JP3362641B2 - Image processing device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus, and more particularly to a function for generating an edge list from intermediate code image data representing each of a plurality of objects drawn in layers according to a predetermined drawing order. And an image processing apparatus having a function of regenerating intermediate code image data from the edge list.

The above-mentioned object means a drawing target such as a figure (graphics), a character (font), an image, etc., and the page description data means image data concerning each object expressed in a page description language. .

[0003]

2. Description of the Related Art Conventionally, in image processing for generating raster data based on page description data representing an object to be drawn, page description data of the object is first converted into intermediate code image data, and then the intermediate code image is converted. A method of generating raster data based on the data has been proposed. The intermediate code image data has an advantage that an object can be expressed with a small amount of data, and the memory used in image processing can be saved by the above method.

As an example of using such intermediate code image data, Japanese Patent Laid-Open No. 6-284297 discloses an intermediate code image data of each object (text, graphics, image) (display in the case of this patent). (List) At the time of generation, be sure to check whether or not it overlaps with other objects that are already in the display list, and if it overlaps with a different type of object, display list of each object again so that it does not overlap. A technique for creating is disclosed (however, it is premised that the object is in a compressed form rather than intermediate code image data). According to this technique, it is possible to perform different compression for each object, and since the display lists do not overlap, the memory writing time of raster data is shortened.

However, in the above technique, when the number of objects per page is quite large, it is enormous that the overlap check and the re-creation of the display list are performed when the intermediate code image data of each object is created. The problem is that they spend a lot of time.

Further, in Japanese Patent Application Laid-Open No. 7-170411, an image processing apparatus which develops image data into a raster image and outputs the raster image is encoded by using a function representing continuity for continuous image data. The technology is disclosed.

This technique is a process for processing the intermediate code image data so as to eliminate the overlap between the objects (hereinafter,
When the edge list is scanned in the sub-scanning line direction in order to restore the object to be processed to the intermediate code image data again after the execution of the (superimposed graphic processing), the run lengths are equally spaced in the sub-scanning line direction. By applying it to the same edge list, it is possible to reduce the memory usage of the intermediate code image data and the processing time for creating the intermediate code image data. However, for the edge lists other than those having the same run length and the same run length in the sub-scanning line direction, there is no effect of reducing the memory usage amount or the intermediate code image data creation processing time. Since the process of determining whether or not the run lengths are the same at equal intervals is executed, the processing time becomes rather long.

Further, the applicant of the present invention is the Japanese Patent Application No. 8-276.
In No. 652, the intermediate code image data for each object converted from the page description data is stored, and the contour data representing the contour of the upper layer object that masks the object drawn on the lower layer side is stored for each object. A patent application has been filed for an image processing method that eliminates overlaps between objects by creating the intermediate code image data from a portion that is left unmasked and created by tracing back from the upper layer.

According to this technique, the above-mentioned Japanese Patent Laid-Open No. 6-2842.
It is not necessary to activate the superimposing graphic processing every time when the intermediate code image data which is the method of 97 is created, and it is activated only when the holding area of the intermediate code image data is insufficient or when the raster data memory writing is not in time, By performing batch processing or processing for a predetermined part,
The processing speed is improved.

However, in the technique proposed in Japanese Patent Application No. 8-276652, since the superposition graphic processing is not performed by recognizing the content of the object, the intermediate code is again executed from each edge list of the object for which the superposition graphic processing is finished. When the image data is generated, the size of the generated intermediate code image data varies depending on the type of object. Also, when a large number of objects overlap one object, the objects on the lower layer side are subdivided and the amount of generated intermediate code image data increases, increasing the memory usage and increasing the raster data. There is a possibility that inconvenience such as a decrease in the expansion processing speed may occur.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and reduces the memory usage of intermediate code image data and the rasterization processing speed at the time of output. It is a first object of the present invention to provide an image processing device capable of improving the performance, and to prevent an increase in the memory usage amount of intermediate code image data and a decrease in the expansion processing speed due to the subdivision of an object by the superposed graphic processing. A second object of the present invention is to provide an image processing device capable of performing the same.

[0012]

In order to achieve the first object, an image processing apparatus according to claim 1 has each of a plurality of objects drawn in layers in a predetermined drawing area in a predetermined drawing order. And a storage unit for storing the converted intermediate code image data for each object in the memory, and a conversion unit for converting the page description data representing the intermediate description code image data for each object. The edge list for each predetermined scan line corresponding to the intermediate code image data is created for each object by tracing the drawing order of the objects so that the overlapping image areas do not overlap, and the created edge list for each object is created. Updating means for updating the stored intermediate code image data for each object according to a predetermined condition By switching the 査 direction, by scanning the edge list for each object that is updated by the update unit, and recreating means for recreating the intermediate code image data for each object from the edge list,
It is characterized by having.

According to the image processing apparatus of the second aspect,
The image processing apparatus according to claim 1, wherein the predetermined condition is a type of object.

Further, in the image processing apparatus according to claim 3,
The image processing apparatus according to claim 1 or 2,
According to the predetermined condition, the re-creating unit sets a mode in which the scanning direction is the main scanning line direction, a mode in which the scanning direction is the sub scanning line direction, and a scanning direction for each edge list according to a predetermined switching condition. It is characterized by switching to any one of the modes for switching to the main scanning line direction or the sub scanning line direction.

Further, in the image processing apparatus according to claim 4,
The image processing apparatus according to claim 3, wherein the predetermined switching condition is a distance between an edge list of a scan target and an edge list that can be a next scan target.

In order to achieve the second object,
An image processing apparatus according to claim 5, wherein the page description data representing each of the plurality of objects drawn in layers in a predetermined drawing area in a predetermined drawing order is converted into intermediate code image data. A predetermined scan corresponding to the intermediate code image data so that the storage means for storing the intermediate code image data for each object in the memory and the image area represented by the intermediate code image data for each object do not overlap. A superimposition graphic process for creating an edge list for each line by tracing the drawing order of the objects for each object and updating the stored intermediate code image data for each object by the created edge list for each object If the graphic processing means to be executed and the type of object are a specific type, And having a control means for controlling to prohibit the superimposed graphic processing on transfected.

In order to achieve the second object,
An image processing apparatus according to claim 6, wherein the page description data representing each of the plurality of objects drawn in layers in a predetermined drawing area in a predetermined drawing order is converted into intermediate code image data. A predetermined scan corresponding to the intermediate code image data so that the storage means for storing the intermediate code image data for each object in the memory and the image area represented by the intermediate code image data for each object do not overlap. A superimposition graphic process for creating an edge list for each line by tracing the drawing order of the objects for each object and updating the stored intermediate code image data for each object by the created edge list for each object The degree of overlap between the graphic processing means to be executed and the plurality of objects is at a predetermined level or higher. If, and having a control means for controlling to prohibit the superimposed graphic processing for the plurality of objects.

