JP2003230003A - Method for generating bit map - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for converting a low resolution image into a high resolution image with high quality. <P>SOLUTION: In the case of deploying an original bit map into a bit map 2 with high resolution, two sets of 3 lines adjacent to each other in a direction Y are scanned in a direction X to detect first and second edges E3, E4, and edges E27 to E29 extended in the direction Y are used to interpolate the lines. Thus, it is possible to reproduce triangles formed by tying particular edges of the original bit map by a straight line on the bit map with high resolution and smoother interpolation can be attained in a short period of time without using a lookup table. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for converting an image to a resolution higher than that of the original image when displaying or printing the image.

[0002]

2. Description of the Related Art In a printer or the like, when printing an image, a bitmap in which pixels forming an original image are two-dimensionally arranged is converted into a bitmap having a large resolution and printed. In some cases, the quality of the printed image is improved by making the corner portion of the pixel pattern in the bitmap smoother.

A method for smoothing a corner portion is disclosed in JP-A-7-283946 or JP-A-7-28869.
No. 3, etc. The conventional method is to detect a pixel pattern of a corner portion from a bitmap and replace the pixel pattern with a smoothed pixel pattern of a look-up table prepared in advance. A method is also known in which the average value of two original pixel rows is inserted between these two original pixel rows to perform smoothing.

[0004]

First, the method of inserting the average value of two original pixel columns and performing smoothing is simple in processing and does not require the preparation of a lookup table. Therefore, it can be introduced easily. be able to. However, according to this method, since the corners are smoothed, the pixels are concentrated in the corners, so that the steps are rather conspicuous. As a result, in the original image, a portion where a plurality of steps are intermittently formed in order to represent an oblique contour is in a wavy state, and there is a problem that the linear contour is damaged by increasing the resolution.

The smoothing method using the look-up table obtains a smoother contour than that of the above method by preparing in advance a pixel pattern in which pixels arranged for smoothing are not concentrated in a corner portion. Is possible. For example, the above-mentioned Japanese Patent Laid-Open No. 7-2
In Japanese Patent No. 83946 and Japanese Patent Laid-Open No. 7-288693, not only pixels are added to fill the corners but also the pixels are cut off to smooth the white / black balance. However, since the lookup table is searched, the processing time is long. Further, it is not easy to generate the lookup table in advance. Further, since the pixel patterns that can be prepared in advance as the look-up table are limited, the range of the corner portion that can be corrected is also limited. Therefore, there is a possibility that the short-period unevenness can be corrected very well, but there is no ability to correct the long-period unevenness. For this reason, as described above, in the original image, if there is a portion where a plurality of steps are intermittently formed in order to express an oblique contour, the resolution is increased to cause a wavy state, and a linear shape is obtained. The problem that the contour is lost occurs.

Therefore, it is an object of the present invention to provide a method and an apparatus which can perform smoothing without using a look-up table and can also smoothly smooth long-period irregularities.
Further, there is provided a method and an apparatus capable of smoothing without impairing a linear contour when increasing the resolution of a portion where a plurality of steps are intermittently formed in order to express an oblique contour in an original image. The purpose is to do.

[0007]

Therefore, in the present invention, corners or steps are not filled with pixels or removed by smoothing, but corners appearing adjacently or side by side, that is, in the original bitmap Focusing on the edges that appear side by side in a certain direction, when increasing the resolution, smoothing is performed by arranging new edges so as to interpolate between these edges. That is, according to the first method of the present invention, the second bitmap with the increased resolution in the first direction is created from the first bitmap in which a plurality of pixels forming an image are two-dimensionally arranged.
A first detection step of detecting first and second edges appearing in a second direction orthogonal to the first direction from the bitmap of, and interpolation between these first and second edges is possible. , Between the third and fourth edges of the second bitmap corresponding to the first and second edges, respectively,
A first addition step of adding edges extending in the first direction so as to interpolate these third and fourth edges.

