JPH05229229A - Electro printing device - Google Patents

Abstract

PURPOSE: To avoid problems associated with the inability of the lustring of a complicated page image in real-time in such a way that image contents are inspected before they are offered to an image generation subsystem, and if it is determined that a page is too complicated, the page is simplified by an image manipulation subsystem. CONSTITUTION: In a controller 7 for receiving and processing page image data from an image input terminal device 6, an image generation subsystem 100 generates page image data in digital form in real-time and gives them to an output terminal device 8. A decomposer 120 determines whether the system 100 can generate page image data to be given to the system 100 in real-time. In addition, an image manipulation subsystem 58 simplifies image data before they are offered to the system 100, after the decomposer 120 determined that page image data exceed the real-time processing capability of the system 100.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic printing device for generating a page image before printing, and more particularly to an electronic printing device for determining page complexity before printing a page.

[0002]

BACKGROUND OF THE INVENTION Electronic printing devices rasterize or generate page images in digital form and then send them to an image output terminal for printing. Rasterization can be implemented in a variety of different ways. For example, one rasterization process involves decompressing a simple image received from a scanner. More complex rasterization processes typically involve the rasterization of certain intermediate formats involved in receiving image information from networked workstations. Briefly, the intermediate format contains instructions that describe straight line sections, curves, characteristics, images, etc. that must be combined to produce the desired page image. The electronic printing device rasterizes this intermediate format before printing. This rasterization is typically done in real time when the page image is transferred for processing operations.

The time required to rasterize a page image is directly related to the complexity of the page image, ie the number, size and type of objects that make up the page image. In some cases, the time required to generate a complex page may exceed the real-time processing capability of the image generation subsystem to successfully perform real-time rasterization. The electronic printing device detects this condition, stops printing the page, and displays an error message to the user on the display. After that, different recovery methods must be implemented depending on the printing device used.
At a minimum, the user must then remove and discard the aborted page. Alternatively to some of the above, some electronic printing devices allow the user to select different operating modes that direct other system resources to the imaging task.

US Pat. No. 4,896,275 converts a complex graphic or image in binary form into a bitmap representation containing only the image data that is absolutely essential for reproduction on an output printer with limited buffer memory. A method is disclosed. Blocks of data are stored in the input buffer at a time, and the data is analyzed one byte at a time. Based on this analysis, a bitmap representation that describes only the required data is generated. The required data contained in the generated bitmap representation is transferred to the output buffer along with the generated horizontal and vertical position information and other parameter information needed to generate the bitmap representation.

As described above, the conventional technique compensates the memory constraint in the electronic printing apparatus by generating the bit map representation including only the essential image data. Also, the prior art does not address the problems associated with real-time rasterization of complex pages.

[0006]

SUMMARY OF THE INVENTION A first object of the present invention is to provide an electronic printing device which avoids the problems associated with the inability to rasterize complex page images in real time.

A second object of the present invention is to provide an electronic printing device which avoids the problems associated with the inability to rasterize complex page images in real time without user intervention.

A third object of the present invention is to provide an electronic printing device which avoids the problems associated with the inability to rasterize complex page images in real time without interrupting printer operation. ..

A fourth object of the present invention is to provide an electronic printing device that avoids the problems associated with the inability to rasterize complex page images in real time while maximizing the use of the printing device's storage space. It is to be.

[0010]

In order to achieve the above and other objects and advantages, and to overcome the above-mentioned drawbacks, the electronic printing device of the present invention prior to sending page content to an image generation subsystem. Inspect the page contents. Provide and analyze an internal intermediate description of the page to determine the number, size and position of objects on the page. It then determines whether there are sufficient system resources to image the page contents in real time. If the page is determined to be too complex, the device rasterizes the page in the background and sends a simple bit / pixel image to the image generation subsystem.

[0011]

DETAILED DESCRIPTION OF THE INVENTION The invention will now be described with reference to the accompanying drawings, in which like elements are designated with like reference numerals.