Further, in the image processing apparatus according to claim 7,
The image processing device according to claim 5 or 6,
When there are a plurality of objects for which superposed graphic processing is prohibited, the control means controls the superposed graphic processing to be executed by the graphic processing means only between the objects for which the superposed graphic processing is prohibited. To do.

In the image processing apparatus according to the first aspect of the present invention, the page description data representing each of a plurality of objects drawn in layers in a predetermined drawing area in a predetermined drawing area by the conversion means is converted into intermediate code image data. Converted,
The intermediate code image data for each object converted by the storage means is stored in the memory. As the intermediate code image data, an edge list, a display list, a run length list, etc. described later can be applied.

Then, the updating means draws the edge list of each predetermined scanning line corresponding to the intermediate code image data of the object so that the image areas represented by the intermediate code image data of each object do not overlap each other. The order is traced back and created for each object, and the stored intermediate code image data for each object is updated by the created edge list for each object.

Here, for example, the updating means creates contour data representing at least the contour of the object on the upper layer side that masks the object to be drawn on the lower layer side by tracing the drawing order of the objects, and the created contour data. By excluding the area from the intermediate code image data for each object, an edge list that eliminates the overlapping of the image areas can be created for each object by tracing the drawing order of the objects. Then, the stored intermediate code image data for each object may be updated by the edge list for each object.

In this example, the updated intermediate code image data, that is, the intermediate code image data obtained by removing the contour data area of the object on the upper layer side of each object from the intermediate code image data of each object is often updated. Since the data amount is smaller than the previous intermediate code image data, the data amount of the intermediate code image data stored in the memory is reduced by the above image processing method.

Further, according to the present invention, the recreating means switches the scanning direction in accordance with a predetermined condition to scan the updated edge list for each object, thereby obtaining the intermediate code image data from the edge list. Recreate each object.

More specifically, as described in claims 2 and 3, the mode in which the scanning direction is the main scanning line direction and the scanning direction is the sub-scanning line direction by the recreating means according to the kind of the object. And the scanning direction is switched to any one of the main scanning line direction and the sub scanning line direction for each edge list according to a predetermined switching condition, and the updated edge list for each object is displayed. By scanning, the intermediate code image data is recreated for each object from the edge list.

For example, when the type of object is a font or black and white graphics, the shape after removing the overlap may be a considerably complicated shape, so that the scanning direction is set to a predetermined switching condition (for example, a request). The edge list is scanned by switching to a mode in which each edge list is switched to the main scanning line direction or the sub-scanning line direction according to the distance between the edge list of the scanning target described in item 4 and the edge list which can be the next scanning target. Is desirable. As an example,
Seen from the edge list of the scan target, the distance to the edge list that can be the next scan target along the sub-scan line direction is shorter than the distance to the edge list that can be the next scan target along the main scan line direction. In this case, it is possible to reduce the data amount of the distance information to the adjacent edge list in the edge list by switching the scanning direction to the sub-scanning line direction, and thus to reduce the memory size for storage. You can save memory.

When the type of object is color graphics, unlike the case of black and white graphics, even if the overlap with other objects is removed, the probability of becoming a rectangle is high, so the scanning direction is sub-scanning. If the edge list is scanned while switching to the line direction mode, it is possible to recreate the edge list as intermediate code image data with a small data amount, such as a rectangular display list or a code using a function indicating continuity. Can
It is possible to reduce the memory size for storing and save the memory.

If the type of the object is an image or a pattern image (= a plurality of images are patterned by a predetermined rule, hereinafter, the image or the pattern image is generically called an image), the intermediate The code image data simply has clip information, and the image entity is stored in another memory area as it is or in a compressed state. Therefore, from the area where the image entity is stored during expansion processing. Intermediate code image data (=) read out in the order of addresses and sorted in the main scanning line direction and the sub scanning line direction
Since it is necessary to perform clipping with a collection of edge lists and write to the memory, it is desirable to switch to a mode in which the scanning direction is the main scanning line direction and scan the edge list.

As described above, depending on the type of the object, the mode in which the scanning direction is the main scanning line direction, the mode in which the scanning direction is the sub-scanning line direction, and the scanning direction is set for each edge list according to a predetermined switching condition. To the main scanning line direction or the sub-scanning line direction, and scans the updated edge list for each object, and the intermediate code image data is scanned for each object from the edge list. By recreating, the data amount of the intermediate code image data can be reduced, so that the memory usage amount can be reduced and the raster data expansion processing speed at the time of output can be improved.

Next, in the image processing apparatus according to claim 5,
The conversion means converts the page description data representing each of the plurality of objects drawn in layers in a predetermined drawing area in a predetermined drawing order into intermediate code image data, and the storage means converts each of the converted objects. The intermediate code image data is stored in the memory.

Then, the graphic processing means sets the edge list for each predetermined scanning line corresponding to the intermediate code image data of the object so that the image areas represented by the intermediate code image data of each object do not overlap. It is created for each object by tracing back the drawing order, and superimposing graphic processing for updating the stored intermediate code image data for each object by the created edge list for each object is executed. That is, the superposed graphic process includes two processes of creating an edge list for each object so that the image areas do not overlap each other and updating the intermediate code image data by the created edge list.

However, when the superimposed graphic processing is to be executed for one object, if the type of the one object (that is, the object serving as the background) is a specific type, the control means causes the Control is performed so that superposed graphic processing for an object is prohibited.

For example, when the type of the object is an image, the intermediate code image data has only the clip information as described above, and the substance of the image remains in another memory area or is compressed. It is held in a closed state. Therefore, in the expansion process,
It is necessary to read from the area where the substance of the image is held in the order of addresses, perform clipping with the intermediate code image data (= aggregation of edge list) sorted in the main scanning line direction and the sub scanning line direction, and write it in the memory.

Therefore, when the type of object is an image, it is desirable that the control means prohibits the superimposed graphic processing by the graphic processing means.

As to the object for which it is not appropriate to execute the superposed graphic processing, the superposed graphic processing is prohibited to increase the memory usage amount of the intermediate code image data due to the subdivision of the object and decrease the development processing speed. Can be prevented.

Further, in the image processing apparatus according to claim 6,
Similar to the image processing apparatus according to claim 5, the graphic processing means causes a predetermined scanning line corresponding to the intermediate code image data so that the image areas represented by the intermediate code image data for each object do not overlap. An edge list for each object is created by tracing back the drawing order of the objects, and superimposition graphic processing is performed to update the stored intermediate code image data for each object by the created edge list for each object. To do.

However, when the degree of overlap between the plurality of objects is equal to or higher than a predetermined level, the control means controls the superimposed graphic processing for the plurality of objects to be prohibited. For example, if the number of times an edge list representing one object is cut by another object is equal to or greater than a predetermined value, it is considered that subdivision has occurred, and it is desirable to prohibit the superimposed graphic processing.

