JP3155595B2 - Encoding method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an encoding method and apparatus, and more particularly, to an encoding method for directly generating, for example, facsimile code data from closed contour data composed of a plurality of line elements, and a method thereof. It concerns the device.

[0002]

2. Description of the Related Art In this type of image processing apparatus, filling an inside of a closed area of image data is one of basic image processing functions, and various filling methods have been proposed. The most basic method is to specify a filling range one by one for each pixel line of a random access memory (RAM) by software, and fill the line pixels in the specified range.

[0003] A typical example of such a method is described in the document "Fundamentals of Interactive Computer Graphics".
(JDFOLEY / A / VAN DAN co-authored in 1982 Addison-Wesley
pp. 456 to 460).

[0004] This method is briefly described below.

In a closed figure F1 shown in FIG. 2 given by a vertex data sequence, packet data shown in FIG. 4 is generated for each of the edge lines e1 to e10 constituting the figure, and these are shown in FIG. Edge table (E
T). At this time, the packet data is created only for the non-horizontal edges except for the edges horizontal to the X-axis. The edge table (ET) has pointer packet tables Ay0 to Ayn (images from the 0th raster to the nth raster
(N + 1 rasters up to a raster). Then, for each of the ridge line edges e1 to e10 that are not horizontal to the X axis, a pointer packet table corresponding to the y coordinate value of the end point having the smaller y coordinate value is set as follows:
The packet data of each edge is connected in a list structure. When a plurality of packets form a list structure from the same pointer packet, the list structure is formed in ascending order by the x value (x _min ) of the end point having the smaller y coordinate value in each packet. A marker code “λ” indicating this is stored in a pointer packet having no corresponding edge packet. If the ridgeline is not at the minimum value or the maximum value in the y-coordinate direction, the position advanced along the ridgeline by one scan from the original y-coordinate value so as not to cause an erroneous determination in the graphic element inside / outside determination. With y
Edge table (ET) as the end point with the smaller coordinate value
Generate In FIG. 2, the end point B of e3, the end point I of e9,
The end point G of e8 corresponds to this.

Each edge packet Ae1 to Ae10 corresponding to each ridge edge has a corresponding ridge edge e
The value of y at the end point of the larger y coordinate of 1 to e10 (y _max
e1~y _max e10) and the value of x of the end points towards the y-coordinate is smaller (x _min e1~x _min e10), increment the x-coordinate value when the y-coordinate value is increased by 1 (Δxe1~Δxe1
0) and pointers (Pe1 to Pe10) for connecting the edge packets of the ridge line having the same y coordinate value of the end point with the smaller y coordinate in ascending order from the one with the smaller x coordinate value. Note that “λ” in the pointers Pe1 to Pe10 means that there are no more edge packets connected (FIG. 5).

The x direction coincides with the scanning line direction (right direction in the drawing), and the y direction coincides with the scanning line increment direction (down direction in the drawing).

Using the edge table (ET) created in this way, a filling process is executed. First,
The scan line y coordinate value is set to the minimum y coordinate value having an edge packet in the edge table (ET). Next, an edge packet is connected to the y-coordinate value of the scanning line, and an active edge table (AET) (see FIG. 6) is initialized to empty.

Thereafter, the active edge table (A
The following processing is repeated until both the ET) and the edge table (ET) become empty. (1) While maintaining the sort order at the x coordinate value (x _min ) of the active edge table (AET), the information of the edge table (ET) at that time and the information of the active edge table (AET) are merged, A new active edge table (AET) that connects the edge packets related to the scanning line y coordinate value is created. (2) Two pairs each having the smallest x-coordinate value (x _min ) of the active edge table (AET) are set as a pair, the interval between them is defined as a filled section in the graphic element, and the filling in the section is executed. (3) The edge packet whose y-coordinate value of the scanning line is the y value (y _max ) of the end point with the larger y-coordinate is deleted from the active edge table (AET) for the operation on the next scanning line. (4) For the edge packet remaining in the active edge table (AET), the x coordinate value (x
_min ). That is, with (x _min + Δx),
Newly set x _min . (5) Such x-coordinate values (x _min) after updating, re-sorted based on the x coordinate value (x _min). (6) The scan line y coordinate is incremented, and the process returns to (1).

[0010] In this manner, the filling is performed. Here, FIG. 6 shows an active edge table (AE) for the graphic F1 shown in FIG. 2 when the scanning line y coordinate value is "14".
T). FIG. 7 also shows the y coordinate values (0
To the active edge table (AE)
12 shows the transition of the state of T).

In addition, various techniques have been proposed for performing filling at high speed by hardware.

In this type of method, after only pixels that define the outline of a figure are drawn on an image memory, this image memory is raster-scanned, filling is started with odd-numbered outline dots on a scanning line, and even-numbered outline dots are started. (The odd / even reversal method).

However, in the case of using such an odd-even inversion method, simply drawing an outline results in L1, L2, L2 in FIG.
There is a problem in that a portion that should not be painted, such as L3, L4, and L5, is painted, and a portion that should be painted is not painted (the broken line portion of the line L3).

In view of the above, there has been proposed a method of setting a rule for contour drawing to measure an improvement. For example, Tokuhei 1
Japanese Patent No. 54752 discloses the writing of contour pixels according to the following five rules.

Rule 1: Do not write horizontal line segments.

Rule 2: Each line segment is 1 per line
Expressed in pixels.

Rule 3: The starting point of each line vector is not written.

Rule 4: The contour line pixel performs an exclusive OR operation with the pixel data stored at the memory address where the pixel is to be written, and writes the result.

Rule 5: Each line segment is specified in one direction from top to bottom or bottom to top.

Of the above-mentioned rules, rule 1 is that an odd number of contour pixels are generated in one line by contour pixels P1 to P2 and P4 to P3 included in a horizontal contour line like lines L2 and L4 in FIG. Is prevented.

Rule 2 states that regardless of the angle of the line segment,
This is for always representing the outline with one pixel per line.

Rule 3 is to remove an upward or downward vertex. If line segments are specified according to rule 5, for example, in one direction from top to bottom, rule 3 removes the contour pixels P5 and P6 of the upward vertices in FIG.

Rules 4 and 5 remove the contour pixels (P7 in this example) at the vertices opposite to the vertices processed by Rule 3.

[0024]

However, in the above-mentioned conventional example, an algorithm for performing intermediate coating from contour data is shown, but an algorithm for directly generating transmission code data from contour data is not shown. . If the above conventional example is to be applied as it is, it is necessary to paint the area surrounded by the outline and develop it into dot data, and then scan this to generate code data, which makes the processing complicated. is there.

The present invention has been made in view of the prior art, and it is an object of the present invention to provide an encoding method and apparatus capable of obtaining encoded data without first expanding dot data from contour data.

[0026]

To achieve the above object, the encoding method of the present invention comprises the following steps. That is, an input step of inputting vector data including the vertex coordinates of the contour, an edge connecting the vertex coordinates of the vector data, and an intersection coordinate of a scanning line parallel to any one of the coordinate axes of the vector data. An intersection detection step to determine, and an encoding step of creating encoded data representing the length of a white run or a black run for each of the scanning lines based on the intersection coordinates detected in the intersection detection step. In the converting step, the encoded data is created without being developed into dot data representing an outline based on the vector data.