1 and 2 show a typical electronic printing device 2 for processing print jobs in accordance with the principles of the present invention.

The printing device 2 is divided into an image input terminal device 6, a controller section 7, and an image output terminal device 8 for convenience of explanation. Although described with respect to a particular printing device, the present invention can be used with other types of electronic printing devices.

The image input terminal 6 produces an image signal or pixel which is representative of the scanned image. The image signal is appropriately processed by the processor 25 and then sent to the controller unit 7. Alternatively to the above, a networked workstation may be connected to the processor 25.

A processor 25 is required to convert the image signal from analog format to digital format so that the printing device 2 can store and handle the image data in the form required to perform the programmed job. The image signal is processed accordingly. The processor 25 further enhances or changes the image signal by processing such as filter processing, threshold processing, screen processing, cropping, enlargement / reduction, and the like. After changing or adjusting the job program, the analog image signal must be input to the processor 25 again.

For convenience of explanation, the controller unit 7 includes an image input controller 50 and a user interface 5.
2, a system controller 54, a main memory 56, an image manipulation subsystem 58, and an image output controller 60. The image data input from the processor 25 to the controller unit 7 is sent to the image compressor / processor 5 of the image input controller 50.
Compressed by 1. When the image data passes through the compressor / processor 51, the image data is N
It is divided into scan line width slices. The compressed image data is placed in the image file along with all the image descriptors that give specific information about the image (eg document height and width (in pixels), compression used, etc.). The image files (representing different print jobs), until transferred to fixed disks 90-1, 90-2, 90-3,
Main memory 5 consisting of random access memory (RAM)
6 is temporarily stored and the image data is kept there until use.

The user interface 52 comprises an operator controller / CRT display combination including an interactive touch screen 62, a keyboard 64, and a mouse 66. The user interface 52 connects the operator and the printing apparatus 2, and the operator uses the user interface 52 to program a print job and other commands, to obtain system operation information,
Instructions, programming information, diagnostic information, etc. can be obtained. For items such as files and icons displayed on the touch screen 62, touch the item displayed on the screen 62 with your finger, or use the mouse 66 to point to the selected item with the cursor and press the switch of the mouse. Is started by.

Main memory 56 stores machine operating system software, machine operating data, and image data currently being processed.

When the compressed image data in main memory 56 needs to be further processed, or when it is requested to be displayed on the touch screen 62 of the user interface 52, or when requested by the image output terminal 8. The compressed image data in the main memory 56 is accessed. If other processing than that performed by processor 25 is requested, it is transferred to image manipulation subsystem 58 where additional processing, such as collation, makeready, etc., is performed. The disassembly is performed by the system controller 54. After processing, the data may be returned to main memory 56, sent to user interface 52 for display on touch screen 62, or image output controller 6.
You can also send it to zero.

The image data sent to the image output controller 60 is the image generation subsystem (hereinafter,
It is decompressed by IGS 100 and is ready for printing. The image data is then sent to the image output terminal 8 for printing. Subsequently, the image data is generally purged from main memory 56 to make room for new image data.

The IGS 100 is suitable for bands. The page image is partitioned into bands, each band being created in real time by an array of video generation channels. The video generation channel feeds a pair of ping-pong filled / empty band buffers. When the previous band is dumped to the image output terminal, the real-time request is driven at the processing speed of the image output terminal 8 because it must "generate" any defined band of pages. As an example, the controller unit 7 has a fixed 2
The 56 scan line band size is retained. The time available to generate a 256 scan line page segment depends on the particular printing device 2 used.

The actual video production time is directly related to the complexity of the printed page. Image output terminal device 8
Although the dump time remains constant, the amount of time the video generation channel spends writing data to the band buffer depends on the complexity of the page segment that it comprises.

Complexity is influenced by many factors, including the number of objects on the page (compressed image segments, character bitmaps, rules, etc.) and the geometrical shapes of those objects. It is possible to generate composite pages that consist of multiple objects that cannot be imaged in real time. In accordance with the present invention, the image manipulation subsystem 58 can be used to support the simplification of fairly complex pages into a single raster. The page simplified by the image manipulation subsystem 58 is IGS10.
At 0 it will not cause any problems.