In this way, for objects whose degree of overlap with other objects is at a predetermined level or higher, superimposing graphic processing is prohibited to increase the memory usage of the intermediate code image data due to object subdivision and the expansion processing speed. Can be prevented in advance.

In the superimposing graphic processing, however, the superimposing graphic processing is prohibited because the edge list is created by tracing back the drawing order of the objects so that the overlapping of the image areas is eliminated and the intermediate code image data is updated by the edge list. If there are multiple objects to be processed, it is necessary to draw the object to be processed later. Therefore, it may be necessary to temporarily store the intermediate code image data representing each object in the work memory, then change the drawing order and store the temporarily stored intermediate code image data in the regular memory again. is there.

Therefore, as described in claim 7, when there are a plurality of objects for which the superimposed graphic processing is prohibited, the control means performs the superimposed graphic processing only between the objects for which the superimposed graphic processing is prohibited. It is desirable to control the execution. As a result, after temporarily storing the intermediate code image data in the working memory as described above,
It is not necessary to change the drawing order and re-store the temporarily stored intermediate code image data in the regular memory, and the processing efficiency can be improved.

[0040]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Various embodiments according to the present invention will be described in detail below with reference to the drawings.

[First Embodiment] First, a first embodiment corresponding to the inventions of claims 1 to 4 set forth in the claims will be described.

(Structure of Image Processing Apparatus) First, the structure of the image processing apparatus in this embodiment will be described below. Figure 1
As shown in FIG. 3, the image processing apparatus 10 interprets code image data described in a page description language by a built-in decomposer, and the code image data is an object to be drawn such as graphics, fonts, images (hereinafter referred to as an object). In this case), the upper processing unit 12 that creates the intermediate code image data divided into band units
A superposed graphic processing unit 14 for performing superposed graphic processing for eliminating overlap between objects in band units; a list storage unit 11 as a memory for storing an edge list generated by the superposed graphic processing; The expansion unit 16 that expands the intermediate code image data into raster data, and the intermediate code image data in real time on the basis of information about the intermediate code image data of each band (such as the address of the intermediate code image data holding area in the memory area) A schedule management unit 18 that determines whether or not expansion processing is possible, a measurement unit 20 that measures or predicts the time required to expand the intermediate code image data of each band, and each band generated by the expansion processing by the expansion unit 16. Buffer 26 for storing raster data of the printer, and printer engine 3 for printing out the raster data And a transfer unit 28 that transfers the raster data stored in the band buffer 26 to the printer engine 30, a band buffer management unit 22 that manages the usage status of the band buffer 26, and when an error occurs in raster data expansion processing or the like. Error processing unit 24 that performs error processing
And are provided.

The image processing apparatus 10 is activated when code image data is input from an external image processing apparatus via a network or from a spool disk, and the input code image data is stored in the upper processing unit 12. It is sequentially interpreted by the decomposer. As previously mentioned,
When the code image data is an object, the intermediate code image data divided into band units is the upper processing unit 12
The band-based intermediate code image data created by the above is held in the intermediate code image data holding area in the memory area built in the upper processing unit 12 for each band. Note that examples of the intermediate code image data here include a display list and a run length list.

When a memory shortage occurs in the intermediate code image data holding area during the above processing, the upper processing unit 1
2, the superimposition graphic processing unit 14 is activated, and the superimposition graphic processing (details will be described later) for erasing the overlap between the image areas represented by the intermediate code image data is activated for each band.
This superposed graphic processing is executed until the memory shortage in the intermediate code image data holding area is resolved.

After the processing of the page description language for one page is completed, the upper processing unit 12 expands the information about the intermediate code image data of each band (the address of the intermediate code image data holding area in the memory area). Notify 16
The expansion unit 16 causes the schedule management unit 18 to determine whether the intermediate code image data of each band can be expanded into raster data in real time.

The schedule management unit 18 is composed of the measuring unit 2
Based on the measurement result or the prediction result of the expansion time of the intermediate code image data of 0, it is determined whether the intermediate code image data of each band can be expanded in real time. Here, when there is intermediate code image data that cannot be expanded in real time, the schedule management unit 18 activates the superimposition graphic processing unit 14 to perform superimposition graphic processing on a band including intermediate code image data that cannot be expanded in real time. To execute. As a result, the overlapping between the image areas represented by the intermediate code image data is eliminated, and unnecessary writing of the intermediate code image data into the band buffer 26 during the expansion processing is prevented, thereby enabling real-time expansion processing.

(Overview of Superposed Figure Processing) Next, the contents of the superposed figure processing executed by the superposed figure processing unit 14 of this embodiment will be described with reference to FIG. It should be noted that in the following, a plurality of overlapping objects are four figures A shown in FIG.
The superposed graphic process for B, C, and D will be described. Therefore, "graphic" is used synonymously with "object".

The superposed graphic processing in this embodiment is similar to the superposed graphic processing proposed in Japanese Patent Application No. 8-276652, and is executed for each object in the reverse order of the drawing order. For example, in FIG. 2, figure D,
Processed in the order of C, B, A.

The superimposing graphic process is an extraction process for extracting an overlapping region of one object and a region in which all objects drawn after the object are merged, and the extracted overlapping region is extracted from the one object. Generation processing for generating the edge list of the excluded area in the working memory of the list storage unit 11, and updating for updating the edge list of the object stored in the storage memory of the list storage unit 11 by the generated edge list. It is composed of processes.

Specifically, in FIG. 2, the figure C and the figure C
The overlapping area with the contour (MASK (D)) of the figure D drawn after is extracted, and the edge list of the area (Cand to MASK (D)) excluding the overlapping area from the figure C is generated and generated. The edge list of the figure C is updated with the edge list of the created area (Cand to MASK (D)).

Since the above-mentioned area (Cand to MASK (D)) is not overwritten by the figures B and A to be subjected to the superimposed figure processing later, the edge list of the figure C is fixed at this point, and the edges of the fixed figure C are determined. The edge list of the figure C is updated by the list. As a result, the edge list generated in the working memory becomes unnecessary after the completion of the update process, so that the working memory in which the edge list is stored can be released and reused in another process.

Similarly, the overlapping area between the shape B and the contours (MASK (DorC)) of the shapes D and C drawn after the shape B is extracted, and the overlapping area is removed from the shape B (Ba
nd to MASK (DorC)) edge list is generated, and the edge list of the figure B is updated by the generated edge list of the area (Band to MASK (DorC)).

Further, an overlapping area between the figure A and the contours (MASK (DorCorB)) of the figures D, C, and B drawn after the figure A is extracted, and the overlapping area is removed from the figure A (Aand ˜MASK (DorCorB)) edge list is generated, and the edge list of figure A is updated with the generated edge list of the area (Aand˜MASK (DorCorB)).