According to the method of creating a bitmap of the present invention, smoothing can be performed if the first and second edges are detected, so a look-up table is unnecessary.
Therefore, the smoothing range is not limited to a predetermined region, and long-period unevenness can be smoothed. Furthermore, by adding an edge that interpolates the third and fourth edges between the third and fourth edges of the second bitmap, pixels are arranged at any of the edges in a concentrated manner. Can also be prevented. Therefore, when increasing the resolution of a portion formed by intermittently forming a plurality of steps to represent an oblique contour, smoothing can be performed without impairing the linear contour.

Further, according to the bitmap creating method of the present invention, the work of creating the lookup table in advance is unnecessary, and since the lookup table is not required,
You can increase the resolution by increasing the magnification in a range that cannot be covered by the look-up table. Therefore, the bitmap creation method of the present invention is capable of enlarging an image with a flexible magnification,
It is possible to output a smooth image with an enlarged or higher resolution.

The method of creating a bitmap according to the present invention can be executed by a program having an instruction capable of executing the above-mentioned detecting step and additional step. Then, this program can be recorded in an appropriate recording medium or provided via a network. Also, from the first bitmap, a second direction orthogonal to the first direction for increasing the resolution can be obtained.
The first and second edges appearing side by side in the direction between the first detecting means and the third and fourth edges of the second bitmap respectively corresponding to the first and second edges. With the bitmap creation device in which the function as the first addition means for adding the edge extending in the first direction so as to interpolate the third and fourth edges is realized by a dedicated circuit, hardware logic, etc. According to the creating method of the invention, it is possible to create a second bitmap having an increased resolution in the first direction from the first bitmap.

It is desirable that the smoothing is performed on an edge which is increased / decreased by one pixel by quantization in the first bit map, and an edge which is increased / decreased by 2 pixels or more is smoothed and the original image is not processed. It is desirable to leave the edge shape of. Therefore, the first
In the detection step of, by scanning three pixels adjacent to each other in the first direction in the second direction orthogonal to the first direction,
It is possible to detect the first and second edges that will appear side by side with increasing resolution.

In the first detection step, when the center of three pixels adjacent in the first direction is the edge detection line,
When the pixel of the edge detection line changes from off to on, the combination of three pixels changes from “off-off-off” (in white and black, “white-white-white”) to “off-
The position after changing to “off-on (white-white-black)” or “on-off-off (black-white-white)” is defined as the first edge, and then “off-on-on (white-white)”. The position after changing to “black-black)” or “on-on-off (black-black-white)” can be the second edge. When the pixel on the edge detection line changes from on to off, the combination of three pixels is “on-on-off (black-black-white)”.
From "ON-OFF-OFF (black-white-white)" or "OFF-ON-ON (white-black-black)" to "OFF-OFF-ON (white-white-black)" before change Position as the first edge, then "off-off-off (white-white-white)"
The position before the change that has changed to can be set as the second edge. Further, when no pattern other than the pattern after the change of the first edge or the pattern of the second edge is detected between the first and second edges, the first and second edges are arranged side by side. Correct as an edge that appears.

Further, in this creating method, smoothing is performed by adding pixels. Therefore, in order not to make the white / black balance extremely non-uniform, it is desirable to add the edges in the range that does not exceed the straight line connecting the third and fourth edges in the first addition step.

When the second bit map also improves the resolution in the second direction orthogonal to the first direction, the second bit map is used.
Also in the direction of, smoothing can be performed in the same manner as described above. That is, from the first bitmap, the first
Between the second detection step of detecting the fifth and sixth edges appearing side by side in the direction of and the seventh and eighth edges of the second bitmap corresponding to the fifth and sixth edges, respectively. And a second additional step of adding an edge extending in the second direction so as to interpolate these seventh and eighth edges.

Similarly, when scanning in the first direction, the third
And the fourth edge can be detected. That is, in the second detection step, when the pixel of the edge detection line changes from OFF to ON when the center of three pixels adjacent in the second direction is the edge detection line, 3
The combination of two pixels changes from "OFF-OFF-OFF" to "OFF-
The position after changing to “off-on” or “on-off-off” is defined as the fifth edge, and the position after changing to “off-on-on” or “on-on-off” is defined as the fifth edge. When the number of edges is 6, and the pixels on the edge detection line change from on to off, combinations of three pixels are changed from "on-on-off" to "on-off-off" or "off-on-on" to " The position before change changed to “off-off-on” is defined as a fifth edge, and the position before change changed to “off-off-off” is defined as a sixth edge, and further, the fifth and sixth When no pattern other than the pattern after the change of the fifth edge or the pattern of the sixth edge is detected between the edges of, the fifth and sixth edges are considered to have appeared side by side and are valid. Further, in the second addition step, the edges in the range not exceeding the straight line connecting the seventh and eighth edges are added.

