JPH09171564A - Plotting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plotting device whereby the volume of intermediate data is drastically reduced. SOLUTION: A plotting command received by an input control part 1 is transmitted one of a raster plotting part 2, a vector plotting part 3 and a character plotting 4 and an edge list is generated. An intermediate data generating part 5 receives the edge list, generates intermediate data which is divided at every band width and executes storage in an intermediate data buffer 6. Intermediate data adds chrominance information and plural intermediate data cells. The intermediate data cells add difference between two run positions and run- length. The plural kinds of data length of the intermediate data cells exist and a format having data width required for indicating position difference is selectively used. An extension output control part 7 takes-out intermediate data at every band from the intermediate data buffer 6 so as to extend it in bit map data, writes it in band buffers 8 and 9 and outputs it from an output device 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drawing device for receiving a drawing command, which is code information such as a page description language (hereinafter abbreviated as PDL), and outputting characters, graphics, and images in a raster scan.

[0002]

2. Description of the Related Art In recent years, devices for simultaneously editing characters / graphics / images and outputting them from printers have become widespread. In this case, the information sent to the printer is PDL.
It is code information such as and is interpreted by a printer to create a bitmap image, which is output as a raster scan.

However, the printers used in such fields are becoming more colorized and higher in resolution, and if one page of drawing primitives is expanded into a bitmap at one time, a huge amount of data will result. Therefore, for example, as described in JP-A-6-119131,
Divide one page into bands with multiple scan lines as a unit,
It is considered that each band is expanded into a bitmap and then output. However, if this method is simply applied, all drawing commands are read and interpreted for each band, the presence / absence of a part included in the band is determined, and the band part is expanded into a bitmap. However, there is a problem that it takes a long processing time.

Further, for example, in the printing apparatus disclosed in Japanese Patent Laid-Open No. 5-246077, graphics data is expanded into low resolution bitmap data which does not have a large data amount and is expanded for each band, for example. And then output. As a result, at least for graphics data, it is not necessary to read and interpret the drawing command for each band, which can speed up somewhat and reduce the amount of data. However, even though it is a high-resolution printing device, there is a problem that high-resolution graphics data cannot be printed or such advantages cannot be utilized.

Further, for example, Japanese Patent Laid-Open No. 5-250109.
As described in Japanese Patent Publication, ADCT for each band
It is also considered that the data is encoded and stored by a method such as the above, and is decoded and output at the time of output. With this method, the data amount of the image for one page accumulated is much smaller than that of the bitmap, and the memory amount can be reduced, and
At the time of output, it is only necessary to decode and output for each band, and it is possible to reduce the memory amount at the time of output and output at a low speed. However, when encoding, it is necessary to once create a bitmap for each band, and since encoding and decoding take time, it is not suitable for real-time output.

As an attempt to reduce the memory amount and the processing time as described above, for example, Japanese Patent Laid-Open No. 5-2246
There is a method using an edge list as described in Japanese Patent No. 37. In this technique, a drawing command is received, and a run indicating the coordinates and length of the beginning of the drawing portion or an edge list that is a list of coordinates of the beginning and end of the drawing portion is created for each scan line. After creating a list for all drawing commands for one page, sort for scan lines. And
For each band, a list of scan lines included in that band is extracted, bit-mapped, and output. According to this method, the drawing command is interpreted only when the edge list is created, and when the bitmap is expanded, only the expansion is performed according to the edge list, so that the processing time can be greatly reduced. Also, the data amount of the edge list is extremely small compared to the bitmap for one page.

However, even in this method, the memory amount of the pointer portion in the list structure forming the edge list becomes large, basically only the information in the main scanning direction is compressed, and it is constant regardless of the size of the run. Since the run is represented by data of size, sufficient reduction of the amount of data has not been achieved.

On the other hand, among the printers described above, 1
Although some gradations can be expressed in dots, some printers require gradations to be expressed in multiple surrounding bits. In this case, in the code information such as PDL sent to the printer, the gradation is expressed by a continuous expression. If you want to print this, perform halftone processing at the final stage of drawing processing on the printer side and directly
Bitmap data of values is being created. For example, as in the image forming apparatus described in Japanese Patent Application Laid-Open No. 5-138947, halftone processing is performed using pattern data generated by the pattern generating unit every time drawing data is created, and data in the frame memory is stored. Binary bitmap data is obtained for each color by combining. In this configuration, for example, one page of frame memory is required for each color. If the resolution of the printer is increased and the image for one page is developed into a bitmap as in this configuration, there is a problem that a huge amount of data will be generated even if it is binary. For example, as described in Japanese Patent Laid-Open No. 6-62229, it has been considered to detect a halftone area and apply dither processing only to that area, but it is possible to reduce the processing time, but the target is Since it is a scanner image, it retains one page of binarized image.

In the device disclosed in Japanese Patent Laid-Open No. 6-70145, the threshold data for binarization is read out row by row and stored in a memory, and the raster data and the threshold data are read out and compared. The binary bit map data is obtained. Since this configuration is sequential processing, it can be applied to, for example, processing for each band. Also, since the threshold data is stored in advance in the ROM,
High-speed halftone processing is possible. However, with this technique, halftone processing is performed on an image expanded into bitmap data, so multivalued bitmap data must be created once, and the processing speed of the entire device decreases. Will end up.

As described above, there is a drawing apparatus that creates intermediate data such as run length expression in the drawing process and creates binary bit map data in band units from the run length expression at the time of printer printing. When applying halftone processing to a bitmap in such a device, first, a multi-valued bitmap is created from intermediate data, and then a binary bitmap is created by halftone processing. The expansion process will take time. Therefore, in a printer with a constant print speed, the development speed does not meet the print speed of the printer and the image may be missing. Therefore, faster halftone processing is required.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and a first object of the present invention is to provide a drawing device in which the capacity of intermediate data is greatly reduced. A second object is to provide a drawing device that performs high speed halftone processing.

[0012]

According to a first aspect of the present invention, there is provided a drawing apparatus which receives a drawing command representing a drawing primitive, generates bitmap data according to the drawing command, and outputs the bitmap data. Drawing processing means for extracting a run for each scanning line in which a drawing primitive corresponding to the drawing information and the drawing command exists and its end coordinates, an intermediate data storage means for storing intermediate data, and the drawing processing means. Two consecutive
The difference between the end coordinates of one run is calculated, one of a plurality of types of intermediate data formats with different data lengths is selected based on the calculation result, and the difference between the selected intermediate data format and the end coordinates and the drawing processing means are used. An intermediate data cell is generated based on the extracted run, and a plurality of intermediate data cells generated for each of the drawing commands are stored in the intermediate data storage means as intermediate data together with the color information extracted by the drawing processing means. Data generating means,
It is characterized in that it has a developing means for developing the bitmap data based on the intermediate data stored in the intermediate data storage means.

According to a second aspect of the present invention, in the drawing apparatus according to the first aspect, the intermediate data generating means stores an intermediate data cell in the intermediate data storage means based on the data length of the selected format. The write address is determined, and the expanding means determines the read start address and the read range of the intermediate data cell from the intermediate data storage means based on the data length of the format of the intermediate data cell. is there.

According to a third aspect of the present invention, in a drawing device which receives a drawing command representing a drawing primitive, generates bitmap data in accordance with the drawing command, and outputs the bitmap data, the color information of the drawing command and the drawing command. The drawing processing means for extracting the run and the coordinates of the end of each scanning line in which the drawing primitive corresponding to is present, the intermediate data storage means for storing the intermediate data, and the bit for each band in units of a plurality of scanning lines. The area of the map data is managed, the difference between the end coordinates of two consecutive runs extracted by the drawing processing means is calculated, and one of a plurality of intermediate data formats having different data lengths is selected based on the calculation result. Intermediate based on the selected intermediate data format and the difference between the end coordinates and the run extracted by the drawing processing means Intermediate data for generating data cells and storing a plurality of intermediate data cells generated together with the color information extracted by the drawing processing means as intermediate data in the intermediate data storage means each time the bands in which two consecutive runs exist are different It is characterized in that it has a generation means and a decompression means for decompressing to the bitmap data for each band based on the intermediate data stored in the intermediate data storage means.