In the extraction processing in the above-described superposed graphic processing, the contour data, for example, the contour data (MASK (DSK) of the graphic D, is used as data representing an area in which all the graphics drawn after the target graphic are merged. )) And contour data (MASK (DorC)) of figures D and C, etc. are used.
This contour data contains only information about the contour of the area and does not include various information about drawing such as line type and color value like the edge list, and therefore the amount of data is very small. As described above, by using the contour data having a small amount of data in the extraction processing, it is possible to reduce the usage amount of the work memory in the extraction processing.

(Detailed Description of Superposed Figure Processing) Next, the superposed figure processing will be described in detail with reference to the flowchart of FIG.

The individual data blocks forming the edge list before updating each figure are referred to as original figure edges, and the individual data blocks forming the edge list after updating each figure are referred to as new figure edges. Further, the contour of the area in which all the figures drawn after the figure to be processed are merged is called a mask. This mask is also represented by an edge list like a figure, and individual data blocks forming the edge list of the mask are called mask edges. In addition,
In FIG. 2, the contour (mask) of the figure D is represented as MASK (D), and the contour (mask) of the figures D and C is represented as MASK (DorC).
These edge list and mask can be composed of, for example, as shown in FIG. 4, storage areas for five types of data such as attributes, start point position, end point position, run length, next mask or pointer to edge list. . If the attribute data is "0", it can be identified as an edge list, and if it is "1", it can be identified as a mask.

In step 101 of FIG. 6, a band obtained by dividing one page into a plurality of parts along the sub-scanning direction is set as the processing range, and in the next step 102, the edge list of the target object is read and the range of the Y coordinate of the figure is set. (Y _S
~ Y _E ) is detected. Then, in the next step 103, it is determined whether or not the target object exists in the set band.

Here, if the target object exists in the band, the process proceeds to step 104 and Y _S is set as the Y coordinate of the scan line to be processed. Less than,
The scan line to be processed is called line Y. In the next step 106, the (X coordinate of the start point, X coordinate of the end point) of the first original figure edge on the line Y is (SX,
EX) the (X coordinate of the start point, X coordinate of the end point) of the first mask edge on the line Y (MSX, MEX)
And set each. Here, the original figure edge and the mask edge are sequentially processed in the main scanning direction on the line Y.

In the following, (SX, EX) is the (X coordinate of the start point, X coordinate of the end point) of the original figure edge on the line Y, and (MSX, MEX) is the (start point of the mask edge on the line Y. X coordinate of the point, X coordinate of the end point)
(NSX, NEX) is the (X coordinate of the start point, X coordinate of the end point) of the next original figure edge on the line Y, (NMS
(X, NMEX) indicates the (X coordinate of the start point and the X coordinate of the end point) of the next mask edge on the line Y, respectively.

Further, the following steps include a process of comparing the above various X coordinate values with each other, and FIGS. 5A to 5F will be used to explain such a process. In each of these FIGS. 5A to 5F, the direction from left to right corresponds to the main scanning direction, and the mask edge (MSX to MEX) before comparison processing and the source before comparison processing are shown above the downward arrow. The figure edges (SX to EX) are shown. Further, the mask edge (MSX to MEX) after the comparison process is provided below the downward arrow.
And the original figure edges (SX to EX) after the comparison processing are shown.

In the next step 108 in FIG. 6, M
It is determined whether SX is larger than EX. Figure 5 (A)
When MSX is larger than EX as shown in FIG. 7, the routine proceeds to step 110, where the subroutine A of FIG. 7 is executed. In subroutine A, (SX, EX) is added as a new graphic edge (step 202), and if (MSX-1) is equal to EX, the original graphic edge and the mask edge can be combined into one mask edge ( MSX, ME
(SX, MEX) is set to (X) (step 20)
8), if (MSX-1) is not equal to EX, add (SX, EX) to the mask edge (step 20)
6). Then, the next original figure edge is set in (NSX, NEX) (step 210), the process returns to the main routine of FIG. 6 and proceeds to step 120 described later.

If MSX is not greater than EX in step 108, the process proceeds to step 112 (MSX ≧ SX).
Then, it is determined whether or not (MEX> EX) and (MSX ≦ EX). As shown in FIG. 5B, (MSX ≧ S
X) and (MEX> EX) and (MSX ≦ EX), the routine proceeds to step 114, where the subroutine B of FIG. 8 is executed. In subroutine B, (SX, MSX-1) is added as a new figure edge (step 222), and (M
(SX, MEX) is set to (SX, MEX) (step 224), and the next original figure edge is set to (NSX, NEX), and the process returns to the main routine of FIG. 6 and proceeds to step 120 described later.

When a negative determination is made in step 112, the process proceeds to step 116 (MSX≤SX) and (MEX
≧ EX) is determined. As shown in FIG. 5C, when (MSX ≦ SX) and (MEX ≧ EX), the process proceeds to step 118, the next original figure edge is set in (NSX, NEX), and the process proceeds to step 120. In step 120, (SX, EX) is set to (NSX, NEX), and the process proceeds to step 136 described later.

When a negative determination is made in step 116, the process proceeds to step 122 (MSX ≧ SX) and (MEX
≦ EX) is determined. When (MSX ≧ SX) and (MEX ≦ EX) as shown in FIG. 5D, the routine proceeds to step 124, where the subroutine D of FIG. 9 is executed. In subroutine D, (SX, MSX-1) is added as a new figure edge (step 242), and (MS
(SX, EX) is set to (X, MEX) (step 244). In addition, (NSX, NEX) becomes (MEX + 1,
EX) is set (step 246) and (NMSX, N
Set the next mask edge to MEX (step 2
48) and returns to the main routine of FIG. 6 and proceeds to step 134 described later.

When a negative determination is made in step 122, the process proceeds to step 126 (MSX≤SX) and (MEX
It is determined whether <EX) and (MEX ≧ SX). As shown in FIG. 5 (E), (MSX ≦ SX) and (M
When EX <EX) and (MEX ≧ SX), the routine proceeds to step 128, where the subroutine E of FIG. 10 is executed.
In subroutine E, (SX, EX) becomes (MEX + 1, E)
X) is set (step 262), and (MSX, ME
(MSX, EX) is set to (X) (step 26
4) Then, the next mask edge is set in (NMSX, NMEX) (step 266), the process returns to the main routine of FIG. 6 and proceeds to step 134 described later.