As described above, the bitmap creating method according to the present invention can be provided as a program, or can be provided as a dedicated chip.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be further described below with reference to the drawings. FIG. 1 shows an example of an original bitmap (first bitmap). This bitmap 1 is a 5 × 9 (5 × 9) bitmap, and an image 11 having four edges E1, E2, E3, and E4 from the left side of the drawing due to black dots.
Is drawn.

The bitmap 8 shown in FIG. 2 is an example of a bitmap in which the resolution of the original bitmap 1 is quadrupled in the row direction X and quadrupled in the column direction Y.
Of E4, smoothing is performed by inserting the average value of two original pixel rows into the corner formed by each of the edges E2 to E4. The edge E1 is not smoothed because it is unknown whether the edge E1 forms a corner. Therefore, on the left side of the edge E4, an edge E84 having a half height of the edge E4 is formed to fill the corner C4, and on the left side of the edge E3, a half height of the edge E3 is filled to fill the corner C3. An edge E83 is formed, and an edge E82 that is half the height of the edge E2 is formed on the left side of the edge E2 to fill the corner C2.

Since the corners C2 to C4 are filled with these edges E82 to E84, the edges E2 to E4 are
The vicinity of is smoothed, and edges E2 to E4 are not emphasized with respect to the image 11 of the original bitmap 1. However, the edges E2-E4
Since the pixels (dots or pixels) are added only in the vicinity of, the edges E2 to E4 are still clear, and these three edges E2 to E4 are still the emphasized image. On the contrary, the image has an impression that only the vicinity of the edges E2 to E4 is slanted, and the bitmap 81 prints an image 81 of an impression in which the contour curvature is finely changed and the contour is wavy.

The bitmap 9 shown in FIG. 3 is also an example of a bitmap in which the resolution of the original bitmap 1 is quadrupled in the row direction X and quadrupled in the column direction Y. In the bitmap 9, not only dots are added to fill the corners using a look-up table, but also the edges are cut off to smooth the white / black balance. Therefore, 3 forming the edge E4
One dot is cut and the corner C4 is filled with three dots, and the part from the corner C4 to the edge E4 of the original image 11 has four fine edges E91, E92, E93 arranged at substantially equal intervals. And E94 smoothed with a substantially linear image. Similarly, the portion from the corner C3 to the edge E3 and the portion from the corner C2 to the edge E2 are smoothed.

Therefore, no emphasized edge is found in the outline of the image 91 formed by the bitmap 9. However, the line forming the contour has a finely varying curvature and gives a wavy impression, as in the image 81 based on the bitmap 8 described above. Therefore, in the image 91 based on this bitmap 9, since the emphasized edges cannot be seen, the outline is smoother as compared with the above-mentioned image 81,
Again, the contour is wavy, and a smooth contour that is close to the straight line of the original image 11 and whose curvature does not change significantly does not appear.

The bitmap 2 shown in FIG. 4 is an example of a bitmap in which the resolution of the original bitmap 1 is quadrupled in the row direction X and quadrupled in the column direction Y by the creating method of the present invention. In this bit map 2, not only dots are added to fill the corners but also the edges are added so as to linearly interpolate between adjacent original edges. Therefore, in the bitmap 2, the original edges are smoothed linearly, and the image 21 is drawn with a linear contour with little variation in curvature.