According to a fourth aspect of the present invention, in a drawing device which receives a drawing command representing a drawing primitive, generates bitmap data in accordance with the drawing command, and outputs the bitmap data, the color information of the drawing command and the drawing command. Intermediate data generating means for generating intermediate data based on the length of run for each scanning line in which the drawing primitive corresponding to and the end coordinates thereof, and intermediate data for storing the intermediate data generated by the intermediate data generating means A storage unit, a halftone matrix storage unit that stores a halftone matrix that is a matrix of binary data of a predetermined size that represents a halftone associated with the value of the color information, and the intermediate data storage unit. When expanding the intermediate data to be converted into bitmap data, the One of the halftone matrices stored in the halftone matrix storage means is selected, and 2 of a part of the halftone matrix selected based on the length and end coordinates of the run included in the halftone data. It is characterized in that it has a expanding means for expanding the value data into bitmap data.

According to a fifth aspect of the present invention, in the drawing apparatus according to the fourth aspect, the halftone matrix stored in the halftone matrix storage means is C in the scanning line direction of the image.
It is characterized by having a word length of PU.

According to a sixth aspect of the present invention, in a drawing device that receives a drawing command representing a drawing primitive, generates bitmap data in accordance with the drawing command, and outputs the bitmap data, the color information of the drawing command and the drawing command. The drawing processing means for extracting the run for each scanning line in which the drawing primitive corresponding to is present and its end coordinates, the intermediate data storage means for storing the intermediate data, and the two consecutive runs extracted by the drawing processing means. The difference between the end coordinates is calculated, and one of a plurality of types of intermediate data formats having different data lengths is selected based on the calculation result, and the difference between the selected intermediate data format, the end coordinates, and the drawing processing means are extracted. Intermediate data is generated based on the run and the color information and stored in the intermediate data storage means. And a halftone matrix storage means for storing a halftone matrix which is a matrix of binary data of a predetermined size and which represents a halftone associated with the value of the color information, and the intermediate data storage means. When developing the stored intermediate data into bitmap data, one of the halftone matrices stored in the halftone matrix storage means is selected based on the value of the color information included in the intermediate data. It is characterized in that it has an expanding means for expanding binary data of a part of the halftone matrix selected based on the run length and the end coordinates included in the intermediate data into bitmap data. is there.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a first drawing apparatus according to the present invention.
It is a block diagram showing an embodiment. In the figure, 1 is an input control unit, 2 is a raster drawing unit, 3 is a vector drawing unit, 4 is a character drawing unit, 5 is an intermediate data generation unit, 6 is an intermediate data buffer, 7 is an expansion output control unit, and 8 and 9. Is the band buffer,
Reference numeral 10 is an output device.

The input control unit 1 receives a drawing command described in PDL and interprets it. The drawing commands include commands for actual drawing as well as commands for environment setting and control. The result of the interpretation is that, according to the drawing primitive drawn by the drawing command, the raster data and the conversion matrix are drawn in the raster drawing unit 2 in the case of raster drawing, and the vector data, the conversion matrix and the color / line width are drawn in the case of vector drawing. If the attribute is vector drawing unit 3, in the case of character drawing, character code, conversion matrix, color /
Drawing attributes such as font type are sent to the character drawing 4.

The raster drawing section 2 performs a process of matching the input raster data with the color of the output device 10 and a process of creating the raster data converted by the conversion matrix. In addition, other image processing may be performed. Further, the position where the raster exists on each scan line and the run length are calculated to create an edge list, and the edge list is passed to the intermediate data generation unit 5 together with the pointer to the raster data.

The vector drawing section 3 performs a fill drawing process and a stroke drawing process. In the filling drawing processing, intersection points where vectors after matrix conversion intersect each other for each scan line are extracted, and an edge list indicating a position and a length to be filled and a color of the output device 10 to be filled are passed to the intermediate data generation unit 5. . In the case of stroke drawing processing, an outline vector is generated from the line width / terminal shape / connection shape and then the filled drawing processing is performed.

The character drawing unit 4 extracts the corresponding vector font from the input character code and performs the same processing as the filled drawing processing of the vector drawing unit 3.

The intermediate data generation unit 5 includes a raster drawing unit 2,
The edge list is received from the vector drawing unit 3 and the character drawing unit 4, and the intermediate data divided for each band width of the band buffer is generated. The intermediate data includes color information and a plurality of intermediate data cells. The intermediate data cell includes a run length and a position difference obtained by calculating a position difference between two runs based on the position information obtained from the edge list. There are a plurality of data lengths of the intermediate data cells, and the intermediate data format of the data length required to show the calculated difference in position is selected. Further, the intermediate data format may be selected in consideration of the run length. The intermediate data cell also contains information for identifying the selected intermediate data format. Since only one color is often used when drawing one drawing primitive, the color information can be configured to be added only once for each drawing primitive. Also, when consecutive runs are included in different band buffers,
Therefore, the intermediate data is divided. Even in that case, the color information can be added.

The intermediate data buffer 6 holds the intermediate data generated by the intermediate data generator 5.

The expansion output control unit 7 extracts the intermediate data from the intermediate data buffer 6 for each band, expands it into bit map data, and writes it into the band buffer 8 or 9. Further, it also controls activation of the output device 10.

The band buffers 8 and 9 store the bitmap data expanded by the expansion output control unit 7. The band buffers 8 and 9 are used as alternation buffers, and one of them can be read by the output device 10 while the expansion output control unit 7 is writing.
As a result, the expansion processing to the bitmap data by the expansion output control unit 7 and the output processing by the output device 10 can be performed in parallel. Of course, the number of band buffers may be one or may not be used. Also,
A configuration including three or more band buffers may be used.

The output device 10 is activated by the expansion output control unit 7 and reads out bitmap data for each band from the band buffer 8 or 9 and outputs it. As the output device 10, it is possible to use a device of a type that once activated, outputs one page at a constant speed. Therefore, the bitmap data of each band needs to be written in the band buffer 8 or 9 within a predetermined time. The expansion output control unit 7 expands the intermediate data into bitmap data within this predetermined time.

Each section will be further described below. FIG.
FIG. 7 is an explanatory diagram of an example of an edge list generated by a raster drawing unit. The raster drawing unit 2 includes an input control unit 1
Passes the raster data and the transformation matrix. Along with the raster image, the raster data is provided with the number of horizontal bytes of the raster image, the number of vertical scan lines, and the number of bits per dot indicating color as a header. Raster drawing unit 2
Converts the value representing the color of each dot to match the color of the output device 10. In addition, conversion processing such as rotation and scaling is performed using the conversion matrix. The raster image shown on the left side in FIG. 2 is one after such conversion processing.

Further, the raster drawing section 2 creates an edge list as shown on the right side of FIG. The edge list includes a pointer to the raster image, the address of the scan line in each scan line, the start position of the raster image, and the run length list. For example, on scan line Y0, the raster image starts at position SX0 and exists for length RL0. Therefore, Y0, SX
0 and RL0 are paired and registered in the list. By extracting the start position and run length of such a raster image in each scan line, an edge list as shown on the right side of FIG. 2 is obtained. This edge list is passed to the intermediate data generator 5.

FIG. 3 is an explanatory diagram of an example of the edge list generated by the vector drawing unit. The vector drawing unit 3 performs a fill drawing process and a stroke drawing process. In either case, the fill drawing process is performed based on the outline vector. In the filled drawing processing, the intersection point where the vectors after the matrix conversion intersect is extracted for each scan line, and the start position to be filled and the run length indicating the length are extracted.