When a negative determination is made in step 126, the routine proceeds to step 130, where it is determined whether MEX is smaller than SX. When MEX is smaller than SX as shown in FIG. 5 (F), the routine proceeds to step 132, where the subroutine F of FIG. 11 is executed. In subroutine F, (SX, E
X) is added as a new figure edge (step 28).
2) Here, if (MEX + 1) is equal to SX, the original figure edge and the mask edge can be combined as one mask edge, so (MSX, MEX) becomes (MS
(X, EX) is set (step 288), and (MEX +
If 1) is not equal to SX, then (SX,
EX) is added (step 286). And (NM
The next mask edge is set in (SX, NMEX) (step 290), the process returns to the main routine of FIG. 6 and proceeds to step 134. In step 134, (MSX, M
After registering (EX) as a mask edge, (MSX,
(NMSX, NMEX) is set in (MEX) and the process proceeds to the next step 136.

At step 136, whether (SX, EX) is empty data (there is no next original figure edge on the line Y), and at step 140 (MSX, ME).
X) is empty data (no next mask edge in line Y). here,
If both (SX, EX) and (MSX, MEX) are not empty data, there is still data to be compared.
Return to step 108.

If (SX, EX) is empty data in step 136, there is no next original figure edge in the line Y, so the flow advances to step 138, and the edge list of the mask at that time is stored in the list storage section 11. To do. However, the edge list of the mask is only the data related to the contour,
Since the amount of data is very small, the area of the list storage unit 11 used can be small. On the other hand, if (MSX, MEX) is empty data in step 140, line Y
Since there is no next mask edge in step 142, step 142
Then, the remaining original figure edge is added as a mask edge, and the edge list of the mask at that time is stored in the list storage unit 11. Similarly to the above, the edge list of the mask is only the data relating to the contour, and the data amount is very small, so that the area of the list storage unit 11 used can be small.

After executing the processing of steps 138 and 142, it is determined in step 144 whether the Y coordinate of the line Y is equal to Y _E. When the processing for one figure to be processed is not completed, the Y coordinate of the line Y is smaller than Y _E , so a negative determination is made in step 144, and the Y coordinate of the line Y is incremented by 1 in step 146. . After that, the process returns to step 106 and the processes of steps 106 to 142 are executed for the new line Y.

In this way, one figure to be processed is processed for each scan line, and the edge list of the original figure edge is updated by the edge list of the new figure edge. When the processing for the line Y whose Y coordinate is equal to Y _E is completed and the processing for one figure is completed, an affirmative decision is made in step 144 and the operation proceeds to step 147, where the list storage unit 11 stores the edge list of the new figure edge. The stored edge list of the original figure is updated. Then, in step 148, it is determined whether the processing has been completed for all the figures.

When there are still graphics which have not been processed, the process returns to step 102 and the processes of steps 102 to 147 are executed for a new graphic. Then, when the processing is completed for all the figures, the superimposed figure processing is ended.

(Operation of First Embodiment) Next, as an operation of the first embodiment, by scanning the edge list generated by the superposed graphic processing along a predetermined direction,
The intermediate code image data recreating process of recreating the intermediate code image data for each object from the edge list will be described. This intermediate code image data re-creation process is executed by the upper processing unit 12 at the time of print output.

In step 302 of FIG. 12, the edge list stored in the list storage unit 11 is read, and one of the edge lists is set as the processing target edge list.
In the next steps 304 and 306, it is determined whether the object represented by the target edge list is an image or color graphics, respectively, and if the target object is an image, step 308.
If the target object is color graphics, the process proceeds to step 312. If the target object is other than that (for example, font or monochrome graphics), the process proceeds to step 310.

Of these, in step 308, the subroutine of the intermediate code image data regeneration processing 1 shown in FIG. 13 is executed. This intermediate code image data regeneration processing 1
Is to recreate the intermediate code image data from the edge list by scanning the edge list along the main scanning line direction (X-axis direction in the two-dimensional coordinate system).

Specifically, in step 332 of FIG. 13, the target scan line (first scan line at the beginning)
It is determined whether or not there is an unprocessed edge list, and if there is an unprocessed edge list, in the order along the main scanning direction with respect to the edge list on the scan line,
The edge list is scanned (step 334) and the intermediate code image data is regenerated (step 336) based on the information obtained by the scanning.

When the above processing is completed for all edge lists on the scan line, step 340
Then, the next scan line is set as the target scan line, and the processes of steps 332 to 336 are executed for the set target scan line.

By executing the processing of steps 332 to 336 for each scan line in this way,
For example, in the order of ... Shown in FIG.
The edge list is scanned along the main scanning direction to regenerate the intermediate code image data.

When the type of the object is an image as described above, the intermediate code image data thereof simply has clip information, and the substance of the image is held in another memory area as it is or in a compressed state. Therefore, in the expansion process, the image is read from the area where the substance of the image is held in the order of address, and the clip is made with the intermediate code image data (= aggregation of edge list) sorted in the main scanning line direction and the sub scanning line direction. Since it is necessary to perform writing in the memory, it is desirable to scan the edge list with the main scanning line direction as the scanning direction as described above.

On the other hand, if the object is a font or black-and-white graphics, step 310 shown in FIG.
The subroutine of the intermediate code image data regeneration processing 2 shown in is executed. In this intermediate code image data regeneration processing 2, the scanning direction is the main scanning line direction or the sub-scanning line direction (in the two-dimensional coordinate system) according to the distance between the edge list to be scanned and the edge list that can be the next scanning target. By switching to (Y-axis direction) and scanning the edge list,
The intermediate code image data is recreated from the edge list.

Specifically, steps 352 and 3 in FIG.
At 54, the first edge list is scanned and the intermediate code image data based on the information obtained by the scan is regenerated, and at the next step 356, it is determined whether or not there are two or more unprocessed edge lists. To do.

If there are two or more unprocessed edge lists, the process proceeds to step 358, and the distance to the edge list that can be the next scan target in the main scanning direction,
The distance from the edge list that can be the next scan target is compared in the sub-scanning direction, and in the next step 360, the direction toward the edge list with the shorter distance is set as the scanning direction based on the comparison result. Then, in the next step 362, the next unprocessed edge list in the set scanning direction is set as the target edge list. Next step 3
In 64 and 366, scanning of the target edge list and regeneration of intermediate code image data based on the information obtained by the scanning are executed.

In this way, the scanning direction is switched to the main scanning line direction or the sub-scanning line direction in accordance with the distance between the edge list to be scanned and the edge list to be the next scanning target, and the edge list is scanned to obtain the intermediate code. Regenerate the image data.

As a result, the edge list is scanned and the intermediate code image data is regenerated in the order of ... Shown in FIG.

The steps 358 to 362 may be processed as follows. For example, as shown in FIG. 17B, one of the intermediate code image data formats expressing the edge list is a 2-digit data type,
It is defined by a 3-digit run length, a 1-digit difference in the Y direction, and a 2-digit difference in the X direction.

