JP2003069835A - Image processor, method, computer program and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform encoding that is accommodated in a target size without trying to reinput image area information of a multi-valued image again. SOLUTION: Multi-valued image data inputted from an inputting part 101 generates, by using an image area information generating part 1701, image area information composed of an image area component denoting whether each pixel exists in an character/line drawing area or halftone area or an image area component denoting whether each pixel is a chromatic color or an chromatic color in each pixel. A reversible encoding part 1705 encodes the information in a block unit and stores the encoded information in a third memory 1709. An encoding controlling part 1713 monitors code quantity, and if the encoding controlling part 1713 decides that the code quantity exceeds target quantity, the encoding controlling part 1713 makes the reversible encoding part 1705 change an image area component coinciding with a condition about image area components that is later inputted and subsequently encode the image area component. Meanwhile, about codes that have been already stored in the third memory 1709, a reversible encoding and recording part 1715 once decodes the codes, changes the image area component, subsequently recodes the codes and stores the resultant codes in the third memory 1709.

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 having a function of compressing and encoding image area information associated with the image data within a certain code amount.

[0002]

2. Description of the Related Art Conventionally, as a still image compression method, a JPEG method using a discrete cosine transform and a method using a Wavelet transform have been widely used. Since this type of encoding method is a variable length encoding method, the code amount changes for each image to be encoded.

In the JPEG method, which is an international standardization method,
Since only one set of quantization matrix can be defined for an image, the code amount cannot be adjusted without prescanning.
When used in a system that stores data in a limited memory, there was a risk of memory over.

In order to prevent this, when the code amount exceeds the planned code amount, the compression ratio is changed to read the original again, or the code amount is estimated in advance by prescan to adjust the code amount. In order to do so, methods such as resetting the quantization parameter have been adopted.

On the other hand, the image information includes image area information attached to the image data in addition to the original image data. The image area information is mainly used for color processing and adjustment of the number of gradations in the image output unit in order to improve the appearance when outputting the image. For natural images that mix chromatic and achromatic colors and black characters that are often seen in documents, changing the type of ink used even for the same black color makes the natural image look like a natural image, while outputting clear characters. You can do it.

Thus, for each pixel, a chromatic color or an achromatic color,
By having the 1-bit attribute flag data indicating whether the character portion or not, it is possible to improve the image quality of the output image at the time of image output, particularly at the time of printout.
The image area information includes information other than the above.

In order to compress the image information, it is necessary to compress the image data as well as the image data. The image area information is a collection of binary data, and it is basically necessary to use a reversible coding method to compress this. Conventionally, Packbits and JB are used to compress the image area information.
The IG coding scheme has been used.

However, the code amount cannot be adjusted only by compressing the image area information by these encoding methods.
When used in a system that stores data in a limited memory, there is a risk of memory over, which is a big problem.

[0009]

However, conventionally, only compression of image data has been studied, and compression of image area information has been rarely studied. not to mention,
It is almost impossible to think that the code amount of the image area information after compression falls within a target value, and the image area information is simply encoded using a certain encoding method.

The present invention has been made in view of the above-mentioned conventional example, and an effective image processing apparatus for controlling the input of image area information within a code amount within a target value, a control method therefor, a computer program, and a storage. It is intended to provide a medium.

[0011]

In order to solve such a problem, for example, an image processing apparatus of the present invention has the following configuration. That is, for each pixel of the multi-valued image data, image area information composed of a plurality of types of image area component data is input,
An image processing device for compression-encoding the image area information,
First encoding means for losslessly encoding the input image area information, storage means for storing the encoded data losslessly encoded by the first encoding means, and encoded data stored in the storage means Of the data encoded by the first encoding means and the second encoding means for decompressing, reversibly encoding and storing in the storage means again, and checking whether the target data amount is exceeded or not. The monitoring means for judging, and when the monitoring means judges that the target data amount is exceeded, the image area information coded by the first coding means and the image area information decompressed by the second coding means are obtained. Control means for requesting to change the image area component data in each of the image area information according to a predetermined condition, and when there is a request for changing the predetermined image area component data by the control means, the first Encoding means can be input subsequently The requested image area component data in the image area information to be encoded is encoded and stored in the storage means, and the second encoding means is the encoded data already stored in the storage means. In the expanded image area information, the requested image area component data is changed, then re-encoded and stored in the storage means.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. First, the basic part will be described.

FIG. 1 is a functional block configuration diagram of an image processing apparatus 100 to which the embodiment is applied. Hereinafter, each part of the figure will be briefly described.

The image processing apparatus 100 has an input unit 101 for inputting an image from an image scanner. In addition,
The input unit 101 may input image data from page description language rendering or the like, or may be realized by reading an image file stored in a storage medium, and may be received from a network in some cases. Is also good.

The encoder 102 encodes the input image data. The encoding method is the well-known JPEG.
By using an encoding method, image data corresponding to a unit of 8 × 8 pixels is orthogonally transformed, and quantization and Huffman encoding processing using a quantization step described later are performed.

The first memory control unit 103 and the second memory control unit 105 receive the encoded data (same encoded data) output from the encoding unit 102, respectively.
The memory 104 and the second memory 106 are controlled to be stored. Here, the first memory 104 stores the finally determined encoded data (compressed to a data amount within a target value) in a network device and an image output device connected to the outside of the basic configuration of FIG. 1. Or a memory for holding the encoded data for output to a mass storage device or the like. The second memory 106 is a working memory that assists the compression coding process for forming the coded data on the first memory.

The counter 107 counts the data amount of the image data compressed and coded by the coding unit 102, holds the count value, and controls the coding sequence based on the count result. To 108.

The encoding sequence control unit 108 detects whether the count value of the counter 107 has reached a certain set value, and when it detects that the set value has been reached (exceeds a target value) A control signal is output to the first memory control unit 103 to discard the stored data of 1. The first memory control unit 103 clears the memory address counter based on this control signal, or
Alternatively, the stored data is discarded by clearing the encoded data management table. In addition, at this time, the coding sequence control unit 108 determines that the first counter 107
Is cleared to zero (input from the input unit 101 is continued), and the encoding unit 102 is controlled to perform encoding at a higher compression rate than before. That is, the data amount of the coded data generated in the coding process of the present apparatus is controlled so as to finally become, for example, 1/2. It should be noted that although it is set to 1/2 here, it can be set arbitrarily.

The coded data after the compression rate change is also
As before, it is stored in the first memory 104 and the second memory 106 via the first memory control unit 103 and the second memory control unit 105, respectively.

Further, the coding sequence control unit 108
Reads the encoded data stored in the second memory 106 so far to the second memory control unit 105,
A control signal is output to the re-encoding unit 109 which is the encoded data conversion means so as to output the encoded data.

The re-encoding unit 109 decodes the input encoded data, performs re-quantization to reduce the amount of data, and then performs the encoding process again, and the encoding unit whose compression rate is changed. The data amount having the same compression ratio as 102 is output to the second counter 110.

The encoded data output from the re-encoding unit 109 passes through the first memory control unit 103 and the second memory control unit 105, and the first memory 10 respectively.
4 and the second memory 106.

Whether or not the re-encoding process has been completed is determined by the second
Is detected by the memory control unit. That is, when there is no more data to read for the re-encoding process, the encoding sequence control unit 108 is notified of the end of the re-encoding process. Actually, the encoding process is completed after not only the reading process of the second memory control unit 105 but also the process of the re-encoding unit 109.

The count value obtained by the second counter 110 is obtained by the first counter 10 after the re-encoding process is completed.
It is added to the counter value held in 7. This addition result represents the total amount of data in the first memory 104 immediately after the re-encoding process is completed. That is, at the time when the encoding process of the encoding unit 102 and the re-encoding unit 109 for one screen is completed, the counter value held by the first counter 107 after the addition is for one screen. Represents the total amount of data generated in the case of encoding (details will be described later).

The encoder 102 terminates the re-encoding process /
Regardless of whether it is not finished, the encoding process is continued as long as the image data from the input unit 101 to be encoded remains.

Whether or not the count value of the counter 107 has reached a certain set value is repeated until the encoding process (encoding and re-encoding) of the image data for one page input from the input unit 101 is completed. The encoding and re-encoding processing is performed under the control according to the detection result obtained here.

A flow chart showing the flow of processing in the above-mentioned configuration of FIG. 1 is shown in FIG. 8, but for simplification of description, it will first be described according to the simplified flow chart of FIG.

As described above, the image processing apparatus 100 of the present invention uses the input unit 101, such as a scanner, to input 1
This is a device that compresses and encodes page image data to a predetermined data amount or less. In order to realize the encoding process, in addition to the input unit 101, an encoding unit 102 and a re-encoding unit 10
9, a first memory 104, a second memory 106, and the like. Encoding processing is performed using these functional blocks based on the flowchart shown in FIG.

The flowchart of FIG. 3 is roughly divided into the following three processing phases. (1) Encoding phase (2) Encoding / re-encoding phase (3) Transfer phase In each of the above processing phases, how image data, encoded data, etc. are processed by flow, FIG. 4 shows visually whether it is stored or not.
Through FIG. 7.

FIG. 4 shows the initial state of the encoding phase corresponding to steps S303 and S305 in the flowchart of FIG. Further, FIG. 5 shows steps S307 to S307.
6 shows the processing state of the encoding / re-encoding phase corresponding to 315, FIG. 6 shows the processing state of the transfer phase corresponding to step S317, and FIG. 7 shows the processing state of the encoding phase after the transfer phase. Each phase will be described below.

<< Encoding Phase >> The encoding process of the image data for one page starts from the initial setting of encoding parameters (step S301). Here, the upper limit value of the encoded data amount that is uniquely determined from the image size to be encoded (the paper size read from the input unit 101 such as a scanner) and the encoding unit 102 (here, a known JPEG encoding method is used). Parameters such as the quantization step (Q1) applied to

Then, in step S303, the first counter 107 performs actual encoding processing (JPEG compression in units of 8 × 8 pixels of the image) and cumulatively counts the amount of encoded data to be output. .

Next, in step S305, it is detected whether or not the count value of the data amount exceeds the upper limit value, and if not, the JPE in step S303.
The G encoding process is continued. This is the initial encoding phase.

The encoded data output from the encoding unit 102 is stored in both the first memory 104 and the second memory 106 as shown in FIG. The area indicated by vertical stripes represents the stored code.

<< Encoding / Re-Encoding Phase >> When the encoding process of the encoding unit 102 progresses and the count value of the data amount exceeds the set upper limit value, the first step is performed in step S307. The coded data in the memory 104 of FIG.
Change the quantization step of 02 to Q2.

When the count value of the data amount of the encoded data exceeds the set upper limit value, it means that the data amount after compression does not fall within the target value. Therefore, it is meaningless to continue the encoding process using the same quantization step, so that the quantization step Q2 having a larger quantization step width than Q1 is changed so that the data amount becomes smaller than before. is there.

After changing the quantization step, step S
In 311 the encoding process of the encoding unit 102 is restarted, and as shown in FIG.
The encoded data is stored only in the second memory 106 as shown in FIG. In parallel with this, the re-encoding process of step S313 is performed. In the re-encoding process, the second memory 10
6, the encoded data stored in 6 is read out, and the re-encoding unit 109 performs re-encoding processing.
04 and 106 are stored. Then, the encoding process and the re-encoding process are continued until all the codes of the vertical stripes are re-encoded. The re-encoded data output from the re-encoding unit 109 has exactly the same code as the encoded data obtained by encoding in the same quantization step as the encoded data output from the encoding unit 102 after changing the quantization step. Data.

Specifically, in this re-encoding process, for each quantized value after Huffman decoding the encoded data once,
This is realized by performing Huffman coding again after performing a bit shift process that produces a result similar to the result of dividing these values by 2 ⁿ . This method enables high-speed re-encoding processing in that the quantization step is changed only by bit shifting and that inverse orthogonal transformation or re-orthogonal transformation processing is not performed. In step 315, the end of the re-encoding process is detected.

Since the amount of data after re-encoding is smaller than the amount of encoded data before re-encoding, as shown in FIG. 5, data is re-encoded in the memory area where the code before re-encoding is stored. The encoded data after encoding can be stored so as to be overwritten. When the re-encoding process is completed, the data amount of the coded data of vertical stripes is reduced to the data amount of the coded data of diagonal stripes shown in FIG.

Steps S307 to 315 described above
Is a process performed in the encoding / re-encoding phase.

<< Transfer Phase >> When the re-encoding process is completed, the transfer process is performed in step S317.
In the transfer processing, as shown in FIG. 6, the diagonal stripe coded data stored in only the second memory 106 in the coding / recoding phase is converted into the diagonal line coded data in the first memory 104. Transfer to the address linked to and store. On the other hand, the diagonal stripes are coded so that the coded data of the diagonal stripes and the coded data of the diagonal stripes, which are dispersed in the second memory 106, are continuously stored in the first memory 104. The encoded data of the second memory 106
Transfer within and connect. This is the process performed in the transfer phase.

When the transfer phase is completed, the process returns to the encoding phase of steps S303 and S305, and the code of the diagonal stripe is output from the encoding unit 102 and stored in the two memories 104 and 106 as shown in FIG. This coding phase is slightly different from the coding phase in the initial state (FIG. 4), and the quantization step at the time of coding by the coding unit 102 is changed from Q1 to Q2, and the two memories 104 and 106 are also used. The encoded data stored in is also a collection of codes processed in various phases. If these differences are ignored, the coding phase immediately after the transfer phase and the coding phase in the initial state can be regarded as the same.

Therefore, by repeating the three phases of the encoding phase, the encoding / re-encoding phase and the transfer phase, the code obtained by finally compressing the image data of one page to the data amount set value or less is stored in the first memory. Can be stored in. Moreover, the input unit 101 only continues the input until the series of processing is completed. That is, it is not necessary to input the image again from the beginning.

The flowchart shown in FIG. 3 describes only the processing corresponding to each phase shown in FIGS. 4, 5 and 6 for easy understanding of the description. However, in reality, the input of the image data of one page ends in some phase. Therefore, depending on which phase the process is completed, the subsequent actions are slightly different. FIG. 8 is a flowchart showing the flow in consideration of this. The flow chart of FIG. 8 considers the relationship between the completion of inputting one page of image data and the various processes described in FIG. 3, and here, in the flow chart of FIG.
1, S803, S805, and S807 are added.

Steps S801, S803, S805
Detects that the input of the image data for one page from the input unit 101 is completed in the encoding phase, the encoding / re-encoding phase, and the transfer phase, respectively.

When it is detected that one page of image data has been input in the encoding phase and the transfer phase (steps S801 and S805), the process proceeds to step S807, the compression encoding process of the page is terminated, and If there is one or more pages of image data to be processed, the compression encoding process of the next one page of image data is started, and if there is none, the process enters the stopped state.

On the other hand, when the input end of the image data for one page is detected in the encoding / re-encoding phase (step S803), the encoding unit 102 operates once until there is no image data to be re-encoded. Therefore, the re-encoding process for passing the encoding process of step S311 and suppressing the image data already encoded by the encoding unit 102 to a predetermined encoded data amount in step S313. Only continue. If all the re-encoding processing is completed and the subsequent transfer processing is not completed, the encoded data of the entire image data for one page cannot be collected in the first memory, and the input of the image data for one page is completed. After that, the re-encoding process and the subsequent transfer process need to be continuously performed. In this case, when it is detected in step S315 that all the re-encoding processing has been completed, encoding /
During the re-encoding phase, the encoded data stored only in the second memory 106 is transferred to the first memory (step S317), and then in the next step S805, the image data for one page is input. When the end is detected, step S80
I will move to 7.

The above is the operation and is also an explanation of the operation in FIG.

<Modification of Memory Storage Method> FIGS. 9 and 10
FIG. 9 is a diagram showing a modification of the memory storage method shown in the conceptual diagrams of FIGS. 5 and 6.

In the conceptual diagram of FIG. 5, in the encoding / re-encoding phase, the encoded data output from the encoding unit 102 is stored only in the second memory 106.
As shown in, during the encoding / re-encoding phase, the encoded data output from the encoding unit 102 is directly stored in both the first and second memories.

From the viewpoint of the encoding unit 102, the encoded data that is encoded and output in any phase is stored in both memories. Also, unlike the conceptual diagram of FIG. 6, as shown in FIG. 10, data transfer between memories is not necessary in the transfer phase. In the case of this modification,
In the re-encoding phase, the encoded data and the re-encoded data are sequentially stored in the order sent to the first memory 104. Therefore, there is a problem that two types of data are mixed.

Therefore, in the case of this modification, in order to deal with this, the encoded data is divided into certain units and managed as a file or a packet. In particular,
A file management table or a packet management table is separately created and managed.

As one method, when storing the data from the encoding unit 102 in the first memory 104, an appropriate unit (for example, since the unit of orthogonal transformation is a block of 8 × 8, 8 × i ( A management number is allocated from the beginning of the image data for each i), i.
A management table is created so that the storage start address of the encoded data corresponding to each management number and the encoded data amount can be stored in the order of the management numbers.

The encoding unit 102 and the re-encoding unit 109 hold the management number of the data being processed, and based on the management number, the start address and the encoded data amount at the time of storing the encoded data are stored in the management table. Write. By doing so, even if the encoded data processed by the encoding unit 102 and the re-encoding unit 109 is stored at random, the management table is accessed in the order of the management numbers, and the start address and the encoded data to be read at that time are read. The first encoded data based on the quantity
If the data is read from the memory 104, the encoded data can be read in order from the beginning of the image. If such a management mechanism is provided, there is no need to store continuous data on the image in the memory so as to be continuous.

The encoding phase after the transfer phase in the conceptual diagram of FIG. 10 is almost the same as the two encoding phases described so far (FIGS. 4 and 7), and the storage state of the code in the first memory. Are only slightly different as shown in FIG. Therefore, the above description and this modification are 3
There is no change in processing one phase repeatedly.

Next, an example of the second basic configuration (the configuration described so far will be referred to as the first example) for performing the characteristic encoding process in the present invention will be described with reference to FIG.

FIG. 2 shows the image processing apparatus 2 in the second example.
It is a block diagram of 00.

A major difference from the image processing apparatus 100 shown in FIG. 1 is that there are two encoding units that perform encoding first in parallel. In the image processing apparatus 200, the image data input from the input unit 201 is coded in parallel by the first coding unit 202 and the second coding unit 205, and two types of coded data having different compression rates are obtained. To generate. Also in this example,
A known JPEG encoding method is used as the encoding method, and 8 × 8 is used.
The image data corresponding to a pixel unit is orthogonally transformed, and quantization and Huffman coding processing using a quantization step described later is performed.

In this example, a case will be described in which the compression rate applied by the second coding section 205 is set higher than that of the first coding section 202. Specifically, the quantization step in the first coding unit 202 is Q1, and the quantization step in the second coding unit 205 is Q2 (= 2 × Q1).

The encoded data output from the encoding unit 202 is stored in the first memory 204 via the first memory control unit 203. At this time, the first counter 2
08 counts the data amount of the encoded data output from the encoding unit 202, holds it, and outputs it to the encoding sequence control unit 209.

On the other hand, the encoded data encoded by the encoding unit 205 is stored in the second memory 207 via the second memory control unit 206. At this time, the second counter 210 counts the data amount of the encoded data output from the encoding unit 205 and holds it. Furthermore,
When the coded data stored in the second memory 207, which will be described later, is transferred to the first memory 204, at the same time, the count value is transferred to the first counter 208.

Now, the first counter 208 is the encoding unit 2
When the count value reaches a certain set value while counting the data amount of the encoded data output from 02, the encoding sequence control unit 209 instructs the memory control unit 203 to perform the same operation as in the first example. A control signal is issued to discard the data stored in the memory 204.

Then, the encoding sequence control unit 209
Sends a control signal to the memory control unit 206 and the memory control unit 203 so that the encoded data stored in the second memory 207 is read out, transferred to the first memory 204, and stored in the first memory 204. Output. As a result, the count value of the second counter 210 is transferred to the first counter 208, and the value is loaded (overwritten) as the count value of the first counter.

In short, since the count value of the second counter 210 represents the data amount of the encoded data stored in the second memory 207, the count value and the encoded data correspond to each other. So that the attachment does not change,
It may be considered that the data is copied to the first counter and the first memory as it is.

Further, the coding sequence control 209 is
A control signal is issued to the first encoding unit 202 and the second encoding unit 205 so that encoding is performed so that the encoded data becomes smaller than ever.

For example, the quantization step S in the first coding unit 202 and the second coding unit 205 is doubled. As a result, the first coding unit 202 inherits the quantization step Q2 (= 2 × Q1) in the second coding unit 205 up to immediately before, and the second coding unit 205 further A large quantization step Q2 × 2 is used to perform a coding process with a higher compression rate in preparation for the next overflow.

Here, the magnification ratio of the quantization step is set to 2 times, but it is not limited to this, and it goes without saying that it can be set arbitrarily. The encoded data output from each of the switched encoding units 202 and 205 is passed through the corresponding memory control units 203 and 206, respectively, and the corresponding memory 2
04 and 207 are stored.

Then, the coding sequence control 209
The encoded data already stored in the second memory is read out to the memory control unit 206, and the re-encoding unit 211 is read.
Send a control signal to send data to. Re-encoding unit 211
Performs re-encoding processing of encoded data in the same manner as re-encoding section 109 in FIG.

The third counter 212 has a re-encoding unit 21.
1 counts the amount of data output, is reset to zero immediately before starting the re-encoding process, and counts the amount of output data during the re-encoding process. This counter 21
2 transfers the count value obtained there to the second counter 210 when the re-encoding process is completed.

The second counter 210 stores the transferred data amount count value in the memory 207 during the re-encoding process by adding the transferred data amount count value to the counter value held in the second counter 210. Then, the total data amount of the encoded data and the re-encoded data is calculated. That is, the amount of data stored in the memory 207 and the count value of the counter 210 match.

Regardless of whether the re-encoding process is completed or not,
If the image data from the input unit 201 to be encoded remains, the encoding process by the two encoding units 202 and 205 is continuously performed. The input unit 20 monitors whether or not the count value of the counter 208 has reached a certain set value.
It is repeated until the encoding process (encoding, re-encoding) of the image data for one page input from 1 is completed, and the above-mentioned encoding and re-encoding processes are performed according to the detection result obtained here. Performed under control.

FIG. 12 is a flow chart showing the flow of processing in the configuration of FIG.

As described with reference to FIG. 2, when there are two encoding units, the image data for one page is encoded based on the flowchart shown in FIG. Note that the description of FIG. 12 is mostly similar to FIG. 8, which is the flowchart in the case of one encoding unit, and those skilled in the art can fully understand the features of the second example from the above description. Therefore, the processing will be described in three phases as in the case of one encoding unit, and the points different from FIG. 8 will be mainly described.

The biggest difference between the above-described flow of FIG. 8 and the flow of this example is that the transfer processing of step S317 moves between step S307 and step S309. In short, it may be considered that the encoding / re-encoding phase and the transfer phase are exchanged (step S
The exception is the processing of discarding the encoded data of 307).

In the initial setting of the coding parameter in step S301, the quantization step Q is set in the first coding section 202.
1 to the second encoding unit 205 at the quantization step Q2.
(= 2 × Q1) is set.

In the encoding phase, steps S801,
S303 and S305 are repeatedly executed. Step S8
01 and step S305 are the same processes as in the case where there is one encoding unit, but only the encoding process of step S303 is different as shown in FIG.

In order to increase the compression rate of the encoded data stored in the first memory 204 step by step, the encoded data stored first is encoded in the quantization step Q1 having the lowest compression rate. The encoded data that stores the data and that is stored in the second memory is the data that is encoded in the quantization step Q2.

When the amount of data being stored in the first memory 204 exceeds the set upper limit value (step S3
05), immediately, the encoded data held in the first memory 204 is discarded (step S307), and the encoded data having a high compression rate held in the second memory 207 is
The data is transferred to the first memory 204 (step S317, see FIG. 14). As a result, the appropriate second candidate coded data that does not exceed the upper limit value can be promptly set to the first coded data without waiting for the end of the first re-encoding process described in the first example (FIG. 1). It can be stored in the memory 207. This is
Is the greatest advantage of applying FIG. 2 with two encoders.

In the second example, the two memories 204, 2
Since it is wasteful to have coded data with the same compression rate in 07, the second memory 207 stores the first data in the first memory 207.
The coded data having a higher compression rate than the coded data stored in the memory 204 is stored. Therefore, the subsequent processing is also performed based on this idea, and after the processing (transfer phase) of transferring the encoded data in the second memory 207 to the first memory 204 is completed, the second processing is performed. The encoded data in the memory 207 is further
Re-encoding is performed so that encoded data having a high step compression rate is retained.

Specifically, first, as shown in FIG. 15, in the encoding / re-encoding phase subsequent to the transfer phase, it is applied to the two encoding units 202 and 205 before the re-encoding. Quantize steps Q1 and Q2 to Q2 and Q3, respectively.
(Step S309), if the input of the image data of one page continues without being completed (step S80)
3) For the subsequent image data, the input data is encoded by the two encoding units in which new quantization steps are set (step S311) and stored in the corresponding memories 204 and 207. Then, in parallel with the above-described encoding process, the encoded data stored in the second memory (the first memory 20
4) is encoded by the re-encoding unit 211 using the quantization step Q3 so as to be changed to encoded data having a compression ratio one step higher than the encoded data in the first memory. Re-encoding process (S3
13) is performed and the re-encoded data is stored in the second memory 207.
Store again.

In the second example, as in the first example,
In the re-encoding process, each quantized value after the Huffman decoding of the encoded data is bit-shifted to produce a result similar to the result of dividing these values by 2 ⁿ , and then the Huffman code is re-encoded. It is realized by the conversion. This method enables high-speed re-encoding processing in that the quantization step is changed only by bit shifting and that inverse orthogonal transformation or re-orthogonal transformation processing is not performed.

When there are two encoders as in the second example, as shown in FIG. 15, the second memory 20 is used.
A situation occurs in which the encoded data and the re-encoded data are mixedly stored in 7. Therefore, as described above, it is also necessary for the second memory 207 to divide the encoded data into certain units and manage them as files or packets. For that purpose, for example, a configuration similar to that of the modification of the first example may be provided.

In FIG. 12, when the end of the re-encoding process is detected in step S315, the process proceeds to the encoding phase (steps S801 and S303). In the encoding phase after the encoding / re-encoding phase, as shown in FIG. 16, not only the encoded data held in the two memories 204 and 207 have different compression rates but also mixed encoded data. The method (address) is also quite different. Therefore,
Again, when the data amount of the first memory 204 exceeds the set value, the encoded data (the code of the + horizontal stripe area) held in the second memory 207 is transferred to the first memory 204. Will need to be done. Considering these points, it is necessary to manage the encoded data as a file or packet not only in the second memory 207 but also in the first memory 204. Therefore, the first memory 204 also needs a management mechanism using the above-mentioned management table.

The state of the encoding phase shown in FIG. 16 is different from the encoding phase (in the initial state) except that the method of mixing the quantization step and the encoded data is different before and after the re-encoding process. (Fig. 13). Therefore, by repeating the encoding phase, the transfer phase, and the encoding / re-encoding phase, it is possible to ensure that the encoded data obtained by compressing the image data of one page to the set upper limit value or less is finally stored in the first memory. It can be stored in 204.

Since the arrangement order of the transfer phase and the encoding / re-encoding phase is opposite to that of the first example, one page of image data, which has been processed after the transfer processing in FIG. Input end detection (step S805)
The timing is almost the same as the detection of the end of input of image data for one page (step S803) performed in the encoding / re-encoding phase. Further, the two detection processes are functionally the same as step S805 and are the same in timing as step S803. Therefore, these two steps detect the end of input of a new page of image data. Integrated as a step to be performed, and step S1
It is written as 201.

In the first and second examples described above, the first memory and the second memory are physically different memories. This is advantageous because the access to the two memories can be independent, and is a feature of the present invention. However, the case where the first memory and the second memory are not physically separate memories is also included in the scope of the present invention. Two areas corresponding to the first memory and the second memory are physically secured on one memory, and the first memory is the first memory area and the second memory is the second memory. It can be understood that the present invention can be realized by a single memory, by re-reading the description given so far as a region.

Further, when the above examples are realized by one memory, some of the data transfer processing described in the transfer phase becomes unnecessary. The details are omitted because they can be easily imagined each time. However, when the two areas are strictly separated from each other, the data transfer processing is required as in the case of physically having two memories. If the same data is shared between the two areas, not only the data transfer process becomes unnecessary, but also the storage capacity can be reduced.

For example, when the encoded data held in the second memory area is transferred to the first memory area, two pieces of information, that is, the head address where the encoded data is stored and the data size, are stored in the second information. Only by transferring from the second memory control unit to the first memory control unit, the same effect as the transfer of the encoded data can be obtained.

When the coded data is stored in the file format or the packet format, the information transferred between the memory control units is slightly increased, and it is necessary to transfer the management table information related to the coded data. is there. Nevertheless, it is more efficient than transferring the encoded data.

By the way, according to the above-mentioned image processing apparatus, even when the input image data exceeds the target size when being encoded, the input image data is kept at the target size while continuing the input. Although it becomes possible to continue the processing so as to fit, in the present invention, in addition to the control of the code amount of the compressed data of the image data, the code amount of the data obtained by encoding the image area information accompanying the image data is set. It also controls.

In the embodiments described below, how the image area information encoding process and the code amount of the encoded data are controlled will be described.

<First Embodiment> FIG. 17 shows a first embodiment in which the present invention is applied to the above-described image processing apparatus. In the figure, the present invention is applied to the basic configuration shown in FIG. 1, and the same functional blocks as those in the configuration of FIG.

The image data input from the image scanner or page description language rendering through the input unit 101 is repeatedly encoded and re-encoded based on the processing method already described, and the code amount for which the encoded data is set is set. Keep it within.

On the other hand, the image data is the image area information generation unit 17
01, and generates the above-mentioned image area information. In this embodiment, since the scanner input image is described,
The image area information is generated based on only the image data, but in the case of an image in which the page description language (PDL) is developed / drawn, the image area information may be generated by also referring to the PDL information. The image area information may be generated by an image input device such as a scanner. In that case, the image area information is also input through the input unit 101, passes directly through the image area information generation unit 1701,
It is sent to the next unit.

Now, regarding the image area information generated by the image area information generation unit 1701, in the embodiment, whether the pixel of interest is a character / line drawing area or a halftone area, and whether it is chromatic or achromatic. Information indicating whether or not is generated. Since each can be expressed by 1 bit, a total of 2 bits of image area information is generated for one pixel (each bit is called image area component information because it constitutes image area information).

The operation of the image area information generator 1701 will be briefly described as follows.

First, it is judged whether the area is a character / line drawing area or a halftone area. In the case of a character / line drawing, the brightness (or density) of the background sharply changes with respect to the background. on the other hand,
If it is in the halftone area, the brightness (or density) of the pixel of interest
Changes little with respect to adjacent pixels. Therefore, the luminance of the target pixel _{L i,} when the luminance of the left and right pixel is defined as _{L i-1, L i +} 1, | L i -L i-1 |> T , or, | L _i -L _{i + When 1} |> T, it can be determined that the pixel of interest is at (the edge of) the character line drawing. Note that | x | here indicates the absolute value of x.

The formula for determining whether or not the concentration is changing sharply is not limited to the above formula. For example, it may be determined whether or not | 2L _i −L _i−1 −L _{i + 1} |> T is satisfied, or it may be determined not only in the one-dimensional direction but in the two-dimensional direction (however, In the case of two-dimensional determination, a memory for storing image data for a plurality of lines is required in the image area information generation unit 1701).

On the other hand, regarding the chromatic / achromatic color judgment, since the input image data is read by the scanner, it is in the R, G, B data format.

The achromatic color is a case in which the RGB color components have the same luminance, so that it is judged as an achromatic color if there is a relation of R = G = B, and if it does not satisfy it. Judge as colored. However, since it is necessary to take into account the accuracy of the CCD of the scanner device, in reality, when all of B-Δ <R <B + Δ R-Δ <G <R + Δ G-Δ <B <G + Δ are satisfied, it is judged as an achromatic color. (Δ is an appropriately small numerical value), and other colors may be determined as chromatic colors.

In some cases, the RGB color space is converted into, for example, luminance, hue, and saturation (for example, Lab color space), and when the saturation is below a predetermined value, it is achromatic color, and when it exceeds the predetermined value, it is chromatic color. You may judge that.

As described above, the image area information generator 1701
From the input image data, 2-bit image area information indicating whether the pixel of interest is a character / line drawing / halftone area, chromatic color or achromatic color is generated and output.

Returning to the explanation of FIG. As above
The generated image area information has a size of data to be collectively coded by the blocking unit 1703, for example, M × N.
Block to a size (hence M × N × 2 bits). The block size is 32 × 32, but in order to improve the coding efficiency, it is larger than 64 × 64 or 128, for example.
It may be x128, and does not necessarily have to be a square size. Therefore, the size is M × N.

By the way, when encoding the image area information, multi-valued lossy compression such as JPEG used for compression of normal image data is not suitable. Therefore, JB, which is lossless compression
Run length coding such as IG or PackBits is used. The lossless encoding unit 1705 performs the lossless encoding on the image area information of the corresponding block.

The encoded image area information is stored in the third memory 1709 via the third memory control unit 1707. At the same time, the fourth counter 1711 cumulatively counts the code amount output from the lossless encoding unit 1705 (reset when the reading of one page is started), and the result is encoded. It is supplied to the part 1713.

The encoding control unit 1713 is provided with a register (not shown), and the target code amount of the image area information is preset in this register. Then, the encoding control unit 1713
Monitors whether the code amount counted by the fourth counter 1711 exceeds this target value. When it is determined that the target value is exceeded, the encoding control unit 1713 issues the following instructions to the lossless code stock 1705 and the lossless code re-encoding unit 1707, and resets the fourth counter 1711. To do.

First, the lossless code re-encoding unit 1707 is instructed to read the encoded image area data from the third memory 1709 and re-encode it. As a result, the lossless code re-encoding unit 1715 reads the encoded image area information in block units from the third memory 1709, decodes it once, performs the process of increasing the run length, and encodes it again, It is stored in the third memory 1709.

The process for increasing the run length is as follows.
We prepared the following two ways. Process P1: All the chromatic / achromatic color identification information at the pixel position where the character / line drawing / halftone pixel identification bit indicates a halftone pixel is changed to chromatic color. Process P2: The identification bit of the character / line drawing / halftone pixel is changed to indicate the halftone pixel.

The encoding control unit 1713 adopts the above process P1 when it determines that the target value is exceeded first while encoding the image area information of a certain page. Even if this process is performed, if it is determined that the target value is exceeded (if it is determined that the target value is exceeded for the second time), the process P2 is used to perform the encoding again.

The chromatic / achromatic color identification information is made chromatic because it does not cause a big problem because the chromatic color space includes achromatic colors. The reason why the identification information of the character / line drawing / halftone is set to halftone is also for the same reason.

In any case, by changing the image area information, the entropy is reduced, so that the data amount after run-length coding is reduced. The attribute data after re-encoding is stored again in the memory 1709, and the code amount is counted by the fifth counter 1717. Then, the lossless code re-encoding unit 1715 uses the lossless encoding unit 1
This process is performed for all codes already encoded by 705. In this way, when there is a command from the encoding control unit 1713, the encoded data stored in the third memory 1709 (data encoded by the lossless encoding unit 1705) is re-encoded and stored. The code amount at this time is counted by the fifth counter 1715, and the count result is added to the fourth counter.

On the other hand, the lossless encoding unit 1705 performs the same processing as that of the lossless code re-encoding unit 1715 on and after the block of interest according to the command issued from the encoding and coding control unit 1713 when the target value is exceeded. Start. That is, when a certain page is encoded and it is determined that the page is over first, a process for increasing the run length is performed on the block from the blocking unit 1703 by the process P1 described above, and the result is encoded. It is converted to and stored in the third memory 1709. During this period, the lossless encoding unit 170
The code amount coded in 5 starts the counting number in the fourth counter (which is reset when it is determined to be over), but as described above, the lossless code re-encoding unit 1
Also in 715, the code amount (fifth counter 1717) at the time of re-encoding is added, and as a result, the attribute information for one page is the same as the result performed in the process P1. The fourth counter 1711 counts the code amount of.

In this way, when it is determined that the target value is exceeded again while switching to the process P1 and the image area information is being coded, the encoding control unit 1713 resets the fourth counter 1711 and , Lossless encoding unit 1
705 and the lossless code re-encoding unit 1715 are instructed to switch to the process P2 described above.

The above is summarized as follows.

The encoding control unit 1713 is the lossless encoding unit 1
When the encoding amount of the image area information in 705 is monitored and it is determined that the encoding amount exceeds the target value, the lossless encoding unit 1705 and the lossless code reencoding unit 1715 perform the process P1. Set the fourth counter 171
Reset 1 The fourth counter 1711 thereafter adds the code amount by the lossless encoding unit 1705 and the count value of the fifth counter 1717. Therefore, when the re-encoding by the lossless code re-encoding 1715 is completed, substantially the same code amount as that in the process P1 is counted from the beginning for one image (or one page image). . Further, the encoded data in the process P1 is stored in the third memory 1709.

When it is determined that the target value is exceeded again during the processing by the processing P1, this time, the lossless encoding unit 1705 and the lossless code re-encoding unit 1715 are set to be performed in the processing P2. The fourth counter 1711 and the fifth counter 1717 are reset.

As a result, the image area information can be losslessly encoded within the target value (target size) while continuing to input the image data from the input unit 101.

Next, a flow chart showing the processing contents of the first embodiment is shown in FIG. 18, and description will be given using this flow chart. As described above, the process of this embodiment is roughly divided into two processes. One is lossless encoding processing and the other is re-encoding processing.

The encoding process consists of the image area information conversion process of step S1805 and the lossless encoding process of step S1807, and the re-encoding process is the decoding process of step S1815 and the image area information conversion process of step S1817. And the re-encoding process of step S1819.

The other steps are the conditional branch and the start and end steps, except for the change in the image area information changing process in S1813.

First, from step S1801, the image area information encoding process is started. In the next step S1803,
It is detected whether or not the input of the image area information for one page of the image is completed, and if it is completed, step S182
If the processing is not completed yet, that is, if the image area information is input, the image area information conversion process of step S1805 is performed.

In the initial state where the re-encoding process has not been activated yet, nothing is processed in the image area conversion processing, and the input image area information is encoded as it is by the lossless encoding processing in the next step S1807. To do.

In the next step S1809, it is determined whether or not the re-encoding process is in progress. If the re-encoding process is in progress, the re-encoding process consisting of steps S1815 to S1819 is executed. If not, the process proceeds to step S1811, and it is determined whether the encoded data (code amount) exceeds the set value.

If it is not over, step S18.
Returning to 03, the encoding process is repeated, and if the encoding process is over, the process content in the image area information conversion process is changed. The contents of the image area conversion processing in steps S1805 and S1817 are changed by the change. Specifically, in the initial state, the process P1, that is, the chromatic / achromatic color of the pixel position where the character / line drawing / halftone identification information in the input image area information is determined to be halftone All the identification information of is made chromatic.

After changing the contents of the image area information conversion processing, re-encoding processing is performed. In the re-encoding process, step S1
At 815, the encoded image area information is subjected to a decoding process to restore the data before encoding. In the next step S1817, the image area information conversion processing is performed, the image area information changing processing is performed, and in the next step S1819, the converted image area information is reversibly encoded.

When the re-encoding process is completed, the process returns to step S1803, and if the image area information is input, it is encoded. If the code amount exceeds the set value even once, the contents of the image area information conversion process are changed, and step S18
After being replaced by the process P1 in the image area information conversion process of 05, lossless encoding is performed in step S1807.

Thus, after the process P1 is replaced,
Again, when it is determined in step S1811 that the code amount exceeds the target value, in step S1813 the image area change in steps S1805 and S1817 is set to be changed to the process P2.

In any case, if the input of the image area information is completed and the re-encoding processing has not been performed, the process proceeds to step S1823 and the image area information encoding processing is ended.

As described above, according to the first embodiment, the image data is encoded within the target size without interrupting or re-inputting one or one page of image data. In addition, the image area information of the image can be losslessly encoded within the target size.

An example of the case where the lossless coding unit and the lossless code recoding unit in the embodiment adopt the packbits coding will be described below.

Here, a concrete example of the present embodiment in the case where the image area information of 2 bits per pixel is added with 6-bit data “000000” to be 8 bits and then the Packbits encoding is performed as a reversible code. Specific processing contents will be described with reference to FIG.

As shown in FIG. 19A, the upper 6 bits of the 8-bit data before the Packbits encoding are all 0, and the corresponding pixel data is character / line drawing / halftone on the upper side of the lower 2 bits. And a flag indicating chromatic color / achromatic color on the lower side. Therefore, the value that the 8-bit data can take is
It is a value of 0 or more and 3 or less. Further, in order to simplify the description, it is assumed that one-dimensional image area information is output from the image area information generation unit 1701.

The image area information generator 1701 outputs the 8-bit data in pixel units. As concrete output data, consider the data shown in FIG.

When this is encoded with Packbits, as shown in FIG.
9 (c) is compressed. In the compressed data, the negative value represents the number of continuous data, and the number of discontinuous data is the positive value. These are called length information, and it is possible to determine from the sign bit of the length information whether continuous data or non-continuous data continues. Each data after compression is 8 bits (1 byte) as in (b). With 1-byte length information, the maximum value that can be represented is half of 255, which is approximately 12
If the length information is 8 or less, it can be encoded by one set of length information and the following image area flag data group, and if it exceeds it, a plurality of sets of length information + image area flag data It is encoded by being divided into groups.

The compressed data shown in FIG. 19C will be examined in detail. Since the initial length information “−4” is a negative value, it represents the number of consecutive continuous data as described above, and represents that four pieces of image area flag data “1” immediately after the length information continue.

The next data "4" is also length information, but since it is a positive value this time, it indicates that four pieces of non-continuous data continue. Therefore, the four data "2, 3, 2, 3" following the "4" represent discontinuous data. FIG. 19
In (c), only the positive length information is underlined so that the length information and the image area flag data can be easily distinguished.

"-5" next to the non-continuous data is also length information of continuous data, which means that five pieces of image area flag data "2" immediately after the length information continue. The next underlined data "3" is the length information of the non-continuous data, the following three data "1, 0, 1" are the image area flag data, and the next "-6, 0" is This indicates that 6 pieces of data “0” continue.

The lossless code re-encoding unit 17 converts the compressed data.
FIG. 1 shows what happens when the re-encoding process is performed in 15.
9 (d) (e) will be described. To simplify the explanation, a case will be described in which all bits are made chromatic by fixing the bit of the chromatic / achromatic color flag to "1" in the re-encoding process.

The encoded image area data is once decoded,
After being returned to the data shown in FIG. 19B, the flag data is replaced to be converted into the data shown in FIG. 19D. When this is encoded with Packbits again, the encoded data of FIG. It can be seen that the encoded data was 15 bytes before re-encoding, but decreased to 6 bytes after re-encoding.

If the count value of the total code amount exceeds the target value set in the register in the encoding control unit 1713 again despite the above-mentioned re-encoding processing, the re-encoding is performed. If the process is completed, the next new re-encoding process is immediately started. If the re-encoding process is not completed, the next new re-encoding process is started immediately after the re-encoding process is completed.

In the new re-encoding process, the remaining 1-bit image area flag is also replaced with "1". As a result, the value of all image area flag data (8 bits) becomes "3", and assuming that the number of data bytes is N, the amount of data after encoding is approximately (2N / 128) +2 bytes.

This is because every time the number of continuous data exceeds 128, a new set of 2-byte encoded data (length information and continuous data) increases.

Since the Packbits encoding circuit, decoding circuit, and data conversion circuit are well-known techniques, description of individual circuit configurations will be omitted.