Now, consider the case where a circle and a triangle are drawn as shown in FIG. Scan lines are indicated by broken lines. Since the top of the circle is drawn on the scan line Y0, the start position SX0 and the run length RL0 that is the fill length are drawn.
Is extracted. And position SX0 and run length RL0
Is associated with the scan line address Y0. In the scan line Y1, since the top of the triangle and the middle of the circle are filled, the start position SX1 and the run length RL1 for filling the top of the triangle, and the start position SX2 and the run length RL2 for filling the circle are filled. To extract. Then, at the address Y1 of the scan line, the start position SX1 and run length RL1, and the start position SX2 and run length R
L2 is associated. In this way, for each scan line, the start position and run length are extracted and associated with the address of each scan line. Further, color information for filling these figures is added to obtain an edge list as shown in FIG. In the case of this raster drawing process, the color to be filled is specified as one color, so
The entire edge list has one color information. The edge list thus obtained is passed to the intermediate data generation unit 5.

Since the character drawing unit 4 also performs the filling process based on the outline font, an edge list similar to that of the vector drawing unit 3 is generated and passed to the intermediate data generating unit 5.

The above raster drawing unit 2, vector drawing unit 3,
The edge list generated by the character disease in the section 4 may store the start position and the end position instead of storing the start position and the run length, and may be converted into the run length when the intermediate data is created.

FIG. 4 is an explanatory diagram of an example of the intermediate data format used when the intermediate data generating unit generates the intermediate data cells, and FIG. 5 is an explanatory diagram of an example of the intermediate data cell generation in the intermediate data generating unit. Is. The intermediate data generation unit 5 receives an edge list as shown in FIGS. 2 and 3 from the raster drawing unit 2, the vector drawing unit 3, and the character drawing unit 4, and generates an intermediate data cell.

The intermediate data generator 5 creates intermediate data for each same color or the same raster data. For example, when creating intermediate data for a certain color, the runs of that color are taken out one by one and processed.
In FIG. 5, (B) is a run that is currently focused on,
Let (A) be the run that attracted attention last time. Here, the trailing edge of the last run (A) and the current run (B)
Calculate the difference in position from the tip of. The calculated difference in the scan line direction is DX, and the difference in the direction orthogonal to the scan line is DY.

At this time, if the run (A) and the run (B) generate an edge list for each scan line,
Most likely the same scan line or the next scan line. That is, the difference DY is highly likely to be 0 or 1. Moreover, the difference DX in the scan line direction is also
It is likely to be a small value. It is possible to reduce the amount of data by using such a property.

Here, the difference in position between the trailing end of the run (A) and the leading end of the run (B) was calculated, but conversely, the difference in position between the leading end of the run (A) and the trailing end of the run (B) was calculated. Can be calculated, or the difference between the positions of the front ends of the two and the difference between the positions of the rear ends of the two can be calculated, and the difference can be obtained with reference to various points.

As shown in FIG. 4, formats for some intermediate data cells are prepared in which the number of bits required to represent the differences DX and DY is changed. Then, according to the values of the differences DX and DY, and further, the value of the run length, one of these formats is selected and used. Here, four formats are prepared in advance. As you can see from these formats, the difference D
The area representing Y is made small and the data lengths of the difference DX and the run length RL are changed. Further, in order to indicate which format the data is, data indicating the type is added to the beginning. Here, the data representing this type need only be 2 bits, as long as the four formats can be identified here. Of course, when the number of formats increases, a data length corresponding to that is required.

The format shown in FIG. 4A is a format suitable for drawing with a portion of several dots which is not drawn sandwiched therebetween, or for drawing thin vertical lines, diagonal lines, characters and the like. Specifically, run length data 3b
It, the difference DY 1 bit, the difference DX 2 bit, and the type 2 bit 8 bit (= 1 byte).

The format shown in FIG. 4B is a format used when drawing a slightly larger figure. This format is composed of 2 bytes, and specifically, for example, run length 6 bits, difference D
It can be configured by Y1 bit, difference DX7 bit, and type 2 bit.

The format shown in FIG. 4C is a format used when drawing a larger figure or a distant portion. This format is 4By
te. Specifically, for example, run length 14 bits, difference DY2 bit, difference DX14 bit
, And can be configured with a type 2 bit.

The format shown in FIG. 4D is used especially at the start of drawing, and is used when the absolute position is clearly indicated by the absolute coordinate X in the scan line direction and the coordinate Y of the scan line. This format is 6 Byte
e. Specifically, the type is 2 bits, the run length is 14 bits, and the absolute coordinates X and Y are 16 bits.
Each bit can be assigned.

When an intermediate data cell is generated using such a format, the format shown in FIG. 4D is rarely used except at the beginning of each drawing primitive, and in many cases, the format shown in FIG. ) Or FIG. 4 (B)
The format shown in is used. Therefore, the data amount of the whole intermediate data becomes very small.

FIG. 6 is an explanatory diagram of an example of the format of the intermediate data. To draw one drawing primitive,
Normally, a plurality of intermediate data cells as described above will be generated. The intermediate data generation unit 5 collects the plurality of intermediate data cells and the color information to generate intermediate data. The intermediate data generated from one drawing primitive includes, for example, as shown in FIG. 6, the number of intermediate data cells, color information, and a column of intermediate data cells. The information on the number of intermediate data cells also includes an identifier for distinguishing between the case where the vector data is filled with one color such as vector data and character data and the case where the color data is output as it is like raster data. I'm out. Further, as the color information, when vector data or character data is drawn, information indicating a certain color used for drawing is stored. When drawing raster data, a pointer to the raster data is stored. As a specific format, information indicating the number of intermediate data cells is 4 Byte.
e, 4 bytes of color information, and then four intermediate data cells shown in FIG. 4 are arranged by the number of intermediate data cells.

When one drawing primitive extends over a plurality of bands, even if the intermediate data cells drawn in the same color are lined up, the number of intermediate data cells and the color information are inserted for each band, and It is generated as intermediate data. By doing so, it is possible to easily develop each band into bitmap data.

Such intermediate data is stored in the intermediate data buffer 6. Since the intermediate data generation unit 5 can specify the number of scan lines included in a band from the received edge list, the number is used as the number of intermediate data cells, and in the case of raster data as color information, a pointer to an image is used. In other cases, the drawing color is output. After that, one of the formats shown in FIG. 3 is selected from the address difference and the run length from the start address and the run length data, and intermediate data cells are sequentially generated and written to the intermediate data buffer 6. At this time,
There are a plurality of types of lengths of the intermediate data cells, but the length may be written while updating the address of the intermediate data buffer 6 according to the type of the intermediate data cell written immediately before.

FIG. 7 is an explanatory diagram of a specific example of the intermediate data. Now, as shown in FIG. 7A, consider a case where a circle is drawn between band 0 and band 1, a triangle is drawn in band 1, and a raster image rotated by 45 degrees is drawn between band 2 and band 3, respectively. In FIG. 6, for convenience of illustration,
The portion where each scan line is drawn is shown by a bar line, and the color of each figure is shown with different hatching. At this time, the intermediate data output to the intermediate data buffer 6 is shown in FIG.
This is shown in FIG.

For band 0, there is a portion for drawing a circle for two scan lines. Since each scan line has one drawing portion, two intermediate data cells are generated. An identifier indicating that this drawing is based on vector data is also added. Then, the color for filling the circle (shown by hatching in the lower right direction) is stored, and then two intermediate data cells are output. Since the first intermediate data cell is the start of drawing, it is necessary to indicate absolute coordinates. for that reason,
The format shown in FIG. 4 (D) is selected, and the intermediate data cell is generated by the run length to be drawn and the absolute coordinates. Further, for the drawing portion of the circle adjacent to it, the difference between the end of the previous drawing portion and the tip of the portion to be drawn is calculated, and the format required to express the difference is selected. In this case, the difference DY in the scan line direction is 1. Here, it is assumed that the format shown in FIG. 4B has been selected.