Here, in FIG. 17A, assuming that the edge list of the current scan target is, there are two edge lists of the next scan target. If the difference DX ′ between the edge list and the edge list in the X direction is 3 or less (= difference DX ′ is within 2 digits), the next scan target is the edge list. on the other hand,
The difference DX ′ in the X direction of the edge list is larger than 3 (= difference DX ′ is 3 digits or more), the difference DX ″ in the X direction of the edge list is 3 or less (= difference DX ″ is 2 digits or less), and When the difference DY ′ is 1 or less (= the difference DY ′ is within one digit), the next scan target is the edge list. As a result, the amount of memory used for storing the intermediate code image data can be reduced.

The processing of steps 358 to 366 is continued until the unprocessed edge list becomes one, and when the unprocessed edge list becomes one, steps 368 and 370.
Then, the scan for the last edge list and the regeneration of the intermediate code image data based on the information obtained by the scan are executed, and the processing is ended.

As described above, when the type of object is a font or black-and-white graphics, the shape after the overlap is removed may be a considerably complicated shape. It is desirable to switch the scanning direction for each edge list to the main scanning line direction or the sub-scanning line direction in accordance with the distance of 1 to scan the edge list. The direction to the shorter edge list is
By scanning in the scanning direction, the data amount of the distance information to the adjacent edge list in the edge list can be reduced, so that the memory size for storing can be reduced and the memory can be saved.

Further, in step 312 which proceeds when the object is color graphics, a subroutine of intermediate code image data regeneration processing 3 shown in FIG. 15 is executed. This intermediate code image data regeneration processing 3 scans the edge list along the sub-scanning direction,
The intermediate code image data is recreated from the edge list.

Specifically, in step 382 of FIG. 15, the scan line of interest (first scan line at the beginning)
If there is an unprocessed edge list in the scan list, and if there is an unprocessed edge list in the main scan direction, the edge list scan (step 384) and regenerating intermediate code image data based on the information obtained by scanning (step 386).

Then, in the next step 388, it is determined whether or not the target scan line is the last scan line, and if it is not the last scan line, step 390.
After setting the next scan line as the target scan line in step 382, the process returns to step 382 and steps 382 to 382.
The process of 386 is executed. However, if there is no unprocessed edge list in the target scan line, it is confirmed in step 394 that all the scan lines have not been processed, and then in step 396, the next scan line is set as the target scan line. , And returns to step 382.

In this way, only for the first unprocessed edge list in all scan lines, the edge list is scanned (step 384) and the intermediate code image data is regenerated based on the information obtained by the scan (step 386). ) Is executed. As a result, the edge list is scanned along the sub-scanning direction.

Further, after the processing for the first unprocessed edge list in each scan line is completed, the first scan line is set as the target scan line in step 392, and the process returns to step 382 to set 2 in each scan line. The process for the th unprocessed edge list is executed.

In this manner, the edge list is scanned along the sub-scanning direction in the order of, for example, as shown in FIG. 16C, and the intermediate code image data is regenerated.

In this way, when the type of object is color graphics, unlike the case of black and white graphics, there is a high probability that a rectangle will be formed even if the overlap with other objects is removed. If the edge list is scanned with the scanning direction as, the edge list can be recreated as intermediate code image data with a small data amount, such as a rectangular display list or a code using a function representing continuity. The memory size can be reduced and the memory can be saved.

In the main routine of FIG. 12, any one of the intermediate code image data regeneration processes 1 to 3 described above is executed for each object according to the type of each object. Then, when the intermediate code image data regeneration processing has been completed for all objects and there is no other band for which superimposed graphic processing is required (step 315 in FIG. 12).
If the determination is negative in step), proceed to step 316,
The intermediate code image data regenerated in steps 308, 310, and 312 is converted into raster data, and in the next step 318, the raster data is printed out. If there is another band that needs the superimposed graphic processing in step 315, the process returns to step 302 and the processing of step 302 and subsequent steps is executed for the band.

According to the first embodiment described above, depending on the type of object, the mode in which the scanning direction is the main scanning line direction, the mode in which the scanning direction is the sub-scanning line direction, and the scanning direction are predetermined switching. Either of the modes for switching to the main scanning line direction or the sub scanning line direction for each edge list according to the condition 1
It is possible to reduce the data amount of the intermediate code image data by switching to one of the modes, scanning the updated edge list for each object, and recreating the intermediate code image data from the edge list for each object. It is possible to reduce the memory usage and improve the rasterization processing speed for raster data at the time of output.

By the way, in the above-described intermediate code image data regeneration processing 3, in order to speed up the processing, the processing shown in FIG.
A band width count table 70 for holding the number of edge lists for each scan line shown in FIGS.
A bandwidth pointer table 80 that holds a pointer to the leading edge list of each scan line may be adopted.

FIG. 18A shows the contents of the count table 70 and the pointer table 80 before performing one scan in the sub-scanning line direction, and FIG. 18B shows one scan in the sub-scanning line direction. Count table 70 after the
The contents of the pointer table 80 are shown respectively.

First, referring to the count table 70, 0
If the count table 70 is not 0, the pointer table 80 of the scan line is referred to obtain a pointer to the leading edge list.

In line 2 of FIG. 18A, the address of the pointer table 80 is a pointer to the mask, which is adjacent to the mask pointed to by the pointer table 80 and the edge list pointed to by the mask. This is because the edge list that is no longer needed after scanning each edge list is converted into a mask for the next object, but is combined into one mask when adjacent to the masks before and after.

The edge list after scanning is converted into a mask, the value of the count table 70 is subtracted by one, and if the result of the subtraction is not 0, the pointer to the next edge list on the same scan line is obtained. , The value of the pointer table 80 is updated with this pointer value (however, when the mask immediately before the edge list and the edge list are adjacent to each other, the pointer to the mask immediately before is set in the pointer table 80). To).

Similarly, by performing processing for the next scan line and repeating the processing until the last scan line, one scan processing in the sub-scan line direction is completed.

By holding the minimum value and the maximum value (the effective scan line width shown in FIGS. 18A and 18B) of the scan line in which the edge list constituting the object of the superimposed graphic processing exists, Since it suffices to access only the count table 70 of the scan lines in that range, it is possible to perform a faster scanning process.

Further, in the above embodiment, an example in which the superposed graphic processing proposed in Japanese Patent Application No. 8-276652 is adopted as the superposed graphic processing is shown, but the present invention is not limited to this, and other superposed graphic processing. Graphic processing may be adopted.

[Second Embodiment] Next, a second embodiment corresponding to the inventions of claims 4 to 7 set forth in the claims will be described. Note that the configuration of the image processing apparatus according to the second embodiment is the same as that of the first embodiment, so description thereof will be omitted.

(Description of Object Subdivision)
FIG. 19 shows a case where a plurality of objects 60 are overwritten on one object 50. Here, when both the upper layer object 60 and the lower layer object 50 are rectangular graphics (however, the colors are different). ),
When expressed in the rectangular intermediate code image data format (both the height and the width are within the range of the rectangular intermediate code image data format), the lower layer graphics is one rectangular intermediate code image data, the upper layer graphic. The space is represented by 23 rectangular intermediate code image data (24 in total).

