JP2001119560A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device that prevents occurrence of image defects by discriminating whether or not rotation processing of raster image data is possible from the standpoint of a memory capacity depending on the result of analysis of input data. SOLUTION: In the case that received image data include raster image data and the rotation of the raster image data is required, a memory consumption capacity required for printing out the image data including a work memory capacity required for rotating the image data is obtained at the analysis of the received image data. Comparing the obtained memory consumed capacity with an idle capacity of the memory discriminates whether or not the rotation of the image data is executable. When the discrimination indicates that the rotation of the image data cannot be executed, the rotation of the image data is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to image processing in an image forming apparatus such as a plotter and a printer.

[0002]

2. Description of the Related Art In a so-called raster printer, 6
About 4 Mbytes of raster image data memory is required for one page of A4 size at a resolution of 00 dpi. If this becomes A0 size in a plotter that can handle large-sized printing paper, a raster image data memory of about 64 Mbytes, which is 16 times larger, is required. For color printing, a raster image data memory of about 256 Mbytes, which is four times larger, is required. This method is generally called a full bitmap method.

As another prior art, there is a banding system in which an ink jet printer or plotter sequentially prints for each image portion (band) by scanning a plurality of times by a head. In this method, raster image data is sequentially developed in a memory having a capacity corresponding to an image portion (band) for one scan of the head. In this case, 1
A partial frame memory having a capacity determined by the number of nozzles of the head and the width of the band is sufficient without requiring a frame memory for a page. When the resolution is 600 dpi, the color is 160 colors, and the number of head nozzles is 160, approximately 2M
All that is needed is a byte frame memory. In the embodiment of the present invention, image processing is performed by this method.

The banding method requires a data storage memory for storing vector data and intermediate image data after raster image data analysis, in addition to the frame memory. This intermediate image data is called DL (display list), and a memory (area) for recording this data
Is called a DL memory. If all the vector data and raster image data can be stored in the DL memory, no image loss occurs.

[0005]

When a large-size printing paper is used with a plotter or the like, printing may be performed by making a vertically long image horizontally long so as not to waste the paper.
In such a case, it is necessary to perform a rotation process for rotating the image by 90 °. At this time, if the image is vector data, it only changes the coordinate value, so there is no pressure on the memory, but if it is raster image data, a working memory area of the width × height of the raster image data is required It becomes. If the rotation process is performed while the working memory area is insufficient, there is a problem that the memory becomes insufficient at the time of the rotation process of the raster image data, resulting in image loss.

Conventionally, such a problem did not occur when only image data to be handled was vector data. However, in recent years, image data in which raster image data such as a photographic image is mixed with vector data has been used. This problem has become apparent as we deal with it.

In order to solve such a problem, the present invention determines whether or not the rotation processing of raster image data is possible due to the memory capacity based on the result of analysis of input data, thereby preventing image loss. It is another object of the present invention to provide a highly reliable image forming apparatus.

[0008]

According to the present invention, there is provided an image forming apparatus for forming an image based on image data input from the outside, comprising: a data analyzing means for analyzing input image data; A memory including a data storage area for storing analysis result data of the means, rotation processing means for performing a rotation process on the analysis result data, and a print image for each band which is a part of an image based on the analysis result data Frame memory means for developing, printing means for forming an image in band units based on the print image developed in the frame memory means, and work necessary for rotating the image based on the analysis result of the data analyzing means Memory consumption calculating means for calculating the memory consumption required for the image printing including the memory capacity for Determining means for determining whether or not the rotation of the image can be executed by comparing with the free space of the memory; and suppressing rotation of the image when the determination means determines that the rotation of the image is not executable. And rotation suppression means.

According to the present invention, it is possible to determine whether or not the raster image data can be rotated when analyzing the input image data. Therefore, unnecessary data (DL described later) is not generated, and loss of processing time when rotation cannot be performed can be prevented. Also, data loss can be prevented.

The image data includes vector data and raster image data, and the memory consumption calculating means separately calculates a memory consumption based on the vector data and a memory consumption based on the raster image data.

For example, with respect to vector data, the memory consumption calculating means obtains a vector value based on a value obtained by accumulating a predetermined fixed-value vector entity data amount for each vector by the number of vectors and the number of bands over each vector. The amount of memory consumption based on the vector data is calculated by the sum of the pointer data amount obtained and the value accumulated for the number of vectors.

[0012] For the raster image data, the memory consumption calculating means calculates a value obtained by accumulating the uncompressed data size of each raster image data, a work data amount based on the number of lines and the width of the maximum size raster image data. , The memory consumption based on the raster image data is calculated.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. Here, an ink jet image recording apparatus that forms a one-band image by one scan by scanning a head having a plurality of nozzles arranged in the paper transport direction in a direction substantially perpendicular to the paper transport direction will be described as an example. .

