JP2000011191A - Color image output method, apparatus and recording medium - Google Patents

Abstract

(57) [Problem] To perform raster processing by identifying an image type with low memory and with high accuracy without modifying an existing PDL interpreter. A drawing command issued from a printer driver (4) is rasterized (7) and stored in a memory (8). The command conversion device 6 identifies the image type of the drawing command, converts the color data of the command into an identification code, rasterizes the image, and stores it in the memory 9. The color conversion / binarization processing devices 10 and 11 read the memories 8 and 9, perform processing according to the image type on the memory 8, and
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Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image output process, and more particularly to a PDL (Page Descriptive).
The present invention relates to a color image output method, apparatus, and recording medium for performing raster processing in an on-language interpreter, and is a technique applied to a controller device such as a color printer or printer driver software installed in a computer.

[0002]

2. Description of the Related Art Generally, when a document created by a computer is output to a printer, the following processing is performed. That is, (1) the document data is converted into a plurality of drawing command groups. (2) A raster image is created by analyzing drawing commands with software called a printer driver or a printer controller device (generally, the above processing is called a raster operation). (3) A printer output signal is generated by performing color conversion processing, pseudo halftone processing, and the like on the raster image. (4) Execute printing.

In order to output a preferable color image, it is necessary to perform different color processing and halftone processing depending on the type of the image, such as a natural image, a character, and a graphic.
Therefore, in order to output color image information including various image types, an architecture that can perform image processing suitable for each image type is required.

Conventional techniques for outputting such color image information include (A) a method of preparing a bitmap memory for each image type and individually creating raster images, and (B) a method of preparing raster images. After generation, a method of scanning a raster image and determining an attribute for each pixel (for example, see Japanese Patent Application Laid-Open No. 9-284548)
and so on.

[0005]

In the above method (A), since a memory for storing a raster image is prepared for each image type, a large amount of memory is wasted when the number of image types to be distinguished increases. There is a problem. Also,
The PDL interpreter that performs the raster operation must also be changed significantly, making it difficult to change the raster operation processing method.

In the method (B), since image area separation is performed using a raster image, there is a problem that erroneous determination is likely to occur. Also in the above-mentioned publication, the image castle separation processing is performed in units of 3 × 3 pixels, so that an erroneous determination may occur.

SUMMARY OF THE INVENTION An object of the present invention is to provide a color image output method, apparatus, and recording medium for performing a raster processing by identifying an image type with high accuracy without memory modification without modifying an existing PDL interpreter.

[0008]

According to the first aspect of the present invention, there is provided a color image output method for developing a document image described by a drawing command into a bit image and outputting the bit image. The document image is developed into a bit image, and the code representing the image type is developed into a bit image.

In the invention according to claim 2, the image type of the document image is determined for each of the rendering commands, a predetermined code is assigned to the determined image type, and the color data in the rendering command is converted to the color data. It is characterized by being converted into a predetermined code and developed.

According to a third aspect of the present invention, different codes are assigned to at least characters and bitmaps in the image type.

According to a fourth aspect of the present invention, a code representing a background is assigned to an area where the document image is not developed.

In the invention described in claim 5, when the drawing instruction is an instruction for performing an operation between a plurality of image types, a predetermined code is assigned to an area where the operation instruction is executed and developed. And

According to a sixth aspect of the present invention, there is provided a color image output apparatus for developing a document image described by a drawing command into a bit image and outputting the bit image to an image output means, wherein the document image is developed into a bit image. First means for storing;
Means for determining the image type of the document image, second means for expanding a predetermined code assigned to the determined image type into a bit image and storing the bit image, and Means for reading, performing an optimum process in accordance with an image type read from the second means to each pixel of the first means, and outputting to the image output means.

According to a seventh aspect of the present invention, there is provided a color image output device for developing a document image described by a drawing command into a bit image and outputting the bit image to a printing unit, wherein the document image is developed into a bit image and stored. A first means for performing the processing, a means for determining an image type of the document image, a means for assigning a predetermined code to the determined image type, and a means for converting color data in the drawing command into the predetermined code. Second means for expanding the predetermined code into a bit image and storing the bit image;
The pixel data is read out from the first and second means in pixel units,
Means for applying optimal processing to each pixel of the first means in accordance with the type of image read from the means and outputting to the printing means.

According to the eighth aspect of the present invention, a computer-readable recording medium in which a program for causing a computer to realize a function of developing a document image described by a drawing command into a bit image and outputting the bit image to a printing apparatus is recorded. A function of expanding the document image into a bit image and storing it; a function of determining an image type of the document image;
Allocating a predetermined code to the determined image type,
A function of expanding the predetermined code into a bit image and storing the function, a function of performing an optimum process according to an image type on each pixel read from the storage function, and a process of performing the optimum process. The computer-readable recording medium stores a program for causing a computer to realize a function of transmitting a bit image document image to the printing apparatus.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be specifically described below with reference to the drawings. (Embodiment 1) FIG. 2 is an example of a color image including various figures. This image contains natural images (bitmaps), fonts (characters), line drawings,
Includes a solid color fill pattern (bar graph). Hereinafter, an embodiment of the present invention will be described by taking the case of printing this image as an example.

FIG. 1 shows a configuration of a first embodiment of the present invention.
1 is a system configuration example when performing a raster operation in a printer controller. Normally, the operating system 2 includes a dedicated module 3 for drawing, and the drawing module 3 manages a drawing process for a display or a printer.

For example, when an operator prints a document image as shown in FIG. 2 edited on a screen by using some application 1 on a printer, the application 1 issues a command to start a print job to the drawing module 3.
Send to Upon receiving the print start message, the drawing module 3 converts the document image data created by the application 1 into a command that can be interpreted by the printer driver 4 and transmits the command to the printer driver 4.

The printer driver 4 converts a command received from the operating system 2 into a drawing command that can be interpreted by the printer controller 5 and transmits the command to the printer controller 5 connected locally or over a network. The printer controller 5 converts the data into data that can be transmitted to the printer 12 by a raster operation and image conversion means described later, and starts a printing operation. When printing is completed, the application 1 sends a print end command to the drawing module 3 and the operator can again edit.

Next, the raster operation processing which is a feature of the present invention will be described. FIG. 4 is a processing flowchart of the raster operation of the present invention.

The drawing command sent from the printer driver 4 is composed of a large number of drawing commands corresponding to image types. Normally, the drawing command includes information such as the type of image to be drawn (eg, bitmap, character, line, pattern, etc.), shape, position information, and color data.
As an example, a drawing command of a character has a command form of DrawText (“home computing ...”, rect, color). Here, “home computing ...” is the content of the text document to be drawn,
Rect is the area on the bitmap to be drawn, color
Represents a drawing color. A command group suitable for each of other image types such as a bitmap is transmitted.

The raster operation for the above-mentioned drawing command is processed in two systems. One is a general raster operation, in which raster processing is performed faithfully by the raster developing device 7 in accordance with a drawing command (RIP (Raster)).
r Image Processor) (step 101), and the generated raster image is stored in the bitmap memory 8 (A) (step 10).
2).

The other is raster development for identifying image types. That is, after the color data of the drawing command is converted into an image type identification code by the command conversion device 6, the same raster processing as in the previous raster operation is performed, and the generated image is subjected to the bitmap memory 9 (B ). In this method, since the first raster development and the second raster development are processed in synchronization, by referring to the bitmap memory B, it is possible to identify an image type without erroneous determination for each pixel.

The processing operation of the present invention will be described below with reference to FIG. Here, for convenience of explanation, an identification code for each image type is assigned as follows. That is, background = 0 character = 1 line = 2 rectangle = 3 bitmap = 4 others = 5 First, in order to be able to identify an area where nothing is drawn, the bitmap memory 8 ( The contents of B) are initialized with the background identification code 0.

After that, raster development is executed by assigning an identification code to each drawing command. As shown in FIG. 4, first, the command conversion device 6 determines whether or not the drawing command is for a character (step 103).
(Step 110), the raster developing device 7 executes raster developing (Step 108), and stores the image type code in the bitmap memory 9 (B) (Step 10).
9).

If it is determined that the command is not a character, it is next determined whether or not the command is a line drawing command (step 10).
4) If it is a line drawing, the color data is changed to 2 which is a line identification code (step 111), and raster development is performed (step 1).
08), and stored in the bitmap memory 9 (B) (step 109). In the same manner, a rectangular drawing command is processed (steps 105 and 112), and a bitmap drawing command is processed (steps 106 and 113). Is assigned (step 107).

How the contents of the bitmap memory B are changed by the above processing will be described with reference to FIG. In FIG. 5, three drawing commands of (1) drawing a bitmap, (2) drawing a character, and (3) drawing a bitmap are executed.

In the first stage (FIG. 5A), 0 representing the background code is assigned to the bitmap memory B. Next, when the bitmap is drawn, the entire drawing area of the bitmap is rewritten with the identification code 4 (FIG. 5B). Next, when a character drawing command is received, since the rasterization is performed by changing the color data to 1, only the character portion is drawn in a color having a value of 1, so that FIG. become that way. When the next bitmap drawing command is received, the same processing as described above is performed,
The contents of the bitmap memory B are updated as shown in FIG.

As described above, in this embodiment, the identification code of the image type can be accurately generated on the bitmap memory even if the objects to be drawn overlap each other in a complicated manner. Further, the bitmap memory B does not necessarily have to have the same storage capacity as the bitmap memory A. For example, in the above example, since there are six types of image type identification codes, a 3-bit memory per pixel may be prepared.

When the above processing is performed on the document data shown in FIG. 2, an image composed of the image type identification codes shown in FIG. 3 is finally generated in the bit map memory B. .

In the above embodiment, six types of allocation patterns are used. However, the present invention is not limited to this example, and patterns of characters and other patterns may be used, or other patterns may be used. However, since the preferable image conversion processing is clearly different at least for characters and bitmaps, it is desirable to assign different identification codes to the two image types.

When a bitmap holding an image type identification code is generated by the above-described processing, an image conversion process is performed on the bitmap memory A while discriminating the image type according to the generated bitmap, thereby generating an output signal to the printer. .
The image stored in the bitmap memory A has 24 bits (or 8 bits) for each pixel as in a normal display.
Bit) of the RGB signal. Since a printer is generally printed with another color signal (usually CMYK data), a color conversion process such as RGB → CMYK conversion is required. Further, in a general color printer such as an ink jet printer, there are many printers having a smaller number of gradations than a display, and in that case, a pseudo halftone process is required. The image conversion processing of this embodiment is not limited to the above-described color conversion processing and pseudo halftone processing, and other processing may be added.

As an example of the optimization processing, RGB → CMYK
The case of color conversion will be described. Generally, RGB → CM
At the time of YK color conversion, it is more desirable from the viewpoint of image quality to output black characters only with black ink and perform color conversion so that the black portion of a continuous tone image such as a natural image is printed in four colors of CMYK. Therefore, when color conversion is performed by the color conversion processing device 10, the bitmap memories A and B are read out on a pixel-by-pixel basis, and color conversion into four colors is performed for pixels having a bitmap code. For pixels with the code
Color conversion is performed so as to output black single color. Also, with regard to the halftone processing in the binarization processing device 11, dither processing is performed for characters, and error diffusion processing is performed for bitmap areas, thereby enabling optimization processing for each image type.

According to the present invention, 0 is assigned as a background identification code to a background portion where no drawing is performed. Therefore, special processing can be performed only on the background area. For example, since the printer does not normally perform printing on the background area, color conversion processing and halftone processing are not performed on pixels for which a background code is set, and C, M, Y, If the data is transmitted to the printer with K = 0, a high-speed printing operation becomes possible.

Further, as a more complicated example, there is a case where arithmetic processing is performed between a plurality of drawing targets. For example, there is a case where a bitmap is drawn on a lower layer, and a character with transparency set is drawn thereon.
In such a case, since the transparency is set for the characters, the bitmap images of the characters and the background are displayed on the screen in a lightly mixed state. In such a case, it is necessary to set a new image type different from the character and the bitmap. Therefore, when an operation instruction between layers is received, a new identification code representing the operation area is set. By setting such a code, optimization such as color conversion processing can be easily performed.

Embodiment 2 Embodiment 1 described above is an embodiment in which a raster operation is performed in a printer controller. By the way, in an inexpensive ink-jet printer or the like, a raster operation is performed by a printer driver without performing a raster operation in a printer controller, developed into a bitmap image, and then transmitted to the printer. FIG. 6 shows a configuration example in this case.

In the first embodiment, the processing such as the raster operation is performed by the device in the controller.
The second embodiment is different from the first embodiment only in that each process such as command conversion and raster development is performed by software of a printer driver (each module such as a command conversion module). Same as 1.

Note that the present invention is not limited to the above-described embodiment, and the software of the above-described printer driver is
It may be recorded on a recording medium such as a D-ROM. When executing the raster operation of the present invention, the processing function of the present invention is realized by reading out the program recorded on the above-mentioned recording medium and incorporating it as a part of the OS.

[0039]

As described above, according to the present invention, the document image described by the drawing command is developed into a bit image and the identification code of the image type is developed into a bit image. The image type can be identified with a small amount of memory and with high accuracy without remodeling, so that it is possible to perform the optimal image processing according to the image type.

[Brief description of the drawings]

FIG. 1 shows a configuration of a first exemplary embodiment of the present invention.

FIG. 2 shows an example of a document image composed of a plurality of image types.

FIG. 3 shows an example of an image type determination result for a document image.

FIG. 4 is a processing flowchart of a raster operation of the present invention.

FIG. 5 shows a process of writing an image type identification code into a memory.

FIG. 6 shows a configuration of a second exemplary embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Application 2 Operating system 3 Drawing module 4 Printer driver 5 Printer controller 6 Command conversion device 7 Raster development device 8, 9 Bitmap memory 10 Color conversion processing device 11 Binarization processing device 12 Printing device

Claims (8)

[Claims] 1. A color image output method for developing a document image described by a drawing command into a bit image and outputting the bit image, wherein the document image is developed into a bit image and a code representing an image type is developed into a bit image. A color image output method. 2. An image type of the document image is determined for each drawing command, a predetermined code is assigned to the determined image type, and color data in the drawing command is converted into the predetermined code. 2. The color image output method according to claim 1, wherein the color image is developed. 3. The color image output method according to claim 2, wherein different codes are assigned to at least characters and bitmaps among the image types. 4. The color image output method according to claim 2, wherein a code representing a background is assigned to an area where the document image is not developed. 5. The image processing apparatus according to claim 2, wherein when the drawing instruction is an instruction for performing an operation between a plurality of image types, a predetermined code is assigned to an area where the operation instruction is executed and developed. Color image output method. 6. A color image output device which develops a document image described by a drawing command into a bit image and outputs the bit image to an image output means, wherein the first means develops the document image into a bit image and stores it. Means for discriminating the image type of the document image, second means for developing a predetermined code assigned to the discriminated image type into a bit image and storing the bit image, and pixel data from the first and second means. Read in units,
A color image output apparatus comprising: means for performing an optimum process according to an image type read from the second means on each pixel of the first means and outputting the processed image to the image output means. 7. A color image output device which develops a document image described by a drawing command into a bit image and outputs the bit image to a printing means, wherein the first means develops the document image into a bit image and stores it. Means for discriminating the image type of the document image, means for allocating a predetermined code to the discriminated image type, converting color data in the drawing command into the predetermined code, A second unit for developing and storing the image as an image; and reading out the image data in units of pixels from the first and second units, and performing an optimum process according to an image type read out from the second unit. Means for applying to a pixel and outputting to the printing means. 8. A computer-readable recording medium storing a program for causing a computer to realize a function of expanding a document image described by a drawing command into a bit image and outputting the bit image to a printing apparatus, wherein the document image Into a bit image, a function to determine the image type of the document image, a predetermined code assigned to the determined image type, and the predetermined code expanded into a bit image and stored. And a function of performing an optimum process on each pixel read from the storage function according to an image type, and transmitting the bit image document image subjected to the optimum process to the printing apparatus. And a computer-readable recording medium on which a program for causing a computer to realize the function of performing the function is recorded.