KR101869302B1 - Raster image conversion apparatus, image scanning apparatus, method for conversion of raster image, and computer-readable recording medium - Google Patents

Abstract

A raster image conversion method is disclosed. The raster image conversion method includes dividing a raster image into a background area, a monochrome area, and a multicolor area, generating a meta command corresponding to each of the divided areas, and generating a meta file based on the generated meta command Wherein generating the meta-instructions comprises vectorizing the outlines of the segmented monochrome regions and generating meta-instructions corresponding to the vectorized outlines.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a raster image conversion apparatus, a raster image conversion method, and a computer readable recording medium,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a raster image conversion apparatus, a raster image conversion method, and a computer readable recording medium, and more particularly to a raster image conversion apparatus, A method of converting a raster image, and a computer-readable recording medium.

Recent methods of converting raster images into electronic forms are convenient for storing and displaying, but it is required to solve the following two common contradictory problems that occur frequently.

The first task is to store information on the form in as small a capacity as possible, and the second task is to prevent the source image from degrading in the process of converting the source image to electronic form.

The most widely known technique among these image conversion methods is the Mixed Raster Content (MRC) (see, for example, ISO / IEC JTC1 / SC29 / WG1 N542, "ITU-T Mixed Raster Content Model as JPEG 2000 Architectural Framework" )to be. This method uses the representation of images as a multi-layered model and uses different compression methods for each layer to reduce the file size.

However, the MRC algorithm does not consider the mapping characteristics of the vector graphics displayed in the initial raster image. For example, if the initial electronic text document that maps and prints does not depend on its scale, the mapping of the symbols of the scanned text that is modified in the means of MRC will depend on the scale of the display.

It should also be noted that known methods for multi-layer analysis and storage of raster images in electronic form select all raster images in separate layers. Thus, even if the source image contains non-critical components of raster graphics, the raster layer, which is similar in size to the entire document, was stored in the document.

U.S. Patent Application 2011007334 discloses a method for reducing file size. A method and system for text vectorization on scanned images is described in the technical solution of the patent application, and a vectorization method is presented to provide smooth mapping of the symbols. However, this method has the disadvantage that the vectorization procedure is considered to be independent of other elements of the image, since only the text displayed on the scanned image is analyzed.

U.S. Patent No. 7289122 discloses a method of applying graphic objects using Bezier curves. However, this method does not take into consideration when converting an entire image into an electronic document format because it has the disadvantage of handling only the approximate calculation method.

An object of the present invention is to provide a raster image conversion apparatus, image reading apparatus, raster image conversion method, and computer readable recording medium capable of converting a raster image into an electronic form metafile.

In order to achieve the above object, a raster image converting method according to an embodiment of the present invention includes dividing a raster image into a background region, a monochromatic region, and a multicolor region, generating a meta command corresponding to each of the divided regions, And generating a meta-file based on the generated meta-instruction, wherein the generating of the meta-instruction comprises: vectoring the outline of the segmented monochrome area, generating a meta-instruction corresponding to the vectorized outline, .

In this case, the method of changing the raster image further comprises the step of determining the separated background area as one of a monochrome background, a gradient background and a multicolor background, and the step of generating the meta-instruction comprises: A meta command for describing a rectangle having a color of the background area is generated and if the determined background area is a gradient background, a meta command for determining the oblique direction and type of the color corresponding to the background area can be generated .

In this case, if the determined background region is a multicolor background, the generating of the meta file may generate a meta file including a raster image corresponding to the background region.

The raster image converting method may further include determining transparency to be applied to the divided background area, wherein the generating of the meta file includes generating a meta file including a meta command corresponding to the determined transparency can do.

The raster image converting method may further include converting a resolution of the raster image corresponding to the divided multi-color area, wherein the step of generating the meta file includes a step of converting the resolution of the meta file Can be generated.

In this case, the raster image converting method further includes a step of determining the shape of the divided polychrome area, and if the determined shape is not a rectangle, dividing the divided polychrome area into a plurality of rectangular areas , And the step of converting the resolution may convert the resolution of the plurality of raster images corresponding to each of the plurality of divided rectangular areas.

In this case, the step of generating the meta-instruction may generate a meta-instruction corresponding to each of the plurality of divided rectangular areas.

On the other hand, the step of generating the meta-instruction may include detecting an outline of the segmented monochrome region, simplifying the detected outline, and generating a meta-instruction corresponding to the simplified outline .

On the other hand, the step of simplifying the detected contour may simplify the detected contour by only a straight line and a Bezier curve.

Meanwhile, the raster image converting method may further include compressing the generated meta-command, and the generating the meta file may generate a meta file based on the compressed meta-command.

Meanwhile, the raster image conversion apparatus according to the present embodiment includes a communication interface unit for receiving a raster image, a control unit for dividing the input raster image into a background region, a monochrome region and a multicolor region, And a file generation unit for generating a metafile based on the generated meta-instruction, wherein the command generation unit performs vectorization of the outline of the separated monochromatic area, and generates a vectorized outline corresponding to the vectorized outline To generate the meta-instruction.

In this case, the command generation unit may determine the separated background area as one of a monochrome background, a gradient background, and a multicolor background, and if the determined background area is a monochrome background, a meta command describing a rectangle having a color of the background area And if the determined background area is a gradation background, a meta command for determining an oblique direction and a type of a color corresponding to the background area can be generated.

