer film 2 is actually formed in accordance with the molded product 8, the transfer film 2 is elongated, so that the pattern is distorted as shown in FIG. become. The same applies to the case where only the transfer film 2 is molded by sucking into a female mold without actually forming a molded product. The manner of forming the transfer film is clearly shown in the top views of FIGS. 5 (c) and 5 (d). Here, an example using a square lattice pattern is shown.
In short, any pattern can be used as long as it is a reference pattern having a plurality of reference points.
In general, patterns such as a grid pattern, a pattern of oblique coordinates, and a pattern of polar coordinates are preferable. In the case of a square lattice pattern, each intersection of the lattice, that is, the four vertices of each square, is the reference point. In addition, if a mark for positioning with the mold is provided on a part of the transfer film and the mark for positioning is matched with the mold at the time of molding, the positioning in a later step becomes easy.

The operator uses the distortion pattern image reading device 11 to input a distortion pattern as shown in FIG. As will be described later, this distortion pattern image reading device 11 is specifically a device such as a video camera, and the read image data is processed by an image processing unit 14 into an image such as a binarization process and a thinning process. The processing is performed, and the position of each intersection (grid point) is detected. On the other hand, the operator operates the image input device 12 to be corrected.
, The picture is input as image data from the composition or original of the picture to be printed.

The distortion correction processing unit 15 generates a corrected image based on the data processed by the image processing unit 14, the data input by the image input device 12 to be corrected, and a previously stored square lattice pattern without distortion. I do. The corrected picture is output to the outside by the corrected picture output device.

Subsequently, the operation of the image processing unit 14 and the distortion correction processing unit 15 will be described in detail in another chapter.

§3 Operation of image processing unit 3.1 Overall procedure The operation of the image processing unit 14 is shown in the flowchart of FIG. First,
In step S1, a binarization process is performed. The image provided from the distortion pattern image reading device 11 is an image having a gradation. For example, one pixel has any density value between 0 and 255. When this is binarized,
All pixels take either "0" or "1". As the binarization method, generally, a binarization using a fixed threshold and a binarization using a floating threshold are known. The former is a method of dividing each pixel into “1” or “0” at a fixed density value (for example, an average value of density values of all pixels). The latter is a method in which the density value serving as a boundary is changed in each part in the image, and is effective when a brightness distribution due to illumination occurs at the time of image reading. FIG. 7A shows an example in which the distortion pattern of the square lattice is binarized.

Subsequently, in step S2, a thinning process is performed.
This is a process of thinning the binarized pattern so that the line width becomes one pixel. Such thinning processing is performed, for example, by referring to “Image Processing Subroutine Package SPIDER U
Since it is a well-known method described in detail from page 491 of "SER'S MANUAL" (Showa 57, published by Kyodo System Development Co., Ltd.), the description is omitted here. FIG. 7B shows an example in which the pattern of FIG. 7A is thinned.

Finally, in step S3, an intersection tracking process is performed. This is a process for determining an intersection V as shown in FIG. 7C from the pattern subjected to the thinning process as shown in FIG. 7B. FIG. 8 is an enlarged view of the thinned pattern shown in FIG. 7B. Here, one pixel is indicated by a circle. The intersection tracking processing determines which pixel is the intersection (that is, the lattice point of the lattice pattern) among the many pixels connected to each other in this manner. Next, details of the intersection tracking processing will be described with reference to the flowcharts of FIGS. 9 and 10.

3.2 Intersection Tracking Processing First, in step S4, the number of connections is calculated for each pixel. Here, the connection number for a certain pixel is
This is a number indicating how many different pixels exist around it. As shown in FIG. 11, the connection number C of the pixel of interest indicated by hatching is 0 to 4 in each of FIGS. Since the thinning processing has been performed, the surrounding pixels are always isolated from each other,
The number of connections C = 4 is the maximum value. The attribute of the point of interest can be determined as follows from the number of links.

C = 0 Isolated point (example: point a in FIG. 8) C = 1 End point (example: point b in FIG. 8) C = 2 Continuous point (example: point c in FIG. 8) C = 3 bifurcation point ( (Example: points d1 to d4 in FIG. 8) C = 4 intersection (example: point e in FIG. 8) Next, in step S5, an initial tracking start point is instructed. The operator can specify a point that can be clearly recognized as an intersection (for example, point e) as the initial tracking start point by viewing the display as shown in FIG. If the operator first specifies this point, the other intersections are automatically determined by the procedure from step S6. In step S6, a tracking start point and a tracking direction are determined. In this case, the tracking start point is the initial tracking start point specified in step S5. Further, the tracking direction may be set in advance, for example, to the right. In the following procedure, the intersection is sequentially tracked rightward from the tracking start point. FIG. 12 shows a conceptual diagram of such intersection tracking. For example, if the tracking start point is point S1, tracking is performed in the direction of the solid arrow in the figure,
Intersections S2, S3, S4 are determined. When tracking in the right direction becomes impossible, tracking in the reverse direction indicated by the broken arrow in the figure is performed from point S1. When tracking in the horizontal direction like this, tracking is performed only in the right or left direction,
No vertical tracking is performed. Therefore, for example, even if it is recognized that the point S5 is an intersection, tracking to the intersection S5 is not performed at present. Actually, the intersection tracking is performed in the following procedure.