When a "complex" page is presented to the IGS 100, a fatal error is detected when the video generation time for a given band exceeds the time required for real-time computation. When the page image is transferred to the image manipulation subsystem 58 for simplicity, printing is suspended for a few seconds. This kind of interruption is not desirable from a system productivity standpoint, especially when it is considered that complex jobs may need to simplify large numbers of pages. Therefore, it is desirable to inform the printing device that a complex page exists before sending it to the IGS 100. Identifying pages that cannot be imaged in real time is called "complexity prediction". Such a page is automatically simplified before submitting the job containing it for printing.

Complexity Prediction Decomposer 120 performs complexity prediction. Decomposer 120 interprets the page description language into a low level format or bitmap. Decomposer 12
The 0 output is translated by the IGS 100. Decomposer 120 generates a list of objects for each segment (ie, band) of the page image. When generating this "band list", we collect statistics related to the complexity of each object in the band. Once the band list has been generated, use those statistics to calculate the page complexity.

A number of factors must be considered when determining complexity. Exact calculation of page complexity requires accurate modeling of IGS 100 performance. Further, the decomposer 120 needs to be tuned so that the object can be generated in a manner that maximizes the bandwidth of the IGS 100. As will become clear from the description below, the actual implementation will, in some cases, strike a balance between the accuracy of the complexity calculations and the addressing performance and system resources. However, the plan is based on the basic promise that the accuracy of complexity calculations should not impose the basic requirement of prohibiting page image failures in IGS.

There are two main factors that prevent the IGS 100 from printing a page due to its complexity. The first is the total image area in the band and the second is the number of objects in the band.
The IGS 100 may be interrupted if either one factor is too large or the two factors combine. Another constraint is the bandlists, fonts, and memory resources available to load the images needed to print the page.

During the printing time, the page to be printed is divided into bands (IGS 100 must image one band at a time). The band is further divided into scan lines. For this example, there are 256 scan lines per band. The time to image one scan line is set to 74.5 μs. The video channel can output data at approximately 32 megabits / second, so 600 spots /
For inches (spi), the theoretical limit for video channels is 3.9 inches / scan line. Video channels cannot process image data continuously because overhead functions such as object dispatching, video channel programming, and state storage must be performed. Moreover, the time for these overhead functions imposes a practical limit on the amount of video channel processable data per band.

As mentioned previously, another limiting factor in determining whether to print a document is the number of objects in the band. There may be two objects in the band, one with a higher priority and one with a lower priority. Higher priority objects are planned to lie in different z-planes higher than lower priority objects in the band. The presence of such objects further complicates the document. The data structure of the IGS 100 includes the number of pointers (high-priority pointers and low-priority pointers),
It has a set size in terms of the number of objects or parameter blocks it can hold. For some documents, it is easy to exceed this number. To determine the complexity, each type of object (high priority object and low priority object) within the band can be tested so that two tests can be performed: pointer buffer overflow and parameter block overflow. It is necessary to know how many (objects) exist.

The IGS 100 allocates an object to a new list parameter block and an old list parameter block for each band. The new list parameter block and the old list parameter block each have limited memory resources. If the object is in, for example, two adjacent bands, the part of the object in the band where the object started is stored in the new list parameter block and the object in the next band is The part is stored in the old list parameter block. Therefore, another limiting factor in determining page complexity is the amount of storage space consumed by the new and old list parameter blocks. If the total number of objects in the band is greater than or equal to the predetermined threshold, then the page is determined to be too complex. After that, the page is IG
It is sent to the image manipulation subsystem 58 before being provided to S100. The decomposer 120 keeps track of the size (words) of the new list parameter block and the old list parameter block needed to process each band. For each new object, i.e. the object stored in the band, an overhead is added to the new list total or the old list total, based on the size of the parameter block that this object produces. FIG. 3 is a table showing an example of many overhead counters corresponding to different objects. These object counters are checked against the allocated size of the parameter block list to determine if the parameter block overflows. If overflow is detected, the page is marked as complex.