In order to achieve the above object, the coding apparatus of the present invention has the following configuration. That is, input means for inputting vector data including vertex coordinates of the contour, an edge connecting each vertex coordinate of the vector data, and an intersection coordinate of a scanning line parallel to one of the coordinate axes of the vector data are obtained. An intersection detecting means to be obtained, and encoding means for creating encoded data representing the length of a white run or a black run for each scanning line based on the intersection coordinates detected by the intersection detecting means, The encoding means creates the encoded data without expanding the dot data representing the contour based on the vector data.

[0028]

In the above arrangement, vector data including the vertex coordinates of the contour is input, and the edge connecting the vertex coordinates of the vector data and the scanning line parallel to one of the coordinate axes of the vector data are determined. Find the intersection coordinates,
White run for each scanning line based on the detected intersection coordinates,
By generating the encoded data representing the length of the black run, the operation is performed so as to create the encoded data without developing the dot data representing the contour based on the vector data.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. <Description of Operation Outline> First, an operation outline in the embodiment will be briefly described.

In this embodiment, a contour oriented in a predetermined direction is used as a contour of a figure. That is, as shown in FIG. 3, a collection of outline vectors (line elements) connected to the clock in the clockwise direction (hereinafter, clockwise) as shown in FIG. (Hereinafter, counterclockwise). Here, an outline vector that continues in the clockwise direction may be considered to mean that if the right side of the outline vector is painted, the corresponding figure is painted (FIG. 9). An outline vector connected in the counterclockwise rotation direction is a figure which is painted when the left side of the outline vector is painted (FIG. 10).

In this embodiment, the direction and inclination of each outline vector are determined, and the direction and inclination of the outline vector immediately before each outline vector are determined.
Then, based on the direction and inclination of the outline vector immediately after, it is determined whether or not the endpoints on the vector other than the endpoints and the endpoints of the corresponding vector are used for determining the boundary points forming a closed section. Thereafter, for each scan, from the odd-numbered boundary determination edge intersecting the scan line to the even-numbered boundary determination edge is calculated as a black run length, and the even to odd numbers are calculated as white run lengths. , And outputs encoded data. <Description of Apparatus Configuration> FIG. 1 is a block diagram showing an example in which the encoding apparatus according to the present embodiment is applied to a facsimile apparatus.
In the figure, 101 is a control unit for controlling the entire apparatus, 102 is a reading unit for reading and inputting a document image photoelectrically, and 103 is an outline data file storing document data as outline vector data. An operation unit 104 is operated by an operator to input a document image transmission instruction and the like. A display unit 105 displays various messages to the operator, device status, and the like. A recording unit 106 records a received image or a document image read by the reading unit 102 by, for example, a thermal method or an electrophotographic method. Reference numeral 107 denotes a modem for modulating or demodulating image data, and reference numeral 108 denotes a communication network control circuit (NCU).

Next, the configuration of the control unit 101 will be described.
Reference numeral 11 denotes a CPU such as a microprocessor for performing overall control according to a control program stored in a ROM 112;
A ROM 12 stores a control program of the CPU 111 and various data. An R 113 is used as a work area of the CPU 111 and stores various data.
AM. Reference numeral 114 denotes a buffer memory,
Data or contour data file 10 read by
3 is stored. Reference numeral 115 denotes an encoding unit that encodes the document image data read by the reading unit and creates encoded data from outline vector data, which is a feature of the present embodiment. A decoding unit 116 decodes the received encoded data to create image data. A transmission / reception buffer 117 stores encoded image data to be transmitted or received encoded image data. In the following description, since the process of encoding and transmitting image data read by the reading unit is known, the process of encoding based on contour data will be described.

As shown in FIG. 11, the contour data stored in the contour data file 103 includes data (N) indicating the number of closed loops included in the target image, and vertexes of each closed loop. It is composed of a data group indicating the number (L) and the coordinate values (x, y) of each vertex. However, each vertex in each closed loop is expressed as a collection of data while maintaining the relationship between adjacent vertices in a predetermined order on each closed loop.

As described above, in this embodiment, the outline data is regarded as a group of data arranged in a predetermined direction. For example, FIG. 3 shows an example of clockwise outline data, and the outline data is as shown in FIG. In FIG. 12, the outline of the graphic F1 in FIG. 3 is a point sequence starting from point A in the order of A → B → C → D → E → F → G → H → I → J → A. Is expressed. In FIG. 12, the number (N) of closed loops is “1”, the number (L) of vertices is “10”, and the coordinate value of each vertex follows.

In the present embodiment, as shown in FIG. 3, the origin (0, 0) of the coordinates is assumed to be at the upper left corner of the image, the main scanning direction (right direction) is set on the x-axis, and the sub-scanning direction ( The vertical direction is described as the y-axis. The outline will be described assuming clockwise data expression. The starting point in each closed loop may be any point on the loop. <Description of Main Processing> FIG. 13 is a flowchart showing the operation processing procedure of the CPU 111 in the facsimile apparatus of the present embodiment, which will be described below.

When the processing is started in step S1, the flow advances to step S2 to check whether or not a facsimile transmission instruction of the outline data is input from the operation unit 104. When the transmission instruction is input, the process proceeds to step S3, where the contour data file 10
3 and stores the data in the buffer memory 104. Here, the outline data is an outline vector data group expressed in the format shown in FIG. 11 as described above. Next, in step S4, data for each edge is created in the data format shown in FIG. 4 according to the rule shown in FIG. 21, and an edge table (ET) in the format shown in FIG. Proceed to step S5.
The details of the edge table creation processing in step S4 will be described later in detail.

Next, in step S5, the scanning line position of interest is set to the first scanning line position in the page. That is, y
= 0 scanning line position. Also, an active edge pointer area is secured as shown in FIG. Then, the process proceeds to step S6, where an active edge table (AET) of the format as shown in FIG. Based on this, in step S7, the run lengths of the white run and the black run are calculated, and a Huffman code corresponding to each run length is output. The processing content of this step S7 will be described later in detail.

Next, the flow advances to step S8 to advance the target scanning line position by one line. That is, if the scanning position of y = i has been noticed, y = i + 1 is set. Then, the process proceeds to step S9, and it is determined whether the processing up to the last scanning line position in the page has been completed. If the processing has been completed up to the last scanning line position, the process proceeds to step S10, and a series of processing ends. If the processing has not been completed up to the last scanning line position in step S10, the process returns to step S6, and the processing of the next line is continued. The determination as to whether or not this is the last scanning line is made by storing the number of scanning lines included in the page to be drawn in advance in a routine (not shown), and determining the number of scanning lines and the current scanning line position of interest. Are determined by comparing. <Description of Edge Table Creation Processing> Next, with reference to FIG. 14, details of the edge table (ET) creation processing in step S4 of FIG. 13 will be described. This edge table is R
It is created in the AM 113.