FIG. 1 is a block diagram showing the configuration of the image forming apparatus according to the present embodiment. In FIG. 1, reference numeral 11 denotes a CPU for controlling the operation of the entire apparatus, and 12 denotes a frame memory and a DL.
In addition to the memory, the RAM is used as a work area for the CPU 11 and a temporary storage area for data. A ROM 13 stores programs and data for driving the image forming apparatus, and is used by the CPU 11.
Reference numeral 14 denotes an interface unit for connecting to an external computer terminal device or the like (not shown), through which plotter description language data such as vector data and vector modification information data is transferred. Reference numeral 15 denotes an LCD display device for performing display for a man-machine interface.
A key operation unit for selecting various settings of the image forming apparatus. 17 is a printing unit of the image forming apparatus, 18 is a CPU 1
This is a system bus that connects 1 to other elements.

FIG. 2 shows a schematic processing flow from input data reception to printing in the present embodiment.

First, input data (vector data) is received from outside (S21), and data analysis is performed on the received data in accordance with a format of a plotter description language (S22). This data analysis means is generally called an interpreter. After analysis, the vector data is
Information such as the start point, end point, line width, and color of each vector is stored in the RAM 12 as an intermediate file. The raster image data is compressed and stored in the RAM 12 (S2
3). These processes are performed until the analysis of the print start data is completed (S24).

After receiving the print start command, the image rotation is determined and the rotation process is performed (S25). Details of this step will be described later.

Thereafter, a display list (DL) is generated for each band from the RAM 12 stored as an intermediate file (S26). What is DL generation?
This is to store in the RAM 12 the band from which band the image is, and what kind of image the band is. When the DL generation is completed, the vector data is converted into raster image data based on the data stored in the DL generation from the first band,
VRC processing for decompressing the compressed raster image data is performed (S27). In this VRC processing, print data suitable for recording is stored in the RAM 12 (frame memory) of FIG.
Expand to An actual printing operation is executed based on the print data in the frame memory (S28).

FIG. 3 is a flowchart showing an example of the process of creating an intermediate file (S23), which is one step in the flow of FIG.

As a result of the data analysis, it is checked whether the given processing target is vector data or raster image data (S231). In the case of vector data, the start point and end point coordinate values of the vector are calculated (S232). The size (memory consumption in the DL) required when registering this vector in the DL is calculated and stored (S23).
3). This registration stores the entity data of a vector in a band where the vector first appears. Further, how many bands (the number of bands) the vector between the start point and the end point spans is calculated (S234).
In addition to the entity data, a memory for a pointer size indicating the entity is required.
Is calculated and stored (S23).
5). Then, the start point and end point information is stored in the intermediate file (S236).

The method of calculating the memory consumption in S233 is as follows.
In the present embodiment, since registering vector entity data in DL requires 14 bytes per vector,

The DL size of the vector entity data + = 14 (1) Here, the symbol “+ =” represents an operation of adding (accumulating) the value on the right side to the current value of the variable on the left side of the equation.

The method of calculating the memory consumption in S235 is as follows.
In the present embodiment, since the size of one pointer requires 4 bytes,

DL size straddling between bands + = (4 * (number of straddling bands−1)) (2)

In step S231, if the processing target is raster image data, as a result of the data analysis, the uncompressed data amount of the raster image data is added as in the following equation (S237). .

Uncompressed data size required for rotation + = uncompressed data size (3)

Further, the number of lines and the width of the input raster image data at this time are calculated and stored by the following equation. This is the working memory capacity required for the raster image data rotation processing.

Copy area size required for rotation = number of lines × width (4)

When a plurality of raster images exist in one page of the print target image, the copy area size required at the time of rotation is the maximum copy area size.

Thereafter, the raster image data is compressed by a compression process using the well-known pack bit method or the like (S
239) and store it in the intermediate file (S236).

FIG. 4 is a flowchart showing the details of the "rotation availability determination &rotation" process, which is one step shown in the flow of FIG.

In determining whether or not rotation is possible, first, the previously registered intermediate file is read (S251). Then, it is checked whether there is a rotation request (S252). If there is no rotation request, this processing ends.

If there is a rotation request, the memory capacity required for rotation is calculated (S253). The memory capacity required for rotating the raster image data is as described in (1) above.
Expression (2), Expression (3), and Expression (4). The sum is compared with the remaining memory capacity (S25).
4). If there is a free memory capacity, the rotation of the raster image data can be performed without data loss, so that the rotation processing is performed (S255).

When there is no free memory capacity, it can be recognized from this determination that data loss will obviously occur anytime even when the image is rotated. In this case, the flow directly proceeds to DL generation (S26) without performing the rotation processing. However, a message to the effect that rotation is not performed due to lack of free memory capacity may be output to the user by character display, indicator lamp lighting, or the like (S256).

FIG. 5 is a diagram for explaining how the actual vector data in the present embodiment is analyzed and DL-expanded. In this example, vector 1 and vector 2 are image data, vector 1 extends from band 1 to band 3, and vector 2 extends from band 3 to band 7. Therefore, the vector 1
Has three bands, and vector 2 has five bands.

DL created for the image data of FIG.
6 is shown in FIG.

In this example, since the vector 1 appears first in the band 1, the entity data of the vector 1 is registered in the DL band 1. The number of bytes is 14.
Since vector 1 straddles bands 2 and 3, DL
In the bands 2 and 3, a pointer to the vector 1 is registered. The number of bytes is 4 bytes each. Similarly,
Since the vector 3 appears first in the band 3, the entity data of the vector 3 is registered in the band 3 of the DL.
Therefore, the total memory consumption in band 3 of the DL is 18 bytes. Since vector 2 extends to the following band 7, for each of bands 4 to 7 of the DL, 4 bytes of the pointer to vector 2 are consumed. Although an extremely simple example is shown here, the actual image data has a more complicated DL content. However, the basic structure is as shown in FIG.

In this embodiment, when the rotation of the raster image is necessary, it is possible to determine whether or not the rotation of the raster image is possible due to the memory capacity before generating the DL. Therefore, it is possible to prevent a loss of processing time when it is determined that rotation cannot be performed because unnecessary DL generation is not performed. In addition, data loss of DL can be prevented.

Although the preferred embodiment of the present invention has been described above, various modifications and changes can be made without departing from the gist of the invention.

[0040]

According to the present invention, in order to solve the problem that the memory capacity is insufficient during the rotation processing of the raster image data and the printing is not performed, the rotation processing of the raster image data can be performed during the data analysis of the input image data. By making the determination as to whether or not the above-described determination is made, it is possible to provide a highly reliable image forming apparatus that does not cause image loss.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of an image forming apparatus according to the present invention.

FIG. 2 is a flowchart illustrating a processing flow from reception of input data to printing of the image forming apparatus of FIG. 1;

FIG. 3 is a flowchart showing a processing example of an intermediate file creation (S23) which is one step in the flow of FIG.

FIG. 4 is a flowchart illustrating details of “rotation availability determination & rotation” processing, which is one step shown in the flow of FIG. 2;

FIG. 5 is a diagram for explaining a state in which actual vector data is analyzed and subjected to DL expansion according to the embodiment of the present invention.

FIG. 6 is a diagram illustrating a memory use state at the time of generating a DL in the image example illustrated in FIG. 5;

[Explanation of symbols]

 11 CPU 12 RAM 13 ROM 14 Interface 15 Liquid crystal display device 16 Key operation unit 17 Printing unit 18 System bus

Claims (4)

[Claims] 1. An image forming apparatus for forming an image based on image data input from the outside, comprising: a data analyzing means for analyzing input image data; and a data storage area for storing analysis result data of the data analyzing means. A memory that includes: a rotation processing unit that performs a rotation process on the analysis result data; a frame memory unit that expands a print image in band units that are a part of an image based on the analysis result data; A printing unit for forming an image in band units based on the developed print image, and a memory required for printing the image, including a working memory capacity necessary for rotating the image based on an analysis result of the data analysis unit A memory consumption calculating means for calculating a consumption amount; comparing the obtained memory consumption amount with a free space amount of the memory; An image forming apparatus comprising: a determination unit that determines whether rotation is executable; and a rotation suppression unit that suppresses rotation of the image when the determination unit determines that rotation of the image is not executable. 2. The image data includes vector data and raster image data, and said memory consumption calculating means separately calculates memory consumption based on vector data and memory consumption based on raster image data. 2. The image forming apparatus according to 1. 3. The method according to claim 1, wherein the memory consumption calculation means calculates a value obtained by accumulating a predetermined fixed-value vector entity data amount per vector by the number of vectors, and a pointer data amount obtained based on the number of bands over each vector. 3. The image forming apparatus according to claim 2, wherein a memory consumption based on the vector data is calculated based on a sum of values accumulated for the number of vectors. 4. The memory consumption calculating means calculates a sum of a value obtained by accumulating an uncompressed data size of each raster image data and a work data amount based on the number of lines and the width of the maximum size raster image data. 3. The image forming apparatus according to claim 2, wherein a memory consumption based on the raster image data is calculated.