Next, consider a case where the superimposed graphic process described in the first embodiment is executed for a band in which the above graphics exist.

FIG. 20 shows a state immediately after the above-described superimposed graphic process is executed on the lower layer object 50. As is clear from FIG. 20, the upper layer object than the lower layer object that is the target of the superimposed graphic processing is the mask 62, and the portion of the object that does not overlap with the mask 62 overlaps and the lower layer object 5 after removal.
It becomes 2. As a result, the 23 objects in the upper layer and the 24 objects in the lower layer form a total of 47 rectangular intermediate code image data, and the memory usage amount of the intermediate code image data is approximately doubled by the superimposed graphic processing. become.

However, since unnecessary writing to the memory in the overlapping portion in the expansion processing is reduced, the processing time does not become long, but the problem that the memory usage amount of the intermediate code image data increases remains.

However, if the lower layer object is an image, the subdivided portion by the upper layer object cannot be represented by the rectangular intermediate code image data (the intermediate code image data which is clip information is mainly used. Since it is not sorted in the scanning line direction and the sub-scanning line direction, the image cannot be called up at high speed in the address order, and it is necessary to read it at discrete addresses or to read rectangular intermediate code image data in the address order), edge It becomes the intermediate code image data of the list aggregate.

Here, the number of edge lists is 24 in the main scanning line direction and the number of scan lines in the sub scanning line direction is equal to the height of the object. For example, assuming that the height is 40 scan lines, the total number of edge lists is 960 (= 24 × 40), which is 1 before the superimposed graphic processing.
What was represented by the rectangular intermediate code image data becomes an intermediate code image data having 960 edge lists after the superposed graphic processing, which causes a sudden increase in memory usage. Further, although it is possible to call the images at high speed in the order of addresses, finally, the images clipped by each edge list are written in the memory, so that the expansion processing time becomes slow.

Therefore, in the second embodiment, when the type of the object is not suitable for the superimposed graphic processing (specifically, image), the overlapping processing for the object is controlled not to be performed. The control operation will be described with the following operation.

(Operation of Second Embodiment) Hereinafter, only when the type of the object is an image, the processing for controlling the overlapping processing for the object will be described with reference to FIG.
A description will be given according to the flowchart in FIG.

In step 402 of FIG. 23, a band obtained by dividing one page into a plurality of parts along the sub-scanning direction is set as the processing range, and in the next step 404, the edge list of the target object is read and the range of the Y coordinate of the object is set. detecting a (Y _S ~Y _E). Then, in the next step 406, it is determined whether or not the target object exists in the set band.

Here, when the target object exists in the band, the process proceeds to step 408, and it is determined whether the target object is an image. Here, if the target object is not an image, step 410.
Then, the process proceeds to step S4 and the above-mentioned superimposed graphic process is executed. On the other hand, if the target object is not an image, step 4
In step 12, the mask edge list is created and stored in the list storage unit 11 in the same manner as in the superposed graphic processing described above.
That is, the mask edge list corresponding to the mask 64 shown in FIG. 21 is generated and stored.

Then, in the next step 414, the intermediate code image data (intermediate code image data from which overlap is not removed) is temporarily held in the work holding block in the list storage section 11.

Since the image retains the original form of the intermediate code image data, the intermediate code image data is retained at the beginning of the intermediate code image data retaining block corresponding to the band, so that the image is formed. Since the objects other than the image are drawn before the objects, the vertical relationship of the objects in the image to be printed out is guaranteed. In other words, the image can be drawn after the object other than the image to prevent the object, which should be above the image, from being overwritten by the image.

Thereafter, the processes of steps 404 to 414 are executed for each target object existing in the band. Then, when the processing is completed for all the target objects existing in the band, the process proceeds to step 418,
Only when the object is an image (that is, when the superimposed graphic processing is not desired to be performed), the drawing order is changed as shown in FIG. 22 and the intermediate code image data 98 other than the image as shown in FIG. Prior to this, the intermediate code image data 96 of the image held in the work holding block is held in the regular holding block in the list storage unit 11 (note that the superimposing graphic processing is performed on the intermediate code image data of the image. If done, FIG. 24
As shown in (A), the intermediate code image data 98 other than the image may be held before the intermediate code image data 96 of the image on which the superimposed graphic processing has been performed).

After that, when the processes of steps 402 to 418 are completed for all the band objects, the process of FIG. 23 is terminated.

As described above, since the object (image) for which it is not appropriate to execute the superimposed graphic processing is controlled so as not to be processed, the memory usage of the intermediate code image data is increased due to the subdivision of the object. It is possible to prevent the expansion processing speed from decreasing.

The intermediate code image data of the image in which the overlap is not removed is temporarily held in the work holding block, and after the processing is completed for all target objects in the band, As shown in 22, since the drawing order is changed and the intermediate code image data held in the work holding block is held in the regular holding block, even if a plurality of images exist in one band, The image on the upper layer side is not overwritten by the image on the lower layer side, and the drawing order can be normally maintained.

When there are a plurality of objects (for example, images in the above) for which the overlapping processing is not performed, the superimposed graphic processing may be performed only between those objects. When the superimposed graphic processing between the objects for which the overlapping processing has not been performed normally ends in this way, the rewriting processing of the intermediate code image data after changing the drawing order as shown in FIG. 22 becomes unnecessary. Becomes
The processing efficiency can be improved.

Further, as the condition for not performing the superimposed graphic processing, besides the type of object, the degree of overlap between the target object and another object can be mentioned. For example, when the degree of overlap is as shown in FIG. 19, the number of times each edge list is cut by the mask is counted, and when the count value is equal to or more than a certain value, it is considered that subdivision has occurred, and It is desirable to control so that overlapping processing of objects is not performed.

In this way, by prohibiting the superimposed graphic processing for an object whose degree of overlap with another object is a predetermined level or higher, the memory usage of the intermediate code image data increases due to the subdivision of the object and the expansion processing speed decreases. Can be prevented in advance.

[0125]

As described above, according to the present invention, the intermediate code image data is recreated by scanning the updated edge list along the appropriate scanning direction. It is possible to reduce the data amount of the intermediate code image data, reduce the memory usage amount, and improve the rasterization processing speed for raster data at the time of output.

According to the invention of claim 5, the superimposing graphic processing is prohibited for an object for which it is not appropriate to execute the superimposing graphic processing. It is possible to prevent an increase and a decrease in the expansion processing speed.

Further, according to the invention of claim 6, the superimposing graphic processing is prohibited for an object having a degree of overlap with another object of a predetermined level or more, so that the memory use of the intermediate code image data by subdividing the object is used. It is possible to prevent an increase in the amount and a decrease in the expansion processing speed.