When the process of creating the edge table is started, the process proceeds to step S51, where the edge table (ET) is initialized. That is, as shown in FIG. 15, a scanning line (here, y = 0) included in the page to be generated
Address pointer (hereinafter also referred to as pointer packet) areas Ay0 to AyN for (N + 1 lines from N to N) are secured in the RAM 113, and a marker value “λ” indicating that no reference data exists is stored in each area. . Next, in step S52, the process proceeds to step S53 with reference to the closed loop number (N) of the outline data given in the format shown in FIG. In step S53, it is determined whether or not the number of closed loops (N) is greater than "0". If the number is not greater than 0, that is, if there is no closed loop, the process proceeds to step S68. And returns to the main process. On the other hand, when a closed loop exists, the process proceeds to step S54.

In step S54, a loop vertex count table pointer is initialized to a position where the vertex count in the zeroth loop is stored in the loop vertex count table of the outline data given in FIG. S55
Proceed to. In step S55, the process proceeds to step S56 with reference to the in-loop vertex number data at the position indicated by the in-loop vertex number table pointer. If the number of vertices in the loop is equal to or more than "2", the process proceeds to step S57.

In step S57, the edge having the last vertex of the loop as the start point and the first vertex as the end point is regarded as the current edge (edge of interest), and the direction of this edge and the increment of x are calculated. In other words, the start point coordinates of the edge are set to (x
_start , y _start ), and the end point coordinates are (x _end , y _end ). When y _start = y _end , the edge direction is horizontal with respect to the X axis, so that the x coordinate increment is not calculated. Also, when y _start = y _end, the edge is a left-facing edge if x _start > x _end and a right-facing edge if x _start <x _end . Also, at this time, if x _start = x _end , it means only one edge where the start point and the end point are coincident, and it is either a part of the previous or subsequent edge or an isolated point . It is assumed that such an edge has been removed in advance from the vertex sequence of the edge constituting the contour when forming the data shown in FIG.

When y _start > y _end , the direction of the edge is determined to be upward, and the increment of x is (x _{st art} -x _end ) /
(Y _start −y _end ).

[0043] y _start <When y _{end The} the orientation of the edge determined to downward increment of x (x _{en d} -x _start) /
(Y _end −y _start ).

After the current edge data creation processing in step S57 is completed, the process proceeds to step S58, in which the edge having the first vertex (the 0th vertex) of the loop as the start point and the next vertex (the first vertex) as the end point is determined. The next edge (the next edge on the contour loop with respect to the target edge, that is, the edge starting from the end point of the target edge) is determined, and the direction of this edge and the increment of x are obtained in the same manner as in step S57. When the processing of step S58 is completed, step S5
9 and move the noted vertex coordinate table pointer to the position shown in FIG.
Is set to the address value at which the data of the 0th vertex coordinate of the loop is stored, and the process proceeds to step S60.

In step S60, the current edge data (the direction of the current edge and the increment of x) immediately before this point is used as the previous edge (on the contour loop with respect to the target edge).
The edge connected immediately before, that is, the edge having the start point of the target edge as the end point) data. Then, the process proceeds to step S61, and the next edge data (the direction of the next edge and the increment of x) immediately before this point is set as the current edge data. Next, the process proceeds to step S62, and next edge data (direction of the next edge and increment of x) is obtained in the same manner as in step S57. At this time, the start point of the next edge is the end point of the current edge, and the end point of the next edge is, of course, the next vertex on the loop with respect to the end point of the current edge. These are obtained by referring to the data of the next vertex position of the target vertex position and the data of the next next vertex position. When the target vertex position at this time is at the final vertex of the loop, , The next edge means that the 0th vertex of the loop is the start point and the 1st vertex is the end point. When the target vertex position is located at the vertex immediately before the final vertex of the loop, control is performed such that the final vertex is the start point and the zeroth vertex is the end point.

When the process of step S62 is completed, the process proceeds to step S63, and based on the previous edge data, the current edge data, and the next edge data at this point, the packet data in the form shown in FIG. create. Then, the packet data is added to the edge table to update the edge table. The contents of this processing will be described later in detail with reference to FIGS. When the update processing of the edge table is completed in this manner, step S
Proceeding to 64, the value of the noted vertex coordinate table pointer is updated to be the position of the next vertex coordinate table on the loop. Then, in step S65, it is determined whether or not processing for all edges in the loop has been completed. If completed, the process proceeds to step S66; otherwise, the process returns to step S60 to perform a series of processes for the next edge. Continue. Whether or not processing for all edges has been completed is determined, for example, for each loop,
The number of times of passing through step S65 is counted, and it can be determined whether or not the number of times has exceeded the number of vertices included in the loop.

In step S66, the in-loop vertex number table pointer is updated to a position for holding the data of the next loop, and the flow advances to step S67. In step S67, it is determined whether or not a series of processes has been completed for all loops included in the contour data. If completed, the process proceeds to step S68; otherwise, the process returns to step S55 and returns to step S55. A series of processing for the loop of is continued. The determination as to whether or not the processing of all the loops has been completed is made, for example, by counting the number of passes through step S67 and determining whether the number of times has exceeded the number of loops included in the contour data. Can be determined. In step S68,
The process of creating the edge table (ET) ends, and the process returns to the main routine. <Description of Edge Table Update Processing> Hereinafter, the edge table update processing in step S63 in FIG. 14 will be described with reference to the flowcharts in FIGS. 16 and 17 and FIG.
In step S63, the process proceeds using the directions of the current edge, the previous edge and the next edge, and the increment of x. FIG. 21 shows rules for generating the packet data of the form shown in FIG. 4 for the current edge.

First, if the current edge is a horizontal edge, that is, the direction of the current edge is leftward or rightward,
No packet data is generated for this edge, and the edge table is not updated. Therefore, they are not shown in FIG. When the current edge is upward or downward,
Start 1 to Start 10 and End 1 to 1 depending on the contents of the front edge data
Consider the last 10 cases separately. In FIG. 21, in the column of the state of the starting point, the current edge is indicated by a solid arrow, the front edge is indicated by a broken arrow, and the direction of the arrow indicates the direction of each edge. It indicates that there is. In the end point status column, the current edge data is indicated by a solid arrow, the next edge is indicated by a dashed arrow, the direction of the arrow indicates the direction of each edge, and the shaded side of each edge is a black data area. Is shown.

First, paying attention to the handling of the starting point of the current edge,
The case where the current edge is upward (start 1 to start 5) will be described.
You. If the front edge is also upward (case 1), the current edge
The start point of the edge is one scan line more than the actual end point along the edge
Create packet data at the point where
You. If the front edge is downward, the end point of the front edge
When the starting point of the current edge is the concave vertex of the closed figure (case
In the case of start 2), the start point is still one scan line deeper than it actually is.
Packet data at the point where
Create data. When it becomes a convex vertex of a closed figure (case start 3)
Means that the starting point is the actual position
Create data. It should be noted that the case start 2 or case start 3
Another is the magnitude of the x increment of the current edge and the x increment of the previous edge.
This is possible by comparing the relationships. That is, x of the leading edge
Increment by Δx_pre , X increment of current edge to Δx_now Then
Δx_pre > Δx_now Is case 2 and Δx
_pre <Δx _now In the case of, the start of the case is 3. Where Δ
x_pre = Δx_now In the case of, it is determined that it is case start 3.
I will do it. When the front edge is facing left (case start 4)
Means that the starting point of the current edge is
When packet data is created, and the leading edge is
5), the starting point of the current edge is one scan line
The point that has moved to the end point along the
Create cut data.