That is, between the edges E3 and E4, edges E27, E28 and E29 extending in the Y direction are formed so as not to reach the straight line L3 obtained by interpolating these edges E3 and E4, and these edges are formed. E3, E2
7, E28, E29 and E4 delineate a straight line. Similarly, between the edges E2 and E3, edges E24, E25 and E extending in the Y direction so as not to reach the straight line L2 obtained by interpolating these edges E2 and E3.
26 are formed, and these edges E2, E24,
A straight line is drawn by E25, E26 and E3. Further, between the edges E1 and E2, edges E21, E22 and E23 are formed so as not to reach the straight line L1 obtained by interpolating these edges E1 and E2, and these edges E1, E21, E22, E23 and A straight line is drawn by E2.

FIG. 5 is a flowchart showing the process of creating a high resolution bitmap according to the present invention. First, in step 51, the original bitmap 1
Is input, a region for creating the high resolution bitmap 2 is secured in step 52. The high-resolution bitmap area may be prepared in the memory in advance, or the area may be dynamically acquired in the memory in this process. Further, in order to form the high resolution bitmap 2, all the areas may be acquired at one time, but as described later, each time the original bitmap 1 is scanned, the high resolution bit of the corresponding portion is acquired. The area for storing the map 2 may be sequentially acquired. Further, in this example, the high resolution bitmap 2 is an integer multiple (4
However, the resolution can be set to any multiple in the X and Y directions (row direction and column direction, or main scanning direction and sub scanning direction). Of course, the resolution does not increase in either direction. That is, it is also possible to make it 1 time.

Next, in step 53, the original bitmap 1 is converted into data for every 3 pixels adjacent in the Y direction.
The process as the first detection step of detecting the edge while scanning in the X direction is started. That is, the edge of the original bitmap 1 is detected by scanning the data of 3 lines adjacent in the Y direction in the bitmap 1 in the X direction. For example, in FIG. 1, the lines Y0, Y1 and Y2 are scanned in the X direction from X0 to X8.

At this time, first, in step 54, the black dot portion of the original bitmap 1 is copied to the high resolution bitmap 2. As a result, as shown in FIG.
The same image as the image 11 of the original bitmap 1
It is reproduced in the high resolution bitmap 2 expanded to 4 × 4. At the same time, in step 55, it is determined whether the first edge has been found.

If the first edge is not found, it is judged in step 56 whether or not it is the first edge. The recognition as an edge is 1 obtained by scanning three lines, for example, lines Y0, Y1 and Y2 in the X direction.
This is performed by comparing the three dot patterns immediately before and the dot pattern obtained this time. Considering the case of changing from white to black, as shown in FIGS. 7A and 7B, the previous dot pattern X71 or X75 is “white-
"White-white", this time dot pattern X72 or X76
Is "white-white-black" or "black-white-white". At this time, the dot of Y73 or Y75 at the position of X72 or X76 is recognized as the first edge. When the first edge is found, step 57 sets a flag or register.

If the first edge has been found, step 58 determines whether the search for the second edge can continue. Dot pattern X73 in FIG. 7A or 7B
Alternatively, if the same dot pattern as when the first edge was found, such as X77, the search is continued. Further, the search is continued even when the dot pattern is X74 or X78. This dot pattern X74 or X7
8 becomes the second edge as described later. in this way,
If the obtained dot pattern is the same as the first edge or if the number of black dots has increased by one, the search is continued. If the number of black dots has decreased or the number of black dots has increased by two, the first search is performed in step 59. The state where the edge has been found is eliminated.

When an edge is detected while scanning each of these three lines in the X direction (similarly in the Y direction), there are changes from white dots to black dots and changes from black dots to white dots. In the case of the change from the white dot to the black dot described above with reference to FIGS. 7A and 7B, 3
If the line at the center of the line is the edge detection line, the dots on that line are white and the dot pattern is "white-white-
The first edge is a portion that becomes a black dot at a position where “white” is changed to “white-white-black” or “black-white-white”. Then, in the subsequent scans, the edge detection line and the first edge line are black, and the remaining lines are white, that is, “white-black-black” with respect to “white-white-black”. , "Black-white-white" to "black-black-
The black dot on the edge detection line at the position where the "white" pattern appears is the second edge. However, when a dot pattern that is neither the same dot pattern as the first edge nor the dot pattern of the second edge appears in the scan after the detection of the first edge, it is not an edge that can be interpolated. , Invalidates the already-discovered first edge, and restarts detection of a new first edge.