First, an intersection detection process is performed in step S7. Now
In FIG. 13 (a), it is assumed that tracking is performed in the direction of the arrow in the figure, and that each intersection up to intersection a has been tracked. Here, "a certain intersection has been tracked" means that a certain pixel is a lattice point of a lattice pattern,
In this state, the coordinate values are also confirmed, and the topological position in the lattice is also confirmed. The confirmation of the topological position is such that, for example, in FIG. 13 (b), the connection state of the intersection as shown by the solid line is correct, and the connection state as shown by the broken line is incorrect. The intersection detection process of step S7 is a process of detecting three intersections b, c, and d connected to the intersection a. Since the intersection behind the arrow has already been tracked, three intersections b, c, and d remain as untracked intersections adjacent to the intersection a, and these three intersections are obtained in step S7.

Next, in step S8, it is determined whether tracking is successful. Among the three intersections, the intersection (the intersection c in this case) located at the topological center is the intersection to be tracked next, and it is determined whether or not this is appropriate as the tracking intersection. . That is, it is determined whether it is appropriate to trace the intersection c after the intersection a. This may be determined, for example, by determining whether the distance between the points ac is within a predetermined range.

If the intersection c is appropriate, the tracking c is recorded as a tracked intersection in step S9 as tracking success. Specifically, a matrix for recording the tracked intersection coordinates is prepared, and the coordinate value of the intersection c is recorded to the right of the coordinate value of the intersection a. By using a matrix in this way, the position of the intersection and the phase relationship can be recorded simultaneously. Subsequently, an untracked intersection is recorded in step S10. here,
The untracked intersections are the intersections b and d in FIG. 13 (a). Since the intersection tracking is performed in the right direction, at this stage the intersections b and d
Are not tracked, but since they were recognized as intersections, we record the fact that these points are intersections but have not been tracked yet.

Thus, the process returns to step S7 again, and the next three intersections e, f, and g
Is detected. Hereinafter, this procedure is repeated, and intersection tracking is performed rightward and rightward. Thus, as shown in FIG. 13 (c), the hatched intersection is recorded as a tracking intersection, and the intersection indicated by a double circle is recorded as an untracked intersection. The intersections indicated by the crosses have not been detected yet.

If the tracking is not successful in step S8, it is determined in step S11 whether the reversal of the tracking direction has been performed so far.If the reversal has not yet been performed, the tracking direction is reversed in step S12, and Tracking continues. That is, tracking is performed in the direction indicated by the dashed arrow in FIG. If the tracking has not been successful and the tracking direction has been reversed, it is determined in step S13 whether or not an untracked intersection remains. If it remains, the process returns to step S6, and tracking is continued with any one of the untracked intersections as a new tracking start point. That is,
In FIG. 13 (c), any one of the intersections indicated by double circles is set as a tracking start point, and first, tracking is performed in the right direction. By this tracking, the intersection that was an untracked intersection (double circle) until now changes to a tracked intersection (hatched), and at the same time an intersection (x mark) that was not detected until now is detected And recorded as a new untracked intersection. Eventually, in the subsequent processing, the intersection sequentially changes from an undetected intersection (x) to an untracked intersection (double circle) and finally to a tracked intersection (hatched). When there are no untracked intersections in this way, all the intersections have been tracked, and the position coordinates of the intersection V as shown in FIG. 7 (c) are obtained.

3.3 Intersection Detection Processing Next, the details of the intersection detection processing in step S7 in FIG.
This will be described with reference to the flowchart in the figure. As described above, this processing is processing for detecting intersections b, c, and d from the intersection a in FIG. 13 (a). First, in step S14, the detection direction is determined. In the example of FIG. 13 (a), if the intersection b is detected, the upward direction is the detection direction. Then, in step S15, one pixel is tracked in the detection direction. That is, attention is paid to the pixel g. Then, it is determined whether the attribute of the focused pixel is a branch point (step S16), an intersection point (step S17), an end point (step S18), or a continuous point (step S19). (Because the pixels are sequentially tracked, they are not isolated points.) This attribute can be determined by referring to the number of connected pixels obtained in step S4 as described above. As long as the tracked pixels are continuous points, the process returns to step S15 to continue tracking one pixel. In the example of FIG. 13 (a), the intersection point a to the point b (at this point, it is not recognized that the point b is the intersection point).
The tracking is performed upward one pixel at a time. (1) If a pixel having the attribute "intersection" is found (step S17), it is determined in step S21 that an intersection has been detected. In this case, the coordinate position of the pixel becomes the coordinate position of the intersection as it is. For example, the attribute of point e in FIG. 8 is “intersection point”, and this coordinate position is the coordinate position of the intersection point as it is.

(2) If a pixel having the attribute “branch point” is found (step S16), a pair of branch points is searched for in step S20, and the average coordinates of the two are set as the coordinate position of the intersection. For example, if the point d1 in FIG. 8 is found as a point having the attribute "branch point", a branch point d2 corresponding to this point is searched for. For this, for example, d2 may be searched as another branch point existing within a predetermined radius from the branch point d1. It is considered that such a pair of branch points was originally one intersection, so the line segment d1d2
Is set as the coordinate position of the intersection. The same applies to the branch point pairs d3 and d4.

(3) If a pixel having the attribute "end point" is found (step S18), in step S22, "intersection cannot be detected"
Make a judgment.

In this manner, the detection of the adjacent intersection is performed. As described above, when performing intersection tracking, three adjacent intersections are detected for one intersection. Therefore, until step S23 is completed for all detection directions, step S14
Are repeated, and three intersections are detected.
Note that such intersection detection is processing that is necessary only when no intersection is detected, and is unnecessary processing when an adjacent intersection is already detected as a tracked intersection or an untracked intersection. .

3.4 Another Method of Obtaining Intersection I As described above, the image of the binarized distortion pattern as shown in FIG. 7A is thinned as shown in FIG. The position of the intersection is to be determined as shown in FIG. 3 (c). Another simpler method for obtaining the position of the intersection will be described here. This method does not require any procedures such as thinning and intersection tracking. From the binarized image shown in FIG. 7 (a), the intersection position (to be exact, not the intersection position itself but the position of a point corresponding to the intersection) can be obtained.

As shown in FIG. 7A, the image of the binarized distortion pattern is a set of white or black pixels. The thinning process described above is a process of narrowing the width of a black portion to one pixel, and the intersection tracking process is a process of further determining the position of a black pixel that is an intersection. In any case, it can be said that the processing focuses on the black pixel. Another method described here is a process that focuses on white pixels. An enlarged view of the pattern shown in FIG. 7A is shown in FIG. Here, the white portion is composed of many white pixels, and the black portion is composed of many black pixels. Now, when the geometric center of gravity W is obtained for each independent white portion,
As shown in FIG. 7 (d), the center of gravity W is determined at the center of each white portion. The position coordinates of the center of gravity W can be obtained by a simple arithmetic operation. The feature of this method is that the center of gravity W
Is used instead of the intersection V. As shown in FIG. 7 (d), the center of gravity W also has a lattice arrangement, just like the intersection V has a lattice arrangement. FIG. 7 (e) shows the relationship between the grid consisting of the intersections and the grid consisting of the center of gravity. Assuming that there is a grid consisting of intersections as shown by the solid lines in this figure, the grid consisting of the centers of gravity is a grid shown by the broken lines in the figure. Although the positions of the respective lattice points are shifted, all have substantially the same phase information as the lattice. Therefore, if the original lattice has a distortion, the lattice formed by connecting the centers of gravity of the lattice has the same distortion. After all, instead of finding the intersection V in FIG. 7 (d), finding the center of gravity W and treating this as the intersection does not cause any trouble. This method has the merit that not only the operation is simple, but also that it is less susceptible to noise mixed in during image reading.

3.5 Another Method of Obtaining Intersections II The above methods are all methods of obtaining intersections after performing thinning processing. Here, a method for obtaining intersections without performing thinning processing will be described. FIG. 14A shows a part of the pattern before the input pattern is thinned. That is, it corresponds to a partially enlarged view of the pattern shown in FIG. Here, each pixel is represented by a white circle. Although a human can recognize this pattern as a part of a horizontal line having a width W, analysis by a predetermined algorithm must be performed in order for the computer to recognize the pattern.

Therefore, first, a circle having a diameter R is defined. Where R> W
Set so that The area surrounded by the circle is called a spot closed area. This spot closed area is
As shown in FIG. 14 (a), the pixel is superimposed on a part of the pattern, and a pixel on or near the boundary of the spot closed area is extracted as a boundary pixel. FIG. 14 (b) is an enlarged view of FIG. 14 (a). Here, the pixels indicated by hatching are the extracted boundary pixels. In this example, the boundary pixels have a distribution divided into two groups, G1 and G2. When the distribution of boundary pixels is divided into two groups in this way, it is determined that the current spot closed area is on a continuous point of the pattern. That is, it is equivalent to FIG. 11 (c) in the above embodiment. After all, the point of this method is that the number of groups in the distribution of boundary pixels should be treated equivalently to the connection number C in the above-described embodiment. In the case of FIG. 14 (b), since the number of groups is 2,
What is necessary is just to treat it as equivalent to the case where the continuous number C = 2.

When the same determination is made for the spot closed area SP3 in FIG. 14 (c), since the boundary pixel is only one group, it becomes equivalent to the case where the number of connections C = 1, and corresponds to FIG. 11 (b). What should I do? That is, it is determined to be an end point.

When the same determination is made for the spot closed area in FIG. 14 (d), the boundary pixels are divided into four groups G1, G2, G3, G4, which is equivalent to the case where the number of connections C = 4. A treatment corresponding to (e) may be performed. That is, the intersection is determined.

When the same judgment is made for the spot closed area in FIG. 14 (e), the boundary pixels are divided into three groups G1, G2, G3, which is equivalent to the case where the number of connections C = 3, and FIG. )
What should be done is equivalent to. That is, it is determined to be a branch point.

As described above, the intersection can be recognized without performing the thinning processing. In FIG. 14 (d), the position of the intersection is a straight line connecting the barycentric position of the group G1 pixel and the barycentric position of the group G2 pixel, the barycentric position of the group G3 pixel and the barycentric position of the group G4 pixel. Intersection PX with a straight line connecting
May be obtained, and these may be used as intersection coordinates.

The tracking from the intersection to the next intersection is shown in Fig. 14 (c).
As shown in (2), when the determination on one spot closed area SP1 is completed, the spot closed area may be moved to SP2 and the same determination processing may be repeated. As shown in FIG. 14 (b), the moving direction of the spot closed area is set to the direction of a straight line 1 connecting the barycentric position g1 of the pixel of the group G1 and the barycentric position g2 of the pixel of the group G2. The movement pitch Pt may be specified by an operator so that Pt <R. However, when Pt << R, processing takes too much time, which is not preferable. FIG. 14 (e)
FIG. 3 shows an example of a branch point, but since a thinning process is not performed, a branch point does not appear theoretically.

§4 Operation of the distortion correction processing section 4.1 Overall procedure As described above, the distortion correction processing section 15 stores in advance reference pattern data as shown in FIG. 5 (c). In addition,
This reference pattern data may be read from the storage device 16. The distortion correction processing unit 15 includes an image processing unit 14.
The distortion pattern data as shown in FIG. 5 (d) is given, and the data of the image to be corrected is provided from the image input device 12 to be corrected. Two coordinate systems are prepared in the distortion correction processing unit 15 as shown in FIG. 4 (b).

Hereinafter, the operation will be described with reference to the basic configuration diagram of FIG. 4 (b) and the flowchart of FIG. First,
The distortion pattern data is given to the first coordinate system 18 (step
S24), the reference pattern data is given to the second coordinate system 19 (step S25). The corrected pattern data is the first
This is given to the coordinate system 18 (step S26). In this example,
The case where the character “A” is treated as a picture will be described. Therefore, on the first coordinate system 18, a normal character (corrected picture) "A" not distorted in the distorted pattern overlaps. The mapping calculation device 20 converts the mapping of the character “A” into the second based on the correspondence between the reference point of the reference pattern on the first coordinate system 18 and the reference point of the distortion pattern on the second coordinate system 19.
The calculation to be performed on the coordinate system 19 is performed (step S27). This mapping shows the distorted letter "A" as shown in FIG.
(Corrected pattern). The image data of the distorted character “A” is output to the corrected picture output device 17.
In response to this, the corrected picture output device 17 (for example, a plotter) draws the distorted character "A" as a corrected copy (step S28). If the distorted character "A" is printed on the transfer film 2 based on the corrected copy and formed and transferred under the same conditions as the previous time, as shown in FIG. As a result, the letter “A” without distortion is transferred to the upper surface of the printed molded product 9.

4.2 Embodiment of Mapping Operation Next, an embodiment of the mapping operation performed by the mapping operation device 20 will be described. As shown in FIG. 4 (b), the mapping operation device 20
The task of obtaining the mapping of each point constituting the picture on the first coordinate system 18 on the second coordinate system 19 is performed. That is, it is only necessary that the mapping point Q on the second coordinate system 19 can be obtained for any one point P on the first coordinate system 18.

Conventionally, there has been known a method of obtaining a function f for converting a normal pattern on the second coordinate system 19 into a distorted pattern on the first coordinate system 18. However, in order to find the mapping point Q of the point P, it is necessary to find the inverse function g of the function f, which is a mathematically very difficult task. Therefore, a method that does not use such a function is considered. Now, one point P is a reference point (lattice point)
If the point is located at the position, the mapping point Q for this point can be easily obtained. That is, in FIG. 4B, the mapping point of one point P1 is the point Q1. The lattice points corresponding to the topological points of the square lattice are the mapping points. The problem is a method of obtaining a mapping point Q2 for a point such as one point P2 inside the lattice. Here, the second point corresponding to the lattice ABCD to which the point P2 belongs
The grid EFGH on the coordinate system can be readily found as a topologically corresponding grid. In the case of this example, since the grid to which the point P2 belongs is the lower right grid, the corresponding grid on the second coordinate system is also the lower right grid. Subsequently, a point Q2 corresponding to one point P2 in the grid ABCD may be obtained in the grid EFGH.
This point Q is ultimately determined as a point at a position corresponding to the point P in phase. As described above, several methods have been conventionally known for obtaining a topologically corresponding point. However, all of the conventional methods have a problem that a step is formed in a picture. That is, as shown in FIG. 16 (a), when the mapping of each point constituting the pattern extending over two adjacent unit lattices is obtained, the mapping as shown in FIG. 16 (b) is obtained. However, in the conventional method, a step is generated as shown in FIG. The inventor of the present application has devised several specific methods capable of obtaining a mapping in which a pattern does not have a step. Four examples will be described below.

The following four methods apply the same rules to all of them. That is, when calculating a mapping for a point (for example, point P in FIG. 16 (a)) that straddles an adjacent unit cell, two grid points (the 16th point) sandwiching the straddling point are obtained.
The mapping (point Q in FIG. 16 (b)) is determined only by the coordinate values of the points B and C in FIG. (A). If the mapping is obtained by a method that satisfies such a condition, the problem that a step is formed in the picture can be solved.

<M: n Division Method> First, the first method will be described with reference to FIG. Now, as shown in FIG. 17 (a), one point P in the grid point ABCD
Is mapped to a square lattice EFGH shown in FIG.
Consider the case of seeking within. First, a square ABCD is created by connecting the grid points ABCD. Then, the intersection point X of the straight line AB and DC is connected to the point P by a straight line, and a ratio m: n at which the point P divides a portion of the straight line in the rectangle ABCD is determined. Further, the intersection point Y of the straight lines AD and BC and the point P are connected by a straight line, and a ratio q: r at which the point P divides a portion of the straight line in the rectangle ABCD is determined. On the other hand, in the square lattice EFGH, a straight line connecting two points IJ dividing the sides EF and HG into m: n and a straight line connecting two points KL dividing the sides FG and EH into q: r are drawn, This intersection is designated as point Q. Since each point is given by a two-dimensional coordinate value of (x, y), the above method can be performed by a very easy operation. As shown in FIG. 18, when the opposite side of the square ABCD, for example, the side BC and AD are parallel, the intersection Y is not obtained. In this case, a straight line passing through the point P and parallel to the side BC or AC is drawn. Just think.

<Equal Partition Method> The second method will be described with reference to FIG. First, the 20th
As shown in FIG. 3A, points I and J passing through the point P and dividing the side AB and the side CD at an equal ratio m: n (AI: IB = DJ: JC = m:
n and points K and L passing through the point P and dividing the side BC and the side AD at equal ratios q: r (AK: KD = BL: LC = q: r)
And a straight line l2 passing through. Using the ratios at this time, m: n and q: r, a mapping point Q is obtained as shown in FIG. 20 (b). That is, two points I ′ dividing the sides EF and HG into m: n, respectively.
The intersection point of a straight line connecting J 'and a straight line connecting two points K'L' that divide the sides FG and EH into q: r may be set as a point Q.

An example of a method for calculating m: n by calculation will be described below. Now
The coordinates of the four points ABCD are (xa, ya), (xb, yb),
(Xc, yc), (xd, yd), and the coordinate value of the point P is (xp, yp)
And Here, coordinate values of points I and J are represented by (xi, yi), (xj, y
j), xi = m · (xb−xa) + xa (1) xj = m · (yb−ya) + ya (2) yi = m · (xc−xd) + xd (3) yj = m · (yc −yd) + yd (4) In general, a straight line passing through two points X1 (x1, y1) and X2 (x2, y2) is (y−y1) (x2−x1) = (x−x1) (y2−y1) (5) is represented by Accordingly, the equation of the straight line l1 is as follows: (y-yi) (xj-xi) = (x-xi) (yj-yi) (6) Substituting equations (1) to (4) into this equation, and x, y
By substituting the coordinates (xp, yp) of the point P into the following equation, an expression for m in the form of am ² + bm + c = 0 (7) is obtained. Here, a to c are coefficients obtained from known coordinate values. By solving the equation (7), m satisfying 0 ≦ m ≦ 1 is obtained.

Since n = 1−m (8), the ratio of m: n can be obtained by calculation. q: r
Is similarly obtained.

<Distortion Amount Method> Next, a third method will be described. First, the ratio of m: n and q: r is determined by using the above-described first method or second method. Here, the case where these ratios are obtained by the first method will be described. In FIG. 19, the difference between the x and y coordinate values of the corresponding vertex of the square EFGH (FIG. 4 (b)) is determined for the x and y coordinate values of each point ABCD. For example, when the coordinate value of the point A is (x, y) and the coordinate value of the point E is (x *, y *), the difference is Δ1x = x−x *, Δ
1y = y−y *. For each point of ABCD,
Determine as shown in the figure. Then, the total sums Δx and Δy of the differences are obtained by the following equations.

Δx = Δ1x · n / (m + n) · r / (q + r) + Δ2x · m / (m + n) · r / (q + r) + Δ3x · m / (m + n) · q / (q + r) + Δ4x · n / (m + n) · q / (Q + r) Δy = Δ1y · n / (m + n) · r / (q + r) + Δ2y · m / (m + n) · r / (q + r) + Δ3y · m / (m + n) · q / (q + r) + Δ4y · n / ( (m + n) · q / (q + r) A point Q is obtained at coordinates obtained by moving the point P by the differences Δx and Δy.

<Triangle Vector Ratio Division Method> Finally, the fourth method will be described with reference to FIG. In this method, as shown in FIG. 21 (a), a square to which point P belongs is divided into two triangles, and the triangle to which point P belongs is extracted to obtain a mapping. That is,
Square ABCD and square EF in the previous three methods
Instead of GH, use triangle ABC (Fig. 21 (b)) and right-angled isosceles triangle DEF (Fig. 21 (c)), respectively, and ignore paired triangles indicated by dashed lines in the figure. I just need.

First, the vector ▼ is subtracted from the point A to the point P, and the coefficients お よ び and b are obtained by expressing the vector ▼ as ▼ = a ▼ + b ▲ with the vector ▼ and the vector ▼ as unit vectors. Where 0 ≦ a ≦
1, 0 ≦ b ≦ 1. And two unit vectors ▲
A vector ▼ represented by ▼ = a ▲ + b で is obtained by ▼ and ▼, and a point Q is obtained as the tip position.

4.3 Supplement on Mapping Operation Finally, a preferred embodiment for performing a specific mapping operation will be supplementarily described.

First, when the pattern data to be corrected is given to the first coordinate system as vector data, it is preferable to obtain a mapping after subdividing this vector data. For example, as shown in FIG. 22 (a), when the pattern to be corrected is given by vectors at five points, when mapping of these five points is obtained and the mapping points are connected by a new vector, fine points between the points are obtained. Information is lost. Therefore, first, as shown in FIG.
After subdividing the vector data and minimizing the length of one vector, as shown in FIG. 3C, if a mapping is obtained in the second coordinate system to obtain a corrected pattern, even fine information between points can be obtained. Will be reproduced.

If the corrected picture data is given as raster data to the first coordinate system, the corrected picture obtained in the second coordinate system may have missing pixels. This is shown in FIG. Here, FIGS. 6A and 6B show a corrected pattern and a distortion pattern given to the first coordinate system, and FIGS. 6C and 6D show a corrected pattern and a corrected pattern given to the second coordinate system. 3 shows a reference pattern. The mapping of the pattern to be corrected shown in FIG. 7A corresponds to the corrected pattern shown in FIG. 7C, but it can be seen that pixel omission has occurred in a portion indicated by a white circle in FIG. This is because a mapping was obtained in the second coordinate system for each pixel in FIG.

One method for dealing with such pixel omission is a method of performing interpolation based on surrounding pixels. For example, a pixel indicated by a black circle in the figure is represented by “1”, and other pixels are represented by “0”.
If the sum of the values of the eight surrounding pixels among the pixels having the value “0” is equal to or more than a predetermined value (for example, 5 or more), the operation of correcting the pixel to “1” is performed. All pixels indicated by white circles in FIG. 9C are corrected to black circles.

Another method for dealing with pixel omission is a method of obtaining an inverse mapping to the first coordinate system and performing interpolation based on a pixel at the position of the inverse mapping. For example, when the inverse mapping to the first coordinate system is obtained for the white circle pixel in FIG.
The mapping should be obtained at the position of any of the black circled pixels. Therefore, if there is a black dot at the position of the inverse mapping, interpolation may be performed so that the original pixel on the second coordinate system is also corrected to a black dot.

It should be noted that such a method of obtaining the inverse mapping can be used not only for interpolation of missing pixels, but also for obtaining the raster data itself of the corrected pattern on the second coordinate system. In this case, for each pixel on the first coordinate system, the operation of obtaining a mapping on the second coordinate system becomes unnecessary. For example, in the example shown in FIG. 23 (c), 10 × 10 pixels are defined on the second coordinate system. It is undecided whether each pixel is "0" or "1". Then, for each pixel, an inverse mapping is obtained on the first coordinate system, and the value of each pixel defined on the second coordinate system is set to “0” based on the value of the pixel at the inverse mapping position. Or "1".

§5 Character Assignment Method The general example of the method of correcting the distortion of the picture film has been described above. Here, the method of correcting the distortion of the picture film having characters in particular will be described.

5.1 First Embodiment As described above, when a picture is transferred to a molded article using a transfer film on which a regular picture is printed, the picture on the molded article is distorted. Therefore, when a regular picture includes a character string, the character string on the molded product has a distortion in the character itself and a distortion in the character arrangement. The first embodiment described here is intended to correct distortion occurring in the arrangement of characters. The procedure will be described below.

First, using the apparatus shown in FIG. 4 (a), a distortion pattern as shown in FIG. 5 (d) is input from the distortion pattern image reading device 11, and this is processed by the image processing unit 14 to perform distortion correction processing. Department
The point given to 15 is the same as in the above-described embodiment. On the other hand, the corrected picture input device 12 inputs a corrected picture, that is, a normal picture without distortion. At this time, the character portion in the regular picture is represented not by the character itself but by a circumscribed rectangle corresponding to the outline figure of the character. For example, in the case of a picture having a character as shown in FIG. 24 (a), a circumscribed rectangle as shown in FIG. 24 (b) is defined, and the picture is replaced with a character as shown in FIG. To represent only this circumscribed rectangle. Therefore, not the characters themselves, but a pattern in which the circumscribed rectangle is drawn is input from the corrected pattern input device 12.