FIG. 4 is a table showing an example of the overhead used for the new list parameter block and the old list parameter block in accordance with the present invention. In this table, the new list overhead of the object = MAX [maximum size of the parameter block for the object (word, or of the new list buffer in terms of number of object type parameter blocks generated in one band time size)〕

After disassembling the page, the decomposer 120
Sends a band list, a font descriptor, and an image descriptor describing a page to the IGS 100. This requires the availability of bandlists, fonts (descriptors and rasters), and images (descriptors and bitmaps) in system memory. There are limits to the memory resources available for communication with the image output terminal device 8. The complexity estimator must also prove that sufficient memory is available to hold all the data needed to image the page.

As shown in the table of FIG. 5, different types of objects have different overhead values due to the particular routine that must be executed. By summing the areas of everything in the band, adding to this the total overhead (number of microinstructions) of processing everything in the band, and comparing this sum with a given limit of words / bands, Can predict complexity.

Video channels may not have a uniform work distribution. Thus, the present invention mimics the loading of video channels when calculating page complexity. The parameter block generator creates a high priority new list and a low priority new list. As discussed previously, these lists describe objects that start in the current band being processed. The objects in these lists are
It is processed in the order in which it was placed in the band list, ie in ascending order of the z-plane. If the dispatcher detects a change in the z-plane and all video channels are not idle, the dispatcher waits for the video channels in use to complete processing and then begins its work.

The processing of the new list can be easily and accurately simulated by the decomposer 120. this is,
This is done by holding n independent areas.
Here, n is the number of video channels in the system.
This area list is kept and sorted in ascending order. For every object added to the band list, the area of that object (+ overhead for processing) needs to be added to the storage bucket of the smallest area (on IGS100, the first available video channel gets the object). The area list is then sorted. When the z-plane changes (ie, at the end of the page), the area storage buckets for all video channels are set equal to the maximum area storage buckets. 6, 7, and 8
Illustrates this graphically.

If the object crosses the band boundary,
The state of the object being processed is stored by the video channel in a high priority old list or a low priority old list. It is difficult to simulate the processing of the old list because the processing order of the objects cannot be determined. The order of objects in the band list is not the order in which the states were saved. This depends on the area in the current band, as shown in FIG. Therefore, it is more difficult to accurately simulate the processing of the old list.

The present invention keeps totalO for each band.
Takes information on ldListArea (object whose state has been stored, ie the total area of objects that continue from the previous band). The invention also takes maximum area information about objects within the band all the time. When the z-plane changes (that is, when the page ends), the new list area for all video channels is maxNewListArea and the average totalOldListArea.
And set to the sum of the largest OldListObjArea. If this sum is greater than or equal to the specified threshold, then the page is resubmitted to the image manipulation subsystem 58. FIG. 10 shows that this can be used to conservatively estimate the loading of the old list.

When determining the complexity of a page, the type of unique image present on the page must be determined.

The new list parameter block overhead counter is incremented by a predetermined number of words for each predictive break starting in the band. This is IGS1
00 is necessary to ensure that it has sufficient resources to process the band. The complexity estimator keeps track of the number of unique images on the page and the total size of the images on the page. This information is necessary to ensure that there are sufficient resources to load the image in memory into IGS 100.

One inherent image type that affects page complexity is a windowed image, that is, an image on a page that has boundaries so that at least a portion of the image is not visible. When calculating the area of a windowed image, the invention uses the y dimension of the image instead of the y dimension of the window to calculate the area. Video channels need this way to generate all image data, even if the image is windowed.

With respect to images, another factor affecting page complexity is image compression (ie, how well the image shrinks). There may be situations where the image compression ratio adds some extra overhead.

Yet another factor affecting page complexity is image magnification. When magnifying an image in the IGS 100, it is very easy to evenly distribute the work among the video channels. An example is
The printing device has multiple video channels (eg, 8 video channels) and the image has, for example, 16
Scan line predicted break frequency and an expansion value of 2. This means that the predictive breaks are 32 scanlines apart and all eight video channels have something to do. However, if the magnification value is 4, the predicted break is 64 and only 4 video channels will be busy. To clarify this, the actual area of the image is calculated and added to the band area.

Yet another factor affecting page complexity is the predicted break size of the image. If the predicted break size of the image is large, the invention
Sometimes it determines if there is a non-uniform distribution of band area. For example, in a printer with 8 video channels, if the predicted break size of the image is 6
If 4, only 4 out of 8 video channels are in use. In this case, the area of each band is calculated and added to the band area.

The complexity must be determined band by band. Accuracy cannot be obtained page by page. For each band, calculate the area of the image using the actual size of the object and add to that band area.

If the object consists of text, consider some complexity factors. The area of the specified character is added to the total area of the band.

For each character that starts in the band, the new list parameter block overhead counter is incremented by a predetermined number of words. This is necessary to ensure that IGS 100 has sufficient resources to process the band. The present invention keeps track of the number of unique fonts on a page and for each font the total size of the raster matrix within the page. This information is needed to ensure that sufficient resources are available to load the raster in memory into IGS 100.

If the character extends to the next band,
Determines character area based on scanLength and the actual scanline in the band.

In the case of text, the overhead is the number of words plus the number of scanlines (xLength).

If the object consists of rules or rectangles, consider some complexity factors.

The actual area of the object in the band is calculated and added to the total area of the band. In the case of rules, it also adds processing overhead to the band area. Overhead is (double xLength in the current band + 110 words / rule)
Is.

For each rule that starts in the band,
Increment the new list parameter block overhead counter by 12 words. This is necessary to ensure that IGS 100 has sufficient resources to process the band.

If the rule extends to the next band, the area of the object is calculated and added to the band area.

As shown in FIG. 11, first, the rule is divided into smaller rules, and the areas of the smaller rules are calculated as follows. For the first band and the last band: (a) Calculate the number of rule scanlines in the band. (B) TotalBandArea = ((yLength / 16) +1) x number of scanning lines For the middle band, TotalBandArea = (yLength / 16) x 256

The rules are divided into smaller rules so that all video channels can act on the object at the same time. Break rules at word boundaries to maximize video channel productivity. There is overhead associated with processing the object. Decomposer 120
Makes sure the size of the rule is at least processing overhead.

Referring now to FIGS. 12, 13 and 14, the rules are split using the following criteria. yMin (the minimum yLength of the rule) = 16, if xLength ≥ 256 4096, if xLength IN [0..15] 4096/16, if xLength IN [16..31] 4096/32, if xLength IN [32. .63] 4096/64, if xLength IN [64..127] 4096/128, if xLength IN [128..255] ruleDelta (the length of smaller rule in y direction) = MAX [yMin, (yLength / 8) ]; rounded up to a multiple of 16.a) Generate first rule: yStart = yStartObject, yEnd = yStartObject + ruleDelta Align the first rule to a word boundary by rounding up yEnd to a mutiple of 16.b) yStart = yEnd +1 c) yEnd = yStart + ruleDelta d) if yEnd ≥ yEndObject then yEnd ≥ yEndObject; Generate Entry; EXIT e) if yEndObject-yEnd <yMin then yEnd ≥ yEndObject; Generate Entry; EXIT f) Generate Entry g) Go to (b)

When the object includes a corner or a curve, the object is divided into a plurality of trapezoids. Consider the following factors to determine complexity. 1) Determine the area of the trapezoid by calculating the area of the box that touches the boundary. Add this area to the total area of the band. For trapezoids, additional processing overhead is added to the band area. The overhead is (2 xLength of the current band)
Double +130 words / trapezoid).

2) For each trapezoid that starts in the band, increment the new list parameter block overhead counter by 22 words. This is necessary to ensure that IGS 100 has sufficient resources to process the band.

If the trapezoid extends to the next band,
The area of the bounding box is calculated and added to the band area.

Referring to FIG. 15, the area of the box touching the boundary is calculated as follows. For the first band and the last band: a) Calculate the number of scan lines of the object in the band. b) TotalBandArea = ((maxYLength / 16) × 256

[0060]

As described above, the present invention determines the complexity of pages to be printed. To make complexity decisions, we evaluate various factors that affect complexity, including the number of objects on the page and the geometrical shapes of the objects. The complexity determination is done prior to providing the page image to the image generation subsystem. If the page is determined to be complex, i.e., the page cannot be imaged in real time, the page is automatically triaged before the job containing the complex page is submitted to the image generation subsystem. Turn into.

In this manner, the printing device avoids printing failures associated with complex pages by examining the page content before providing it to the image generation subsystem.
Page content inspection is performed without user intervention and avoids printing device outages that are typically associated with printing failures due to page complexity, thus improving overall productivity of the printing device. In addition, most pages are kept in a compact intermediate format and are not simplified before serving to the image generation subsystem unless the page is determined to be complex, thus maximizing storage space usage within the device. To be done.

Although the present invention has been described in terms of particular embodiments, those skilled in the art will recognize many other alternatives, modifications and equivalents. Therefore, the preferred embodiments of the invention described herein are illustrative of the invention and not limiting. Various changes can be made within the spirit and scope of the invention described in the claims.

[Brief description of drawings]

FIG. 1 is a perspective view showing an electronic printing apparatus of the present invention.

FIG. 2 is a block diagram showing components of the printing apparatus of FIG.

FIG. 3 is a diagram showing a table of an example of a correspondence relationship between an overhead counter and an object.

FIG. 4 shows a table of example overheads used for new list and old list parameter blocks.

FIG. 5 is a diagram showing a table of examples of types of objects and corresponding overhead values.

FIG. 6 is a schematic representation (1) of a new list process.

FIG. 7 is a schematic representation (2) of the new list process.

FIG. 8 is a schematic representation (3) of the new list process.

FIG. 9 is a diagrammatic representation of old list processing.

FIG. 10 is a diagram showing estimation of old list loading.

FIG. 11 is a diagram showing a method of dividing a rule into smaller rules.

FIG. 12 is a diagram (No. 1) showing a method of decomposing rules.

FIG. 13 is a diagram (No. 2) showing a method of decomposing rules.

FIG. 14 is a diagram (No. 3) showing the method of decomposing rules.

FIG. 15 is a diagram showing a method of calculating the area of a trapezoid.

[Explanation of symbols]

 2 electronic printing device 6 image input terminal device 7 controller section 8 image output terminal device 25 processor 50 image input controller 51 image compressor / processor 52 user interface 54 system controller 56 main memory 58 image manipulation subsystem 60 image output controller 62 interactive touch Screen 64 Keyboard 66 Mouse 90-1, 90-2, 90-3 Fixed Disk 100 Image Generation Subsystem (IGS) 120 Decomposer

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Andrew D. Post New York, USA 14564 Victor East Main Street 277 (72) Inventor Richard T. Lauria New York, USA 14526 Penfield Glen Valley Live 11 (72) Inventor Keith Amey New York, USA 14502 Macedon Monroe Wayne County Line Road 3226 (72) Inventor Gary Padrypski USA California 90250 Hawthorn West One Handed and Nineteenth Places 5013

Claims (1)

[Claims] 1. An image input terminal device for inputting page image data, a controller unit for receiving and processing page image data from the image input terminal device, and receiving and printing page image data from the controller unit. And an image generation subsystem that generates the page image data in digital format in real time and gives the image output terminal device to the image output terminal device. A decomposer that determines whether the image generation subsystem can generate the page image data to be provided to the subsystem in real time, and the decomposer determines that the page image data exceeds the real-time processing capability of the image generation subsystem. After determining, prior to providing image data to the image generation subsystem, an electronic printing apparatus characterized by comprising an image manipulation subsystem, to simplify the image data.