Next, when the current edge is downward (start 6)
10), if the front edge is upward, the front edge
The end point of the edge, that is, the start point of the current edge, becomes the convex vertex of the closed figure.
(Case start 6), the starting point is the actual position point itself
To create packet data. On the other hand, the beginning of the current edge
When a point becomes a concave vertex of a closed figure (case 7),
The point is one scan line closer to the end point along the current edge than it is.
Create packet data assuming that it is at the moved point. Previous
Edge is downward (case start 8) and right
In (Case Start 10), the start point is the actual position point itself
To create packet data. Also, the front edge is to the left
Start point (case start 9), the starting point is one scan
At the point moved to the end point along the edge
Generate packet data. Here, case start 6
The start edge 7 is determined by the x increment Δx of the current edge._now And before d
X increment x_pre By comparing the magnitude relationship with
Noh. That is, Δx_pre <Δx_now In case of
6, Δx_pre <Δx _now Is case 7
You. Note that Δx_pre = Δx_now Is case start 6
Is determined.

Next, a description will be given focusing on the handling of the end point of the current edge.

First, when the current edge is upward (final 1)
5) will be described. If the next edge is also upward (case end 1), packet data is created with the end point of the current edge being the actual point itself. If the next edge is down,
When the start point of the next edge, that is, the end point of the current edge becomes a concave vertex of the closed figure (case end 3), the end point of the current edge is shifted by one scanning line from the actual position to the start point side along the current edge. Create packet data assuming that it is at the return point. on the other hand,
When it becomes a convex vertex of the closed figure (case end 2), the packet data is created with the end point of the current edge being the actual position point itself. When the next edge is to the left (end of case 4)
The packet data is created on the assumption that the end point of the current edge is located at a point which has returned to the start point along the edge by one scanning line from the actual position. When the next edge is rightward (case end 5), the packet data is created with the end point of the current edge being the actual position itself. Here, Case 2
Or the end of case 3 is determined by the x increment Δx _{now of the} current edge.
This can be done by comparing the magnitude relationship between x _post and the next edge x increment Δx _post x _post . That is, case Δx _now <Δx _post is case end 2, and case Δx _now > Δx _post is case end 3. However, in the case of Δx _now = Δx _post , it is determined that case end 2 is reached.

Next, when the current edge is downward (final 6)
-End 10) will be described. When the next edge is upward, when the start point of the next edge, that is, the end point of the current edge is a convex vertex of a closed figure (case end 6), the end point of the current edge is the packet data as the actual position point itself. create. When it becomes a concave vertex of a closed figure (case end 7),
The packet data is generated on the assumption that the end point of the current edge is located at a point returned to the start point side along the edge by one scanning line from the actual position. Further, when the next edge is downward (case end 8), the packet data is created with the end point of the current edge being the actual position point itself. If the next edge is rightward (end of case 10), packet data is created on the assumption that the end point of the current edge is one scan line back from the actual position along the current edge. Here, whether the end of the case is 6 or the end of the case 7 is determined by the x increment Δx of the current edge.
_This can be done by comparing the magnitude relationship between _now and the next edge x increment Δx _post . In other words, Δx _now <in the case of Δx _post is a case end 6, Δx _{no w>} in the case of Δx _post is the case end 7. In the case of Δx _now = Δx _post , it is determined that case end 6 is reached.

According to the above generation rules, packet data in the form shown in FIG. 4 is generated for the current edge.

The processing described above is performed in step S6 of FIG.
3, but the CPU 111 ends up with FIG.
The processing is performed according to the flowchart shown in FIG.

First, when the series of processing is started in step S63, the flow advances to step S631. At this time, as the input data, the front edge data (the direction of the front edge and the x increment Δx
_pre ), the current edge data updated in step S61 (the coordinate values of the start and end points of the current edge (respectively (x _start , y _start ), (x _end , y _end )), the direction, and the x increment Δx _now ) And step S62
In a next edge data created (orientation and x increment [Delta] x _{po st} follows the edge). In step S631, it is determined whether or not the direction of the current edge data is horizontal (that is, whether it is rightward or leftward). If horizontal, the process proceeds to step S644, and a series of processes is completed to complete this process. Next step (step S6 in FIG. 14)
Return to 4).

If it is not horizontal in step S631, the flow advances to step S632 to determine whether or not the current edge is upward. If it is upward, the flow advances to step S633 to generate packet data for the upward edge. Go.
On the other hand, if it is not upward (if it is a downward edge), the process proceeds to step S645, and thereafter, generation of packet data for the downward edge is performed.

It is determined that the current edge is an upward edge.
In step S633, the edge pattern of the form shown in FIG.
Create a blanket once. That is, y_max = Y
_start , X_min = X_end , Δx = Δx_now Created as
In this case, the pointer indicates "λ" (there is no connection
). In addition, step S6
33, when registering this edge packet in ET
The edge packet connects to which pointer packet.
Value y indicating whether it should be data_min Also set. Where y
_min = Y_end Set as Where y_max Is the current edge
At both end points (start point and end point) of
The value of the endpoint y, x_min And y_min Is y
Means the x and y values of the coordinate value of the smaller end point of the coordinates
I do. x increment Δx means that a point on the current edge is
Move along the y-coordinate from smaller to larger
Means the change in x-coordinate per scanning line.
In the embodiment, the positive direction of the x coordinate is rightward, and the positive direction of the y coordinate is
Since the direction is assumed to be downward, as described above, y
_max , X_min , Δx, y_min Is set. In this way
When the process of step S633 is completed, the process proceeds to step S634.
No.

In step S634, it is determined whether or not the front edge is downward. If it is downward, the flow advances to step S635; otherwise, the flow advances to step S636. In step S635, it is determined whether the start point of the current edge corresponds to case start 2 or case start 3 by the method described above. If the start point of the current edge corresponds to case start 2, the process proceeds to step S637.
And decrease y _max by “1”. If not, the process proceeds to step S638. In step S636, it is determined whether the start point of the current edge corresponds to case start 4 (ie, whether it corresponds to case start 1 or case start 5), and if it corresponds to case start 4, the process proceeds to step S638. Otherwise, the process advances to step S637 to set y _max to “1”.
That is, the starting point of the upward edge is reduced by one scanning line. When the processing of step S637 is completed, step S6
Proceed to 38. This ends the processing for the start point when the current edge is upward.

Next, in step S638, it is determined whether or not the next edge is downward, and if it is downward, step S639 is performed.
The process proceeds to step S640 otherwise. In step S639, it is determined whether the end point of the current edge corresponds to case end 2 or case end 3 based on the above-described method.
Proceed to 643; otherwise (case end 3), proceed to step S641. In step S640, it is determined whether the direction of the next edge is to the left, that is, whether the end point of the current edge corresponds to case end 4 (case end 1 or case end 5), and if it corresponds to case end 4, it is determined in step S641. And increase x _min by Δx. That is, assuming that the end point of the upward edge is narrowed by one scanning line, the x coordinate value is corrected. If not, the process advances from step S640 to step S643 to register the packet data in the ET. When the process of step S641 is completed, step S64
_Proceeding to 2, the y _min is increased by "1", that is, the end point of the upward edge is reduced by one scan, and the y coordinate value of the end point is corrected. Upon completion of the process in the step S642, the process proceeds to a step S643.

On the other hand, a case will be described in which it is determined in step S632 that the current edge is not upward, that is, it is a downward edge.

In this case, the process proceeds to step S64 in FIG.
The process then proceeds to 5 and once generates an edge packet of the form shown in FIG. That is, y _max = y _end , x _min = x
_start , Δx = Δx _now , and the pointer has “λ” (a marker indicating that there is no connection) here. In addition, set y _min = y _start . In the next step S646, it is determined whether or not the front edge is upward. If it is upward, the flow advances to step S647; otherwise, the flow advances to step S648.

In step S647, it is determined whether the start point of the current edge corresponds to case start 6 or case start 7 by the above-described method. If it corresponds to the case start 6 (vertex of the convex portion), the process proceeds to step S651, and if it corresponds to the case start 7 (vertex of the concave portion), the process proceeds to step S649.
Proceed to. In step S648, it is determined whether or not the start point of the current edge corresponds to case start 9 (that is, whether it corresponds to case start 8 or case start 10), and if it corresponds to case start 9 (when the front edge is to the left) ) Proceeds to step S649 to increase x _min by Δx, that is, assuming that the designation of the downward edge is reduced by one scanning line, and the x coordinate value is corrected. Upon completion of the process in step S649, the process proceeds to step S650, in which y _min is increased by "1", that is, the value is corrected on the assumption that the start point of the downward edge is reduced by one scan. This completes the processing for the start point of the current edge.

Upon completion of the process in step S650, the flow advances to step S651 to determine whether the next edge is upward.
If it is upward, the process proceeds to step S652; otherwise, the process proceeds to step S653. In step S652, whether the end point of the current edge corresponds to case end 6 or case end 7
Is determined by the above-described method. Then, if it corresponds to case end 6, the process proceeds to step S643 in FIG. 16, and if it corresponds to case end 7, the process proceeds to step S654. In step S653, it is determined whether or not the end point of the current edge corresponds to case end 9 (that is, whether it corresponds to case end 8 or case end 10). Proceed to step S643; otherwise (case end 8 or case end 10), proceed to step S654 to decrease y _max by "1", that is, reduce the end point of the downward edge by one scanning line. When the process ends in step S654, the process proceeds to step S643.
Proceed to.

As described above, in each of the cases where the current edge is upward and downward, an edge packet for the current edge is generated in accordance with the rule shown in FIG.

In step S643, the edge packet generated above is additionally registered in the edge table (ET). That is, to add edge packet in the current edge list connection edge packet leading to pointer packet Ayy _min corresponding to y = y _min in the edge table. First, an area for holding the edge packet of the current edge is secured on the RAM 113. Next, the pointer packet Ay
_Examine the value of y _min and if the value is still “λ”,
The edge packet of the current edge is rewritten to the address of the area holding the edge packet of the current edge, and is connected to the pointer packet in a list. Pointer packet Ayy _min
Has a value other than the existing “λ”, there are some edge packets already connected in a list, and the value of x _min of these edge packets is The edge packet of the current edge is inserted into the list-connected edge packet sequence so as to be in ascending order as viewed from the side. This is realized by copying the value of the pointer of the packet immediately before insertion into the pointer portion of the edge packet of the current edge and rewriting the address value of the edge packet of the current edge in the pointer portion of the previous packet. Thus, when the process of step S643 is completed, the process proceeds to step S644, where a series of processes for updating the edge table is completed, and the process returns to the upper routine that called this process. <Explanation of Processing for Generating Contour of Interest Scanning Line> Next, the “generation processing for the contour of interest scanning line” in step S6 in FIG. 13 will be described. The processing proceeds according to the following procedure using the active edge table (AET) at that time.

The active edge table (AE)
T) is initialized in step S5, and is initially empty (the state where the marker “λ” is written). Thereafter, even if the process is once terminated and the process proceeds to step S7, the state of the active edge table is held until the process returns to step S6 again. (1) While maintaining the sort order at the x coordinate value (x _min ) of the active edge table (AET), the information of the edge table (ET) at that time and the information of the active edge table (AET) are merged. , A new active edge table (AET) connecting the edge packets related to the scanning line y coordinate value is created. (2) Access is made from the smaller x coordinate value (x _min ) of the active edge table (AET), and the process proceeds as follows.

To make the story easier to understand, the symbols are defined as follows.

X _size : number of pixels of the input image in the main scanning direction n: number of edge packets registered in the AET (n = 0 indicates that the AET is empty) x _{min (i)} : registered in the AET X _min value of the i-th (counted from the smaller of x _min ) edge packet being _processed . i
Takes a value from 0 to n + 1. However, when i = 0, x _{min (0)} = −1, and when i = n + 1, X _{min (n + 1)} = x _size .

At this time, each run length (RL (i), i = 0,
.., N) is RL (i) = x _tmp (i + 1) −x _tmp (i) x _tmp (i) = x _min (i) (when i is an odd number) or x _tmp (i) = x _min (i) +1 (when i is an even number).

When i is an even number, RL (i) represents a white run length, and when i is an odd number, RL (i) represents a black run length.

When each run length is obtained, the corresponding Huffman code is output. However, when RL (n) = 0, no code is output, and EO is added after the code of RL (n).
The L (end of line) code is added, and the code output for that line is terminated. However, if the total code length of the line is smaller than the prescribed number of bits, fill bits “0” are inserted between the RL (n) code and the EOL code until the prescribed number of bits is reached. FIG. 18 shows Huffman codes corresponding to white run and black run lengths. (3) An edge packet in which the y coordinate value of the target scanning line is set to the y value (y _max ) of the end point having the larger y coordinate is converted into an active edge table (A) for the operation in the next scanning line.
ET). (4) For the edge packet remaining in the active edge table (AET), the x coordinate value is updated using the incremental data (Δx) for the operation in the next scanning line. That is, (x _min + Δx) is newly set as x _min . (5) Such x-coordinate values (x _min) after updating, re-sorted based on the x coordinate value (x _min).

After the sorting is completed, step S8
To update the scanning line of interest to the next scanning line position, and step S9
It is determined whether or not the processing of one page has been completed. If not completed, the process moves to step S6. E if finished
A code indicating OP (end of page) is output, and the process ends.

FIG. 19 shows an edge table obtained by this embodiment in contrast to FIG. That is, FIG.
, The edge e10 is an upward edge, the front edge e9 is also an upward edge, and the next edge e1 is a downward edge. Therefore, the start point of the edge e10 corresponds to the case start 1 and the end point corresponds to the case end 2 shown in FIG. are doing. Therefore, e10: y _max = 8, x _min = 7, Δx = −1, y
_min = 3.

Hereinafter, similarly, the edge e1 is a downward edge.
Yes, the start point corresponds to case start 6, and the end point corresponds to case end 10.
E1: y_max = 5, x_min = 7, Δx =
1, y _min = 3.

Since the edge e2 is a horizontal edge, no edge packet is generated. Next, the edge e3
Is a downward edge, and the start point corresponds to the case start 10 and the end point corresponds to the case end 9, so that e3: y _max = 15, x
_min = 19, Δx = 0, y _min = 6.

Since the next edge e4 is a horizontal edge,
No edge packet data is generated. Further, the edge e
5 is an upward edge, and the start point corresponds to the case start 4 and the end point corresponds to the case end 3, so e5: y _max = 15, x
_min = 15, a _{Δx = 1, y mi n =} 14.

Next, the edge e6 is a downward edge,
The start point corresponds to the case start 7 and the end point case end 9, and e6: y
_max = 16, x _min = 13, Δx = −1, y _min = 14
Becomes

Since e7 is a horizontal edge, no edge packet is generated.

Next, the edge e8 is a downward edge,
Since the start point corresponds to case start 9 and end point case end 6, e8: y _max = 18, x _min = 7, Δx = −1, y
_min = 17.

Further, the edge e9 is an upward edge,
Since the start point corresponds to case start 3 and end point case end 1, e9: y _max = 18, x _min = 1, Δx = 5/9,
y _min = 9.

The above is summarized in an edge table.
As shown in FIG. An active edge table (AET) is generated based on FIG.
FIG. 20 shows how the AET changes when the AET is sequentially increased one by one from zero.

In the above discussion, y _max and y
_min is treated as a non-negative integer value. Further, x _min and Δx are handled as real number data (that is, having information of a decimal part) having sufficient accuracy in use. However, the x coordinate when updating the scanning line to the next line is a value obtained by adding the calculated Δx to the x coordinate of the immediately preceding edge in the calculation, but the pixel on the memory can only be located at an integer position. Therefore, the actual x coordinate is changed when Δx is added and a carry occurs below the decimal point. <Second Embodiment> In the first embodiment, the method and the apparatus for forming the MH code from the edge packet data have been described. Here, from the edge packet data, the MR
A method of configuring the code will be described. For the structure of the MR code currently used, see “FAX,
Image Signal Processing for OA ”79 published by Nikkan Kogyo Shimbun
The explanation is given from page to page 83. The difference between the present method and the conventional method is that, in the case of the present method, a changed pixel is found from edge packet data, whereas in the conventional method, an image is scanned to find sequentially changed pixels. Therefore, once a changed pixel is found, the subsequent processing can be performed in the same manner as in the conventional method. Here, a method of finding a changed pixel from an edge packet will be described. here,
A changed pixel is a pixel that has changed to a color different from the color of the previous pixel on the same scanning line.

Since the MR method encodes using two-dimensional correlation, the active edge table (AET) is also
Two AETs (CUR) for the target scanning line and an AET (BEF) for the preceding scanning line (reference scanning line) are required. Before describing the MR encoding process, five types of changed pixels are defined.

A ₀ : Reference change pixel or start change pixel on the target scanning line. Its position is determined by the immediately preceding encoding mode. At the start (left end) of the target scanning line, a ₀ is a pixel virtually placed immediately before (left) the first pixel.

A ₁ : The next changed pixel to the right of a ₀ of the target scanning line. This pixel has the opposite color to a ₀ and is the next changed pixel to be coded.

A ₂ : The next changed pixel which is further to the right of a ₁ of the target scanning line.

B ₁ : The next change pixel on the reference scanning line to the right of the start change pixel a ₀ . having the same color as a _1.

B ₂ : the next change pixel on the reference scanning line to the right of b ₁ .

If a ₁ , a ₂ , b ₁ , b ₂ other than a ₀
When there are no pixels, these are assumed to be pixels virtually considered immediately (right) immediately after the last (right end) pixel of each scanning line.

Next, three modes are defined as follows with reference to FIG. Path Mode: This is defined as "if b ₂ is located to the left of a _1". Vertical mode: coding is performed at the relative position of a ₁ b ₁ . a
The _one is in any of the left and right _{b 1, V L (a 1} b
₁ ) or V _R (a ₁ b ₁ ). a ₁ b ₁
Are up to 0, ± 1, ± 2, ± 3, and above are expressed in horizontal mode. Horizontal mode: represents the case of the above combination in the case of starting the _{coding, H + M (a 0 a} 1) + M and (a ₁ a _2). Here, M (•) is an MH codeword representing the color and run length, respectively. FIG. 23 shows code words in each mode. Also, T
Is T = 1 and T = 0 when the next scanning line is one-dimensional encoding and one-dimensional encoding.

The processing will be described with reference to the flowchart in FIG.

Steps S701 to S704 are described below.
The description is omitted because it is the same as S1 to S4 in FIG. In step S705, the reference scan line active edge table AET (BEF) and the target scan line active edge table AET (CUR) are initialized, and the target scan line position is set to the first scan line position in the page. In step S706, an AET in the format as shown in FIG. 6 at the target scanning line position is generated. However, AET (CU
If R) is not empty, the edge bucket at the scan line position of interest is added to this, and the AET is sorted in ascending order of x _min.
(CUR).

In step S707, AET (BE
F) and five types of changed pixel positions a using AET (CUR)
₀ , a ₁ , a ₂ , b ₁ , and b ₂ are determined, one of the three modes is determined from the positional relationship between them, and the corresponding code is output as shown in FIG. Step S707 will be described later. After the processing of step S707 ends,
Proceeding to step S708, the contents of the AET (CUR) are copied to the AET (BEF). Then, the processing performed in the first embodiment described above, the edge bucket having the same value of the target scanning line number and the value of y _max is set to the AET (CUR).
Remove from. In step S709, the target scanning line is moved to the next scanning line. In step S710, it is determined whether or not the above processing has been performed up to the last scanning line in the page. If the processing has not been performed, the process proceeds to step S706. If the processing has been performed, the process ends.

FIG. 25 is a flowchart showing the process of detecting a changed pixel position and outputting a code in step S707.
Here, the position of the coordinates (0, 0) defined as shown in FIG. 2 is changed to (1, 1) in order to facilitate correspondence with the conventional MR coding. Accordingly, the edge table is also obtained by adding "1" to the values of y _max and x _min respectively.

First, in step S721, a₀ =
(A₀P, a₀C) = (0,0) and step S
At 722, a₁ = (A₁P, a₁C) detect. In addition, here
And a ₁ Is, as described above, a of the target scanning line.₀ Next to the right of
Are changed pixels. Where x _min cur (i), x_min 
bef (j) is the activity corresponding to the target scanning line.
X of the i-th edge bucket in the edge table_min of
Active edge table corresponding to values and reference scan lines
X of the j th edge bucket of_min Are shown.

Also, a₀ , A₁ , A_Two , B₁ , B_Two No
The data structure is, as shown in FIG.
60 (xP) and an area 261 indicating the color of the pixel at that position
(XC). In this case, active
Indicated by the j-th edge packet in the edge table
The pixel color is black when i is odd and white when i is even.
Therefore, instead of the pixel color, set a flag indicating whether the pixel is odd or even.
You may. Also, a₀P, a₀C is a₀ Pixel position
And a flag indicating whether the number is even or odd. a ₁P, a
₁C, a_TwoP, a_TwoC, b₁P, b₁C, b_TwoP, b_TwoSame for C
You.

Here, CP [x (i)] and CC (i) are defined as follows.

