JP3968989B2 - Image processing apparatus, image processing method, and storage medium storing image processing program - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image processing apparatus, an image processing method, and a storage medium storing an image processing program for performing processing necessary for outputting an image, particularly ROP (Raster Operation) processing.
[0002]
[Prior art]
In recent years, printers have spread to general offices and homes, and the performance such as print speed and print image quality has been dramatically improved. As a result, the content of documents to be printed out uses more characters and characters. However, it is complicated to use a large number of color photographs without performing color reduction processing at a higher resolution, or to introduce more advanced deformation processing. When printing out such a complicated document, a process of superimposing drawing elements (drawing objects) such as characters, graphics (graphics), bitmap images (photos, etc.) to be drawn, that is, between drawing elements The use of logic processing is becoming essential. As a specific example, this is the case where, for example, in the part where the rectangle overlaps on the photo, the rectangle is regarded as transparent, and the photo that was originally overwritten with the rectangle is processed to show through. It corresponds to.
[0003]
Such logical operation processing for superposition is generally known as so-called ROP processing. ROP processing is usually performed by rasterizing data of each drawing element described in a page description language (hereinafter referred to as “PDL”), and then specifying the logic specified in the form of code in the PDL. It is executed according to the arithmetic expression. Therefore, a device driver such as a printer driver, that is, a device driver for controlling a graphics device such as a printer or a display, interprets these logical operation codes and performs ROP processing according to the method indicated in the code. Need to run.
[0004]
[Problems to be solved by the invention]
Conventionally, when ROP processing is performed, all color separation components of rasterized raster image data are targeted for processing regardless of the processing contents. This is because as the document becomes more complex, it is almost always necessary for the printout to support full color. Therefore, for example, if raster image data is composed of color separation components of Y (yellow), M (magenta), C (cyan), and K (black), the drawing element to be subjected to ROP processing is drawn in black and white. Even in such a case, the ROP process is also performed for each color separation component of Y, M, and C, which originally does not require the ROP process.
[0005]
That is, conventionally, since all the color separation components were processed when performing the ROP process, there is a difficulty in the speed of the process. In particular, when processing a complicated document as described above, the amount of data to be processed becomes enormous, and it is necessary to execute ROP processing between various drawing elements. As a result, the printing speed (image output speed) may be reduced.
[0006]
Accordingly, an object of the present invention is to provide an image processing apparatus, an image processing method, and a storage medium in which an image processing program is recorded, which enables rapid ROP processing even for image data composed of a plurality of color separation components. And
[0007]
[Means for Solving the Problems]
The present invention is an image processing apparatus devised to achieve the above object, and when logical operation processing is required for rasterizing image formation data composed of a plurality of color separation components, the logical operation processing is required. And a logical operation means for executing the logical operation processing only for the color separation component determined to be necessary by the determination means.
[0008]
In addition, the image processing method according to the present invention is configured to determine a color separation component that requires a logical operation process when the logical operation process is required for rasterizing image formation data including a plurality of color separation components. And a logical operation step for executing the logical operation processing only for the color separation component determined to be necessary by the determination means.
[0009]
The storage medium storing the image processing program according to the present invention is a storage medium storing a computer-readable image processing program, and a logical operation process is performed for rasterizing image formation data composed of a plurality of color separation components. When necessary, color separation components that require the logical operation processing are determined, and the logical operation processing is executed only for the color separation components determined to be necessary.
[0010]
According to the image processing apparatus having the above configuration, the image processing method according to the above procedure, or the storage medium storing the image processing program according to the above procedure, the logical operation processing, that is, ROP processing necessary for rasterizing the image formation data is executed. In this case, a color separation component that requires the ROP process is determined. Here, examples of the color separation component include components based on the BGR color system and components based on the YMCK color system. After determining the necessary color separation components, the ROP process is executed only for the necessary color separation components. Therefore, for example, in the case of image formation data for a black and white image, the ROP process is not performed on all color separation components constituting the image formation data.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an image processing apparatus, an image processing method, and a storage medium storing an image processing program according to the present invention will be described with reference to the drawings.
[0012]
First, a system configuration in which the image processing apparatus according to the present invention is used will be described. FIG. 1 is a block diagram illustrating an example of a schematic configuration of an image processing apparatus according to the present invention, and FIG. 2 is a schematic diagram illustrating an example of a system configuration in which the image processing apparatus is used.
[0013]
As shown in FIG. 2, the image processing apparatus described in the present embodiment includes a plurality of client apparatuses 1a, 1b,..., A print server apparatus 2, and a printer apparatus 3, each of which is a network such as a LAN (Local Area Network). 4 is used in a network system connected through the network 4.
[0014]
Each of the client devices 1a, 1b,... Is composed of, for example, a personal computer or a workstation, and electronically creates a document such as a document or an image and issues a print output job for printing out the document. is there. At this time, in each of the client devices 1a, 1b,..., The contents of the document to be printed out are represented by, for example, PDL format data (hereinafter referred to as “PDL data”).
[0015]
The print server device 2 has a function as a computer device. When a print output job is received from each client device 1a, 1b,..., The print output job is sequentially transferred to the printer while managing the execution order. The apparatus 3 is made to execute.
[0016]
The printer apparatus 3 sequentially executes print output jobs issued by the client apparatuses 1a, 1b,... Using a known electrophotographic technique or ink jet printing technique.
[0017]
The image processing apparatus described in the present embodiment is mounted on any one of these apparatuses 1a, 1b,. Alternatively, the image processing program recorded on a computer-readable recording medium such as a CD-ROM may be installed in each client device 1a, 1b,... Or the print server device 2.
[0018]
Next, a schematic configuration of the image processing apparatus used in the above network system will be described. The image processing apparatus described here performs predetermined image processing on PDL data, which is image formation data for printing out a document. As the predetermined image processing, there is a logical operation processing required when rasterizing PDL data, that is, ROP processing for superimposing drawing elements instructed to draw by PDL data.
[0019]
In order to execute such ROP processing, in the image processing apparatus, as shown in FIG. 1, an input interface (hereinafter referred to as “input end”) A that receives PDL data to be processed, and image data after image processing In addition to an output interface (hereinafter referred to as “output terminal”) B for outputting the data, a rasterizing unit 11, a determining unit 12, and a logical operation unit 13 are provided.
[0020]
When the PDL data is input to the input terminal A, the rasterizing unit 11 performs rasterization according to the contents thereof to generate raster image data, and performs a logical operation according to the content of the PDL data on the logical operation unit 13. It is what you specify. However, the rasterizing unit 11 generates raster image data for each drawing element.
[0021]
The determination unit 12 examines the contents of the drawing command related to the logical operation from the PDL data input to the input terminal A, and determines from the result whether the logical operation can be executed only for a specific color separation component. It is. Here, examples of the color separation component include components based on the BGR color system and components based on the YMCK color system.
[0022]
The logical operation unit 13 performs the logical operation designated by the rasterizing unit 11 on the raster image data output from the rasterizing unit 11 according to the determination result of the logical operation on the specific color separation component in the determining unit 12. And the result is output to the output terminal B. Note that the image data output from the output terminal B may be PDL data after rasterizing only an area requiring a logical operation, or raster image data after rasterizing all PDL data. Good.
[0023]
Next, an example of processing operation when the image processing apparatus as described above executes ROP processing will be described. FIG. 3 is an explanatory view showing a specific example of PDL data processed by the image processing apparatus, FIG. 4 is an explanatory view showing the meaning of a drawing command included in the PDL data, and FIG. 5 is shown in FIG. FIG. 6 is an explanatory view showing a drawing result by the DrawRectangle command in the PDL data, FIG. 6 is an explanatory view showing a drawing result by only the DrawCircle command in the PDL data shown in FIG. 2 and a partial enlargement result, and FIG. FIG. 6 is an explanatory diagram showing a drawing result and a partial enlargement result based on the PDL data shown in FIG.
[0024]
For example, consider the case where the PDL data shown in FIG. 3 is input in order from the top to the input terminal A of the image processing apparatus. At this time, the rasterizing unit 11 sequentially interprets the input PDL data in the input order, and generates and outputs corresponding raster image data in the surface order for each color separation component. If there is a drawing command for designating the logical operation content in the PDL data, the content is output to the logical operation unit 13.
[0025]
Examples of drawing commands included in the PDL data include those shown in FIG. The meaning of each drawing command is uniquely defined.
[0026]
Note that the drawing commands related to the logical operation in the PDL data shown in FIG. 3 are the drawing commands within the range of the “logical operation related command” shown in the drawing. Only the command will be described. Also, among the drawing commands, commands that specify drawing attributes, such as logical operation mode and drawing color, can be specified within the range after the StartPage command and before the EndPage command, that is, within the same page. Unless specified, the specified content of the command is valid.
[0027]
Within the range of the “logical operation related command”, first, the logical operation mode is designated by the InsertMode command. Since the argument of the InsertMode command next to the StartLogicalPage command is “Overwrite”, the logical operation mode is “overwrite”, that is, the drawing result by the subsequent drawing command is output as it is.
[0028]
In the SetPenColorSpace, SetPenColor, and SetPaintMode commands following the InsertMode command, the drawing color space is a BGR color system, that is, a color space composed of B (blue), G (green), and R (red) color separation components. The drawing colors are B = 255, G = 128, R = 128 (hereinafter referred to as “light blue”), and the drawing method is designated as “Fill”, that is, “filling”. Each color component value is 8 bits / pixel (that is, the value range is 0 to 255). Thereby, drawing by the drawing command following each of these commands is performed according to the designation of each command.
[0029]
In the SetPoint command following each of these commands, the drawing start position is specified as (100, 100). Note that (100, 100) is a coordinate expression format, where the numerical value on the left side in parentheses indicates the coordinate position in the main scanning direction, and the numerical value on the right side indicates the coordinate position in the sub scanning direction. The coordinate unit is determined by the resolution specified by the Resolution command. The coordinate origin is the upper left corner of the paper, and the main scanning and sub-scanning directions are the horizontal and vertical directions of the paper, respectively. That is, (100, 100) is a coordinate position moved from the upper left corner of the paper by 100 pixels in the main scanning direction and 100 pixels in the sub scanning direction.
[0030]
A rectangle is drawn with the following DrawRectangle command. At this time, the drawing color space is set to BGR, the drawing color is light blue, the drawing method is filled, the drawing start position is set to (100, 100), and the lengths in both the main scanning and sub-scanning directions of the rectangle are set to 4760 pixels and 6816 pixels, respectively. Therefore, a rectangle whose inside is painted light blue is drawn from (100,100) to (4860,6916).
[0031]
FIGS. 5A, 5B, and 5C are diagrams respectively showing the states of the B, G, and R components after a rectangle is drawn by the DrawRectangle command. For the pixel values, refer to the legend in the figure.
[0032]
Subsequently, within the range of the “logical operation related command” of the PDL data shown in FIG. 3, the logical operation mode is designated as “Transparent”, that is, “transparent” by the second InsertMode command. In this logical operation mode, the values of the pixels at the same coordinates of the two raster images to be superimposed are compared and one of them is selected. Here, a pixel value having a small value in the BGR color space is selected for each color component. Shall be selected.
[0033]
In the SetPenColor, SetPaintMode, and SetPoint commands following this InsertMode command, the drawing colors are B = 255, G = 0, R = 128 (hereinafter referred to as “purple”), the drawing method is “Pattern1”, and drawing starts. The position is specified as (2000,3500). “Pattern1” is a drawing method for drawing a pattern in which the drawing color specified by the SetPenColor command and white pixels are arranged in a staggered pattern for each pixel. The next DrawCircle command draws a circle. At this time, the drawing color is purple, the drawing method is drawing the pattern described above, the drawing start position is (2000,3500), and the circular radius is specified as 1000 pixels, so the center is (2000,3500). A circle having a radius of 1000 pixels is drawn by the pattern drawing method described above.
[0034]
FIGS. 6A, 6B, and 6C are diagrams respectively showing the states of the B, G, and R components when only a circle is drawn by the DrawCircle command. FIGS. 6D and 6E are enlarged views of portions surrounded by a thick frame in FIGS. 6B and 6C, respectively. For the pixel values, refer to the legend in the figure.
[0035]
Therefore, the rasterizing unit 11 sequentially interprets the PDL data shown in FIG. 3 to generate raster image data, and when there is a drawing command for designating the logical operation content, the content is output to the logical operation unit 13, and the logical operation is performed. When the printer unit 3 prints out the ROP process in the arithmetic unit 13, a printout as shown in FIG. 7A is obtained from the printer device 3. The contents of the hatched portion in the figure are shown in the legend in FIG. Further, the point in FIG. 7A designated by the arrow and the coordinate value indicates the coordinate origin designated by the coordinate origin designated by the SetPoint command in the PDL data shown in FIG. FIG. 7B is an enlarged view of a portion surrounded by a thick frame in FIG. 7A.
[0036]
However, in the image processing apparatus according to the present embodiment, when the printout shown in FIG. 7A is obtained from the PDL data shown in FIG. 3, the contents of the drawing command related to the logical operation by the determination unit 12 from the PDL data. From the result, it is determined whether or not the logical operation can be executed only for a specific color separation component of the BGR color separation components.
[0037]
Here, considering the necessity of the logical operation for each color separation component of the BGR, referring to FIG. 5 and FIG. 6, first, for the purple pixels in the pattern drawing portion, two raster images to be superimposed Among the color component values of the pixels at the same coordinates, the B component and the R component are the same value, so there is no need to compare them. That is, the light blue rectangular pixel value drawn earlier may be stored as it is. For the G component, the rectangle has a pixel value “128”, which is different from the circular pixel value “0”, so that a small pixel value “0” is selected by comparing the two.
[0038]
On the other hand, for the white pixels in the pattern drawing portion, the B component is “255” and the same value, but the G component has the rectangular pixel value “128”, whereas the circle is “255”. The R component has a rectangular pixel value “128” while a circular shape “255”. Therefore, it is necessary to compare the pixel values of the G component and the R component. However, when one of the pixel values is “255” or “0”, it is not necessary to compare them. The same applies to the G component of the purple pixel in the pattern drawing portion.
[0039]
In other words, to summarize the above, for the purple pixels in the pattern drawing portion that are in the light blue rectangle drawn earlier and in the circle drawn later, the thin pixels of the same coordinates are used. The G component value of the pixel in the blue rectangle may be replaced with the purple G component value “0”. On the other hand, for both the B and R components, it is not necessary to rewrite the light blue rectangular pixel values drawn earlier in any part of the pattern drawing portion. That is, only the G component may be subjected to a logical operation.
[0040]
The determination unit 12 determines whether or not a logical operation as described above is necessary for each color separation component, and outputs the result to the logical operation unit 13. Of course, in determining whether or not a logical operation is necessary, the necessity depending on the drawing area may be added. That is, by analyzing each drawing command, the color separation component to be drawn and its region can be known, and based on this, it is determined whether or not a logical operation is necessary.
[0041]
As a result, the logical operation unit 13 performs a logical operation on the raster image data output from the rasterizing unit 11 only for the color separation components that require the logical operation according to the determination result in the determination unit 12. In the case of the example described above, the logical operation unit 13 performs a logical operation only on the G component. For color separation components or regions that do not require a logical operation, the logical operation unit 13 does not change the raster image data output from the rasterizing unit 11 at all.
[0042]
As described above, in the image processing apparatus according to the present embodiment, the determination unit 12 needs to perform a logical operation on the raster image data generated by the rasterization unit 11 according to the contents of the PDL data input to the input terminal A. Only the color separation component determined to be a logical operation is performed by the logical operation unit 13, and the resulting raster image data, that is, the raster generated from the input PDL data and subjected to the necessary ROP processing Image data is output from the output terminal B. The raster image data output from the output terminal B is used for printout in the printer device 3 as it is or after being subjected to necessary color conversion processing.
[0043]
Therefore, when the image processing apparatus according to the present embodiment or the image processing method implemented by the image processing apparatus is used, the logical operation process necessary for rasterizing the PDL data, that is, the ROP process is executed. Since the color separation component that needs to be processed is determined and the ROP process is executed only for the necessary color separation component, all the color separation components that constitute the PDL data even though this is not necessary No ROP processing is performed on the system. Therefore, compared with the prior art, it is possible to shorten the execution time of logical operations, reduce the computation load of computing means such as a CPU (Central Processing Unit), and reduce the amount of access to the memory used by the CPU. As a result, ROP Processing can be speeded up.
[0044]
This is particularly suitable when processing a complicated document, that is, when the amount of data to be processed is enormous and ROP processing between various drawing elements needs to be executed. In other words, by speeding up the ROP process, it is possible to print out PDL data related to a document at a higher speed than in the past even for a complicated document.
[0045]
Moreover, even if the ROP process is accelerated, the process for unnecessary color separation components is omitted, and the processed image, that is, the result of the printout, is not different from the conventional case and the image quality is deteriorated. There is nothing.
[0046]
In the present embodiment, the processing for each color separation component by the BGR color system has been described as an example, but the same processing is performed by L ^* a ^* defined by the YMCK color system or CIE (International Lighting Commission) ^. Needless to say, the present invention can also be applied to other color spaces such as b ^* color system. When applying to other color spaces, the judgment criteria may be changed from the drawing color space specified by both the SetPenColorSpace and SetPenColor commands described above and the color space when raster image data is output from the output terminal B. In particular, if the two color spaces are different, the determination criteria may be changed depending on whether the execution of the logical operation is performed before or after performing the color space conversion.
[0047]
For example, when the color space at the time of outputting raster image data from the output terminal B is YMCK, and color space conversion is performed before execution of the logical operation, a rectangle drawn in light blue is Y = Draws with 127, M = 127, C = 0, K = 0, and the pixels that are purple in the pattern drawing are drawn with Y = 127, M = 255, C = 0, K = 0, and white The rendered pixel is drawn with Y = M = C = K = 0. Here, the pixel value represents a normal luminance value in the BGR space, but it should be noted that the pixel value represents a density value in the YMCK space. A criterion of “take the smaller of the color component values of the pixels at the same coordinates”. Is replaced with the criterion “take the larger of the color component values of the pixels at the same coordinates”. According to this judgment criterion, whether or not the logical operation is required for each color component of YMCK is considered, only the pixels of the circular part of the M component need the logical operation, and compared with the rectangular M component value “127”. The M component value of the power circle is “255” or “0”, and the M component value of the rectangular pixel having the same coordinate as the pixel of the circular M component value “255” is set to “255” without comparison. It should be replaced. That is, in the above-described embodiment, only the G component is the target of the logical operation, but in the example described here, only the M component is the target.
[0048]
In the present embodiment, the case where the raster image data output from the output terminal B is used for printout in the printer apparatus 3 has been described as an example. It can also be used for screen display, public line, wireless communication, transmission to remote places such as the Internet, and storage in a storage medium such as a semiconductor memory or a hard disk. This means that the present invention can be applied not only to the network system that prints out the document described in the present embodiment, but also to a device driver for controlling a graphics device such as a display.
[0049]
【The invention's effect】
As described above, according to the image processing apparatus, the image processing method, and the storage medium storing the image processing program according to the present invention, when ROP processing is performed for rasterizing image formation data composed of a plurality of color separation components However, since the logical operation is executed only for the necessary color separation components, the ROP processing can be speeded up by shortening the processing execution time and reducing the calculation load. Therefore, it is particularly suitable for processing a complicated document, that is, when the amount of data to be processed is enormous and it is necessary to execute ROP processing between various drawing elements. In addition, this does not cause degradation of image quality after processing.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating an example of a schematic configuration of an image processing apparatus according to the present invention.
FIG. 2 is a schematic diagram illustrating an example of a system configuration in which an image processing apparatus is used.
FIG. 3 is an explanatory diagram showing a specific example of PDL data.
FIG. 4 is an explanatory diagram showing the meaning of a drawing command included in PDL data.
5A and 5B are explanatory diagrams showing a drawing result by a DrawRectangle command in the PDL data shown in FIG. 3, wherein FIG. 5A shows a state of a B component after drawing, and FIG. 5B shows a G component after drawing. FIG. 8C is a diagram showing the state of the R component after drawing.
6A and 6B are explanatory diagrams showing a drawing result only by a DrawCircle command in the PDL data shown in FIG. 3 and a partial enlargement result thereof. FIG. 6A is a diagram showing a state of a B component after drawing, and FIG. The figure showing the state of G component after drawing, (c) is the figure showing the state of R component after drawing, (d) is the figure showing the partial expansion result of G component, (e) is the partial expansion result of R component FIG.
7A and 7B are explanatory diagrams showing a drawing result based on the PDL data shown in FIG. 2 and a partial enlargement result thereof. FIG. 7A shows a drawing result, and FIG. 7B shows a partial enlargement result.
[Explanation of symbols]
11: Rasterize unit, 12: Judgment unit, 13 ... Logical operation unit

Claims (6)

A determination means for determining a color separation component that requires the logical operation processing when the logical operation processing is required for rasterizing the image forming data including a plurality of color separation components;
An image processing apparatus comprising: a logical operation unit that executes the logical operation process only on a color separation component that is determined to be necessary by the determination unit. A conversion means for converting the image formation data into frame sequential raster image data;
The image processing apparatus according to claim 1, wherein the logical operation unit performs logical operation processing on the raster image data converted by the conversion unit. A determination step of determining a color separation component that requires the logical operation processing when the logical operation processing is required for rasterizing the image formation data including a plurality of color separation components;
An image processing method comprising: a logical operation step for executing the logical operation processing only for a color separation component determined to be necessary by the determination means. A conversion step of converting the image formation data into frame sequential raster image data;
4. The image processing method according to claim 3, wherein in the logical operation step, logical operation processing is performed on the raster image data converted in the conversion step. A storage medium storing a computer-readable image processing program,
When logical operation processing is required for rasterizing image formation data composed of a plurality of color separation components, the color separation components that require the logical operation processing are determined,
A storage medium storing an image processing program, wherein the logical operation process is executed only for a color separation component determined to be necessary. 6. The storage medium storing an image processing program according to claim 5, wherein the image forming data is converted into frame sequential raster image data, and logical operation processing is executed on the converted raster image data.

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