In band 1, first, intermediate data for drawing the remaining portion of the circle is generated. This portion exists as a drawing portion for each of the two scan lines. The number of intermediate data cells is set to 2, and color information is output. Then, two intermediate data cells are output. Since the first intermediate data cell is the start point of drawing a circle in this band, the start position is indicated by absolute coordinates.
The format (D) is used. In the next scan line, the format of FIG. 4A is used in this example.

Further, in band 1, a triangle is drawn. As the intermediate data therefor, the number of intermediate data cells is 3, color information (shown here as upward-sloping hatching), and three intermediate data cells follow. In this case as well, since the drawing is started at the first intermediate data cell, the start position is indicated by absolute coordinates. Therefore, the format shown in FIG. 4D is used, and thereafter the format is selected according to the difference in coordinates. Here, FIG. 4 (B), (A)
Format has been selected and intermediate data cells have been generated.

In band 2, a part of the raster image is drawn. The number of intermediate data cells in this band is 3, and an identifier indicating that it is raster data is added. Further, as color information, a pointer to image data indicating a raster image is output. In FIG. 7, the pointer is indicated by “*”. Furthermore, three intermediate data cells follow. The first intermediate data cell uses the format of FIG. 4D to indicate the drawing start point in absolute coordinates, the second uses the format of FIG. 4B, and the last uses the format of FIG. 4C. The band 3 is similar to the band 2.

In this way, it is divided into band units,
When the intermediate data of the entire page is written in the intermediate data buffer 6, the expansion output control unit 7 extracts this, expands it into bitmap data for each band, and writes it in the band buffer 8 or 9. For example, the expansion output control unit 7 expands the intermediate data for the first band into a bitmap, writes it in the band buffer 8, and activates the output device 10. The activated output device 10 reads the bitmap data from the band buffer 8 and performs a printing process. The expansion output control unit 7 writes the bitmap data in the band buffer 8, and after starting the output device 10, expands the intermediate data for the second band into a bitmap and writes it in the band buffer 9 while the output device 10 is printing. .
After printing the bitmap data in the band buffer 8, the output device 10 reads the bitmap data in the band buffer 9 and performs a printing process. The expansion output control unit 7 expands the intermediate data for the third band into a bitmap after the printing process is completed for the bitmap data in the band buffer 8 by the output device 10, and writes it in the band buffer 8. Hereinafter, the expansion output control unit 7
Writes the bitmap data for each band alternately every time the bitmap data in the band buffer 8 or 9 is processed by the output device 10. Also, the output device 10
Alternately reads the bit map data from the band buffer 8 or 9 and performs the printing process. This operation is repeated until the final band is reached, and one page is printed.

In the above structure, when the normal resolution is set to about 600 spi, the intermediate data stored in the intermediate data buffer 6 is about 1/50 of the bitmap data. When the bandwidth is reduced to about 1/16, the two band buffers 8 and 9 require about 1/8 of the memory of the frame buffer, so that the output is possible with the memory capacity of about 15% of the frame buffer as a whole. Became. Further, by managing the data amount of the intermediate data, it is possible to easily cope with output from a limited small memory at the sacrifice of image quality due to a thinning operation or the like.

Like the above-mentioned intermediate data, in the vector data and the character data, only one color information is held for many intermediate data cells. This is because the designated color is often one even if possible. When a large number of colors are used for one drawing primitive, it is necessary to separate the intermediate data for each color. In addition, when another drawing primitive is overwritten on a certain drawing primitive, the overlapping portion is almost always the color of one of the drawing primitives or a mixed color. In the case of using either color, the run length of the intermediate data cell of either drawing primitive may be corrected for the overlapping portion. Further, when the mixed color is used, the intermediate data of the overlapping portion is created as the intermediate data of another color. However, at present, such overwriting is rarely performed. Therefore, the amount of data does not increase in most cases.

In the above example, the intermediate data is generated for each drawing primitive, but not limited to this, for example, the edge list of a plurality of drawing primitives is sorted by the scan line, and the same color is drawn regardless of the drawing primitives. It may be configured to extract the portion and generate the intermediate data. Further, in the above example, the edge list is generated once and the intermediate data is generated based on the edge list, but the intermediate data may be directly generated in each drawing unit.

The process from receiving the drawing command to generating the intermediate data will be described in detail below using a specific example. FIG. 8 is an explanatory diagram of a specific example of a graphic to be drawn, and FIG. 9 is an explanatory diagram of an example of a drawing command for drawing the graphic shown in FIG. Here, the processing for drawing the figure shown in FIG. 8 will be specifically described.

In order to draw the figure shown in FIG. 8, it is assumed that a drawing command for creating an outline as shown in FIG. 9 has been sent to the input control unit 1. In the drawing command shown in FIG. 9, “(1.1,3.9) moveto” is a movement command for the current position, and the start point of the straight line 1 is (1.
1, 3, 9). Next, “(1.1, 1.
1) "lineto" is a command for drawing a straight line from the current position to the specified position. Here, (1.
A straight line from (1,3.9) to (1.1,1.1) is drawn. In addition, the point specified here becomes the new current position and becomes the start point of the next straight line 2. Similarly, "(7.9,
1.1) lineeto "is the current position (1.1,
This is an instruction to draw a straight line from 1.1) to (7.9, 1.1), and this (7.9, 1.1) is the end point of the straight line 2 and the start point of the straight line 3. Similarly, "(1.
A straight line 11 is drawn by "9,3.9) lineto". Further, by "close", a straight line from the starting point of the straight line 12 (1.9, 3.9) to the starting point of the straight line 1 (1.1, 3.9) is drawn, and a closed figure is obtained. Become. Here, by "50 fill", the closed figure is filled with the color 50. In this way, the figure shown in FIG. 8 is drawn. In FIG. 8, a bold line indicates a straight line drawn by the drawing command shown in FIG. 9, and a straight line number is added to the side.

The input control unit 1 interprets the drawing command as shown in FIG. 9 and issues a vector creation command from the straight line 1 to the straight line 12 to the vector drawing unit 3. That is, a vector corresponding to the thick line in FIG. 8 is created and passed to the vector drawing unit 3. The vector drawing unit 3 receives the vector creation command and holds it internally as vector data.

Next, the input control unit 1 issues a command to fill with the color 50 to the vector drawing unit 2-3. The vector drawing unit 3 first sends a command for initializing with the color 50 to the intermediate data generating unit 5. Upon receiving this, the intermediate data generation unit 5 sets the field of the number of intermediate data cells of the intermediate data as shown in FIG. 6 for each band to 0, invalidates the portion of the following intermediate data cells, and holds the color value 50. To do.

First, the vector drawing section 3 creates a display list. FIG. 10 is an explanatory diagram of an example of the display list. The display list is a list of vector data that intersects each scan line. Horizontal lines (starting point and ending point have the same y coordinate) are not added to the display list. A vector intersecting with a plurality of scan lines is added to the display list of scan lines corresponding to the smaller y coordinate of the start point and end point of the vector data. In this case, since the number of the corresponding scan line is an integer value, 0.5 is added to the smaller y coordinate of the vector data to obtain a value obtained by taking the integer part.

Scan = int (min (y) +0.5)) In FIG. 8, the scan line is indicated by a broken line. In the case of the example shown in FIG. 8, the straight line 1 and the straight line 3 intersect in the scan line 1. Therefore, scan line 1 has a straight line 1
And the straight line 3 are connected. Further, in the scan line 2, straight lines 1, 3, 5, 7, 9, 11 intersect. Of these, the straight lines 1 and 3 are connected to the display list of the scan line 1, so the straight lines 5, 7 and
9 and 11 can be connected. In this way, the display list as shown in FIG. 10 is created.

The information contained in the cell of each line in the display list is considered at the first scan line (coordinate value is an offset of 0.5) connected to the cell.
For example, the y coordinate of scan line 0 is 0.5 and the y coordinate of scan line 1 is 1.5. ) And its straight line intersect, the x-coordinate (SX), the amount of movement of the x-coordinate when one scan line goes up (DX), and how many scan lines this straight line intersects (DY) are stored. For example,
In the cell of line 1, SX = 1.1, DX = 0.0, D
Y = 3 is stored. Also, in the cell of line 3,
SX = 7.9, DX = 0.0, and DY = 4 are stored.

Next, the vector drawing unit 3 scans the display list as shown in FIG. 10 to sequentially create the edge list corresponding to the drawing object in each scan line. In this procedure, each scan line is converted in the order of active list → fill list → edge list. The procedure will be described below.

Scanline 0 does not do anything because it has no corresponding display list and no active list is created. FIG. 11 is an explanatory diagram of an example of the active list when the scan line 1 is processed. For scan line 1, there are line 1 and line 3 in the display list. Add it to the active list. This state is shown in FIG. The active list is a list of cells of the line that is valid in the current scan line and has the same data structure as the cells of the lines of the display list. However, the data in the cell is updated every time the scan line is processed.

Next, a filled list is created. FIG.
FIG. 7 is an explanatory diagram of an example of a filling list when processing scan line 1. The filled list is for extracting x-coordinate values intersecting the scan line from the active list and sorting by the x-coordinate values. For example, referring to the active list shown in FIG. 11 for the scan line 1, the x-coordinate 1.1 of the point where the scan line 1 intersects the straight line 1 and the x-coordinate 7.9 of the point where the scan line 1 intersects the straight line 3 are extracted, and FIG. A filled list as shown in is created.

The vector drawing section 3 creates an edge list based on the filled list. FIG. 13 is an explanatory diagram of an example of the edge list of the scan line 1. For example, when the regions to be drawn are viewed in ascending order of the X-coordinates of the filled list sorted in ascending order,
The area between the odd number and the even number is the area to be drawn. Here, the integer part of the X coordinate is used. From the fill list shown in FIG. 12, the area from the coordinate “1” of the first cell to the coordinate “7” of the second cell is the area to be filled, so as shown in FIG. An edge list with coordinates 7 is generated. At this time, run length data may be created, and the edge list may be configured by the start coordinates and run length. The edge list and scan line number as shown in FIG. 12 are passed to the intermediate data generation unit 5.

The intermediate data generating section 5 determines which band is included by looking at the scan line number. Then, the value of the variable NUM indicating the number of intermediate data cells of the intermediate data of this band is referred to.
Is 0, the area necessary for writing the number data is secured at the current point position of the corresponding band of the intermediate data buffer 6, and the current point is incremented. Further, in order to count the number of intermediate data cells, the current point before the increment is separately stored. Then, the stored color value 50 is written in the current point and the current point is advanced.

Next, based on the given edge list,
Write the intermediate data cell. First, when the variable NUM indicating the number of intermediate data cells is 0, the absolute coordinate format (the format shown in FIG. 4D) is immediately selected. Then, an intermediate data cell is generated according to this format, and the intermediate data cell is written at the current point. Further, the current point is updated to the write position of the next intermediate data cell, and the value of the variable NUM indicating the number of intermediate data cells is incremented.

The absolute coordinates in the Y direction used when the intermediate data cell is generated use the offset of each band,
(Scanline number% bandwidth) can be used. Then, BX = ex, BY = (scan line number% band width) is registered as the coordinate value address of this band, that is, the end coordinate (BX, BY) of the run (A) described in FIG.

If the variable NUM indicating the number of intermediate data cells of the band is not 0, the coordinate values of the intermediate data cells with respect to the edge list are DX = sx-BX, DY = (scan line number% band width) -BY. Figure 4 calculated
The format that can be expressed smallest is selected from among (A) to (D) shown in (1) to (3) and converted into an intermediate data cell according to the selected format and written. Of course, the current point is updated by the corresponding data length. The variable NUM is also incremented.

FIG. 14 is an explanatory diagram showing an example of the intermediate data buffer at the time of processing the scan line 1. When the edge list of scan line 1 as shown in FIG. 13 is received, if this is the first edge list of the band, an area for the number of intermediate data cells is secured and the color value 50 is written. Then, using the absolute coordinate format shown in FIG. 4D, the starting point sx = 1, the scan line number 1,
An intermediate data cell is created by the run length 7 from the start point to the end point. In FIG. 14, the format number T of this format is 3. The created intermediate data cell is written in the intermediate data buffer 6. This state is shown in FIG.

Next, the process for scan line 2 is started. First, update the active list. FIG. 15 is an explanatory diagram of an example of the active list at the time of processing the scan line 2. First, when the scan line 1 is processed, the data in the cells of each line connected to the active list is updated. That is, SX = SX + DX and DY = DY-1 are calculated for line 1 and line 3.
At this time, if there is a cell in which DY is 0, it is removed from the active list. Further, the data corresponding to the scan line 2 of the display list is added to the active list. In this example, line 5, line 7, line 9, line 1 from the display list shown in FIG.
One cell is added to the active list. As a result, the active list becomes as shown in FIG.

FIG. 16 is an explanatory diagram of an example of the edge list of the scan line 2. Based on the active list shown in FIG. 15, a filled list is created and sorted in the same manner as the scan line 1, and an edge list is created.
Lines 1 to SX = 1.1, lines 11 to SX = 1.
9 is taken out and the first filled list sx = 1, ex
= 1 is created. Also, from line 9 SX = 5.1,
SX = 5.9 is taken out from the line 7 and the filled list sx = 5, ex = 5, and SX = 7.1 from the line 5
SX = 7.9 is taken out from the line 3 to create the filled lists sx = 7 and ex = 7, respectively, and the edge list as shown in FIG. 16 is obtained.

FIG. 17 is an explanatory diagram showing an example of the intermediate data buffer during the scan line 2 processing. The edge list as shown in FIG. 16 created as described above is
It is passed to the intermediate data generation unit 5 together with the scan line number 2. Since the value of the variable NUM indicating the number of intermediate data cells in band 0 is 1 this time, the processing of intermediate data cells is immediately started.

First, DX = sx-BX, DY = (scan line number% band width) -BY, RL = ex-sx +
Each value is calculated by the calculation of 1. At the start of processing of scan line 2, BX = 7 and BY = 1 are held. According to the first edge list shown in FIG. 16, DX = 1-7
= -5, DY = 2-1 = 1, RL = 1. From the calculation result, the format shown in FIG. 4B is selected, an intermediate data cell is created, and the intermediate data cell is written at the position of the current point. The current pointer is updated by 2 bytes. Further, the variable NUM is incremented to 2 and is changed to BX = 1 and BY = 2.

In the second edge list, DX = 3, D
Y = 0, RL = 1, the format shown in FIG. 4A is selected, an intermediate data cell is generated, and the intermediate data cell is written at the position of the current point. The current pointer is updated by 1 byte. Also, variables NUM = 3, BX =
4, changed to BY = 2. Similarly, in the third edge list, DX = 3, DY = 0, RL = 1.
The format shown in (A) is selected, an intermediate data cell is generated and written at the position of the current point.
The current pointer is updated by 1 byte. Also,
The variables are changed to NUM = 3, BX = 7, and BY = 2.

In this way, the three intermediate data cells in the scan line 2 are written in the intermediate data buffer, and the processing of the scan line 2 is completed. The contents of band 0 of the intermediate data buffer 6 at this time are as shown in FIG.