CP [X (i)] = x (i) When i is an odd number x (i) +1 When i is an even number CC (i) = 1 When i is an odd number = 0 When i is an even number At this time , A ₀ P <CP [x _min cur (i) and a ₀ C}
For the minimum i = i ₀ that results in CC (i), a ₁ = (a
₁ P, When a ₁ C), the _{a 1 P = CP [x min} cur (i 0)] a 1 C = CC (i 0). If i ₀ does not exist, a ₁ P = X _size +
1, set a ₁ C = 0.

Next, in step S723, b₁ =
(B₁P, b₁C), b_Two = (B_TwoP, b _TwoPerform C) detection.

B₁ = (B₁P, b₁For C), CP
[X_min bef (i)> a₀P and CC (i) = a₁C
Minimum i = i₁ For b₁P = CP [x_min bef (i₁)] B₁C = CC (i) and b_Two = (B_TwoP, b_TwoFor C), CP [x_min 
bef (i)]> b₁The minimum i = i that is P_Two Against b_TwoP = CP [x_min bef (i_Two)] B_TwoIt can be determined that C = CC (i). Where i₁ , I_Two B does not exist₁P
= B_TwoP = X_size+1, b ₁C = b_TwoSet C = 0.

When a ₀ , a ₁ , b ₁ , and b ₂ are determined, the flow advances to step S725 to determine whether b ₂ P <a ₁ . If so, the flow advances to step S726 to output the code of the pass mode (see FIG. 23), and the flow advances to step S727.
, The value of b ₂ P is set in a ₀ P. At this time, a
The value of ₀ C is: CP [x _min cur (i)] ≦ b ₂ P <CP [x _min cur
(i + 1)] detects the i = i ₃ satisfying, is set to _{a 0 C = CC (i 3} ). Thereafter, the process returns to step S723.

On the other hand, if the determination in step S725 is "N
o ”, the process proceeds to step S728, and | a₁P-b₁P | ≦
It is determined whether the number is three or not. When this condition is satisfied,
Proceeding to step S729, the vertical mode code is output.
You. a₀ Is a₀P = a₁P, a ₀C = a₁C is set
It moves to step S726.

Further, the determination in step S728 is "No".
If so, the flow advances to step S731 to set a_Two Enter detection operation
You. In step S731, CP [x_min cur (i)]
> A ₁The smallest i = i that is P_Four For a_Two Set the value of
To This i_Four If does not exist a_TwoP = x_size+1,
a_TwoSet C = 0. Thereafter, the process proceeds to step S732.
See, a₀A determination is made that P = 0 and a₀If P = 0,
Proceeding to step S733,₁P, a₀Decrease the value of P by "1"
To reset. On the other hand, in step S732, a₀P = 0
If not, the process proceeds to step S734, where the horizontal mode
Output a signal. Thereafter, in step S735, a
₀P = a_TwoP, a₀C = a_TwoSet to C and go to step S736
enter. Where a₀P = x_sizeDetermines whether it is +1
If so, the process proceeds to step S737 to end the process.
Otherwise, the process returns to step S722, and
Execute the process.

By configuring the coding portion as described above, a coding code can be directly generated from the active edge table, so that there is no need to temporarily convert outline vector data into dot data, thereby simplifying the processing.

The method described in the second embodiment is strictly compatible with the MMR method. To cope with the MR method currently used, a K-factor is introduced, and 1
Line and MH coding may be performed. This can be easily configured by combining the first embodiment and the second embodiment.

In a method of encoding in pixel units such as an arithmetic code, a next odd-numbered edge from a pixel indicated by a value obtained by adding “1” to x _min of an even-numbered edge packet in the active edge table is used. from x _min packets to the pixel indicated by the value obtained by subtracting 1 sequentially encoded as a white, from the pixel represented by x _min of the odd-numbered edge packet to the pixel represented by x _min of the next even-numbered edge packet May be encoded as black. <Description of Third Embodiment> In the first embodiment, in the edge packet generation rule shown in FIG.
The rules may be changed as follows for each set of と and 終 1, and 始 8 and 終 8.

That is, case start 1: the start point of the current edge is
It is assumed that it is “as it is without packing”, and the case end 1: the end point of the current edge is “to pack one scanning line”.

[0109] Case start 8: The start point of the current edge is "one scan line", and case end 8: the end point of the current edge is "no change".

The flow of the processing shown in FIGS. 16 and 17 also corresponds to these steps in step S636 for the first case and step S640 for the first case.
However, it can be easily understood that it is changed according to the change of the rule. Step S64 is performed for case start 8.
It can also be easily understood that the step S653 is changed for the case end 8 for the case end 8.

The above change is that a vertex shared by two consecutive outline edges that are directed upward or downward is processed only as a point on an edge ending at the vertex, or the vertex is It implies that it may be processed only as a point on the edge that is the starting point, and unless it is processed as a point on both edges or not as a point on either edge, It can be considered that this means that either is acceptable. <Explanation of Fourth Embodiment> In the first embodiment, the outline has been described as taking the clockwise data representation. However, the present invention is not limited to this, and takes the counterclockwise data representation. It is possible to deal with the case. When expressing counterclockwise data, the rule for generating an edge packet shown in FIG. 27 may be used. In this case as well, the handling of the starting point of the current edge is determined based on the direction and the degree of inclination of the current edge and the previous edge, and the handling of the end point of the current edge is determined based on the direction and the degree of inclination of the current edge and the next edge. The flow of the process of updating the edge table according to the generation rule of the edge packet expressing the counterclockwise data is also substantially the same as that in FIGS. 16 and 17 described above, and steps S636, S640, S648,
The only difference is that “Y” and “N” in S653 are all opposite. <Description of Fifth Embodiment> In the same manner as the modification described in the third embodiment, the case of the fourth embodiment is different from the first embodiment in the rule of FIG. Case end 1
1, and the case start 18 and the case end 18 are respectively combined, and the case start 11: the start point of the current edge is set to "clamp one scan line", and the case end 11: the end point of the current edge is set to "no change" Or the case start 18: the starting point of the current edge may be "as is without clogging", and the case end 18: "only one scanning line may be clogged". <Explanation of the Sixth Embodiment> In the above embodiment, the origin of the coordinates is described as being at the upper left of the image, but the present invention is not limited to this. That is, the position of the origin and the determination method and the orientation of in the description according to the direction of the coordinates, y _max, ymin, x
Of course, the same processing can be performed by changing the handling of _min , Δx, and the like. <Explanation of the Seventh Embodiment> In the above-described embodiment, only one-turn edges, that is, edges (point edges) whose start point and end point coincide with each other, form a contour when forming the data shown in FIG. Although it has been described that the edge has been removed from the vertex sequence of the edge, the present invention is not limited to this. That is, when examining the edge data, the data of the point edge may be ignored and the above-described processing may be continued. In the processing of FIG.
Creation of current edge data in step S57, step S58
In the next edge data creation procedure of step S62 and the next edge data creation procedure of step S62, if the edge being processed is a point edge, the next vertex data is further read in, and the data is newly processed as (x _end , y _end ). Should be continued. At this time, the updating of the position of the target vertex, the counting of the number of vertices at the processing corner, and the like may be adjusted according to the number of skipped vertices. Thus, it is of course possible to remove point edges during the creation of the edge table. <Description of Eighth Embodiment> The configuration of the edge table is not limited to the configuration described above. That is, the pointer packet may be formed into data having a two-dimensional list structure as shown in FIG. The pointer packet has a y-coordinate value (y _min ) of the smaller end point of the y-coordinate of the edge of the edge packet connected in a list from the pointer packet (a plurality of edge packets are connected in a list in order from the pointer packet) In some cases, the y
_min are all equal values), and when the y-coordinate value is viewed in ascending order, the pointer to the next pointer packet among the pointer packets having the edge packets connected in a list is And a pointer term to an edge packet connected to the pointer packet.

