JP6155604B2 - Image processing apparatus and image processing method - Google Patents

Description

  The present invention relates to an image processing apparatus and an image processing method suitable for image formation on a print medium.

  Conventionally, in page printers and the like, there has been a demand for higher printing resolution and higher printing speed, but the CPU (Central Processing Unit) that controls the operation of the printer alone can meet these requirements. It has become difficult to meet. In particular, in a color printer, in addition to various types of image processing, more processing such as drawing processing of C, M, Y, and K color images, color conversion processing, and brush composition processing is required.

  Here, the flow of processing in the printer according to the prior art will be schematically described. For example, PDL (Page Description Language) data created by a personal computer or the like is transferred to a printer via a predetermined interface such as a network or a cable. The printer analyzes the transferred PDL data and creates an intermediate language that can be executed by the drawing unit of the printer. The drawing unit analyzes the created intermediate language to generate image data, and performs gradation processing on the generated image data to obtain binary image data. The binarized image data is drawn on the band memory and written to the band memory. Image drawing is performed for each color of C, M, Y, and K.

  The printer encodes the image data of each color drawn in the band memory by a binary image compression algorithm such as JBIG (Joint Bi-level Image Coding Expert Group), and writes the generated codes to the memory. When printing, the printer reads the code from the memory with a delay for each of the C, M, Y, and K plates, decodes the code, and transfers the decoded data to the printer engine corresponding to each of the C, M, Y, and K plates. To print.

  On the other hand, there is a brush composition process as one of image processes related to drawing in a printer. The brush composition process is a process for creating and drawing a desired color using, for example, R, G, and B colors. Conventionally, the first color illustrated in FIG. 18B and the example illustrated in FIG. 18C are illustrated for the values “1” and “0” of the binary brush pattern illustrated in FIG. There is known a brush composition processing method in which a brush pattern is drawn by applying the second color and switching between the first color and the second color.

  In Patent Document 1, when 3D graphics drawing is performed, when drawing in order from the polygon positioned in front, the actual polygon is stored in the frame memory while drawing a value (mask value) in a flag RAM (mask buffer). A technique for drawing is disclosed. The above-described brush composition processing can be realized by using the technique of Patent Document 1.

  In the method disclosed in Patent Document 1, if the bit read from the mask buffer is “1”, the hidden surface processing of the polygon is performed without drawing the pixel. However, when the method of Patent Document 1 is applied to brush composition processing in a printer and the mask buffer is configured at 1200 dpi, which is a general resolution of the printer, a large capacity is required for the memory used as the mask buffer. Therefore, in the method disclosed in Patent Document 1, it is conceivable to have a memory used as a mask buffer outside. In this case, it is necessary to access the memory of the mask buffer separately from the memory for drawing, and there is a problem that high speed cannot be expected.

  The present invention has been made in view of the above, and an object of the present invention is to enable brush composition processing to be executed at a higher speed with a smaller memory capacity.

In order to solve the above-described problems and achieve the object, the present invention provides a generation unit that generates a drawing pattern and a brush pattern to be combined with the drawing pattern in units of lines, and the drawing pattern is a line. A first storage unit that is written in units, and a plurality of third storage units that can store bits corresponding to the positions of the lines for the number of divided lines obtained by dividing the maximum number of lines stored in the first storage unit, A second storage unit comprising: a selection unit that selects, from a plurality of third storage units, a third storage unit including a bit at a position corresponding to a line to be synthesized by the brush pattern generated by the generation unit; and a brush The drawing pattern is written on the line for combining the pattern and the drawing pattern read from the first storage unit and the brush pattern generated by the generation unit to the first storage unit. Whether rare, and a third of the bits stored in the storage unit, determining unit based on the bit value at a position corresponding to the line to be synthesized which is selected by the selection unit, synthesized When the determination unit determines that the drawing pattern is not written in the line to be combined in the first storage unit, the unit does not read the drawing pattern from the first storage unit.

  According to the present invention, there is an effect that the brush composition processing can be executed at a higher speed with a smaller memory capacity.

FIG. 1 is a block diagram illustrating a configuration of an example of an image forming apparatus according to an embodiment. FIG. 2 is a diagram for explaining an overview of processing according to the embodiment. FIG. 3 is a diagram for explaining an overview of processing according to the embodiment. FIG. 4 is a diagram schematically illustrating an example of an intermediate language according to the embodiment. FIG. 5 is a diagram illustrating an example of a command in an intermediate language according to the embodiment. FIG. 6 is a block diagram illustrating a configuration of an example of a drawing unit according to the embodiment. FIG. 7 is a block diagram illustrating a configuration of an example of a photographic image drawing unit according to the embodiment. FIG. 8 is a block diagram illustrating a configuration example of the CMYK graphics drawing unit according to the embodiment. FIG. 9 is a block diagram illustrating a configuration of an example of the brush composition processing unit according to the embodiment. FIG. 10 is a diagram for schematically explaining the brush composition processing according to the embodiment. FIG. 11 is a block diagram illustrating a configuration of an example of a brush synthesis processing circuit for realizing the brush synthesis processing according to the embodiment. FIG. 12 is a block diagram illustrating a configuration of an example of a vertical line memory according to the embodiment. FIG. 13 is a diagram illustrating an example of a bit pattern generated by the bit pattern generation unit according to the embodiment. FIG. 14 is a flowchart illustrating an example of processing performed by the brush composition processing unit according to the embodiment. FIG. 15 is a diagram illustrating an example of a background image. FIG. 16 is a diagram for explaining that a large delay occurs in the read process in the read modify write process. FIG. 17 is a diagram for explaining that a large delay does not occur in the writing process. FIG. 18 is a diagram for explaining an example of the brush composition process.

(Configuration applicable to the embodiment)
Hereinafter, embodiments of an image processing apparatus, an image processing method, and an image forming apparatus will be described in detail with reference to the accompanying drawings. FIG. 1 is a block diagram illustrating an exemplary configuration of an image forming apparatus 1 according to the embodiment. In the image forming apparatus 1, a CPU (Central Processing Unit) 10 is connected via a CPU I / F 11 to a bus 13 (hereinafter referred to as an AXI bus 13) according to an AXI (Advanced eXtensible Interface) bus. A ROM (Read Only Memory) 22 and a panel controller 23 are connected via the local I / F 21.

  The AXI bus 13 is connected to the main memory 14 via the memory controller 25. At the same time, the drawing unit 15, the encoding unit 16, the decoding unit 17, and the communication controller 20 are connected to the AXI bus 13. The output of the decoding unit 17 is connected to an engine controller 18 that controls the printer engine 19.

  The AXI bus 13 controls data transfer between the connected units. The CPU I / F 11 is an interface between the CPU 10 and the AXI bus 13, and the CPU 10 is connected to each part of the image forming apparatus 1 via the CPU I / F 11 and the AXI bus 13. The panel controller 23 is connected to a panel 24 provided with an operator and a display unit for performing user operations.

  The ROM 22 stores font information such as various programs and characters in advance. The CPU 10 controls the operation of the image forming apparatus 1 using a RAM (Random Access Memory) (not shown) as a work memory according to a program stored in advance in the ROM 22. The CPU 10 can also use the main memory 14 as a work memory. Further, the CPU 10 issues a command for controlling the printer engine 19 to the engine controller 18. The communication controller 20 controls communication with an external device such as a personal computer (PC) connected via a network.

  Control of access to the main memory 14 via the AXI bus 13 is performed by the memory controller 25. The main memory 14 includes, for example, a program area, a PDL data area, an intermediate language storage memory area, a band memory area, a CMYK page code data area, and other areas.

  The program area stores a program for the CPU 10 to operate. In the PDL data area, for example, PDL (Page Description Language) data transferred from a personal computer via the communication controller 20 is stored. The intermediate language storage memory area stores an intermediate language generated by the CPU 10 based on the PDL data. In the band memory area, band image data of C, M, Y, and K color plates according to a drawing pattern drawn on the CPU 10 based on the PDL data is stored. The CMYK band code data area stores encoded band image data (referred to as band code data) of each version of CMYK. The other area is an area for storing data other than those described above, and can be used as a work memory when the CPU 10 executes a program, for example.

  The drawing unit 15 reads and analyzes the intermediate language generated by the CPU 10 based on the PDL data, draws a drawing pattern according to the analysis result, and writes band image data based on the drawing pattern in the band storage area of the main memory 14 Process. The drawing unit 15 generates a brush pattern according to the analysis result of the intermediate language, and performs brush processing on the band image written in the band storage area of the main memory 14 using the brush pattern.

  The band image drawn by the drawing unit 15 is read from the main memory 14 and subjected to encoding and decoding processing by the encoding unit 16 and the decoding unit 17 via the AXI bus 13. Supplied. The engine controller 18 controls the printer engine 19 according to the supplied band image, whereby an image is formed on the print medium and printing is performed.

  In such a configuration, for example, PDL data generated by a personal computer is received by the communication controller 20 via the network and stored in the PDL data area of the main memory 14. The CPU 10 reads and analyzes the PDL data from the PDL data area of the main memory 14, generates an intermediate language based on the analysis result, and stores it in the main memory 14. The drawing unit 15 performs drawing processing of a drawing pattern in accordance with the intermediate language read from the main memory 14 and generates band image data for each version of CMYK. The generated band image data of each version of CMYK is written in the band memory area of the main memory 14. The drawing unit 15 further generates a brush pattern as necessary, reads out band image data from the band memory area, performs brush synthesis processing using the brush pattern, and converts the band image data based on the brush-processed pattern into the main memory 14. Write back to the original address in the band memory area.

  The encoding unit 16 compresses the band image data of each version of CMYK read from the band memory area of the main memory 14 using a compression encoding method using MTF (Move To Front) control and Huffman encoding. The process is applied. Code data obtained by compression-coding band image data is stored in the CMYK page code data area of the main memory 14. The decoding unit 17 decodes the CMYK version code data read from the CMYK page code data area of the main memory 14, outputs the CMYK version image data, and sends the image data to the engine controller 18. The engine controller 18 controls the printer engine 19 in accordance with the CMYK version image data received from the decoding unit 17 to perform printout.

(Outline of processing according to the embodiment)
Next, an outline of processing according to the embodiment will be described with reference to FIGS. 2 and 3. 2 and 3, the band memory 50 corresponds to the band memory area of the main memory 14 described above, and is a memory in which a drawing pattern is generated by drawing processing based on the analysis result of PDL data and written as image data. In the embodiment, as illustrated in FIG. 2 and FIG. 3, brush composition processing for a drawing pattern is performed using a band memory 50 and a vertical line memory 51 included in the drawing unit 15.

  As shown in FIG. 2A, in the band memory 50, the coordinates in the X-axis direction are in units of pixels, and the bandwidth is defined according to the maximum number of pixels stored in the X-axis direction. The coordinates in the Y-axis direction are in line units, and the band height is defined according to the maximum number of lines stored in the Y-axis direction. In the example of FIG. 2A, the upper left corner of the area of the band memory 50 is the origin of coordinates in the X-axis direction and the Y-axis direction. The Y coordinate or line address increases from the top to the bottom of the figure, and the X coordinate or pixel address increases from the left to the right of the figure. As an example, a rectangular drawing pattern drawn in the band memory 50 has a region indicated by the X and Y coordinates of the upper left corner and the X and Y coordinates of the lower right corner of the rectangle.

  The vertical line memory 51 is a memory that holds 1-bit information for each Y coordinate corresponding to each line of the band memory 50 in the Y-axis direction. In the vertical line memory 51, the Y coordinate corresponding to the first line of the band memory 50 is set as the origin, and the value of the Y coordinate increases corresponding to the line of the band memory 50 from the top to the bottom of the figure. To do. That is, the value of the Y coordinate of the vertical line memory 51 corresponds to the address of the vertical line memory 51. In the vertical line memory 51, the value of the bit of the coordinate corresponding to the line in which the image data based on the drawing pattern is written in the band memory 50 is, for example, “1”, and corresponds to the line where the image data based on the drawing pattern is not written. The value of the coordinate bit is, for example, “0”.

  When the image data based on the drawing pattern is not written in the band memory 50 (initial state), as illustrated in FIG. 2B, the bit values of the respective addresses of the vertical line memory 51 are all “0”. . On the other hand, in the example of FIG. 2A, since image data of a rectangular drawing pattern is written from the third line to the sixth line, in the vertical line memory 51, the corresponding data in FIG. The bit values at the third to sixth addresses from the top are “1”, and the bit values at other addresses are all “0”.

  In the embodiment, when the brush compositing process is performed, the drawing unit 15 sets the bit value of the address corresponding to the line on which the brush compositing process is performed based on the value corresponding to the line in the vertical line memory 51 for each line to “1”. ”Or“ 0 ”. If the value of the bit is “1”, the image data based on the drawing pattern is written in the line of the band memory 50, and the drawing unit 15 uses the drawing pattern from the line of the band memory 50. The image data is read out and subjected to brush synthesis processing, and the image data of the drawing pattern subjected to the brush synthesis processing is written back to the position of the line in the band memory 50.

  On the other hand, if the bit value of the address corresponding to the line on which brush synthesis processing is performed in the vertical line memory 51 is “0”, the drawing unit 15 may not have written image data based on the drawing pattern on the line. I understand. In this case, the drawing unit 15 does not read out the image data from the band memory 50 and assumes that the value of the drawing pattern of the line is a predetermined value (for example, “0”). I do. In this way, by performing the brush composition process with reference to the contents of the vertical line memory 51, access to the main memory 14 can be reduced, and the process can be speeded up.

  FIG. 3A shows an example when a background image 52 is drawn on the band memory 50. In this example, the background image 52 is written over substantially the entire area of the band memory 50, and the first line and the last line are lines in which the background image 52 is not written. Therefore, also in the vertical line memory 51, the bit value is set to “0” only at the first coordinate and the rear end coordinate corresponding to the first line and the last line, and the bit value is set to “1” at the other coordinates. Yes.

  FIG. 3B shows an example in which a drawing image 53 is drawn on the background image 52. In this case, since the background image 52 has already been written in the band memory 50 for the line on which the drawing image 53 is drawn, all the bit values of the coordinates corresponding to the line in the vertical line memory 51 are “1”. It is said that. Therefore, the drawing unit 15 reads out image data from the line in the band memory 50 in the same manner as the normal drawing process, and performs a changing process to replace the portion corresponding to the drawing image 53 with the image data of the drawing image 53. The changed image data is written back to the original line position of the band memory 50. In this way, the process of changing the data read from the memory and writing it back to the original position in the memory is called read-modify-write.

(Details of processing of embodiment)
Hereinafter, the process according to the embodiment will be described in more detail. FIG. 4 schematically illustrates an example of an intermediate language processed by the drawing unit 15 according to the embodiment. In the example of FIG. 4, the intermediate language includes a band initialization command, a graphics brush setting command, a graphics dither setting command, a rectangle drawing command, a photographic image color conversion parameter setting command, a photographic image dither setting command, a photographic image drawing command, Band end commands are described sequentially. Actually, there are intermediate languages for C, M, Y, and K colors.

  FIG. 5 shows an example of the above-described intermediate language command according to the embodiment. In the example of FIG. 5, each command has a data width of 32 bits. The first 32 bits are used as a command header, followed by each parameter of the command. Each command can be specified for each color of C, M, Y, and K.

  FIG. 5A shows an example of a band initialization command. In the band initialization command, following the command header (band information setting command header), setting parameters for the head address of the band, the band height, and the band width are designated. When receiving the command, the command analysis unit 62 described later with reference to FIG. 6 stores the band head address, the band height, and the width.

  FIG. 5B shows an example of a graphics drawing halftone parameter setting command which is one of the graphics drawing commands for drawing graphics. Following the command header, dither X and Y sizes that specify the size of the dither in the X and Y directions, and a threshold start address are specified. This command sets a halftone threshold for graphics drawing.

  FIG. 5C shows an example of a halftone parameter setting command for drawing a photographic image, which is one of photographic drawing commands for drawing a photographic image. Following the command header, dither X and Y sizes that specify the size of the dither in the X and Y directions, and a threshold start address are specified. This command sets a halftone threshold for drawing a photographic image.

  FIG. 5D shows an example of a color conversion parameter setting command for drawing a photographic image, which is one of photographic drawing commands for drawing a photographic image. Following the command header, a color conversion calculation flag, a grid point start address, and a gamma table start address are designated. With this command, color conversion parameters for drawing a photographic image are set.

  FIG. 5E shows an example of a band end command for instructing the end of drawing of the defined band. This band end command has only a command header. When receiving the command, the command analysis unit 62 described later with reference to FIG. 6 ends the processing of the band.

  FIG. 5F is a graphics drawing brush setting command which is one of the graphics drawing commands for drawing graphics. The brush X and Y sizes for specifying the size of the brush in the X direction and the Y direction, and the brush head address. Is specified. This command designates the brush size and the brush head address at the time of brush composition processing. When receiving the command, the command analysis unit 62 described later with reference to FIG. 6 transfers, for example, the brush size and the brush head address to the CMYK graphics rendering unit 63 described later.

  FIG. 5G shows an example of a graphics drawing quadrilateral drawing command for instructing quadrilateral drawing, which is one of the graphics drawing commands for drawing graphics. Following the command header, a color value is designated, and further, drawing parameters of the X and Y coordinates of the upper left corner and the X and Y coordinates of the lower right corner of the rectangle are designated. Upon receiving this command, the command analysis unit 62 described later in FIG. 6 converts the X and Y coordinates of the upper left corner of the rectangle, the X and Y coordinates of the lower right corner, and the rectangle command name into a horizontal line conversion unit 70 described later in FIG. And draw processing.

  FIG. 5H shows an example of a photographic image drawing scaling execution command which is one of photographic drawing commands for drawing a photographic image. Following the command header, the drawing version, source image X width, DIS image X width, source image Y width, DIS image Y width, drawing X coordinate, drawing Y coordinate, and source image start address are specified. Is done. Upon receiving this command, the command analysis unit 62 described later in FIG. 6 stores each parameter specified in the command in a photographic image scaling parameter storage unit (not shown), and activates a photographic image drawing unit 61 described later.

  FIG. 6 shows an exemplary configuration of the drawing unit 15 according to the embodiment. The drawing unit 15 includes an interface (I / F) 60, a photographic image drawing unit 61, a command analysis unit 62, a CMYK graphics drawing unit 63, a brush composition processing unit 64, and a vertical line memory 51.

  The I / F 60 is an interface between the drawing unit 15 and the memory controller 25, and transmits a memory request requesting reading (reading) and writing (writing) to the main memory 14 to the memory controller 25. When the memory ACK (ACK) corresponding to the memory request is received from the memory controller 25, the I / F 60 transmits a memory address to be read or written to the memory controller 25. The I / F 60 receives read data read from the main memory 14 from the memory controller 25. Further, the I / F 60 transmits write data to be written to the main memory 14 to the memory controller 25.

  The command analysis unit 62 reads the drawing command described with reference to FIG. 5 from the main memory 14 and analyzes it. More specifically, the command analysis unit 62 transmits the address of the intermediate language storage memory area of the main memory 14 to the I / F 60, and the drawing command read from the area of the main memory 14 according to this address is sent to the I / F 60. Receive from F60.

  The command analysis unit 62 analyzes the received drawing command. If the drawing command is a photo drawing command, the command analyzing unit 62 transmits an activation signal to the photo image drawing unit 61 to activate the photo image drawing unit 61 and A switching signal instructing to select data based on the drawing command is transmitted to the brush composition processing unit 64. Then, the command analysis unit 62 transfers the drawing parameters of the photo drawing command to the photo image drawing unit 61.

  On the other hand, if the received drawing command is a graphics drawing command, the command analysis unit 62 sends an activation signal to the CMYK graphics drawing unit 63 to activate the CMYK graphics drawing unit 63 and data based on the graphics drawing command. A switching signal instructing to select is transmitted to the brush composition processing unit 64. Then, the graphics drawing command parameters are transferred to the CMYK graphics drawing unit 63.

  Further, if the received drawing command is a command for instructing brush setting in the graphics drawing command (see FIG. 5F), the command analysis unit 62 turns on the brush on / off signal to instruct to perform brush composition. The state is transmitted to the brush composition processing unit 64.

  The photographic image drawing unit 61 performs a photographic drawing process according to the parameters of the photographic drawing command transferred from the command analysis unit 62, and generates a drawing pattern for drawing in the band memory area of the main memory 14. For example, the photographic image drawing unit 61 transmits the address of the original image (source image) for performing photographic drawing to the main memory 14 via the I / F 60. Source image data read from the main memory 14 according to this address is transmitted from the memory controller 25 and transferred to the photographic image drawing unit 61 via the I / F 60. The photographic image drawing unit 61 performs predetermined image processing on the source image data to generate a drawing pattern, and for example, draws a drawing unit in units of words to be drawn, a drawing address, and the like to the brush composition processing unit 64. The drawing length and the drawing Y coordinate indicating the line to be drawn are transferred. When the drawing by the photo drawing command is completed, the photographic image drawing unit 61 transmits a drawing end signal indicating that to the command analysis unit 62.

  A CMYK (Cyan, Magenta, Yellow, Black) graphics drawing unit 63 performs a graphics drawing process according to the parameters of the graphics drawing command transferred from the command analysis unit 62, and draws a drawing pattern for drawing in the band memory area of the main memory 14. Is generated. The graphics drawing unit 63 transfers, for example, a drawing unit in units of words to be drawn, a brush pattern, a drawing address, a drawing length, and a drawing Y coordinate indicating a drawing line to the brush composition processing unit 64. . When the drawing by the graphics drawing command is completed, the CMYK graphics drawing unit 63 transmits a drawing end signal indicating that to the command analysis unit 62.

  The brush composition processing unit 64 is a part that characterizes the embodiment, and includes a drawing pattern, a drawing address, a drawing length and a drawing Y coordinate received from the photographic image drawing unit 61, a drawing pattern received from the CMKY graphics drawing unit 63, Based on the brush pattern, the drawing address, the drawing length, and the drawing Y coordinate, the brush composition processing is performed.

  More specifically, the brush composition processing unit 64 designates the drawing Y coordinate as an address for performing the brush composition processing in the band memory area of the main memory 14 via the I / F 60, and the image read according to this address. Data is read through the I / F 60. The brush composition processing unit 64 performs brush composition processing on the read image data according to the brush pattern, and the image data subjected to the brush composition processing in the band memory area of the main memory 14 via the I / F 60. Write back to the original address of.

  The brush composition processing unit 64 transfers the drawing Y coordinate to the vertical line memory 51 during the brush composition processing. The vertical line memory 51 transfers the bit value of the address corresponding to the drawing Y coordinate to the brush composition processing unit 64 as a background flag. Based on the background flag, the brush composition processing unit 64 determines whether image data based on the drawing pattern has already been written on the line indicated by the drawing Y coordinate in the band memory area.

  If it is determined that the image data based on the drawing pattern has already been written to the line, the brush composition processing unit 64 reads the image data based on the drawing pattern from the line in the band memory area of the main memory 14 and reads the image data. Brush synthesis processing is performed on the image data based on the drawn pattern. On the other hand, when it is determined that the image data based on the drawing pattern is not written on the line, that is, the writing of the image data is the writing of the image data based on the first drawing pattern on the line, the brush composition processing unit 64 The image data is not read from the band memory area of the main memory 14, and data of a predetermined value (for example, value “0”) is regarded as image data based on the read drawing pattern. Brush composition processing.

  FIG. 7 shows an exemplary configuration of a photographic image drawing unit 61 according to the embodiment. The photographic image drawing unit 61 includes a source image reading unit 80, a color conversion processing unit 81, a line memory 82, a gradation processing unit 83, a drawing pattern generation unit 84, and a controller 85. The controller 85 controls the overall operation of the photographic image drawing unit 61 and activates the photographic image drawing unit 61 in accordance with the activation signal transmitted from the command analysis unit 62.

  The source image reading unit 80 reads source image data from the main memory 14. For example, the source image reading unit 80 transmits, for example, an address on the main memory 14 of the set source image to the memory controller 25 via the I / F 60. The memory controller 25 reads the source image data line by line from the main memory 14 according to this address, and transfers it to the source image reading unit 80 via the I / F 60. The source image reading unit 80 transfers the transferred source image data to the color conversion processing unit 81.

  The color conversion processing unit 81 performs color conversion processing on the source image data according to the set color conversion parameters (see FIG. 5D). The image data obtained by performing the color conversion process on the source image data is temporarily stored in the line memory 82. The gradation processing unit 83 performs gradation processing on the image data stored in the line memory 82 and transfers the image data subjected to the gradation processing to the drawing pattern generation unit 84.

  The drawing pattern generation unit 84 collects the values of the gradation-processed image data into word lengths to form a drawing pattern. At the same time, the drawing pattern generation unit 84 draws the drawn drawing pattern into the band memory area of the main memory 14, the drawing length that specifies the drawing length, and the drawing Y coordinate that specifies the drawing line. And generate The drawing pattern generation unit 84 transfers the generated drawing pattern, drawing address, drawing length, and drawing Y coordinate to the brush composition processing unit 64.

  FIG. 8 illustrates an exemplary configuration of the CMYK graphics drawing unit 63 according to the embodiment. The CMYK graphics drawing unit 63 includes a horizontal line conversion unit 70, a waterside line drawing unit 71, and a controller 72. The controller 72 controls the overall operation of the CMYK graphics rendering unit 63 and activates the CMYK graphics rendering unit 63 in response to the activation signal transmitted from the command analysis unit 62.

  The horizontal line conversion unit 70 receives the graphics drawing command (see FIGS. 5B, 5F, and 5G) from the command analysis unit 62, converts the parameter included in the command into a horizontal line, Transfer to the horizontal line drawing unit 71. The horizontal line is represented by the Y value (Y coordinate) of the horizontal line and the horizontal line start point value and end point value. The horizontal line drawing unit 71 stores a drawing pattern in units of words, a drawing length for designating a drawing length, and a drawing pattern for drawing a horizontal line based on the horizontal line data from the horizontal line conversion unit 70 into the main memory. 14 generates a drawing address for specifying an address for drawing, a drawing Y coordinate for specifying a drawing line, and a brush pattern for specifying brush composition processing. The horizontal line drawing unit 71 transfers the generated drawing pattern, drawing address, drawing length, drawing Y coordinate, and brush pattern to the brush composition processing unit 64.

  FIG. 9 shows an exemplary configuration of the brush composition processing unit 64 according to the embodiment. The brush composition processing unit 64 includes a multiplexer (MUX) 90, a drawing address register 91, a length register 92, a drawing pattern buffer 93, a brush pattern buffer 94, a brush on / off register 95, and a drawing Y coordinate register 96. , A brush composition processing circuit 97, a read drawing pattern buffer 98, a write buffer 99, a read control unit 100, and a write control unit 101.

  The MUX 90 receives a drawing pattern, a drawing address, a drawing length, and a drawing Y coordinate from the photographic image drawing unit 61 and the CMYK graphics drawing unit 63, respectively. Further, a brush pattern is further input from the CMYK graphics drawing unit 63. The MUX 90 selects a drawing pattern, a drawing address, a drawing length, and a drawing Y coordinate input from one of the photographic image drawing unit 61 and the CMYK graphics drawing unit 63 in accordance with the switching signal received from the command analysis unit 62. When the switching signal indicates the CMYK graphics drawing side, the MUX 90 further selects a brush pattern.

  The drawing address register 91, length register 92, drawing pattern buffer 93, brush pattern buffer 94, and drawing Y coordinate register 96 store the drawing address, drawing length, drawing pattern, brush pattern, and drawing Y coordinate selected by the MUX 90, respectively. To do. The brush on / off register 95 stores the brush on / off signal input from the command analysis unit 62.

  Both the drawing address and the drawing length stored in the drawing address register 91 and the length register 92 are transferred to the read control unit 100 and the write control unit 101, respectively. Both the drawing pattern and the brush pattern stored in the drawing pattern buffer 93 and the brush pattern buffer 94 are transferred to the brush composition processing circuit 97. Further, the brush on / off signal stored in the brush on / off register 95 is also transferred to the brush synthesis processing circuit 97.

  The drawing Y coordinate stored in the drawing Y coordinate register 96 is transferred to the vertical line memory 51. The vertical line memory 51 outputs the background flag to the brush composition processing circuit 97 and the read control unit 100.

  The read control unit 100 reads (reads) image data from the band memory area of the main memory 14, and the drawing address and drawing length transferred from the drawing address register 91 and the length register 92 are transmitted via the I / F 60. It transmits to the memory controller 25. Further, the read control unit 100 receives the drawing pattern read from the band memory area of the main memory 14 by the memory controller 25 via the I / F 60 and transfers it to the brush synthesis processing circuit 97 via the lead drawing pattern buffer 98. To do. Hereinafter, the drawing pattern read by the read control unit 100 from the band memory area of the main memory 14 is referred to as a lead drawing pattern.

  Here, the read control unit 100 controls whether to read image data from the band memory area of the main memory 14 in accordance with the background flag output for each line from the vertical line memory 51. For example, when processing the m-th line, a background flag corresponding to the m-th line is input from the vertical line memory 51 to the read control unit 100. The read control unit 100 indicates that the input background flag value indicates that image data has not been written in the band memory area of the main memory 14 in accordance with the drawing pattern on the m-th line (for example, value “0”). If so, control is performed so that the image data is not read from the main memory 14. On the other hand, if the value of the background flag is a value (for example, a value “1”) indicating that image data is written by a drawing pattern on the m-th line in the band memory area, the main memory 14 reads the value as usual. The image data is read out.

  The write control unit 101 writes (writes) image data to the band memory area of the main memory 14 and stores the drawing address and drawing length transferred from the drawing address register 91 and the length register 92 in the write buffer 99. The drawing pattern is transmitted to the memory controller 25 via the I / F 60. Hereinafter, the drawing pattern transferred to the light control unit 101 is referred to as a light drawing pattern.

  The brush composition processing circuit 97 reads a drawing pattern from the lead drawing pattern buffer 98 and also reads a drawing pattern and a brush pattern from the drawing pattern buffer 93 and the brush pattern buffer 94, respectively. When the brush on / off signal stored in the brush on / off register 95 indicates that the brush composition processing is performed, the brush calculation is performed using each of the read drawing patterns and the brush pattern, and the brush pattern is synthesized. Process.

  The brush composition process will be schematically described with reference to FIG. 10A to 10D show the respective drawing patterns and brush patterns with the line positions corresponding to the vertical direction for each pixel. 10A shows an example of the lead drawing pattern value read from the lead drawing pattern buffer 98, and FIG. 10B shows an example of the drawing pattern value read from the drawing pattern buffer 93. Here, for the sake of explanation, each drawing pattern is shown as being binary image data.

  FIG. 10C shows an example of brush pattern values read from the brush pattern buffer 94. In the brush pattern, “● (black circle)” indicates the value “0”, and “◯ (white circle)” indicates the value “1”. The brush composition processing circuit 97 selects the lead drawing pattern value of FIG. 10A when the value is “0”, and selects the drawing pattern value of FIG. 10B when the value is “1”. As a result, as illustrated as a light drawing pattern value in FIG. 10D, a combined drawing pattern in which the drawing patterns in FIGS. 10A and 10B are combined according to the brush pattern is generated. . The light drawing pattern value illustrated in FIG. 10D is written into the band memory area of the main memory 14 by the write control unit 101.

FIG. 11 shows an example of the configuration of a brush composition processing circuit 97 for realizing the brush composition processing described with reference to FIG. Brush synthesis processing circuit 97 includes n number of AND circuits each 110 _1, 110 _2, ..., and 110 _n, MUX 111 _1, 111 _2, ..., and 111 _n. Note that the value n corresponds to the number of pixels of a processing unit in one line.

For example, each lead drawing pattern value of the m-th line # 0, # 1, ..., # n is the logical product circuit 110 _1, 110 _2, ..., it is input to one input terminal of 110 _n, respectively. Each AND circuit 110 _1, 110 _2, ..., to the other input terminal of the 110 _n, from the vertical line memory 51, background flag corresponding to the m-th line is entered.

Each MUX 111 _1, 111 _2, ..., 111 _n, respectively, the control input terminal 112 _1, 112 _2, ..., 112 _n and, second selection input terminal 113 _1, 113 _2, ..., 113 _n and 114 _1, 114 ₂ ... 114 _n .

Each MUX 111 _1, 111 _2, ..., in 111 _n, each control input 112 _1, 112 _2, ..., with respect to 112 _n, the brushes pattern value # 0, # 1, ..., # n are input. Also, one of the selected inputs 113 _1, 113 _2, ..., 113 each AND circuit against _n 110 _1, 110 _2, ..., 110 _n output are inputted, the other selection input terminal 114 _1, 114 ₂ ,..., 114 _n are input with respective drawing pattern values # 0, # 1,. Each MUX 111 _1, 111 _2, ..., 111 _n, each control input 112 _1, 112 _2, ..., in accordance with each brush pattern value input to 112 _n, switches one and the other selection input terminal, respectively.

In such a configuration, if the value of the background flag is “1”, each of the AND circuits 110 ₁ , 110 ₂ ,..., 110 _n has the lead drawing pattern value # 0, which is input to one input terminal. A value corresponding to # 1,..., #N is output. In this case, each MUX 111 ₁ , 111 ₂ ,. 111 _n represents the respective lead drawing pattern values # 0, # 1,..., #N and the drawing pattern values # 0, # 1,..., #N as described with reference to FIG. Pattern values selected by switching according to # 1, # 2,..., #N are output as pattern values # 0, # 1,.

On the other hand, if the value of the background flag is “0”, each of the AND circuits 110 ₁ , 110 ₂ ,..., 110 _n forcibly outputs the value “0”. In this case, each of the MUXs 111 ₁ , 111 ₂ ,..., 111 _n has the drawing pattern values # 0, # 1,..., #N turned on / off to the brush pattern values # 0, # 1,. The values switched accordingly are output as post-brush pattern values # 0, # 1,..., #N.

FIG. 12 shows an exemplary configuration of the vertical line memory 51 according to the embodiment. In the embodiment, the vertical line memory 51 includes a plurality of registers 121 ₁ , 121 ₂ ,..., 121 _k ,..., 121 _256, and information on each line in the band memory area of the main memory 14 in the band height direction. Keep divided. In this example, the band height is 8192 lines, and the vertical line memory 51 has 256 registers 121 ₁ , 121 ₂ ,..., 121 _{k ,.} . These registers 121 ₁ , 121 ₂ ,..., 121 _k ,..., 121 ₂₅₆ are initialized by an initialization signal. Note that the register 121 _k indicates any register among the registers 121 _{1 to} 121 ₂₅₆ .

  The vertical line memory 51 further includes MUXs 120 and 122, a bit pattern generation unit 130, a logical product circuit 131, a logical sum circuit 132, and a determination unit 133. From the drawing Y coordinate register 96, a value of a drawing Y coordinate indicating a line to be drawn by writing image data with a drawing pattern is input to the vertical line memory 51. Here, the drawing Y coordinate is data having a bit length of 16 bits. In the vertical line memory 51, the upper 11 bits of the 16-bit bit length of the drawing Y coordinate are input to the MUXs 120 and 122 as selection signals, and the lower 5 bits are input to the bit pattern generation unit 130.

  The bit pattern generation unit 130 generates a 32-bit pattern in which the value of the bit position corresponding to the 5-bit value is “1” as illustrated in FIG. 13 from the input lower 5-bit value. And output. In the notation on the output side in FIG. 13, “32′b” at the left end indicates that each successive value from the right side is a binary value having a bit length of 32 bits. The 32-bit binary value is LSB (Least Significant Bit) at the left end and MSB (Most Significant Bit) at the right end.

MUX120 and 122, registers 121 _1, 121 _2, ..., 121 _k, ..., from 121 ₂₅₆ to select the register 121 _k corresponding to the value k of the upper 11 bits of the drawing Y coordinate.

The logical sum circuit 132 outputs a logical sum of each value of the 32-bit bit pattern generated by the bit pattern generation unit 130 and each 32-bit value of the register 121 _k selected by the MUX 122. The 32-bit output of the OR circuit 132 is written to the register 121 _k selected by the MUX 120.

As described above, in the embodiment, the logical sum operation is performed based on the value of the drawing Y coordinate indicating the line (Y coordinate) on which the drawing has been performed, and the operation result is stored in the register 121 _k selected according to the upper bits of the drawing Y coordinate. Store. When the image data is first written with a drawing pattern for a certain line in the band memory area of the main memory 14, information indicating that drawing has been performed on the line is stored in the vertical line memory 51. Remembered.

The logical product circuit 131 outputs the logical product of each value of the 32-bit bit pattern generated by the bit pattern generation unit 130 and each 32-bit value of the register 121 _k selected by the MUX 122. The 32-bit output of the AND circuit 131 is input to the determination unit 133. The determination unit 133 determines whether or not there is a bit having a value “1” among the 32-bit outputs of the input AND circuit 131. If there is at least one bit having the value “1” among the 32 bits, the background flag having the value “1” is output as the presence of the background. On the other hand, the determination unit 133 outputs a background flag having a value “0” as no background if there is no bit having a value “1” among the 32 bits.

Thus, in the embodiment, the bit pattern generated from the value of the drawing Y coordinate, each register 121 _1, 121 _2, ..., 121 _k, ..., a logical AND operation between a value stored in 121 ₂₅₆ And the presence / absence of the background is determined based on the calculation result. At that time, the information of each line is divided and stored in a plurality of registers, and the determination is performed based on the upper bits and lower bits of the drawing Y coordinate, so that the logic can be simplified.

  For example, the present invention is not limited to the above example, and it is conceivable to use 8192 flip-flop circuits corresponding to 8192 lines. In this case, a selector that selects one output from the outputs of 8192 flip-flop circuits is used. It becomes necessary and the logic becomes complicated.

  FIG. 14 is a flowchart illustrating an example of processing performed by the brush composition processing unit 64 according to the embodiment. The process according to the flowchart of FIG. 14 is executed every time one line is drawn according to the drawing command.

  In step S100, the brush composition processing unit 64 determines whether to draw a photographic image according to the switching signal. If it is determined that a photographic image is to be drawn, the process proceeds to step S101. In this case, the photographic image drawing unit side is selected in the MUX 90, and the drawing address register 91, the length register 92, and the drawing pattern buffer 93 store the drawing address, drawing length, and drawing pattern by the photographic image drawing command, respectively.

  In step S <b> 101, the brush composition processing unit 64 writes the image data based on the drawing pattern to the address indicated by the drawing address stored in the drawing address register 91 in the band memory area of the main memory 14. When the drawing pattern is written, the process proceeds to step S107 described later.

In the brush composition processing circuit 97, when drawing a photographic image, each brush pattern value # 0 to #n is a value for selecting the selection input ends 114 _{1 to} 114 _n of the MUXs 111 _{1 to} 111 _n , respectively. The input drawing pattern values # 0 to #n are output as brush processed pattern values # 0 to #n as they are. Further, along with the processing in step S 101, the drawing Y coordinate indicating the drawn line is transferred from the drawing Y coordinate register 96 to the vertical line memory 51.

  If it is determined in step S100 described above that the drawing is not a photographic image drawing, the process proceeds to step S102. In step S102, the brush composition processing unit 64 determines whether or not the brush composition processing is turned on according to the brush on / off signal. If it is determined that the brush synthesis process is turned off, the process proceeds to step S101. In this case, the CMYK graphics drawing unit side is selected in the MUX 90, and the drawing address register 91, the length register 92, and the drawing pattern buffer 93 store drawing addresses, drawing lengths, and drawing patterns according to CMYK graphics drawing commands, respectively. The brush composition processing unit 64 writes the image data based on the drawing pattern to the address indicated by the drawing address stored in the drawing address register 91 in the band memory area of the main memory 14. When the drawing pattern is written, the process proceeds to step S107 described later.

  If it is determined in step S102 that the brush synthesis process is turned on, the process proceeds to step S103, and the brush synthesis processing unit 64 determines the value of the background flag output from the vertical line memory 51. If it is determined that the value of the background flag is a value “1” indicating that a drawing pattern has already been written in a line corresponding to the drawing Y coordinate in the band memory area of the main memory 14, the process proceeds to Step The process proceeds to S104.

  In step S104, the brush composition processing unit 64 reads the image data from the address indicated by the drawing address stored in the drawing address register 91 in the band memory area of the main memory 14, and reads the drawing pattern based on the read image data. A pattern.

That is, in the flag synthesis processing circuit 97, the logical product of the background flag and the drawing pattern is obtained in each of the AND circuits 110 _{1 to} 110 _n according to the value of the background flag. In this case, since the value of the background flag is set to “1”, the values of the lead drawing pattern values # 0 to _#n from the logical product circuits 110 _{1 to} 110 _n are directly used as the post-brush processing pattern values # 0 to # 0. #N is output to each of the MUXs 111 _{1 to} 111 _n . And a process transfers to step S106 mentioned later.

  On the other hand, when it is determined in step S103 that the value of the background flag is “0” indicating that the drawing pattern has not yet been written to the line corresponding to the drawing Y coordinate in the band memory area of the main memory 14. The process proceeds to step S105. In step S105, the brush composition processing unit 64 does not read the image data from the main memory 14, and sets all the values of the lead drawing pattern to “0”.

That is, in the flag synthesis processing circuit 97, the logical product of the background flag and the drawing pattern is obtained in each of the AND circuits 110 _{1 to} 110 _n according to the value of the background flag. In this case, since the value of the background flag is “0”, the value “0” is output from each of the AND circuits 110 _{1 to} 110 _n . This value “0” is input to each of the MUXs 111 _{1 to} 111 _n as the lead drawing pattern values # 0 to #n. Then, the process proceeds to step S106.

  In step S106, the brush composition processing unit 64 uses the lead drawing pattern generated in step S104 or step S105, the drawing pattern read from the drawing pattern buffer 93, and the brush pattern read from the brush pattern buffer 94. To perform brush composition processing.

That is, in the brush composition processing circuit 97 of the brush composition processing unit 64, for example, the MUX 111 ₁ controls the lead drawing pattern value # 0 and the drawing pattern value # 0 input to the selection input terminals 113 ₁ and 114 ₁ respectively. switch according brush pattern value # 0 input to the end 112 _1, and outputs it as a brush processed pattern value # 0. Similarly, pattern values # 2 to #n after brush processing are output for the other MUXs 111 _{2 to} 111 _n .

  When the brush composition process is performed in step S106, the process proceeds to step S107. In step S <b> 107, the brush composition processing unit 64 writes the image data based on the drawing pattern subjected to the brush composition processing into the band memory area of the main memory 14 in accordance with the drawing address stored in the drawing address register 91.

  More specifically, the brush composition processing unit 64 outputs the brush-processed pattern from the brush composition processing circuit 97 as a drawing pattern, and transfers the output drawing pattern to the light control unit 101 via the write buffer 99. . The write control unit 101 transmits the drawing pattern, the drawing address transferred from the drawing address register 91, and the drawing length transferred from the length register 92 to the controller 25 via the I / F 60. The memory controller 25 writes the image data of the transmitted drawing pattern in the position indicated by the drawing address in the band memory area of the main memory 14.

  In the next step S108, the brush compositing processing unit 64 sets a value “1” for the address corresponding to the drawing Y coordinate in the vertical line memory 51, and the series of processing according to the flowchart of FIG. .

Specifically, in the vertical line memory 51, along with the corresponding register 121 _k is selected according to the drawing Y-coordinate, the bit pattern based on the drawing Y-coordinate in the bit pattern generator 130 is generated. The logical sum circuit 132 obtains the logical sum of the value of the register 121 _k and the bit pattern generated by the bit pattern generation unit 130 and writes the calculated logical sum value to the register 121 _k .

  As described above, in the embodiment, when the brush composition process is performed, the drawing pattern is not yet written on the line based on the background flag output from the vertical line memory 51 according to the target line of the brush composition process. When the determination is made, the line is not read from the main memory 14 and the value of the lead drawing pattern is set to “0”, and the brush synthesis process is performed. Therefore, it is possible to speed up the reading of the drawing pattern from the main memory 14 during the brush composition process.

  Further, since the brush compositing process is performed in units of lines, the memory capacity required for storing the brush pattern can be reduced, and the brush pattern as described with reference to FIG. 18 can be handled.

  According to the prior art, for example, when the brush synthesis process is performed on the background image 200 that covers one page with a graphics image as illustrated in FIG. 15, for example, the value “1” of the binary brush pattern The first color by the background image 200 and the second color by the foreground image to be combined with the background image 200 are applied to the “0” portion to switch between the first color and the second color. draw.

  Conventionally, at the time of this brush composition processing, the background image 200 is read from the main memory 14 as a lead drawing pattern, the foreground image is read as a drawing pattern, synthesized using the brush pattern, and written back to the main memory 14. A read-modify-write process was performed. In this read modify write process, as illustrated in FIG. 16, a large delay occurs in the read process. On the other hand, the write process has a small delay with respect to the read process, as illustrated in FIG.

  In the embodiment, since the read process in the read-modify-write can be omitted on the line where the image data based on the drawing pattern has not yet been written, the brush composition process can be executed at a higher speed.

  The above-described embodiment is a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the scope of the present invention.

First image forming apparatus 13 AXI bus 14 main memory 15 drawing unit 25 a memory controller 50 the band memory 51 vertical line memory 60 Interface 61 image drawing unit 62 the command analyzing unit 63 CMYK bra fixture drawing unit 64 brush synthesis processing unit 110 _1, 110 ₂ ,..., 110 _n , 131 AND circuits 111 ₁ , 111 ₂ ,..., 111 _n , 120, 122 MUX
121 ₁ , 121 ₂ ,..., 121 _k ,..., 121 ₂₅₆ registers 130 bit pattern generation unit 132 OR circuit 133 determination unit

Japanese Patent No. 3332165

Claims (3)

A generating unit that generates a drawing pattern and generates a brush pattern to be combined with the drawing pattern in units of lines;
A first storage unit in which a drawing pattern is written in line units;
A plurality of third storage units each capable of storing bits corresponding to the positions of the lines for the number of divided lines obtained by dividing the maximum number of lines stored in the first storage unit, and the plurality of third storage units A selection unit that selects a third storage unit including a bit at a position corresponding to a line to be combined by the brush pattern generated by the generation unit, and a second storage unit
A combining unit that combines the brush pattern and the drawing pattern read from the first storage unit;
Each of the first storage units is stored in the third storage unit selected by the selection unit as to whether or not a drawing pattern is written in a line to be synthesized by the brush pattern generated by the generation unit. A determination unit that determines based on a bit value at a position corresponding to the line to be combined among the bits ;
The synthesis unit is
An image characterized by not reading out a drawing pattern from the first storage unit when the determination unit determines that a drawing pattern is not written in a line to be combined in the first storage unit. Processing equipment. The synthesis unit is
The said determination part synthesize | combines a predetermined drawing pattern with the said brush pattern, when it determines with the drawing pattern not being written in the said line position in the said 1st memory | storage part. The image processing apparatus described. A generation step of generating a drawing pattern and generating a brush pattern to be combined with the drawing pattern in units of lines;
From the plurality of third storage units capable of storing bits corresponding to the positions of the respective lines corresponding to the number of divided lines obtained by dividing the maximum number of lines stored in the first storage unit in which the drawing pattern is written in line units, A selection step of selecting a third storage unit including a bit at a position corresponding to a line to be synthesized by the brush pattern generated by the generation step, and the drawing pattern generated by the generation step is written in the first storage unit Storing information indicating the selected line;
It said brush pattern, and combining steps for combining the drawing pattern read from said first storage unit,
Each of the first storage units is stored in the third storage unit selected in the selection step as to whether or not a drawing pattern is written in a line to be combined with the brush pattern generated in the generation step. A determination step of determining based on a bit value at a position corresponding to a line to be combined among the bits ,
The synthesis step includes
The image is characterized in that the drawing pattern is not read from the first storage unit when the determining step determines that the drawing pattern is not written in the line to be combined in the first storage unit. Processing method.