According to the seventh aspect of the present invention, when there are a plurality of objects for which superposed graphic processing is prohibited, the superposed graphic processing is executed only between the objects for which superposed graphic processing is prohibited. Since it is controlled, after temporarily storing the intermediate code image data in the working memory,
It is not necessary to change the drawing order and store the intermediate code image data in the regular memory again, and the processing efficiency can be improved. Further, especially when the object is an image, not only the intermediate code image data holding the clip information but also the source data can be reduced.

[Brief description of drawings]

FIG. 1 is a functional block diagram of an image processing apparatus according to first and second embodiments.

FIG. 2 is a diagram showing an outline of superposed graphic processing.

FIG. 3 is a diagram showing a drawing area in which a plurality of figures (objects) are overwritten.

FIG. 4 is a diagram showing a structure of an edge list and a mask.

FIG. 5 is a diagram for explaining a process of comparing coordinates between a mask edge and an original figure edge, and (A) shows (MSX>
EX), the process of (B) is (MSX ≧ SX)
And (MEX> EX) and (MSX ≦ EX), (C) is (MSX ≦ SX) and (MEX ≧ E).
X), processing (D) is (MSX ≧ SX) and (MEX ≦ EX), (E) is (M
SX ≦ SX) and (MEX <EX) and (MEX ≧ S
FIG. 4 is a diagram for explaining a process in the case of X) and a process in the case of (F) (MEX <SX).

FIG. 6 is a flowchart showing a main routine of superposed graphic processing.

FIG. 7 is a flowchart showing a subroutine A.

FIG. 8 is a flowchart showing a subroutine B.

FIG. 9 is a flowchart showing a subroutine D.

FIG. 10 is a flowchart showing a subroutine E.

FIG. 11 is a flowchart showing a subroutine F.

FIG. 12 is a flow chart showing a main routine in the first embodiment.

FIG. 13 is a flowchart showing a subroutine of intermediate code image data regeneration processing 1.

FIG. 14 is a flowchart showing a subroutine of intermediate code image data regeneration processing 2;

FIG. 15 is a flowchart showing a subroutine of intermediate code image data regeneration processing 3.

FIG. 16A is an intermediate code image data regeneration processing 1
It is a diagram showing a scanning order of the edge list in
FIG. 9B is a diagram showing the scanning order of the edge list in the intermediate code image data regeneration processing 2, and FIG. 8C is a diagram showing the scanning order of the edge list in the intermediate code image data regeneration processing 3.

FIG. 17A is an intermediate code image data regeneration processing 2
FIG. 6 is a diagram for explaining a process of determining the scanning direction of the edge list based on the distance between the edge lists in FIG.
(B) is a diagram showing an example of an intermediate code image data format expressing an edge list.

FIG. 18 is a diagram showing a count table and a pointer table used for high speed scanning of an edge list in the intermediate code image data regeneration processing 3;
(A) is a diagram showing a count table and a pointer table before scanning, and (B) is a diagram showing a count table and a pointer table after one scanning.

FIG. 19 is a diagram showing a state in which many objects are overwritten on one object.

FIG. 20 is a diagram showing a state in which an object in a lower layer is subdivided by superimposing graphic processing.

FIG. 21 is a diagram showing a state in which an object (image) which is not desired to be subjected to superposed graphic processing is masked.

FIG. 22 is a diagram showing a method of holding a plurality of intermediate code image data when there are a plurality of intermediate code image data of an object (image) for which superimposing graphic processing is not desired.

FIG. 23 is a flowchart showing a main routine in the second embodiment.

FIG. 24A is a diagram showing a conventional method for holding intermediate code image data, and FIG. 24B is a method for holding intermediate code image data of an object (image) for which superimposition graphic processing is not desired in the second embodiment. It is a figure which shows the method.

[Explanation of symbols] 10 Image processing device 11 List storage 12 Upper processing unit 14 Superposed figure processing unit 16 Development Department 26 band buffer 30 printer engine

Claims (7)

(57) [Claims] 1. A conversion unit for converting page description data representing each of a plurality of objects drawn in layers in a predetermined drawing area in a predetermined drawing order into intermediate code image data, and for each converted object. A storage unit for storing the intermediate code image data in a memory, and an edge list for each predetermined scanning line corresponding to the intermediate code image data so that the image area represented by the intermediate code image data for each object does not overlap. Is created for each object by tracing the drawing order of the objects, and updating means for updating the stored intermediate code image data for each object by the created edge list for each object, and according to predetermined conditions. The scan direction to switch the edge direction for each object updated by the updating means. An image processing apparatus comprising: a re-creating unit that re-creates the intermediate code image data for each object from the edge list by scanning the strike list. 2. The image processing apparatus according to claim 1, wherein the predetermined condition is a type of object. 3. The re-creating means responds to a predetermined scanning condition in a mode in which the scanning direction is a main scanning line direction, a scanning direction is a sub scanning line direction, and a scanning direction in a predetermined switching condition according to the predetermined condition. The image processing apparatus according to claim 1, wherein the edge list is switched to any one of a main scanning line direction and a sub-scanning line direction for each edge list. 4. The image processing apparatus according to claim 3, wherein the predetermined switching condition is a distance between an edge list to be scanned and an edge list to be scanned next. 5. A conversion unit for converting page description data representing each of a plurality of objects drawn in layers in a predetermined drawing area in a predetermined drawing order into intermediate code image data, and for each converted object. A storage unit for storing the intermediate code image data in a memory, and an edge list for each predetermined scanning line corresponding to the intermediate code image data so that the image area represented by the intermediate code image data for each object does not overlap. A graphic processing means for executing superimposing graphic processing for updating the intermediate code image data of each object stored by the created edge list of each object by tracing the drawing order of the objects And if the object type is a specific type, An image processing apparatus comprising: a control unit that controls to inhibit tatami graphic processing. 6. A conversion unit for converting page description data representing each of a plurality of objects drawn in layers in a predetermined drawing area in a predetermined drawing order into intermediate code image data, and for each converted object. A storage unit for storing the intermediate code image data in a memory, and an edge list for each predetermined scanning line corresponding to the intermediate code image data so that the image area represented by the intermediate code image data for each object does not overlap. A graphic processing means for executing superimposing graphic processing for updating the intermediate code image data of each object stored by the created edge list of each object by tracing the drawing order of the objects If the degree of overlap between multiple objects is above a certain level, An image processing apparatus comprising: a control unit configured to control a superposed graphic process for a number of objects. 7. The control means controls, when there are a plurality of objects for which superposed graphic processing is prohibited, to execute superposed graphic processing by the graphic processing means only between objects for which the superposed graphic processing is prohibited. The image processing apparatus according to claim 5, wherein the image processing apparatus comprises: