JPH05244367A - Image processor - Google Patents

Abstract

PURPOSE:To control the compressed code data storing area in an image storage device where an area is secured so that a memory overflow does not occur again when the memory overflow occurs. CONSTITUTION:The storing area is secured in a data storing means (page buffer) 6 based on the predicted quantity of compression sign data so that a control means 2 for inputting and compressing image data is provided and image data inputted from respective image input means is compressed by a data compressing means 4 so as to be stored in the data storing means 6 and stored in a data storing means (disk) 7. Then, stored data is read so as to be extended in a data extending means 5. When the storing area which is secured in the data storing means 6 overflows while inputting image data at the time of transmitting data to an image output device 20, the storage of compressed code data to the data storing means 6 is held, the input and compression processing of image data is continued and compressed code data is measured so that the storing area of the data storing means 6 is secured and an image input is permitted again.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus for compressing image data input from image input means into compressed code data, accumulating the compressed code data, decompressing the compressed code data and sending it to the image output means.

[0002]

2. Description of the Related Art In recent years, with the widespread use of personal computers and word processors, image information to be subjected to processing such as copying in office work has been diversified and increased in quantity. Along with this, it is needless to say that even a copying machine for producing a copy of an original needs to further improve the image quality of the image to be copied. In addition to enlarging or reducing image information for copying, various other functions are required. For this purpose, for example, an electronic RDH that electronically performs a copying operation in a state where a plurality of originals are sorted by an arbitrary number of copies.
(Electronic Recirculating Document Handler)
Edit the original image so that the original image becomes a booklet in which the original images are arranged in page order by copying both sides of a large number of originals on a single side of the recording paper and dividing each page into two pages. Then, there is a bookbinding function for copying.

Conventionally, as a copying machine that can realize this kind of function, for example, there is the following digital copying machine. That is, in this digital copying machine, an original is copied into an ADF (automat
By setting the icDocment Feeder), the document is automatically conveyed by the ADF to the platen of the copying machine, the image of the document is read by the scanner, once converted into a digital signal and stored. Then, the stored image information is read out and IOT (Image Output) is set.
The image is recorded by the terminal (Terminal), and the copy function of the document is realized.

In such a digital copying machine, when storing the image information of the document read by the scanner, the informational redundancy of the image information of the document is compressed so that more image information can be stored. An image storage device is used that stores image information while reducing the amount of information.

In this image storage device, image information read from a scanner is compressed by a compressor and then stored in a large-capacity storage device such as a hard disk. At this time, the time required to store the image information in the storage device is about 1 megabyte / second including the seek time, and the normal transfer speed of the image information sent from the compressor to the storage device. Since it is slower than about 10 megabytes / second, the image compressed by the compressor cannot be transferred to the storage device and stored as it is. Therefore, a buffer memory that temporarily stores image information in page units is provided between the compressor and the storage device, and image information transferred from the compressor is temporarily stored in page units in this buffer memory. To do. Then, the image information temporarily stored in the buffer memory is transferred to and stored in the storage device in synchronization with the storage device.

After that, when the image information is taken out from the storage device, similarly, in order to absorb the speed difference, the image data is temporarily stored in the above-mentioned buffer memory, and when one page of image information is gathered, it is expanded. The image is stored by the IOT after being transferred to a container and sequentially decoded.

[0007] Such a buffer memory has a certain amount of storage capacity in order to improve the synchronization, and in consideration of the difference in document size and the variation in the compression ratio of image information, or the input to the storage device. It is desirable to be dedicated for output. However, the increase in memory capacity directly leads to an increase in the cost of the entire device, so in reality,
It is often implemented as a general purpose and multipurpose common buffer memory by devising a management method of the buffer memory. Therefore, the buffer memory is dynamically controlled by a plurality of jobs, and each job is managed so that the minimum required buffer memory is allocated each time.

By the way, as for the image compressor for compressing the image information, the size of the code data to be output is not constant due to the regularity of the image, the print ratio, etc., and the compression ratio is generally unstable. ing. In such a compressor, the amount of compressed code data after compression varies greatly depending on the image information, and it is impossible to know the exact amount of compressed code data until the actual compression. Therefore, after securing the area of the buffer memory described above, the scanner data image information is input and image compression is started, but the compression code data amount after compression is set in advance, for example, the document size such as A4 or B5, or the photograph. Predict with a value such as an average compression ratio based on experience according to the type of original such as original, halftone original, and character original, and secure a buffer memory area with some margin That is generally done conventionally.

However, as a result of the actual compression, the so-called memory overflow may occur even if it exceeds the buffer memory area secured with some margin.
I can't get rid of 00%. In response to such a memory overflow, as disclosed in Japanese Patent Laid-Open No. 60-100873, when a memory overflow occurs, input of image information and storage in a buffer memory are interrupted, and another memory overflow occurs. A method has been devised in which the area released by the job is added to secure a larger area, and then the data is stored again in the buffer memory.

[0010]

However, although the above-described countermeasure seems to be good at first glance, as described above, the amount of compressed code data after compression varies greatly depending on the image information, and the compression actually ends. Until then, it is impossible to know the exact amount of compressed code data. Therefore, in the above countermeasure, the memory overflow may occur again at the time of re-input, and the re-input may be repeated. Further, since the processing does not proceed while taking such steps of trial and error, the productivity of the entire system is greatly affected.

Therefore, the present invention is to solve the above-mentioned problems, and when a memory overflow occurs, a compression code of an image storage device which can secure an area so that the memory overflow does not occur again. It is an object of the present invention to provide a method for controlling a data storage area.

[0012]

Therefore, according to the present invention, an image input means 11 for inputting image data as shown in FIG.
To 19, a data compression unit 4 for compressing image data into compressed code data, and a data storage unit 6 capable of storing at least one page of image data or compressed code data.
A data storage means 7 for storing and accumulating the data stored in the data storage means 6, a data decompression means 5 for decompressing the compression code data to restore the original image data before compression, and an image output for outputting the image data. In order to compress the image data for a plurality of pages input from the means 20 and the image input means, a storage area is secured in the data storage means 6 based on the predicted amount of the compression code data, and then the image data is input. And the control means 2 for controlling each means so as to perform compression, and the image data input from the image input means 11 to 19 is compressed into compressed code data by the data compression means 4 and stored in the data storage means 6 to store the data. In the image processing device configured to store the data in the storage means 7, read the stored data, decompress it in the data decompression means 5, and send it to the image output means 20. If the storage area secured in the data storage means 7 overflows while the image data is being input, it is provided with a data amount measuring means for measuring the amount of compressed code data obtained by compressing the data and a storage area overflow detecting means 22 of the data storage means. The storage of the compressed code data in the data storage means 6 is suspended, the input of image data and the compression process are continued to measure the compressed code data amount of the image data, and the data storage means 6 is measured with the measured compressed code data amount. Is secured and the image input is permitted again.

[0013]

In the image processing apparatus of the present invention, the data amount measuring means for measuring the compressed code data amount obtained by compressing the image data and the overflow detecting means 2 in the storage area of the data storing means 2 are provided.
2, the image data input from the image input means 11 to 19 is compressed into compressed code data by the data compression means 4, stored in the data storage means 6 and stored in the data storage means 7, and then the stored data is read out. When the storage area secured in the data storage means 7 overflows during image data input when the data is expanded by the data expansion means 5 and sent to the image output means 20, the storage of the compressed code data in the data storage means 6 is suspended. Since the input and compression processing of the image data is continued to measure the compressed code data amount of the image data, the storage area of the data storage means 6 is secured by the measured compressed code data amount, and the image input is permitted again. When the image is re-input, the compressed code data can be stored in the storage area secured in the data storage unit 7 without overflow.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration of an embodiment of an image processing apparatus of the present invention, and FIG. 2 is a diagram showing a configuration example of a page buffer transfer circuit.

In FIG. 1, the image control apparatus 1 includes a multiplexer 3 for switching the image data of the image reading apparatus and the image data of an external device such as a PC or FAX, a compressor 4 for compressing the image data, and a compression code data. 5, a page buffer 6, a page buffer 6, a disk 7 as a large-capacity data storage memory, and a page buffer having a composite counter for counting the compressed code data output from the compressor 4 and an address generation circuit. It comprises a transfer circuit 22 and a control circuit 2.

The scanner 18 is an image reading device that reads a document using, for example, a CCD sensor and inputs image data, and performs offset adjustment and gain adjustment of a read signal to convert analog image data into digital image data. , Gap correction, shading correction, etc. When reading a color image, R (red), G
Image data of the three primary colors separated into (green) and B (blue) are taken out, and for example, END (equivalent neutral density conversion), color masking, document size detection, color conversion, UCR (undercolor) Removal) and black generation, halftone dot removal and edge enhancement, TRC (color tone correction control), reduction / enlargement processing, and editing processing. The ADF 19 is attached to the scanner 18 and automatically feeds the read document.

The PC 17 is an arbitrary personal computer, and the PC decomposer 16 expands the code data of the PC 17 into a bit map. IOCP
Reference numeral 11 denotes an external device control circuit device including a PC image data input circuit 15, a page buffer 12, an image transfer circuit 14, and a control circuit 13. The image data stored in the IOCP page buffer 12 is appropriately divided and transferred. To do.

The image output device 20 can control the on / off of the laser beam for each pixel based on the binary data generated from the image data to reproduce a halftone image by halftone dots, for example, a laser printer. Is. The UI 21 is composed of a display, a control panel, and the like, and inputs various functions and editing settings, and displays and outputs their contents.

The components of the image control device 1 are as follows. The multiplexer 3 connects the input side bus connected to the image bus 8 to the scanner image bus 9 or IO.
It is switched to the CP image bus 10. Compressor 4
Has a compression mode and a through mode, and compresses data in the compression mode by, for example, an adaptive predictive coding method. The adaptive predictive coding method is a method in which, for example, image data is simultaneously predicted by a plurality of predictors for every 8 pixels, and the predictor with the highest hit rate is used for the prediction of the next 8 pixels. In this case, the pixel signal that the prediction hit

[0], the deviated pixel signal is replaced by [1].

As shown in FIG. 2, the page buffer transfer circuit 22 includes an address generation circuit 31 and two counters 32,
It is composed of 33. The address generation circuit 31 is a circuit which is initialized by the control circuit 2 and generates the address of the page buffer 6 for each transfer unit. The output (compressed code data) of the compressor 4 is generated by this address generation circuit 31. It is stored in the page buffer 6 according to the address. Further, the address generation circuit 31 can fix the generated address to the specific address designated by the control circuit 2. Of the two counters 32 and 33,
One is an up counter 3 for measuring the code data amount.
3, the control circuit 2 reads the code data amount,
The counter value can be reset to 0. The other is a down counter 3 that detects memory overflow.
2, the count value can be initialized by the control circuit 2. Moreover, when the count value becomes 0, an interrupt signal is generated in the control circuit 2, and this signal causes the control circuit 2 to generate an interrupt signal.
Can recognize that a memory overflow has occurred.

The decompressor 5 has a decompression mode and a through mode, and decompresses the compressed data in the decompression mode to restore the original image data before compression.

The page buffer 6 stores image data for several pages of an original, and temporarily stores write data of the disk 7 and read data from the disk 7, and outputs image data for image output. Is temporarily stored in the disk 7 without being written, and the control circuit 2 edits the data such as rewriting or replacement and outputs the data.

The disk 7 is a large-capacity data storage memory for storing a large amount of compressed coded data, and the disk controller HDC controls writing and reading. The data stored on the disk 7 includes binary and multi-valued image data and code data.
The code data is, for example, input from the IOCP image bus 10 through the multiplexer 3 and the compressor 4 without performing the bitmap processing in the PC decomposer 16. Therefore, in this case, the compressor 4 is in the through mode. In addition, the through mode is used when the image data input to the compressor 4 is directly stored in the page buffer 6 or directly output without performing the compression processing by the compressor 4 and the expansion processing by the decompressor 5. ..

Next, an outline of the operation of the image control device 1 having the above configuration will be described. First, when a request for image information input is received from the operator through the UI 21 for inputting a job designation, the control circuit 2 checks the empty area of the page buffer 6, and determines the document size such as A4 and B5, the text document, the photo document character / The area of the page buffer 6 is secured with a certain amount of margin with respect to the compression code data amount preset as the compression code data amount after compression based on the attributes of the input image such as a photo mixed document and a graphic document. To do.
Then, the scanner 18, the ADF 19, and the IOCP 11 are instructed to input the image information, the MPX 3 is selected, and the compressor 4 that compresses the input image and the page buffer 6 that temporarily stores the compressed compression code data are activated. At the same time, the address generation circuit 3 of the page buffer transfer circuit 22.
1, an up counter 33 that measures the amount of compressed code data output from the compressor 4, and a down counter 32 that detects an overflow of the storage area of the page buffer 6 are initialized. When each processing unit is started in this way,
The compression code data starts to be stored in the reserved area of the buffer memory 6.

At this time, when the compressed code data tries to exceed the area secured by the buffer memory 6 during the input of the image information, the down counter 32 becomes 0, so that a memory overflow is detected and the information is interrupted by the control circuit. 2 will be notified. In that case, the control circuit 2 prevents the page buffer transfer circuit 22 from overwriting the area reserved by the buffer memory 6 and overwriting the area used by another job.
The writing of the compression code data is interrupted by fixing the address to 1.

At this time, in the conventional image processing apparatus, the scanner 18, the ADF 19 and the IO for inputting the image information of the document are input.
The CP 11 and the compressor 6 for compressing the input image are also stopped, but in the present invention, they are continued.
Then, after the scanner 18, the ADF 19, the IOCP 11 and the compressor 4 finish the input process of the image information, the control circuit 2
Reads the measured value of the compressed code data amount output from the compressor 6 from the up counter 33 of the page buffer transfer circuit 22. Then, when the area of the buffer memory 6 is secured when the image information is input again, the area of the measured compressed code data amount is secured so that the memory overflow does not occur again.

FIG. 3 is a flow chart for explaining the flow of processing by the control circuit 2. First, when a job request is input from the operator through the UI 21 (step 100), the control circuit 2 checks the empty area of the page buffer 6 and attributes of the input image such as a binary image such as a character or a photograph or a halftone dot image. Predict the amount of compressed code data after compression from
Furthermore, with a certain amount of leeway, page buffer 6
Area is secured (step 101). Then, the down counter of the page buffer transfer circuit 22 is set to the predicted compressed code data amount (step 102), to the address of the page buffer 6 where the address generation circuit has secured the area (step 103), and the up counter is set to 0. (Step 104), each is initialized. Next, the compressor 4 for compressing the image is activated (step 105), and the scanner 18 or the IOCP 11 for inputting the image information of the original is instructed to input the image information (step 106). When each section is set in this way, the compressed code data starts to be stored in the secured area of the page buffer 6, and the control circuit 2 waits for the end of the input of image information (step 107).

Here, it is assumed that an overflow, which is the subject of the present invention, has occurred. In that case, the compressed code data is stored in the entire area secured in the page buffer 6 during the input of the image information, and the down counter of the page buffer transfer circuit 22 becomes zero. Therefore, an interrupt signal is input from the page buffer transfer circuit 22 to the control circuit 2 (step 108). Therefore, the control circuit 2 stores the control information indicating that a memory overflow has occurred in the interrupt process (step 109) so as not to overwrite the area reserved by the page buffer 6 to the area used by another job. To do. For example, the address generation circuit of the page buffer transfer circuit 22 is set so as to generate an arbitrary fixed address in the page buffer 6 that secures the area (step 110), and the interrupt processing is ended (step 1).
11).

When the scanner 18 or IOCP 11 and the compressor 4 have finished the processing of inputting and compressing the image information, the control circuit 2 checks the control information stored in the interrupt processing that the memory overflow has occurred (step 112). ). Then, when the overflow does not occur, the input processing of the image information is normally terminated (step 116), but when the overflow which is the subject of the present invention occurs, the compression code output from the compressor 4 is generated. Measure the amount of data. In this measurement, the up-counter of the page buffer transfer circuit 22 is read and the compressed code data amount is read (step 113).

Then, in order to input the image information again,
This time, the area of the page buffer 6 is secured with the measured accurate compression code data amount (step 115). Therefore, after that, since the address of the page buffer 6 which has secured the area again is set in the address generation circuit of the page buffer transfer circuit 22, the flow after step 103 is repeatedly executed. This allows the page buffer 6
Since the area of is secured with the correct compression code data amount,
Overflow cannot occur, and the image information input process ends normally (step 116).

By the procedure described above, the control circuit 2
Is capable of accurately knowing the occurrence of overflow and the amount of compressed code data at that time. If an area of an accurate amount of compressed code data is secured from the page buffer 6 when inputting image information again. , It is possible to prevent the memory overflow again.

The present invention is not limited to the above embodiment, but various modifications can be made. For example, in the above embodiment, the address generation circuit of the page buffer transfer circuit 22 is set so as to generate an arbitrary fixed address in the page buffer 6 which has secured the area due to the occurrence of the memory overflow. The compression in the page buffer 6 may be stopped and the compression process may be continued, or a dummy address when a memory overflow occurs may be set in advance.

[0033]

As described above, according to the present invention, a counter for measuring the amount of compressed code data is provided, and when a memory overflow occurs by the counter, the compression process is continued without interruption and the compressed code is continued. Since the amount of data is measured, it is possible to secure an area of an accurate amount of compressed code data at the time of recovery, and it is possible to prevent memory overflow.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of an image processing apparatus of the present invention.

FIG. 2 is a diagram showing a configuration example of a page buffer transfer circuit.

FIG. 3 is a flowchart for explaining the flow of processing by the control circuit 2.

[Explanation of symbols]

1 ... Image control device, 2 ... Control circuit, 3 ... MPX (multiplexer), 4 ... Compressor, 5 ... Decompressor, 6 ... Page buffer, 7 ... Hard disk, 8 ... Image bus, 9 ... Scanner image bus, 10 … IOCP image bus, 11… IOCP
(Input / Output Coprocessor), 12 ... IOCP page buffer, 13 ... IOCP control circuit, 14 ... Image transfer circuit, 15 ... PC data input circuit, 16 ... PC decomposer, 17 ... PC (personal computer), 18
… Scanner, 19… ADF (Auto Document Termina
l), 21 ... UI (User Interface), 22 ... Page buffer transfer circuit.

Claims (1)

[Claims] 1. An image input means for inputting image data,
Data compression means for compressing image data into compressed code data, data storage means capable of storing at least one page of image data or compressed code data, and data storage means for storing / accumulating the stored data of the data storage means. ,
Data decompression means for decompressing compressed code data to restore the original image data before compression, image output means for outputting image data, and compression of image data for a plurality of pages input from the image input means. The image input from the image input means is provided with a control means for controlling each means so as to input and compress the image data after the storage area is secured in the data storage means based on the predicted amount of the compressed code data. The data is compressed into compressed code data by the data compression means, stored in the data storage means and accumulated in the data storage means, and then the accumulated data is read out, decompressed by the data decompression means and sent to the image output means. In an image processing apparatus, an overflow detection of a storage area of a data amount measuring unit and a data storage unit that measures a compressed code data amount obtained by compressing image data. If the storage area secured in the data storage means overflows during the image data input, the storage of the compressed code data in the data storage means is suspended and the input and compression processing of the image data is continued. An image processing apparatus, which measures a compression coded data amount of the image data, secures a storage area of a data storage unit with the measured compression coded data amount, and permits image input again.