Subsequently, the distortion correction processing unit 15 corrects the pattern, and the corrected pattern is output via the output device 17. The circumscribed quadrangles on the corrected picture and the arrangement thereof output in this manner are distorted as shown in FIG. 25 (a), for example. Based on the distorted circumscribed square array, the operator assigns characters to optimal positions as shown in FIG. That is, the distorted circumscribed square arrangement gives the operator a measure of character assignment. A transfer film is created based on the picture to which the characters are assigned in this manner. If the transfer film is formed in conformity with the molded product, the arrangement of the characters of the picture transferred on the molded product becomes less distorted.

5.2 Second Embodiment The first embodiment described above attempts to correct the distortion that occurs in the arrangement of characters, but the second embodiment described here corrects the distortion that occurs in the arrangement of characters. At the same time, it is intended to correct the distortion of the character itself. This second
In this embodiment, the procedure up to the step of outputting the corrected picture as shown in FIG. 25A is exactly the same as that of the first embodiment. However, in the first embodiment, characters of the same standard (for example, true colors) are assigned to the distorted circumscribed rectangle.
The second embodiment is different from the first embodiment in that a deformed character corresponding to the degree of distortion of the circumscribed rectangle is allocated. In general, various modified characters are prepared for a computer typesetting machine. For example,
The identity shown in FIG. 26 (a) is compared with the flat body of (b) and (c)
And modified characters such as italic in (d) are prepared in advance. Further, it is also possible to use a deformed character reduced or enlarged at an arbitrary magnification. Therefore, the operator looks at each of the distorted circumscribed rectangles on the corrected picture and selects the most suitable modified character, and allocates the selected modified character to an optimal position of each circumscribed rectangle. For example, if a circumscribed rectangle without distortion as shown in FIG. 27 (a) is obtained, the identity may be assigned, but in the case of FIG. 27 (b), a 30% flat body is assigned. In the case of FIG. 10C, a 30% long body is used, in the case of FIG. 10D, a 30 ° horizontal italic is used, and in the case of FIG. The vertical italics may be assigned respectively. Also, FIG.
In such a case, it is sufficient to assign a character whose identity is reduced by 30%. Further, in the case shown in FIG. 3G, a 30% flat body may be replaced by a 30 ° horizontal oblique body. In this way, various deformed characters are allocated on the transfer film, but if this transfer film is molded according to the molded product, the characters of the picture transferred on the molded product have less distortion. It is close to the true color, and the arrangement is also less distorted.

5.3 Effects of the Above-mentioned Embodiments In each of the above-mentioned embodiments, not the characters themselves, but a method of inputting a contour figure of the characters as a pattern and correcting this is adopted. Of course, a method of inputting the character itself as a picture and correcting the character itself is also conceivable, but such a method has the following problems.

(1) Problems at the time of input When a character itself is input as a picture, the following problems occur.

(I) Considering the case of inputting characters using an input device such as a scanner, a general flatbed scanner has a low resolution and cannot input fine characters accurately. If a large drum scanner is used, accurate input is possible, but the whole system becomes expensive.

(Ii) There is also a method of generating characters inside the system without inputting characters from the outside. In such a case, a character font equivalent to the computer typesetting machine for each typeface, such as Mincho and Gothic, is stored in the system. Must be carried, which makes the system bulky and costly.

(2) Problems During Processing Input characters become fine images, and the distortion correction process takes time.

(3) Problems at the time of output When outputting the corrected pattern by the plotter, fine characters cannot be accurately drawn because the pen of the plotter has a certain thickness.

In the present invention, only the outline of a character is input, distortion correction processing is performed on the outline, and the corrected outline is output, so that the above-mentioned problems are all solved.

§6 Industrial applicability As described above, an example in which the present invention is applied to the simultaneous injection painting method has been described. However, the present invention can be widely used in general for distortion correction of a transfer film or a laminating film. For example, in the process of manufacturing a can using a molding means or a molded product using a resin (for example, an in-mold molded product or a shrink film), when printing a pattern before molding,
Although the distortion of the picture is caused by the expansion and contraction of the material, even in such a case, if the corrected picture obtained by the present invention is printed, a picture without distortion after molding can be obtained.

In the above embodiment, the distortion correction of the transfer film has been described as an example. Such a transfer film is ultimately peeled off from the molded article, but can be applied to a laminating film that is finally bonded to the molded article and becomes a part of the product.

〔The invention's effect〕

As described above, according to the present invention, a transfer film on which a reference pattern is printed is molded in accordance with a molded product to obtain a distortion pattern, and the distortion pattern has a pattern having a regular character contour figure without distortion. A picture of the pattern on the first coordinate system is obtained on the second coordinate system on which the reference pattern has been created by superimposing on the first coordinate system, and characters assigned based on the outline figure on this map are used as the composition. As a result, it is possible to easily and accurately correct a composition having characters.