FIG. 29 shows an example of an edge table configured with pointer packets having the format shown in FIG. FIG. 29 is an edge table configured for the outline graphic given in FIG. As described above, an edge table having a two-dimensional list structure can be configured in substantially the same procedure as in the above-described embodiment. However, if the pointer packet area is previously secured for the number of scanning lines of an image, No, every time one edge packet is generated,
It is determined whether or not there is an existing pointer packet that holds y _min of the edge represented by the corresponding edge packet. Then, if there is, the corresponding edge packet is added to the list of edge packets consisting of the pointer packet,
If not, a new pointer packet is generated, y _min is stored in the pointer packet, the relevant edge packet list is connected, and the newly generated pointer packet is changed to y.
Add to the list connection of the pointer packet sequence in the order of _min
The operation of inserting it is performed.

The generation of the active edge table using such an edge table is the same as that of the first embodiment.

By adopting the list structure having such a two-dimensional structure, it is not necessary to prepare a pointer packet area for the number of scanning lines of an image. This produces a unique effect that a small amount of random memory area is required for the table.

The present invention may be applied to a system composed of a plurality of devices or an apparatus composed of one device. Needless to say, the present invention can also be applied to a case where the present invention is achieved by supplying a program for implementing the present invention to a system or an apparatus.

As described above, contour line data as viewed from the main scan is generated based on the connection relationship between the line element of interest in one continuous direction of the line elements and the line elements adjacent before and after the line element. By generating codes to be transmitted from the contour data, the processing can be speeded up and simplified.

[0117]

As described above, according to the present invention, when code data is generated from vector data representing a closed contour, high-speed processing can be performed with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration in which an encoding device according to an embodiment is applied to a facsimile device.

FIG. 2 is a diagram illustrating an example of outline graphic data.

FIG. 3 is a diagram illustrating an example of clockwise outline graphic data used in the embodiment.

FIG. 4 is a diagram showing a data configuration of edge packet data.

5 is an explanatory diagram of an edge table (ET) of the outline graphic data of FIG. 2 according to a conventional method.

6 is an explanatory diagram of an active edge table (AET) of the outline graphic data of FIG. 2 in a conventional method.

7 is a diagram for explaining transition of an active edge table (AET) of the outline graphic data of FIG. 2 according to a conventional method.

FIG. 8 is a diagram for explaining a problem inherent in the odd-even inversion method.

FIG. 9 is a diagram illustrating an internal region of a clockwise outline closed figure.

FIG. 10 is a diagram illustrating an internal region of a left-handed outline closed figure.

FIG. 11 is a diagram showing outline data in the form of a coordinate string of an outline figure.

12 is a diagram illustrating outline data in the form of a coordinate sequence of the outline graphic data of FIG. 3;

FIG. 13 is a flowchart showing an encoding operation of the facsimile apparatus in the first embodiment.

FIG. 14 shows an edge table (E) in the first embodiment.
12 is a flowchart illustrating a generation procedure of T).

FIG. 15 is a diagram showing an initialized address pointer area.

FIG. 16

FIG. 17 is a flowchart illustrating a procedure for generating packet data and updating an edge table in the first embodiment.

FIG. 18 is a diagram for explaining a modified Huffman (MH) code.

FIG. 19 is an explanatory diagram of an edge table (ET) based on the outline graphic data of FIG. 3;

FIG. 20 is a diagram for explaining transition of the outline graphic data active edge table (AET) of FIG. 3;

FIG. 21 is a diagram illustrating a packet data generation rule for a clockwise outline in the first embodiment.

FIG. 22 is a diagram for explaining the definition of a changing pixel in the MR method.

FIG. 23 is a diagram for describing encoding of MR encoding.

FIG. 24 is a flowchart showing a flow of an encoding process in the facsimile apparatus of the second embodiment.

FIG. 25 is a flowchart of a code output process in step S707 of FIG. 24.

FIG. 26 is a diagram showing a data structure of a changed pixel in the second embodiment.

FIG. 27 is a diagram illustrating a packet data generation rule for a left-handed outline according to another embodiment.

FIG. 28 is a diagram illustrating a data structure of pointer packet data in another embodiment.

FIG. 29 is an explanatory diagram of an edge table (ET) of the outline graphic data of FIG. 3 in another embodiment.

[Explanation of symbols]

 101 control unit 103 contour data file 104 operation unit 111 CPU 112 ROM 113 RAM 114 buffer memory 115 encoding unit 116 decoding unit 117 transmission / reception buffer

──────────────────────────────────────────────────続 き Continuation of the front page (56) References IEICE Transactions, Vol 63-D, No. 10, (1980), pp. 899-906, H. Hoshino, et al., "Coloring method for simple images by run length" (58) Fields investigated (Int. Cl. ⁷ , DB name) G06T 11/40 200 G06T 9/00 H04N 1/41

Claims (6)

(57) [Claims] 1. Vector data including vertex coordinates of a contour is
Input means for inputting, and an edge connecting each vertex coordinate of the vector data
And parallel to one of the coordinate axes of the vector data.
Based on intersection coordinates detected by the intersection detection means for obtaining intersection coordinates with the scanning line.
Coded data representing the length of white run and black run for each scanning line
Encoding means for creating data , wherein the encoding means displays contours based on the vector data.
The encoded data can be converted to
An encoding device characterized by being created. 2. The intersection detecting means represents each edge.
Create an edge table containing edge data, and
The intersection between the position of the scanning line of interest and the edge
Create an active edge table containing data indicating points
2. The intersection coordinates are obtained by calculating
Encoding device. 3. The encoding created by said encoding means.
Transmitting means for transmitting data, and decoding for decoding received encoded data into image data
Means for recording image data decoded by the decoding means
2. The encoding apparatus according to claim 1, further comprising: a recording unit .
apparatus. 4. Vector data including vertex coordinates of a contour is
An input step of inputting, and an edge connecting each vertex coordinate of the vector data
And parallel to one of the coordinate axes of the vector data.
An intersection detection step of obtaining intersection coordinates with a scanning line, and the intersection coordinates detected in the intersection detection step.
Coded data representing the length of white run and black run for each scanning line
Encoding step of creating a contour based on the vector data in the encoding step.
The encoded data without expanding the dot data to represent
An encoding method characterized by creating. 5. The method according to claim 1, wherein the intersection detecting step represents each edge.
Create an edge table containing edge data, and
The intersection between the position of the scanning line of interest and the edge
Create an active edge table containing data indicating points
5. The intersection coordinates are obtained by performing
Encoding method. 6. The encoded data created in said encoding step.
And a decoding step of decoding received encoded data into image data.
Recording that records and processes the image data decoded by said decoding step
5. The encoding according to claim 4, further comprising:
Method.