FIG. 18 is an explanatory diagram showing an example of the intermediate data buffer after the completion of all scan line processing. Similarly, the scan lines 3, 4, and 5 are processed. Also in the scan line 3, as in the scan line 2, three intermediate data cells are written in the intermediate data buffer. In scan line 4, line 1 and line 11 are deleted from the active list, and lines 3, 5, 7,
For 9, the filled list and the edge list are created, and two intermediate data cells are generated. Further, in scan line 5, lines 3 and 5 from the active list are displayed.
Is deleted, and the filled list for lines 7 and 9,
An edge list is created and one intermediate data cell is created. These generated intermediate data cells are written to the intermediate data buffer. In FIG. 18, each intermediate data cell has a format according to the format used in FIG.
Corresponding to (D), T: 0 to 3 are shown.

When the scan line 5 is processed and the scan line 6 is processed, the active list becomes empty and there is no additional display list. At this time, the vector drawing unit 3 sends an end command to the intermediate data generating unit 5. Then, the intermediate data generation unit 5 causes the variable NU
For the band in which M is not 0, the value of the variable NUM is set in the area of the number of intermediate data cells secured in the intermediate data,
Write a flag that indicates whether it is a constant color image or a raster image. In FIG. 18, the number of intermediate data cells is 10
Is stored, and “Graphic” is stored as a flag. This completes the process for one drawing object. Band 0 of the intermediate data buffer 6 in the final state is shown in FIG.

As described above, in this specific example, since the drawing process is performed in units of scan lines, the probability that the relative distance to the previously processed data can be naturally represented by a small value is high. Taking advantage of that feature, the format of the intermediate data cell is a variable length format of 8, 16, 32, and 48 bits as shown in FIG. As a result, the intermediate data created during the drawing process is naturally represented by a small data length.

Since vector data is often filled with the same color, it is only necessary to insert one color data for each drawing object, and this also reduces the data. Only by using such an intermediate data format, 27 bytes are sufficient as shown in FIG. 18 even in this specific example. When the conventional edge list is held as it is, 16 bytes (edge list cell) x 10 = 160 bytes, and if the bitmap has only the smallest bounding box, 5 (vertical) x 7 (horizontal) x 4 (color) = 1
40 bytes are also required. Also, this format is
Since the run length can be reproduced by simple bit operation and addition, the calculation time is short and the memory access time can be reduced by the amount of data reduction. Since the CPU operation time can be much faster than the memory access time, this reduction in memory access time usually enables the run length to be reproduced faster than reproducing the run length from data such as an edge list. You can

FIG. 19 is a block diagram showing a second embodiment of the drawing apparatus of the present invention. In the figure, the same parts as those in FIG. Reference numeral 11 is a binary memory. In the second embodiment, an example of performing halftone processing is shown. The expansion output control unit 7 reads the intermediate data stored in the intermediate data buffer 6, expands it into bitmap data, and writes it into the band buffer 8 or 9. At this time, in the case of a drawing primitive such as vector data or character data that is filled with a single color, half-tone processed bitmap data is generated while using the binarization memory 11. The binary memory 11 stores binary data generated from a halftone matrix corresponding to a color value.

FIG. 20 is an explanatory diagram of an example of the halftone matrix, and FIG. 21 is an explanatory diagram of binary data stored in the binarizing memory. The halftone matrix is
The threshold value of the color value is stored for each dot. For example, in the upper left dot in the 4 × 4 halftone matrix shown in FIG. 20, the color value is 72.
If it is above, dots are formed, and if it is below, dots are not formed. In addition, in FIG. 20, the color value is assumed to be a value of 0 to 255. Binarization is performed with such a threshold value, and 1 is set when dots are formed, and 0 is set when dots are not formed. By making the threshold value of each dot of the halftone matrix different, it is possible to make the dots slightly different depending on the color value, and thereby, the halftone can be expressed. For example, if the color value is 50, only the central 3 dots having a threshold value of 50 or less will be formed. That is, the binary pattern as shown in FIG. Similarly, the binary patterns for color values of 150, 200, and 250 are as shown in FIG.
As shown in (C) and (D).

In FIG. 21, two 4 × 4 patterns are shown in succession. As a result, the number of dots in the horizontal direction is 8
And If each dot is represented by 1 bit, 8 dots in the horizontal direction
Dots can be expressed in 1 Byte, for example,
Each binary pattern shown in FIG. 21 can be represented by 4 bytes. By thus creating the binary data according to the byte length or the word length of the CPU, the halftone processing can be speeded up.

Although binary data for four color values is shown in FIG. 21 as a typical example, data of such a binary pattern is actually used for color values 0, 1, 2 ,.・
.., 255 can be stored in the binarized memory 11 in association with each other.

FIG. 22 is a flow chart showing an example of halftone processing in the second embodiment of the drawing apparatus of the invention. Here, x and y are the absolute coordinates of the drawing start point, run is the run length, color is the color, sw and s
b is the word position of the drawing start point and the bit position within the word,
ew and eb represent the word position at the drawing end point and the bit position within the word, and CW represents the number of bits within one word. Also, b
Reference numeral b is a band buffer, and the dot position at the position (i, j) is indicated by bb [i] [j]. bp is a variable that holds one row (one byte) of binary data in the binary memory 11. msk [s] [e] is data for extracting data from the sth bit to the eth bit in one word and masking other bits. When one word has 8 bits, 0 ≦ s ≦ e ≦ 7. For example, msk [2] [6] is data “00111110”.

First, in S21, it is determined whether or not the intermediate data to be expanded into the bitmap data has ended.
If the intermediate data has ended, 2 of the band being processed
When the digitization process is completed and the band is the first band, the output device 1
0 is started and the process for the next band is started.

At S22, the intermediate data is read out,
One of the intermediate data cells is taken out. If the intermediate data cell has the format shown in FIG. 4D, the absolute coordinates x and y are taken out as they are, and if the intermediate data cell has another format, the absolute coordinates x and y are calculated from the relative coordinates DX and DY. In addition, the color information stored in the intermediate data
Take out as lor.

At S23, the binary data is retrieved from the binary memory 11. At this time, first, which of the binary patterns shown in FIG. 21 is used is determined by the value of color, and which line of the determined binary pattern is used is determined by the value of the absolute coordinate y. For example,
As shown in FIG. 21, in a set of binary patterns with four rows, it is possible to determine which row of the binary pattern is used by taking the remainder of 4 of the absolute coordinate y. The data for one row of the binary pattern used is stored in the variable bp.

In S24, the word position sw at the drawing start point and the bit position sb in the word, and the word position ew at the drawing end point and the bit position eb in the word are obtained. That is, if "%" is an operator that takes the remainder of division, it can be calculated by sb = x% CW eb = (run + x)% CW sw = x / CW ew = (run + x) / CW.

In S25, the word position sw at the drawing start point is compared with the word position ew at the drawing end point. sw =
In the case of ew, since the drawing start point and the end point exist in the same word, in S26, the drawing end point from the bit position sb of the drawing start point in the binary pattern of 1 Byte stored in the variable bp. The bit pattern up to the bit position eb of is extracted, and the bit pattern is written as it is in the band buffer. Writing to the band buffer is performed by taking the logical sum of the data written to the band buffer up to that point. The position of the band buffer to be written is specified by the absolute coordinate y and the word position sw of the drawing start point.

If the word position sw at the drawing start point is smaller than the word position ew at the drawing end point, that is, if the drawing start point and the drawing end point belong to different words, the process proceeds to S27. In S27, first, a binary pattern is written from the bit position sb at the drawing start point to the end of the word. In S29, a binary pattern is written from the beginning of the word including the drawing end point to the bit position eb of the drawing end point. In S28, the binary pattern is written in a word existing between the word including the drawing start point and the word including the drawing end point. Writing the binary pattern bp to the band buffer bb is almost the same as in S26. S27
Then, in the binary pattern bp, the bit position sb to the word end CW-1 is masked, and the logical sum with the band buffer bb [y] [sw] is calculated. Further, in S28, the binary pattern bp and the band buffer bb
The logical sum of [y] and [sw + i] is calculated. Where i =
sw + 1 to ew-1. Further, in S29, in the binary pattern bp, from the beginning of the word to the bit position eb
Are masked, and the logical sum with the band buffers bb [y] [ew] is calculated. Then, the process returns to S21 and the process for the next intermediate data cell is performed.

As described above, the halftone processing of the present invention is performed by directly writing the necessary portion of the binary data stored in the binary memory 11 to the band buffer. Therefore, it is possible to perform the development to bitmap data and halftone processing at the same time,
Very fast development and halftone processing is possible. Further, the processing speed can be further improved by setting the data length of the binary data to a unit that can be easily handled by the CPU.

As the band buffer for writing the binary data, the band buffer 8 and the band buffer 9 are alternately used. Then, after writing to one of the band buffers, when reading of the other band buffer by the output device 10 is completed, writing to the other band buffer is started. When the output device 10 is activated from the expansion output unit 9, the output device 10 starts reading from one band buffer, reads the bitmap data while switching to the other band buffer alternately, and performs a printing process.

FIG. 23 is an explanatory diagram of an example of a specific drawn image for explaining an example of the halftone process. An example of the above-described operation will be described by taking the case of drawing the image shown in FIG. 23 as an example. In FIG. 23, there are a rectangle drawn with a color value of 50, a triangle drawn with a color value of 150, and a line segment (thin rectangle) drawn with a color value of 250. The intermediate data buffer 6 stores intermediate data for drawing these figures. Based on this intermediate data
The process of expanding the bitmap while performing the halftone process is performed by the scan line 550 (absolute coordinate y = 55).
0) will be described. It is assumed that at least the binarized data shown in FIG. 21 is stored in the binarized memory 11. The number of rows of binarized data in this case is four. In addition, one word has 8 bits, and the color value ranges from 0 to 255. Further, it is assumed that the band buffer stores the data up to the scan line 549 that has already been processed and that the scan line 550 and the subsequent lines to be processed are cleared by 0.

First, in S22, the intermediate data is read and one of the intermediate data cells is taken out. In this example, 50 is stored as the color value in the intermediate data. In addition, although a large number of intermediate data cells are arranged side by side, the one corresponding to the scan line 550 is taken out from among them. From this intermediate data cell, the run length 243 and the relative coordinates DY = 1 and DX = -242 are extracted. From these values, absolute coordinates x = 10, y = 55
0 is calculated.

Next, in S23, the binarized data is extracted. The offset of the scan line 550 in the height direction (y coordinate) with respect to the halftone matrix is obtained by yoffset = (scan line) Mod (halftone matrix height) = 550% 4 = 2. Further, since the color value is 50, the pattern “01100110” on the third row of the binary data or the data shown in FIG. 21A is extracted as the variable bp.

In S24, the word coordinates sw and ew and the bit coordinates sb and eb at the drawing start point and the end point are calculated. Since the x coordinate (start coordinate) of the drawing start point is 10 and the run length is 243, sw = start coordinate / word length (width of bp) = 10/8
= 1 sb = start coordinate% word length (bp width) = 10% 8
= 2 ew = (start coordinate + run length-1) / word length (width of bp) = 252/8 = 31 eb = (start coordinate + run length-1)% word length (width of bp) = 252% 8 = 4 is calculated.

Comparing sw and ew in S25,
Since ew> sw, 2 in S27 to S29 in this case.
Write value or data. In the writing process, writing is performed by a logical sum with new binarized data so as not to erase the part that has been previously written. For example, in word 1, binary data may be written to 0 to 1 bit when drawing is performed in an area such as sx = 1 and ex = 9 before this processing. . Word 1 in this state
When writing to, the logical sum is written before writing back so that the previously written binary data is not erased. In this specific example, the same word is never written in duplicate.

In S27, the writing process for the word sw (= 1) is performed. First, the binarized data bp and msk
The logical product of [2] and [7] (= 00111111) is calculated.
As a result, 2 to 7 bits of the binarized data bp are valid. In this case, "00100110" is obtained. The logical sum of this data and the data of bb [550] [1] is taken and written to bb [550] [1].

Next, in S28, from word 2 to word 30 (bb [550] [2] to bb [550] [3
0]) is simply ORed with bp and written back.

In S29, the last word 31 is 2
Quantized data bp and msk [0] [4] (= 111110
00) is calculated and "01100000" is obtained. The logical sum of this data and the data of bb [550] [31] is calculated and written back to bb [550] [31]. In this way, the processing on the rectangular scan line 550 with the color value of 50 is completed. Then, the process for the next intermediate data cell is performed.

Next, the processing for the scan line 550 in the triangle whose color value is 150 will be described. In this case, the color value 150 is obtained from the intermediate data in S22. Also, the relative coordinates and run length are obtained from the intermediate data cell. In this case, the absolute coordinates obtained from the relative coordinates are y = 550 and x = 323. The run length run is 13.

In S23, the pattern "01100110" on the third line is extracted from the binarized data when the color value shown in FIG. 21B is 150 and stored in the variable bp. The word position and bit position at the drawing start point and end point in S24 are sw = 40, sb = 3, ew = 4.
1 and eb = 7. Here, since ew> sw,
In this case, the word 40 is the first process, the word 41 is the last process, and the intermediate process is eliminated. Therefore, in S27, bp and msk [3] [7] (= 0001111
1) and the logical product and get "00000110",
After taking the logical sum of this and bb [550] [40],
Write back. In S28, nothing is done, and in S29, bp
And msk [0] [7] (= 11111111) are ANDed, and the logical product of this and bb [550] [41] is taken and written back.

Next, a vertical line (thin rectangle) having a color value of 250
The process for the scan line 550 in FIG. In this case, in S22, the color value 2 is calculated from the intermediate data.
Get 50. Also, absolute coordinates y = 550 and x = 509 are obtained from the relative coordinates obtained from the intermediate data cell. The run length run is 2. The binarized data retrieved from the binarized memory 11 in this case is as shown in FIG.
Data “111111” on the third line of the pattern shown in (D)
10 ". The word position and bit position at the drawing start point and the end point are sw = 63, sb = 5, ew = 6.
3, eb = 6. Here, since sw and ew are equal, one word includes the beginning and the end. In this case, in S26, bp and msk [5] [6] (= 0000011)
0) is ANDed to obtain "00000110",
Calculate the logical sum of it and bb [550] [63],
Write to bb [550] [63].

Since 0 is written in the word which has not been written in the initial setting, it is not necessary to write it again.

In the structure using the binarization memory 11 as in the second embodiment, of course, an extra memory amount is required for the binarization memory. However, binary memory 1
The memory size of 1 is an 8 × 8 halftone matrix, the word length of the CPU is 32 bits, and 32 × 8 × 256 × 4 bits / in a matrix of four colors.
8bit = 32KByte is enough. Since the amount of this memory is about 1/1000 in view of the capacity of the frame buffer, the increase in memory capacity does not pose a problem. On the contrary, the halftone processing and the expansion processing can be speeded up by only slightly increasing the memory amount, and the effect of the entire apparatus is great.

In the second embodiment, in the above description, the intermediate data buffer is assumed to store the intermediate data described in the first embodiment as an example.
With such a configuration, the data amount of the intermediate data can be significantly reduced, so that even if the binarized memory consumes a certain amount of memory, it is possible to reduce the memory amount more than that, and at a high speed. Halftone processing can be realized.

However, the halftone processing and the expansion processing in the second embodiment can be applied not only to such intermediate data, but are described in, for example, the above-mentioned Japanese Patent Laid-Open No. 5-224637. Even when such an edge list is used as intermediate data, the same effect can be obtained. For example, since the coordinates of the edge are passed for each scan line in the edge list, in the example shown in FIG. 23, the coordinates of the drawing start point and the end point of the line of the three figures are obtained in the scan line 550. By processing these sequentially,
It is possible to realize halftone processing and development processing using binarized data.

[0110]

As is apparent from the above description, according to the present invention, since the intermediate data is created by using the difference between the coordinates of two runs, the data amount of the intermediate data can be reduced. , It is possible to reduce the amount of memory required to store the intermediate data. In particular, for an image in which fonts and graphic drawings are mainly drawn such as PDL, the memory capacity can be significantly reduced as the resolution becomes higher. Further, since the memory access time is shortened, bit matting can be performed at a higher speed than in the past, and high-speed drawing processing can be realized.

Further, binarized data expanded for each color value is prepared in advance, and the binarized data is specified from the intermediate data and used as it is as bitmap data to output it to a binary device. It is possible to perform the halftone processing for high speed at high speed.

Further, the adoption of such intermediate data,
By adopting the halftone processing using the binarized data, there is an effect that the memory capacity can be greatly reduced, an image without omission can be output, and high-speed drawing processing can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of a drawing apparatus of the present invention.

FIG. 2 is an explanatory diagram of an example of an edge list generated by a raster rendering unit.

FIG. 3 is an explanatory diagram of an example of an edge list generated by a vector drawing unit.

FIG. 4 is an explanatory diagram of an example of an intermediate data format used when generating an intermediate data cell in the intermediate data generation unit, and FIG. 5 is an explanatory diagram of an example of generation of an intermediate data cell in the intermediate data generation unit.

FIG. 5 is an explanatory diagram of an example of generation of intermediate data cells in the intermediate data generation unit.

FIG. 6 is an explanatory diagram of an example of a format of intermediate data.

FIG. 7 is an explanatory diagram of a specific example of intermediate data.

FIG. 8 is an explanatory diagram of a specific example of a graphic to be drawn.

9 is an explanatory diagram of an example of a drawing command for drawing the figure shown in FIG.

FIG. 10 is an explanatory diagram of an example of a display list.

FIG. 11 is an explanatory diagram of an example of an active list at the time of processing scan line 1.

FIG. 12 is an explanatory diagram of an example of a filling list during scan line 1 processing.

FIG. 13 is an explanatory diagram of an example of an edge list of scan line 1.

FIG. 14 is an explanatory diagram showing an example of an intermediate data buffer during scan line 1 processing.

FIG. 15 is an explanatory diagram of an example of an active list during scan line 2 processing.

16 is an explanatory diagram of an example of an edge list of scan line 2. FIG.

FIG. 17 is an explanatory diagram showing an example of an intermediate data buffer during scan line 2 processing.

FIG. 18 is an explanatory diagram showing an example of an intermediate data buffer after completion of all scan line processing.

FIG. 19 is a block diagram showing a second embodiment of the drawing apparatus of the invention.

FIG. 20 is an explanatory diagram of an example of a halftone matrix.

FIG. 21 is an explanatory diagram of binary data stored in the binary memory.

FIG. 22 is a flowchart showing an example of halftone processing in the second embodiment of the drawing apparatus of the invention.

FIG. 23 is an explanatory diagram of an example of a specific drawn image for explaining an example of halftone processing.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Input control part, 2 ... Raster drawing part, 3 ... Vector drawing part, 4 ... Character drawing part, 5 ... Intermediate data generation part, 6 ... Intermediate data buffer, 7 ... Expansion output control part, 8, 9 ... Band buffer 10 ... Output device, 11 ... Binary memory.

Claims (6)

[Claims] 1. A drawing apparatus that receives a drawing command representing a drawing primitive, generates bitmap data according to the drawing command, and outputs the bitmap data, and the existence of the drawing primitive corresponding to the color information of the drawing command. Drawing processing means for extracting the run and its end coordinates for each scanning line, intermediate data storage means for storing intermediate data, and difference between the end coordinates of two consecutive runs extracted by the drawing processing means. One of a plurality of types of intermediate data formats having different data lengths is calculated based on the calculation result, and the intermediate is selected based on the selected intermediate data format, the difference between the end coordinates, and the run extracted by the drawing processing means. A plurality of intermediate data cells generated for each of the drawing commands are extracted by the drawing processing means. Intermediate data generation means for storing the intermediate data together with the color information as intermediate data in the intermediate data storage means; and expansion means for expanding the intermediate data stored in the intermediate data storage means into the bitmap data based on the intermediate data. A drawing device. 2. The intermediate data generating means determines an address to write the intermediate data cell into the intermediate data storage means based on the data length of the selected format, and the expanding means determines the format of the intermediate data cell. 2. The drawing apparatus according to claim 1, wherein the read start address and the read range of the intermediate data cell from the intermediate data storage unit are determined based on the data length. 3. A drawing device that receives a drawing command representing a drawing primitive, generates bitmap data according to the drawing command, and outputs the bitmap data, and the existence of the drawing primitive corresponding to the color information of the drawing command. Drawing processing means for extracting the run and its end coordinates for each scanning line, intermediate data storage means for storing intermediate data, and managing the area of the bitmap data for each band in units of a plurality of scanning lines. The difference between the end coordinates of two consecutive runs extracted by the drawing processing means is calculated, one of a plurality of types of intermediate data formats having different data lengths is selected based on the calculation result, and the selected intermediate data format and the intermediate data format are selected. An intermediate data cell is generated and continuous based on the difference between the end coordinates and the run extracted by the drawing processing means. Intermediate data generating means for storing a plurality of intermediate data cells generated together with the color information extracted by the drawing processing means as intermediate data in the intermediate data storing means each time the bands in which two runs exist are different, A drawing device having a developing means for expanding the bitmap data for each band based on the intermediate data stored in the intermediate data storage means. 4. A drawing device that receives a drawing command representing a drawing primitive, generates bitmap data according to the drawing command, and outputs the bitmap data, and the existence of the drawing primitive corresponding to the color information of the drawing command. Intermediate data generating means for generating intermediate data on the basis of the run length for each scanning line and its end coordinates, intermediate data storing means for storing the intermediate data generated by the intermediate data generating means, and the color information. Halftone matrix storage means for storing a halftone matrix, which is a matrix of binary data of a predetermined size, which represents a halftone associated with the value of, and a bit map of the intermediate data stored in the intermediate data storage means. The halftone matrix storage unit based on the value of the color information included in the intermediate data when the data is expanded. Select one of the halftone matrices stored in the columns and select a bit in the binary data of a part of the halftone matrix selected based on the length and end coordinates of the run included in the halftone data. A drawing device having a developing means for expanding to map data. 5. The drawing apparatus according to claim 4, wherein the halftone matrix stored in the halftone matrix storage means has a length of a word length of the CPU in a scanning line direction of an image. 6. A drawing device that receives a drawing command representing a drawing primitive, generates bitmap data according to the drawing command, and outputs the bitmap data, and the existence of the drawing primitive corresponding to the color information of the drawing command. Drawing processing means for extracting the run and its end coordinates for each scanning line, intermediate data storage means for storing intermediate data, and difference between the end coordinates of two consecutive runs extracted by the drawing processing means. One of a plurality of types of intermediate data formats having different data lengths is calculated based on the calculation result, the selected intermediate data format, the difference between the end coordinates, the run and the color information extracted by the drawing processing means. Intermediate data generating means for generating intermediate data on the basis of the color information, and storing the intermediate data in the intermediate data storage means; Halftone matrix storage means for storing a halftone matrix, which is a matrix of binary data of a predetermined size, which represents a halftone associated with the report value,
Of the halftone matrix stored in the halftone matrix storage means based on the value of the color information included in the intermediate data when the intermediate data stored in the intermediate data storage means is expanded into bitmap data. And a rasterizing means for rasterizing the binary data of a part of the halftone matrix selected based on the length and the end coordinates of the run included in the intermediate data. A drawing device.