In this case, if the determined background area is a multicolor background, the file generator may generate a meta file including a raster image corresponding to the background area.

Meanwhile, the command generation unit may detect an outline of the divided monochrome area, simplify the detected outline, and generate a meta command corresponding to the simplified outline.

Meanwhile, the file generation unit may compress the generated meta-commands and generate a meta file based on the compressed meta-commands.

On the other hand, the image reading apparatus according to the present embodiment includes a scan unit for scanning a document to generate a raster image, a process for dividing the generated raster image into a background region, a monochromatic region, and a multicolor region, And a file generation unit for generating a meta file based on the generated meta command, wherein the command generation unit performs vectorization of the outline of the separated monochrome area, Lt; RTI ID = 0.0 > meta < / RTI >

In this case, the command generation unit may determine the separated background area as one of a monochrome background, a gradient background, and a multicolor background, and if the determined background area is a monochrome background, a meta command describing a rectangle having a color of the background area And if the determined background area is a gradation background, a meta command for determining an oblique direction and a type of a color corresponding to the background area can be generated.

Meanwhile, the command generation unit may detect an outline of the divided monochrome area, simplify the detected outline, and generate a meta command corresponding to the simplified outline.

In this case, it is preferable that the command generation unit simplify the detected contour by only a straight line and a Bezier curve.

On the other hand, in the computer-readable recording medium including the program for executing the raster image conversion method according to the present embodiment, the raster image conversion method includes the steps of dividing the raster image into the background region, the monochromatic region, Generating a meta-instruction corresponding to each of the divided regions, and generating a meta-file based on the generated meta-instruction, wherein the generating the meta-instruction comprises: And generates a meta-instruction corresponding to the vectorized outline.

1 is a flowchart for explaining a method of converting a raster image into a metafile according to the present embodiment,
2 shows an example of a raster image,
3 shows a visualization sequence of each category in a region when a metafile is displayed,
Figure 4 is a block diagram illustrating the configuration of a computer system implementing the method of Figure 1;
FIG. 5 is a flowchart specifically illustrating a step of storing the multicolor area of FIG. 1;
FIG. 6 is a flowchart specifically illustrating the storing step of the monochromatic region of FIG. 1;
7 is a diagram for explaining an example of an operation for tracking the outline of an area,
8 is a diagram illustrating an example of a method for calculating an interval of an outline in which a limited preliminary important point is located,
9 is a diagram for explaining a process of detecting a key point of an outline corresponding to an example of a monochrome area,
Figure 10 is an illustration of an example of a simplified outline in a monochromatic region,
11 is a flowchart for explaining a procedure for deriving an approximation of an outline,
Figure 12 shows an example in which the coordinates at the key point of the simplified outline are modified,
13 is a diagram showing an example of a Bezier curve,
14 is a diagram for explaining a calculation process for a check point of a Bezier cover,
15 is a diagram for explaining a process of deriving an approximate value of a Bezier curve,
16 is a diagram showing an example of an approximation of a curve in a monochromatic region made up of continuous Bézier curves,
17 is a view showing an image obtained by enlarging and displaying a monochrome area in an initial raster image and a result of mapping a monochrome area after an approximate protrusion;
18 is a block diagram showing a configuration of a raster image conversion apparatus according to an embodiment of the present invention,
19 is a block diagram showing the configuration of a picture reading apparatus according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, for a clear interpretation of the terms to be used below, it is specified that the metafile is a file type in which data of various kinds (in particular, raster and vector data types) are stored. In general, a metafile structure may be represented as a sequence (or sequence list) of instructions (metafile entries) having a possible set of arguments. At the time of execution of the metafile, specific tasks corresponding to each command (for example, visualization of a line section, mapping of pieces of a raster image, etc.) are performed. For example, the metafile may be, but is not limited to, Portable Document Format (PDF), XML Paper Specification (XPS), PostScript (PS), Enhanced Metafile (EMF)

1 is a flowchart for explaining a method of converting a raster image into a metafile according to the present embodiment.

Referring to FIG. 1, a raster image is prepared (101). Specifically, a document can first be captured or scanned to generate a raster image, or a raster image generated from a specific external device can be received.

The background area and the background type of the raster image are sensed (102). The background type in this embodiment is described as being one of a monochrome background, a gradient background, and a multicolor background. Here, a monochrome background is a background area having (approximately) the same intensity and color, and a gradation background is a background area in which the change in brightness and color is constant (can be expressed by a specific function). And a multicolor background is a background area of a raster image that does not correspond to a solid background and a gradient background. For example, the background of a raster image containing characters may be separated by a multicolored background.

The identified background is defined as a command (or meta-command) of the meta-language corresponding to the format of the selected meta file (103). For example, it is possible to refer to each type of background as a command in the metafile. However, the present invention is not limited thereto.

A solid background can be defined as a command in the metafile that indicates the background color. And the gradient background may be defined as a command in the metafile indicating the range of the oblique direction, brightness, or color. And a multicolor background may correspond to a background raster image stored within the metafile.

On the other hand, the background may have transparency that is not mapped during the creation process at the time of executing (or reproducing) the metafile. In other words, although transparency is not applied to the background in the above-described process, transparency may be set in the background at the time of implementation. In addition, at the time of implementation, not only the above-described deformation but also deformation at other portions is possible.

And detects a multicolor area including a raster image or a complex picture (104). Wherein the multicolor region is a group of coherent pixels (or points) of the raster image defined in a portion of the initial raster image.

The sensed polychrome region is stored in the metafile (105) as a raster image with appropriate instructions of the metafile. At this time, the task of defining the parameters of each multicolour region and the positions of the variables in the image is also performed.

And senses a monochromatic region (i.e., a region of approximately the same brightness and color) closely connected to each other (106). At this stage, the monochrome region can be defined as a series of graphical commands that map the vector graphic components in the metafile. At this time, an operation of deriving an approximation to the shape of the monochromatic region can be performed.

The result of the vectorized monochrome region is stored in the metafile (107).

In the description of FIG. 1, the background region, the monochromatic region, and the multicolor region are separately detected, but each region can be detected in one step at a time. In the description of FIG. 1, the step of storing in the meta file is separately performed for each area, but the storing step for each area may be performed collectively in one step.

As described above, the method of converting the raster image into the metafile according to the present embodiment can reduce the size of the metafile. Specifically, compression without loss of quality is possible in that the raster image itself is not stored in the metafile.

As described above, the raster image converting method according to the present embodiment proposes an effective approach to the quality of the file in terms of magnitude. Specifically, the storage is performed by the most appropriate method for each area. In particular, rendering by a vector of monochromatic regions provides independence of mapping of monochromatic regions from the extent of the visualization (or range of printing, for example). Specifically, enlargement of a normal raster image causes deterioration of an image, but the raster image conversion method according to the present embodiment does not cause deterioration of an image even if the image is enlarged to perform vectorization for a monochromatic area.

On the other hand, the raster image conversion method as described above can be implemented as at least one executable program for executing the raster image conversion method as described above, and the executable program can be stored in a computer readable recording medium.

Thus, each block of the present invention may be embodied as computer-writable code on a computer-readable recording medium. The computer-readable recording medium may be a device capable of storing data that can be read by a computer system.

Figure 2 shows an example of a raster image.

2, the raster image is composed of a background region 201, monochrome regions 202 and 205, a rectangular multicolor region 203, and a non-rectangular multicolor region 204.

3 is a diagram showing a visualization sequence of each category in a region when a metafile is displayed. On the other hand, the order in which the regions are stored corresponds to the visualization order of each region as shown in Fig. For example, the visualization of a metafile often occurs when overlaid with transparent or translucent layers or areas. The background area 303 becomes the lower layer while the meta file is mapped and the multicolor area 302 and the monochrome area 301 are overlaid on the background area 303. [

4 is a block diagram illustrating the configuration of a computer system that implements the method of FIG.

4, a computer system for converting a raster image into a metafile according to the present embodiment includes a device 402 for receiving an initial raster image, a processor 403, a memory 404 for storing instructions of the program 405 ). And data transfer between the system constituent units is performed using the data transfer bus 401.

The input device 402 may be a device for receiving or generating an initial raster image, such as a digital camera, a memory for storing screen shots, or the like. The metafile generated as a result of the execution of the program command is stored in the memory. The metafile stored in the memory may be transmitted to the printer or the display device, and may be stored in a separate storage device.

Although the present embodiment has been shown and described with respect to a computer system including only four configurations, the computer system in the implementation may include configurations other than those described above. Such a computer system may be any device capable of using a user's graphic interface as well as a personal computer, a mobile phone, a TV, a multifunction device, and the like. An example of the personal computer and the multifunction peripheral will be described later with reference to FIG. 18 and FIG.

FIG. 5 is a flow chart for explaining the step of storing the multicolor area of FIG. 1 in detail.

Referring to FIG. 5, first, a multi-color area is sensed (501). Specifically, the multicolor area is a group of coherent pixels of a raster image defined in a part of the initial raster image, so that a group of coherent pixels in the raster image can be detected as multicolor areas.

And determines the shape of the multicolor area (502). Specifically, it is possible to determine whether or not the shape of the identified polychrome region is rectangular.

Then, it is determined whether the determined shape of the polychrome region is a rectangle (503). Specifically, it is judged whether or not the multicolor area is a rectangle in that only a rectangular image can be stored in the meta file.

If the polychromatic area is not a rectangle (503-No), the clipping area for the polychromatic area is determined. Specifically, as described above, only a rectangular image can be stored in the meta file, and a polygonal area that is not a rectangle can be divided into a plurality of rectangular clipping areas. As described above, in the present embodiment, a plurality of clipping regions are determined for a polygonal region that is not a rectangle, so that more accurate mapping to a multicolor region is possible.

Then, the size of the raster image of the multicolor area is adjusted according to the preset resolution (504). Specifically, the initial raster image scanned typically has a resolution of 300 DPI, while the resolution of the display is 72 DPI or 86 DPI. In this regard, the raster image of the multicolor area can be reduced to a shape (or a predetermined size) having a preferred resolution in the display.

The shape of the multicolor area is defined using the command of the metafile (505). For example, a rectangular polychrome area can be defined as a matrix transformation, a size of an image piece to be stored, a compression method, a color space, and the like. Where the matrix variant can reflect a number of parameters that affect the mapping of image fragments when the metafile is displayed. Examples of such variables include the resolution of the visualization of the image fragment (this resolution may differ from the resolution of the initial raster image), the shift of the image fragment corresponding to the coordinates of the document visualized as the playback of the metafile, And so on. For a non-rectangular polygonal region, a series of graphics commands defining the shape of the clipping region may be defined.

The commands in the metafile and the raster image fragment are compressed 506. Although the present embodiment has shown and described compressing the command and the raster image of the metafile, the compression step is not essential and may be omitted depending on the implementation method. And here, the compression method can follow the method selected in the corresponding metafile. For example, a lossless compression scheme may be applied to a command of a metafile, and a lossy compression scheme may be applied to compression of a raster image fragment.

The metafile command and image fragment are stored in the metafile (507). Specifically, the compressed instructions and raster image fragments can be stored in a metafile.

FIG. 6 is a flowchart specifically illustrating the storing step of the monochromatic region of FIG. 1;

The monochromatic region can be stored as a description of the color and shape of each region by a series of graphic commands of the metafile, as described above. By storing the monochromatic regions of the raster image in a vector format, it becomes independent of good region mapping and view scaling.

Referring to FIG. 6, the inner and outer contours of the monochromatic region are first tracked (601). At this time, the monochromatic region can have only one outer contour without the inner contour. The monochromatic region may also have one outer contour and a plurality of inner contours.

And defines a color filled in the monochromatic region (602).

The contour point is approximated to a series of segments using straight lines and curves supported in the format of the selected metafile (603).

Then, the approximated series of intervals and the colors filled in the monochromatic region are defined as appropriate commands of the metafile (604).

Then, the defined command is compressed (605) and the compressed command is stored in the metafile (606).

Meanwhile, the clipping area of the polygonal area other than the rectangle defined in step 503 of FIG. 5 is similar to the monochromatic area, except that only the outer contour is present, and the above-described method can be applied to the clipping area. Specifically, a clipping section of a polygonal area other than a rectangle can be defined as a series of approximated sections.

7 is a diagram for explaining an example of an operation of tracking the outline of the area.

After detection of a monochromatic region, the components of the monochromatic region are separated from the background, and the monochromatic region can be represented by a group of linked pixels. Normally, when describing a raster image, the position of the pixel is defined by coordinates and the pixels have a square shape.

In the embodiment of the present invention, the contour is defined as the boundary between the background and the detected monochromatic region.

Referring to Fig. 7, the pixels of the area are designated by the dark gray square 701. Thus, the outline passes through the points assigned to the corner points of the pixel and the points indicated by the white points. The concrete point of the contour has a non-integer coordinate called a so-called "virtual". The contour tracing procedure starts at the starting point 703 of the contour and proceeds until it reaches the starting point again along the contour in a predetermined direction. The tracking direction of the outline can be determined by the requirement of the format of the selected metafile. For example, in a non-zero winding rule of a winding, the outer contour is defined as the movement of the hour hand of the watch in the direction of movement, while the inner contour is defined as moving counterclockwise or vice versa. These rules make it possible to accurately fill monochrome areas with the specified colors while the metafile is being displayed.

After outline tracking for a monochrome region, it is performed to reduce the number of elements of the outline through the definition of the most significant significant points of the outline. The method of detecting the critical points of the contour consists of the following two steps. The first step is to define a contour piece in which a limited preliminary critical point is located, and the second step is to select a combination of one of the possible combinations between critical points that provide a minimum error.

FIG. 8 shows an example of a method of calculating an interval of an outline in which a limited preliminary important point is located.

In an implementation, a pair of points that are most spaced corresponding to each point of the contour corresponding to a predetermined criterion is placed. For example, in FIG. 8, the most distant pair of points corresponding to points in contour 803 are 802, 806. In the present embodiment, if the outline is located in an approximated straight line and the approximation error does not exceed a preset value, it is assumed that the two points of the outline are the most distant. Where the approximation error can be calculated as the sum of the squares of the distance 801 between each point in the approximate position of the contour 805 and a suitable approximated line 804.

This set of most distant point pairs allows sensing the key point and defining the position of the contour. For example, point 809 in FIG. 8 is most distant from the group of points in the contour represented by point 807. And point 808 is most distant from all points of the contour represented by point 810. [ Thus, in the analyzed fragment, the points 808 and 809 of the contour have the most tangent number, thereby defining the boundary of the position of the contour 811 to sense the key point.

9 is a diagram showing an example of a monochromatic region having a specific position of a contour preferred for sensing a key point. Here, the specific position is indicated by the transliteration area 902.

And detects one key point at the determined specific position. Specifically, it is possible to combine a possible plurality of key points at a determined specific position and a possible plurality of key points at different specific positions, and to determine each specific position having a minimum error occurring in the estimation of the contour consisting of successive straight lines One key point can be detected.

The resultant key point 901 is shown in FIG. The approximate result for a straight line segment combination containing a minimum error is shown in FIG.

The approximation of the contour is performed using a series of straight lines and a section of curves based on the key points of the contour. This procedure is shown in FIG.

First, a coordinate modification of the key point of the simplified outline of the monochrome region is performed (1101). Specifically, the new estimation interval 1203 corresponds to a new key point 1201 for a particular coordinate 1202 so as to have a minimum error due to the approximation of the contour, as shown in Fig. Thus, the modification of the coordinates is limited to the vicinity of the initial key point 1202.

In the present embodiment, the predetermined neighborhood corresponds to one pixel size. For example, the new key point does not exceed half the pixel distance from the initial key point.

An approximation is performed 1202 using a straight line and a duration of the curve corresponding to the format of the selected metafile with the simplified outline defined by the particular key point. At this stage, the number of used velocities of the vector graph and the number of key points are clearly defined.

The number of curves is reduced 1103 to soften the contour mapping during the playback of the metafile, or to have a low amount of graphics commands required of the metafile.

A series of straight lines and curves are converted into instructions describing in the metafile (1104)

Preferably, the approximation of the outline of a monochromatic region can be approximated to the outline of a monochromatic region using two graphical functions (straight line section and third order bezel curve section) supported by most existing metafiles. Specifically, the display instruction word of the straight line section generally has an argument defining the start and end of the section. And the visualization commands of the tertiary baseline curve have arguments that define the start and end of the curve, the two normalized checkpoints of the curve, and the shape of the curve.

Bezier curves are used to describe the position of the contour, and are applied to the key points of the contour in which the two sections overlap. Therefore, triangles are analyzed in the parameter calculations of Bezier curves. Where one vertex of the triangle is the key point and two sides of the triangle are the approximated intervals adjacent to the key point.

Referring to FIG. 13, to simplify the Bezier curve parameter calculation, the Bezier curve checkpoint 1302 is located on the side adjacent to the peak 1301. At this time, the checkpoint of the curve is defined by two parameters [alpha] and [beta], ranging from 0 to 1, and the variation of the two parameters is shown in Fig. The value of the parameter shown in FIG. 13 is only an example, and is not limited thereto.

14 and 15 are diagrams showing steps of calculating a check point of a beige curve.

이 곱해지면 래스터 이미지의 픽셀의 측면 길이에 대응되는 것이 바람직하다. 평행 이동된 직선(1406)은 베지어 커브 α 와 β 의 체크 포인트로 정의될 수 있는 포인트(1402, 1405)의 근사화된 구간과 교차하게 된다. 여기서 α 와 β 값은 평행 이동된 직선(1406)을 자른 구간의 정규화된 길이와 동일하며, 비례 계수 이내에서 정확하다. 하나의 예로서 도 14에 도시된 바와 같이 계수α 는 포인트(1401, 1402)에 의한 구간의 길이와 구간(1401-1403)의 길이의 비율과 동일하고, 비례 계수가 곱해진다. 여기서 비례 계수는 4/3이 바람직하다. 이 경우, 베지어 커브는 키 포인트(1409, 1509)의 인접하는 크로스 포인트를 지나게 된다. Referring to FIG. 14, the average points 1401 and 1407 of a section that intersects the key point 1403 in the outline analyzed in the previous step are calculated. And a straight line 1408 via the calculated average points 1401 and 1407. [ The adjacency of the key points is limited by the circle 1404 of the predetermined radius. Here,

Is preferably multiplied by the side length of the pixel of the raster image. The translated straight line 1406 intersects the approximated section of points 1402 and 1405, which can be defined by the checkpoints of Bezier curves? And?. Here, the values of [alpha] and [beta] are equal to the normalized length of the cut section of the parallel shifted straight line 1406, and are accurate within a proportional coefficient. As one example, as shown in FIG. 14, the coefficient? Is equal to the ratio of the length of the section by points 1401 and 1402 to the length of sections 1401-1403, and is multiplied by the proportional coefficient. Here, the proportional coefficient is preferably 4/3. In this case, the Bezier curve passes through the adjacent crosspoints of the key points 1409 and 1509.

The Bezier curve corresponding to the calculated parameter is shown in Fig. Referring to FIG. 15, the approximated Bezier curve 1505 is passed through the average points 1501 and 1506, and the checkpoints 1502 and 1504 of the curve are calculated by the method described above.

는 이 단계에서 계산된다. 파라미터

이 허용된 범위(

)를 만족한다면 파라미터 α 와 β는 수정되지 않는다. 반면에 파라미터

의 상태가

이면, 베이저 커브의 체크 포인트는

에 대응되는 값으로 교체가 된다. 그리고 파라미터

의 상태가

이면, 적절한 평균 포인트에 의해 한정되는 직선의 두 구간으로 근사화 커브가 교체되고, 분석된 체크 포인트에 두 구간을 서로 인접시키는 결정이 이루어진다. 예를 들어, 도 15에서

인 상태면, 베이저 커브는 포인트(1501, 1503)에 의해 한정되는 제1 구간과 포인트(1503, 1506)에 의하여 한정되는 제2 구간으로 교체될 수 있다. After the parameters of the Bezier curve are calculated, a check is made to see if the number of states matches the checkpoint of the Bezier curve. parameter

Is calculated at this stage. parameter

This allowed range (

), The parameters [alpha] and [beta] are not modified. On the other hand,

The state of

, The checkpoint of the base curve is

Is replaced with a value corresponding to " And the parameters

The state of

, The approximation curve is replaced with two sections of the straight line defined by the appropriate average point, and a determination is made to adjoin the two sections to the analyzed checkpoint. For example, in FIG. 15

The base curve can be replaced by a first section defined by points 1501 and 1503 and a second section defined by points 1503 and 1506. [

16 is a diagram showing an example of an approximation of a curve in a monochromatic region formed by a continuous Bezier curve.

FIG. 17 is a diagram showing an image obtained by enlarging and displaying a monochromatic region in an initial raster image and a result of mapping a monochromatic region after an approximate protrusion. FIG. Referring to FIG. 17, it can be seen that their mappings do not depend on the view scale, since the provided approximations correspond to a vector representation of the region shape.

18 is a block diagram showing a configuration of a raster image conversion apparatus 100 according to an embodiment of the present invention.

18, the raster image conversion apparatus 100 includes a communication interface unit 110, a storage unit 120, a user interface unit 130, a command generation unit 140, a file generation unit 150, 160). Here, the raster image conversion apparatus 100 may be a PC, a notebook, or the like.

The communication interface unit 110 is formed to connect the raster image conversion apparatus 100 to an external device and is connected to a USB (Universal Serial Bus) port as well as a wireless or wired connection mode through a local area network It is also possible to connect them through a network.

Then, the communication interface unit 110 can receive the raster image from the external device (for example, the image reading device). Here, raster images are JPEG, BMP, and bitmap images. The communication interface unit 110 may transmit the generated metafile to an external device.

The storage unit 120 stores a raster image. The storage unit 120 stores the metafile generated by the file generation unit 150, which will be described later. Meanwhile, the storage unit 120 may be implemented as a storage medium in the raster image conversion apparatus 100 and an external storage medium, for example, a removable disk including a USB memory, or a web server through a network.

The user interface unit 130 includes a plurality of function keys that a user can set or select various functions supported by the raster image conversion apparatus 100. The user interface unit 130 can display various information provided by the raster image conversion apparatus 100 have. The user interface unit 130 may be realized by a device such as a touch pad that can simultaneously implement input and output, or may be implemented by combining input devices such as a mouse and a keyboard, and display devices such as a CRT monitor, an LCD monitor, have.

The user interface unit 130 may select a raster image changed to a metafile and select a type of the metafile to be converted. Here, the type of the metafile may be Portable Document Format (PDF), XML Paper Specification (XPS), PostScript (PS), Enhanced Metafile (EMF), or the like.

The command generation unit 140 divides the input raster image into a background region, a monochromatic region, and a multicolor region. Where the background area is a group of pixels (or points) that are consistent throughout the raster image. And the multicolor region is a group of consistent pixels of a raster image that is limited to a portion of the raster image. And the monochromatic region is a region of (approximately) the same brightness and color.

The instruction generation unit 140 generates a meta instruction corresponding to each of the divided regions. Specifically, the command generation unit 140 may determine the separated background area as one of a monochrome background, a gradient background, and a multicolor background, and may generate a corresponding meta command if the determined background area is a monochrome background and a gradient background. For example, if the determined background area is a monochrome background, a meta command that describes a rectangle having a color of the background area is generated. If the determined background area is a gradient background, a meta command that determines the direction and type of the color corresponding to the background area Command can be generated.

For the multicolor region, the command generation unit 140 determines whether the multicolor region is a rectangle. If the multicolor region is not a rectangle, the command generation unit 140 divides the multicolor region into a plurality of rectangular regions, You can create a meta-instruction.

For the monochromatic region, the command generation unit 140 can detect the outline of the monochrome region, simplify the detected outline into straight and bezier curve segments, and generate a meta instruction corresponding to a series of straight lines and curve segments have.

The file generation unit 150 generates a meta file based on the generated meta command. Specifically, the file generating unit 150 may generate a meta file including a meta command generated by the command generating unit 140 and a raster image corresponding to an area. For example, for a monochrome background and a gradient background, only meta-commands corresponding to the monochrome background and the gradient background are included in the metafile, and for a multicolor background, a raster image corresponding to a multicolor background and a meta- have.

At this time, the file generation unit 150 may perform scaling to lower the resolution of the raster image corresponding to the multicolor background, and may include the scaled raster image in the meta file.

For a multicolor area, a meta-command that describes a raster image corresponding to a multicolor area and a position of a raster image corresponding to a multicolor background may be included in the meta file. At this time, the file generation unit 150 may include a meta command describing the raster image and the position of each raster image in the clipping interval, which is classified when the multicolor area is not a rectangle, in the meta file. Also, the file generating unit 150 may perform scaling on the raster image corresponding to the multicolor area, and may include the scaled raster image on the meta file.

For the monochromatic region, the file generation unit 150 may include vectorized meta-instructions in the meta file. As described above, in this embodiment, only the meta-instructions corresponding to the monochromatic region are included in the meta file, so that a meta file having a smaller capacity can be generated.

Meanwhile, when the meta command is included in the meta file, the file generator 150 may perform lossless compression and include the meta command in the meta file.

The control unit 160 performs control for each configuration in the raster image conversion apparatus 100. Specifically, the control unit 160 controls the command generation unit 140 to generate a meta command corresponding to the selected raster image when the raster image to be converted is selected through the user interface unit 130 and the conversion command is input , And control the file generation unit 150 to generate a meta file including the generated meta-commands.

As described above, the raster image conversion apparatus 100 according to the present embodiment divides an input raster image into a background region, a monochromatic region, and a multicolor region, generates a meta command in a manner optimized for each region, and generates a meta file Bar, and small capacity metafiles. Furthermore, vectorization is performed for the monochromatic region, and a command corresponding to the monochromatic region is stored in the metafile, so that a smaller capacity metafile can be generated.

19 is a block diagram showing a configuration of a picture reading apparatus 200 according to an embodiment of the present invention.

19, the image reading apparatus 200 includes a communication interface unit 210, a storage unit 220, a user interface unit 230, a scan unit 240, a command generation unit 250, a file generation unit 260 and a control unit 270. [ Here, the image reading apparatus 200 may be a multifunction peripheral (MFP) that implements a copying machine, a facsimile machine, a scanner, or a combination thereof through a single device.

The communication interface unit 210 is formed to connect the image reading apparatus 200 with an external device and is connected not only in a wireless or wired manner through a local area network and an Internet network but also through a USB (Universal Serial Bus) port It is also possible to connect them.

The communication interface unit 210 can transmit the raster image generated by the scanning unit 240, which will be described later, to an external device. The communication interface unit 210 may transmit the metafile generated by the file generation unit 260 to an external device.

The storage unit 220 stores a raster image. Specifically, the storage unit 220 may store a raster image generated by the scan unit 240, which will be described later.

The storage unit 220 stores the metafile generated by the file generation unit 260, which will be described later. Meanwhile, the storage unit 220 may be implemented as a storage medium in the image reading apparatus 200 and an external storage medium, for example, a removable disk including a USB memory, or a Web server through a network.

The user interface unit 230 includes a plurality of function keys that a user can set or select various functions supported by the image reading apparatus 200 and can display various information provided by the image reading apparatus 200. [ The user interface unit 230 may be implemented by a device such as a touch pad that performs input and output simultaneously, or may be implemented by combining a display device such as a CRT monitor, an LCD monitor, an LED, or the like, have.

The user interface unit 230 can receive a scan command or a metafile generation command, and can select a type of metafile to be converted. Here, the type of the metafile may be Portable Document Format (PDF), XML Paper Specification (XPS), PostScript (PS), Enhanced Metafile (EMF), or the like.

The scan unit 240 scans a document to generate a raster image.

The command generation unit 250 divides the input raster image into a background region, a monochromatic region, and a multicolor region. Where the background area is a group of pixels (or points) that are consistent throughout the raster image. And the multicolor region is a group of consistent pixels of a raster image that is limited to a portion of the raster image. And the monochromatic region is a region of (approximately) the same brightness and color.

The instruction generation unit 250 generates a meta instruction corresponding to each of the divided regions. Specifically, the command generation unit 250 may determine the separated background area as one of a monochrome background, a gradient background, and a multicolor background, and may generate a corresponding meta command if the determined background area is a monochrome background and a gradient background. For example, if the determined background area is a monochrome background, a meta command that describes a rectangle having a color of the background area is generated. If the determined background area is a gradient background, a meta command that determines the direction and type of the color corresponding to the background area Command can be generated.

For a multicolor area, the command generator 250 determines whether the multicolor area is a rectangle. If the multicolor area is not a rectangle, the command generator 250 divides the multicolor area into a plurality of rectangular areas, You can create a meta-instruction.

For the monochromatic region, the instruction generation unit 250 can detect the outline of the monochromatic region, simplify the detected outline into straight and bezier curve segments, and generate a meta instruction corresponding to a series of straight lines and curve segments have.

The file generation unit 260 generates a meta file based on the generated meta command. Specifically, the file generating unit 260 may generate a meta file including a meta command generated by the command generating unit 250 and a raster image corresponding to an area. For example, for a monochrome background and a gradient background, only meta-commands corresponding to the monochrome background and the gradient background are included in the metafile, and for a multicolor background, a raster image corresponding to a multicolor background and a meta- have.

At this time, the file generation unit 260 may perform scaling to lower the resolution of the raster image corresponding to the multicolor background, and may include the scaled raster image in the meta file.

For a multicolor area, a meta-command that describes a raster image corresponding to a multicolor area and a position of a raster image corresponding to a multicolor background may be included in the meta file. At this time, the file generating unit 260 may include a meta command describing the raster image and the position of each raster image in the clipping interval, when the multicolor area is not a rectangle. Also, the file generating unit 150 may perform scaling on the raster image corresponding to the multicolor area, and may include the scaled raster image on the meta file.

For the monochromatic region, the file generation unit 260 may include vectorized meta-instructions in the meta file. As described above, in this embodiment, only the meta-instructions corresponding to the monochromatic region are included in the meta file, so that a meta file having a smaller capacity can be generated.

Meanwhile, when the meta command is included in the meta file, the file generation unit 260 may perform lossless compression and include the meta command in the meta file.

The control unit 270 performs control for each configuration in the image reading device 200. [ Specifically, when the control unit 270 receives a scan command or a metafile creation command through the user interface unit 230, the controller 270 controls the scan unit 240 to generate a raster image by reading the manuscript, The control unit 250 controls the command generation unit 250 to generate a corresponding meta command and controls the file generation unit 260 to generate a meta file including the generated meta command.

As described above, the image reading apparatus 200 according to the present embodiment divides the input raster image into a background area, a monochrome area, and a multicolor area, and generates a meta-command in a manner optimized for each area to generate a meta file , A small capacity metafile can be generated. Furthermore, vectorization is performed for the monochromatic region, and a command corresponding to the monochromatic region is stored in the metafile, so that a smaller capacity metafile can be generated.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the appended claims.

100: raster image conversion apparatus 110: communication interface unit
120: storage unit 130: user interface unit
140: command generation unit 150: file generation unit
160: control unit 200: image reading device
210: communication interface unit 220:
230: user interface unit 240: scan unit
250: command generation unit 260: file generation unit
270:

Claims (20)

In the raster image conversion method,
Separating the raster image into a background region, a monochromatic region, and a polychromatic region;
Generating a meta-instruction corresponding to each of the divided regions; And
And generating a meta file based on the generated meta-instruction,
Wherein the generating the meta-instruction comprises:
Vectorizing the outline of the segmented monochrome region, generating a meta instruction corresponding to the vectorized outline,
If the shape of the divided multicolor area is not a rectangle, the divided multicolor area is divided into a plurality of rectangular areas,
The generating of the metafile comprises:
And generating a meta file including a raster image corresponding to each of the plurality of divided rectangular regions. The method according to claim 1,
Determining the divided background area as one of a monochrome background, a gradient background, and a multicolor background,
Wherein the generating the meta-instruction comprises:
If the determined background area is a monochrome background, generating a meta command describing a rectangle having a color of the background area,
If the determined background area is a gradation background, generating a meta command for determining an oblique direction and a type of a color corresponding to the background area. 3. The method of claim 2,
The generating of the metafile comprises:
If the determined background area is a multicolor background, generating a meta file including a raster image corresponding to the background area. 3. The method of claim 2,
Further comprising: determining transparency to be applied to the divided background area,
The generating of the metafile comprises:
And generating a meta file including a meta command corresponding to the determined transparency. The method according to claim 1,
Converting a resolution of a plurality of raster images corresponding to each of the divided plurality of rectangular zones,
The generating of the metafile comprises:
And generating a meta file including a plurality of raster images whose resolution is changed. delete 6. The method of claim 5,
Wherein the generating the meta-instruction comprises:
And generating a meta-instruction corresponding to each of the plurality of divided rectangular regions. The method according to claim 1,
Wherein the generating the meta-instruction comprises:
Detecting an outline of the divided monochromatic region;
Simplifying the detected contour; And
And generating a meta-instruction corresponding to the simplified outline. 9. The method of claim 8,
Wherein the step of simplifying the detected contour comprises:
Wherein the detected contour is simplified by only a straight line and a Bezier curve. The method according to claim 1,
Further comprising compressing the generated meta-instruction,
The generating of the metafile comprises:
And generating a meta file based on the compressed meta-instructions. A raster image conversion apparatus comprising:
A communication interface unit for receiving a raster image; And
And a control unit for dividing the input raster image into a background region, a monochromatic region, and a multicolor region, generating a meta command corresponding to each of the divided regions, and generating a meta file based on the generated meta command ,
Wherein,
Vectorizing the outline of the segmented monochrome region, generating a meta instruction corresponding to the vectorized outline,
If the shape of the divided multicolor area is not a rectangle, the divided multicolor area is divided into a plurality of rectangular areas,
And generates a meta file including a raster image corresponding to each of the plurality of divided rectangular regions. 12. The method of claim 11,
Wherein,
Determining the separated background area as one of a monochrome background, a gradient background, and a multicolor background,
If the determined background area is a monochrome background, generating a meta command describing a rectangle having a color of the background area,
And generates a meta-instruction for determining the oblique direction and the type of the color corresponding to the background area if the determined background area is a gradation background. 13. The method of claim 12,
Wherein,
And generates a meta file including a raster image corresponding to the background area if the determined background area is a multicolored background. 12. The method of claim 11,
Wherein,
Detecting a contour of the divided monochromatic region, simplifying the detected contour, and generating a meta-instruction corresponding to the simplified contour. 12. The method of claim 11,
Wherein,
Compresses the generated meta-instruction, and generates a meta file based on the compressed meta-instruction. In the image reading apparatus,
A scan unit for scanning a document to generate a raster image; And
And a controller for dividing the generated raster image into a background region, a monochrome region, and a multicolor region, generating a meta command corresponding to each of the divided regions, and generating a meta file based on the generated meta command ,
Wherein,
Vectorizing the outline of the segmented monochrome region, generating a meta instruction corresponding to the vectorized outline,
If the shape of the divided multicolor area is not a rectangle, the divided multicolor area is divided into a plurality of rectangular areas,
And generates a metafile including a raster image corresponding to each of the plurality of divided rectangular areas. 17. The method of claim 16,
Wherein,
Determining the separated background area as one of a monochrome background, a gradient background, and a multicolor background,
If the determined background area is a monochrome background, generating a meta command describing a rectangle having a color of the background area,
And generates a meta-instruction for determining an oblique direction and a type of a color corresponding to the background area if the determined background area is a gradation background. 17. The method of claim 16,
Wherein,
Detecting the outline of the divided monochrome region, simplifying the detected outline, and generating a meta instruction corresponding to the simplified outline. 19. The method of claim 18,
Wherein,
And the detected contour is simplified by only a straight line and a Bezier curve. A computer-readable recording medium containing a program for executing a raster image conversion method,
The raster image conversion method includes:
Separating the raster image into a background region, a monochromatic region, and a polychromatic region;
Generating a meta-instruction corresponding to each of the divided regions; And
And generating a meta file based on the generated meta-instruction,
Wherein the generating the meta-instruction comprises:
Vectorizing the outline of the segmented monochrome region, generating a meta instruction corresponding to the vectorized outline,
If the shape of the divided multicolor area is not a rectangle, the divided multicolor area is divided into a plurality of rectangular areas,
The generating of the metafile comprises:
Generating a metafile including a raster image corresponding to each of the plurality of divided rectangular regions.

Images