For example, if the number of black dots is reduced, the first
It is an edge tilted in the opposite direction to the edge of and cannot be interpolated between them. Further, when changing to "black-black-black", there is a step having a distance of 2 dots or more, and the height of the step cannot be detected by comparing three lines. A step having a distance of 2 dots or more is unlikely to have occurred in quantizing a curve or a straight line into dots,
If this is smoothed, the sharpness of the image is rather lowered, which leads to deterioration of the image. Therefore, in this example, only one dot edge is detected and smoothed. Therefore, by scanning three lines, it is possible to detect all the edges that require smoothing.

On the other hand, as shown in FIGS. 7C and 7D, in the case of a change from a black dot to a white dot, the dot on the edge detection line of the dot pattern is black, and the dot pattern is "black-black". Change from "white" to "black-white-white" (Fig. 7
(D)), or "white-black-black" to "white-white-black"
The black dot on the edge detection line at the position changed to becomes the first edge. Then, in subsequent scans, "black-white-
The second edge is the black dot before the change in the position at which the dot pattern changed from "white" or "white-white-black" to "white-white-white" is detected. Then, in the scan subsequent to the detection of the first edge, the dot pattern is not the same as the dot pattern "black-white-white" or "white-white-black" next to the first edge, and If a dot pattern that is not an edge pattern "white-white-white" is detected, it is not an edge that can be interpolated, so the already discovered first edge is invalidated, and a new first edge is detected again. Start.

The relationship between the first edge and the second edge thus detected, that is, the length between the first and second edges is determined by the line to be detected, that is, X.
It is valid from the beginning to the end in the direction or Y direction, and there is no limitation. Therefore, it is possible to detect even very long unevenness at a long distance, and it is possible to perform smoothing accordingly.

In this way, when the first and second edges appearing adjacent or side by side in the X direction and which can be further interpolated are detected in step 60, in step 61, the high resolution bitmap 2 is displayed. The first additional step of reproducing the interpolated image of the first and second edges is performed. That is, an edge extending in the Y direction is added so as to interpolate the first and second edges. In the processing as the first additional step of this example, the first edge and the second edge of the original image 11 are connected by a straight line, and the resulting triangle is overlaid on the high resolution bitmap 2. At this time, the dots that completely fall inside the triangle are black dots to interpolate to form edges extending in the Y direction. This makes it possible to connect specific edges of the original bitmap 1 with straight lines and reproduce the resulting triangle on the high-resolution bitmap 2, making it smoother in a short time without using a lookup table. Various interpolations can be performed.

For example, in FIG. 6, lines Y0, Y
When 1 and Y2 are scanned in the X direction, the edge E3 is detected as the first edge and the edge E4 is detected as the second edge. Therefore, edges E3 and E4
Are connected by a straight line L3, and the dots that do not reach the straight line L3 are converted into black dots, whereby the edges E27, E28, and E29 extended in the Y direction shown in FIG. 4 are formed. In this example, dots that partially extend outside the triangle formed by the straight line L3 are not converted into black dots, and the edges to be added do not extend beyond the straight line L3 in the Y direction. In the smoothing of this example, the contour is smoothed by increasing the number of black dots, so the ratio of black dots in the smoothed image 21 to the original image 11 increases. Therefore, by minimizing the number of black dots added for smoothing, it is possible to prevent a large change in the black / white ratio.

When the second edge is found and the interpolation between the first and second edges is finished, the information of the first and second edges is cleared in step 62 to the end of the line, ie Until the end in the X direction, the process returns to step 53 to detect the edge and the process of adding a dot between the edges are repeated. And step 63
Check to see if you have scanned to the end of the line. If it is the end of the line, the edge detection information is cleared in step 64, and it is confirmed in step 65 whether all the lines have been scanned. If the line remains,
Only one line is shifted in step 66, for example, lines Y1, Y2 and Y3 are set. Then, returning to step 53, the three lines are newly scanned in the X direction to search for a new edge and to add dots between the edges for smoothing.

Further, in step 65, it is determined whether or not the smoothing process is completed while scanning in the X direction up to the end of the original bitmap 1. When all the lines in the Y direction have been scanned,
In step 67, it is confirmed whether or not scanning is performed in both directions. If one remains, the scan direction is changed to the Y direction in step 68, three lines are set in the X direction, the edges are detected while scanning in the Y direction in the same manner as above, and the detected edges are separated. Dot is added and smoothing processing is performed. That is, the direction is switched and the second
The detection step and the second additional step are performed. Then, when scanning in both directions and smoothing are completed in step 67, the resolution is increased in the X and Y directions,
A smoothed high resolution bitmap 2 is created.

Therefore, as shown in FIG. 8, a dot is added so as to interpolate between the function 32 for detecting an edge while scanning in the X direction and the first and second edges detected in the X direction. A processor 31 having a function 33, a function 34 for detecting an edge while scanning in the Y direction, and a function 35 for adding a dot so as to interpolate between the first and second edges detected in the Y direction. Alternatively, by providing the printer 30 with a built-in control board, the low-resolution original bitmap 1 supplied from the host computer 39 can be converted into the high-resolution bitmap 2 and supplied to the printing mechanism 36. Therefore, from the printer 30, with high resolution, no waviness,
It is possible to obtain the printout 39 in which the image is drawn by the smoothly connected contours.

The processor 31 or the control board capable of executing the processing shown in FIG. 5 has the functions 32 and 34 for detecting edges and the functions 33 and 35 for adding dots implemented by hardware logic such as a dedicated circuit. It may be. Alternatively, a recording medium such as a ROM or a RAM storing a program having an instruction capable of executing the edge detecting process and the dot adding and interpolating process shown in FIG. 5 is realized. Is also good.

In the above description, an example of creating a bitmap whose resolution is increased in the X and Y directions has been described, but a bitmap whose resolution is increased in only one of them is also created in the same manner. It is possible. In this case, if the resolution is increased in the Y direction, it is possible to perform smoothing simply by scanning in the X direction.
It is not necessary to scan in the Y direction. The present invention can be applied not only when the resolutions are equally increased in the X direction and the Y direction, but also when the resolutions in the X direction and the Y direction are different.

In the above, an example in which the present invention is applied to a printer is shown. However, the device is not limited to the printer but any other printing device as long as the device outputs an image with a bit map, that is, a pixel matrix or a pixel pattern. Alternatively, the present invention can be applied to a display or the like.

[0041]

As described above, according to the method of creating a bitmap of the present invention, when converting a bitmap for printing or displaying an image into a bitmap having a higher resolution, the original Smoothing is performed by adding an edge for interpolation between the edges of the bitmap to improve the image quality. Therefore, smoothing can be performed without using a work bitmap, a look-up table, or the like, and the trouble of creating the look-up table is unnecessary. Further, since it is possible to save the time for referring to the lookup table, it is possible to perform smoothing in a shorter time.

Furthermore, regardless of the distance, if edges appearing side by side in a certain direction are detected, smoothing can be performed between the edges, so that long-period irregularities can also be the object of smoothing. Therefore, it is possible to solve the problem that the contour is wavy by increasing the resolution. Also, smoothing can be performed regardless of the magnification. As described above, according to the present invention, it is possible to manufacture a high resolution bitmap capable of outputting an image having a sharper and sharper contour in a short time.

[Brief description of drawings]

FIG. 1 is an example of an original bitmap.

[Fig. 2] High resolution original bitmap, 2
This is an example of smoothing by inserting the average value of two original pixel columns.

FIG. 3 is an example of smoothing an original bitmap with high resolution, using a lookup table to add dots to corners and cut edges.

FIG. 4 is an example in which an original bitmap has a high resolution and is smoothed by the creating method of the present invention.

FIG. 5 is a flowchart showing an outline of a bitmap creating method of the present invention.

FIG. 6 is a diagram showing a process of smoothing by the method shown in FIG.

FIG. 7 is a diagram illustrating an example of detecting an edge.

FIG. 8 is a diagram showing an outline of a printer to which a bitmap creating method of the present invention is applied.

[Explanation of symbols]

1,2,8,9 Bitmap 11, 21, 81, 91 images E1-E4 Original bitmap edges E21-E29 Added edges

Continued front page    F-term (reference) 2C062 AA24                 5B057 AA11 CA02 CA06 CA12 CA16                       CB02 CB06 CB12 CB16 CC01                       CD05 CE03 CE11 CF05 CH07                       CH08 CH11 CH18                 5C076 AA21 AA32 BA06 BB03                 5C077 LL05 LL19 MP04 PP03 PP47                       PQ08 PQ12 PQ23 PQ25 RR19                       SS02 SS06 TT02

Claims (21)

[Claims] 1. When creating a second bitmap having a higher resolution in a first direction from a first bitmap in which a plurality of pixels forming an image are two-dimensionally arranged, the first bitmap is formed.
A first detecting step of detecting first and second edges appearing in a second direction orthogonal to the first direction from the bitmap of, and corresponding to the first and second edges, respectively. Between the third and fourth edges of the second bitmap,
A first adding step of adding an edge extending in the first direction so as to interpolate the third and fourth edges. 2. The method according to claim 1, wherein in the first detecting step, three pixels adjacent to each other in the first direction are connected to the second pixel.
A method for creating a bitmap by scanning in the direction of, and detecting the first and second edges. 3. The method according to claim 2, wherein in the first detecting step, when the center of three pixels adjacent to each other in the first direction is an edge detection line, the pixel on the edge detection line is turned on from off. If it changes to, the combination of the three pixels is “off-off-off”.
To "Off-Off-On" or "On-Off-Off"
To the first edge after the change to
A position after changing to “off-on-on” or “on-on-off” is defined as the second edge, and when the pixel of the edge detection line changes from on to off, a combination of the three pixels Is "on-on-off"
To "On-Off-Off" or "Off-On-On"
The position before the change from "OFF-OFF-ON" to the first edge, and the position before the change to "OFF-OFF-OFF" as the second edge, and Between the first and second edges, the first
A method of creating a bitmap that validates the first and second edges when a pattern other than the pattern after the change of the edge or the pattern of the second edge is not detected. 4. The method of creating a bitmap according to claim 1, wherein in the first adding step, an edge in a range not exceeding a straight line connecting the third and fourth edges is added. 5. The method according to claim 1, wherein when the second bitmap also has improved resolution in the second direction, the fifth bitmap appears in the first direction from the first bitmap. And a second detection step of detecting a sixth edge, and between the seventh and eighth edges of the second bitmap corresponding to the fifth and sixth edges, respectively. The second to interpolate 8 edges
A second adding step of adding an edge extending in the direction of. 6. The method according to claim 5, wherein in the second detecting step, three pixels adjacent to each other in the second direction are set to the first pixel.
A method of creating a bitmap by scanning in the direction of, and detecting the fifth and sixth edges. 7. The method according to claim 6, wherein in the second detection step, when the center of three pixels adjacent to each other in the second direction is an edge detection line, the pixel on the edge detection line is turned on from off. If it changes to, the combination of the three pixels is “off-off-off”.
To "Off-Off-On" or "On-Off-Off"
To the fifth edge after the change to
A position after changing to “off-on-on” or “on-on-off” is defined as the sixth edge, and when the pixel of the edge detection line changes from on to off, a combination of the three pixels Is "on-on-off"
To "On-Off-Off" or "Off-On-On"
To the "off-off-on" before the change position is the fifth edge, then the "off-off-off" before the change position is the sixth edge, further, Between the fifth and sixth edges, said fifth
A method of creating a bitmap that validates the fifth and sixth edges when a pattern other than the pattern after the change of the edge or the pattern of the sixth edge is not detected. 8. The method of creating a bitmap according to claim 5, wherein in the second adding step, an edge in a range not exceeding a straight line connecting the seventh and eighth edges is added. 9. A program for creating a second bitmap having an increased resolution in a first direction from a first bitmap in which a plurality of pixels forming an image are two-dimensionally arranged, said program comprising: A first detecting step of detecting first and second edges appearing in a second direction orthogonal to the first direction from the first bitmap; and the first and second edges corresponding to the first and second edges, respectively. Between the third and fourth edges of the second bitmap, the first so as to interpolate these third and fourth edges.