[Brief description of the drawings]

FIG. 1 is a basic configuration diagram of a general apparatus for performing the simultaneous injection painting method, FIG. 2 is an explanatory diagram of the simultaneous injection painting method, and FIG. 3 is a view illustrating a transfer film distorted as a result of performing the simultaneous injection painting method. It is. FIG. 4 (a) is a block diagram showing a basic configuration of a transfer film distortion correcting apparatus according to the present invention, and FIG. 4 (b) is a detailed explanatory diagram of a distortion correction processing unit in the apparatus shown in FIG. 4 (a). ,
FIG. 5 is a diagram showing that the transfer film is deformed by molding, and FIG. 6 is a flowchart showing a processing procedure of the image processing unit in the apparatus shown in FIG. 7 (a) to 7 (c) are diagrams showing processing results along the flowchart of FIG. 6, wherein FIG. 7 (a) is a pattern after binarization processing and FIG. 7 (b) is a thinning processing FIG. 14C shows the pattern after the intersection tracking processing. FIG. 7D is an enlarged view of FIG. 7A, and FIG. 7E is a conceptual view showing that the center of gravity can be used as an intersection. 8 is an enlarged view of the pattern after the thinning processing shown in FIG. 7 (b), FIG. 9 is a flowchart showing the detailed procedure of the intersection tracking processing in FIG. 6, and FIG.
It is a flowchart which shows the detailed procedure of the intersection detection processing in a figure. FIG. 11 is a diagram showing the principle of calculation of the number of links shown in FIG. 9,
FIG. 12 is a conceptual diagram of the intersection tracking processing shown in FIG. 9, and FIG. 13 is an explanatory diagram of the intersection tracking processing shown in FIG. FIG. 14 is an explanatory diagram of a method of obtaining an intersection without performing a thinning process. No.
FIG. 15 is a flowchart showing a processing procedure of a distortion correction processing unit in the apparatus shown in FIG. 4, FIG. 16 is a view for explaining a step generated in a picture by a mapping operation, and FIGS. 17 and 18 are m: FIG. 19 is an explanatory diagram of the n-division method, FIG. 19 is an explanatory diagram of the distortion amount space method according to the present invention, FIG. 20 is an explanatory diagram of the equal division method according to the present invention,
FIG. 21 is an explanatory diagram of a triangle vector ratio dividing method according to the present invention, FIG. 22 is an explanatory diagram of a method for obtaining a mapping after performing vector subdivision on a pattern represented by vector data, and FIG. 23 is raster data. About the pattern represented by
FIG. 24 is an explanatory diagram of a method for performing pixel omission interpolation of a mapping, FIG. 24 is an explanatory diagram of a character outline figure used in the present invention, and FIG. 25 is an explanation of character allocation in a distortion correction method according to the first embodiment of the present invention. FIG. 26 is a diagram showing an example of a deformed character used in the distortion correction method according to the second embodiment of the present invention, and FIG.
FIG. 14 is an explanatory diagram of character assignment in the distortion correction method according to the example of FIG. DESCRIPTION OF SYMBOLS 1 ... Supply roll, 2 ... Transfer film, 3 ... Cylinder, 4 ... Heater, 5 ... Male type, 6 ... Female type, 7 ... Winding roll, 8 ... Molded product, 9 ... Printed products, 11 ……
Distortion pattern image reading device, 12
13 arithmetic processing unit, 14 image processing unit, 15 distortion correction processing unit, 16 storage device, 17 corrected image output device,
18 ... first coordinate system, 19 ... second coordinate system, 20 ... mapping operation device.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-64-9775 (JP, A) JP-A-61-261094 (JP, A) JP-A-49-10956 (JP, A) JP-A-61-9610 267057 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B41M 3/00 B41M 3/12 B41M 1/40 B44C 1/165

Claims (2)

(57) [Claims] 1. A distortion pattern obtained by distorting a two-dimensional pattern film on which a reference pattern having a plurality of reference points is formed in a three-dimensional shape according to a molded product. In a two-dimensional first coordinate system, and in the first coordinate system, a picture in which a contour figure representing a contour of a character to be given to the molded article is drawn as a corrected picture. Superimposing on the distortion pattern on a coordinate system, defining the reference pattern on a second coordinate system, based on a correspondence between a reference point on the reference pattern and a reference point on the distortion pattern, Obtaining a mapping of a picture on the first coordinate system on the second coordinate system; outputting the mapping obtained on the second coordinate system as a correction picture; On the basis of Distortion correcting method of a picture film having a character, characterized in that it comprises the steps of performing a character assignment, the. 2. The method according to claim 1, wherein a circumscribed rectangle is used as the outline figure, and in the character allocating step, a deformed character corresponding to the degree of distortion of the circumscribed rectangle is allocated. A method for correcting distortion in picture films.