A first additional step of adding an edge extending in the direction of. 10. The method according to claim 9, wherein in the first detecting step, three pixels adjacent to each other in the first direction are scanned in the second direction to detect the first and second edges. A program having instructions for performing a process. 11. The method according to claim 10, wherein in the first detecting step, when the center of three pixels adjacent to each other in the first direction is an edge detection line, the pixel on the edge detection line is turned on from off. If it changes to, the combination of the three pixels is “off-off-off”.
To "Off-Off-On" or "On-Off-Off"
To the first edge after the change to
A position after changing to “off-on-on” or “on-on-off” is defined as the second edge, and when the pixel of the edge detection line changes from on to off, a combination of the three pixels Is "on-on-off"
To "On-Off-Off" or "Off-On-On"
The position before the change from "OFF-OFF-ON" to the first edge, and the position before the change to "OFF-OFF-OFF" as the second edge, and Between the first and second edges, the first
A program having instructions for executing processing for validating the first and second edges when a pattern other than the pattern after the change of the edge or the pattern of the second edge is not detected. 12. The program according to claim 9, wherein in the first adding step, an instruction is added to execute a process of adding an edge in a range not exceeding a straight line connecting the third and fourth edges. 13. The method according to claim 9, wherein when the second bitmap also has improved resolution in the second direction, the fifth bitmap appears in the first direction from the first bitmap. And a second detection step of detecting a sixth edge, and between the seventh and eighth edges of the second bitmap corresponding to the fifth and sixth edges, respectively. The second to interpolate 8 edges
A second additional step of adding an edge extending in the direction of. 14. The method according to claim 13, wherein in the second detecting step, three pixels adjacent to each other in the second direction are scanned in the first direction to detect the fifth and sixth edges. A program having instructions for performing a process. 15. The method according to claim 14, wherein in the second detecting step, when the center of three pixels adjacent to each other in the second direction is an edge detection line, the pixel on the edge detection line is turned on from off. If it changes to, the combination of the three pixels is “off-off-off”.
To "Off-Off-On" or "On-Off-Off"
To the fifth edge after the change to
A position after changing to “off-on-on” or “on-on-off” is defined as the sixth edge, and when the pixel of the edge detection line changes from on to off, a combination of the three pixels Is "on-on-off"
To "On-Off-Off" or "Off-On-On"
To the "off-off-on" before the change position is the fifth edge, then the "off-off-off" before the change position is the sixth edge, further, Between the fifth and sixth edges, said fifth
A program having instructions for executing processing for validating the fifth and sixth edges when a pattern other than the pattern after the change of the edge or the pattern of the sixth edge is not detected. 16. The program according to claim 13, wherein in the second adding step, an instruction is added to execute a process of adding an edge in a range not exceeding a straight line connecting the seventh and eighth edges. 17. A bitmap creation device for creating a second bitmap having a higher resolution in a first direction from a first bitmap in which a plurality of pixels forming an image are two-dimensionally arranged. , First detecting means for detecting first and second edges appearing in a second direction orthogonal to the first direction from the first bit map, and to the first and second edges, respectively. Between the third and fourth edges of the corresponding second bitmap, the first and second edges are arranged to interpolate the third and fourth edges.
And a first adding means for adding an edge extending in the direction. 18. The method according to claim 17, wherein the first detecting means scans three pixels adjacent to each other in the first direction in the second direction to detect the first and second edges. , Bitmap creation device. 19. The bitmap generation device according to claim 17, wherein the first adding unit adds an edge within a range not exceeding a straight line connecting the third and fourth edges. 20. The resolution according to claim 17, wherein the second bitmap also has a higher resolution in the second direction, and further, the fifth and fifth appearing in the first direction from the first bitmap. Between the first detecting means for detecting the sixth edge and the seventh and eighth edges of the second bitmap corresponding to the fifth and sixth edges, respectively, the seventh and eighth edges are provided. The second to interpolate the edges of
And a second adding means for adding an edge extending in the direction. 21. The bitmap creation device according to claim 20, wherein the second adding unit adds an edge in a range not exceeding a straight line connecting the seventh and eighth edges.