In the above embodiment, the image area flag of each pixel is described as 2 bits for simplification in the description, but other information may be added as the image area flag as described above. .

Theoretically, if there are N bits as the type of the image area, there will be 2 ^N image area conversion processes. However, it is necessary to increase the compression rate each time conversion is performed. In any case, the larger the number of bits of the image area information, the more the number of times of re-encoding processing can be performed, and the code amount can be controlled in multiple stages.

As described above, the lossless encoding processing of the image area information data is controlled independently of the compression encoding processing of the image data, and each is stored in the data within the target code amount.

The two types of encoded data are multiplexed when being output to an externally connected network device, image output device, mass storage device, or the like. In consideration of the multiplexing, the units for encoding the two types of data are set to the same size, and the encoded data generated by encoding one unit is managed and stored as one packet or file. . At the time of multiplexing, two types of packet data having the same image position are concatenated, for example, in the order of image data / image area data to form one packet and output to the outside.

Since the two encoding processes are independently controlled, the image data compression encoding processing unit may have another configuration. Therefore, even if the units 1701 to 1717 that perform lossless encoding processing of image area information data are added to the configuration of FIG. 2, the same processing can be performed. The configuration is shown in FIG.
The operations of 1 to 1717 are exactly the same as those of FIG. 17, and the operation of the image data compression portion is also the same as that of FIG.

<Modification of First Embodiment> In the above embodiment, one of the 2 bits of the image area component information is a character / line drawing /
The halftone identification bit and the other chromatic / achromatic color bit were treated as one having a value of 0 to 3. However, the character / line drawing / halftone identification information and the chromatic / achromatic identification information are originally independent information. Therefore, it may be possible to make a block composed of character / line drawing / halftone identification bits and a block composed of chromatic / achromatic identification bits independent, and to encode them independently. . As a result, each bit in each block consists of the same type of bits only, and the compression efficiency can be improved in the first stage. As a result, some bits of the image area information are fixed. It is possible to reduce the probability of conversion into a value and increase the probability that the original image area information can be compression-encoded as it is.

<Second Embodiment> In the second embodiment,
Even if the number of bits of image area information is the same as in the first embodiment,
A processing method capable of finely controlling the code amount by increasing the number of times of re-encoding processing will be described. The configuration of this embodiment is also the same as that of the first embodiment, except that
This is a compression method of image area flag data in the lossless encoding unit 1705 and the lossless code re-encoding unit 1715.

In the first embodiment, the image area flag data is replaced with a fixed value bit by bit.
In the second embodiment, the number of states is degenerated. For example,
The 2-bit image area flag can represent 4 states, but by degenerating this into 3 states in the first re-encoding process and degenerating it into 2 states in the second re-encoding process, The information entropy before encoding is reduced, and the data amount after encoding (code amount) is finely reduced.

If the first embodiment is expressed using the term number of states, it can be said that the number of states is reduced to half each time image area information is re-encoded.

In the first embodiment, the number of states is substantially halved by one re-encoding process, whereas in the present embodiment, the number of states is reduced by one. It is natural to be able to reduce

FIG. 21 shows the processing result of the second embodiment.
This will be described with reference to (a) to (e).

FIG. 19A shows the same data as the image area flag data shown in FIG. 19B, in which all of the two 2-bit states are present. The definition of the four states is as follows. (1) Chromatic character line drawing part (corresponding to data "3") (2) Achromatic character line drawing part (corresponding to data "2") (3) Chromatic color halftone (corresponding to data "1", (Also referred to as chromatic image portion) (4) Achromatic halftone (corresponding to data "0", also referred to as achromatic image portion) In the second embodiment, the first re-encoding process Of the four states, two states of (3) chromatic halftone and (4) achromatic halftone are combined to reduce to one state (3 ′) halftone. This results in the following three states. This corresponds to the process P1. (1) Chromatic character part (2) Achromatic character part, (3 ') Halftone Specifically, the data "0" is replaced with "1" to reduce the above state. The data after the state degeneration changes to the data shown in FIG. This is Packbi
When ts encoded, the encoded data shown in FIG. 21 (c) is obtained. It can be seen that the code amount is slightly smaller than that of the encoded data before re-encoding in FIG. 19C.

In the second re-encoding process, the two states of (1) the chromatic color character portion and (2) the achromatic color character portion are combined to be reduced to one state (1 ') character portion. This allows
There are the following two states. (1 ') Character part (3') Non-character part This time, the data "2" is replaced with "3" to reduce the above state. The data after state degeneration is shown in FIG.
The data is changed to that shown in (d). This data is shown in Figure 19.
This is the same as the data in (d). This is Packbits
The encoded data that has been encoded is shown in FIG.
It becomes the same encoded data as (e).

In the first embodiment, the 15-byte data before re-encoding is reduced to 6 bytes by one re-encoding, but in the present embodiment, it is reduced to 11 bytes by the first re-encoding. However, it is reduced to 6 bytes at the second re-encoding. After all, in the second embodiment, it is possible to obtain a code amount that changes finely and decreases, which cannot be obtained in the first embodiment, so that compressed data of an image area flag close to the target code amount can be obtained.

<Application Example> In the first embodiment and its modification, and further in the second embodiment, an apparatus for reading an image from an image scanner is taken as an example to describe the functional operation of the apparatus. Most of the functions (including the encoding process) can be realized by the computer program as described above.

Therefore, the present invention may be applied to an application program that operates on a general-purpose information processing device such as a personal computer. When applied to an application program, a GUI for allowing the user to specify an image file as a compression source and allowing the user to select a target size may be provided. The target value at this time can be arbitrarily set by the user, but it is difficult to understand the numerical setting, so select from an intuitive and easy-to-understand menu that considers the document size and image quality (high, medium, low, etc.). Then, it will be better to make a decision.

Although the quantization step has been described as an example of the encoding parameter of the encoding unit, as long as data having different compression rates are mixed, the image quality between them does not feel uncomfortable. May use other parameters. However, for example, in the configuration of FIG. 1, in order to make the data to be re-encoded from the re-encoding unit 109 substantially the same as the encoded data from the encoding unit 102 after the parameter change, As shown in the form, a method of increasing the quantization step is preferable.

Further, as described above, the present invention can be realized by an application program that operates on a general-purpose device, so the present invention also includes a computer program. Further, since the computer program is usually executed by setting a storage medium such as a floppy disk or a CDROM in the device and copying or installing the storage medium, such a storage medium is naturally included in the scope of the present invention.

Further, in the embodiment, the image data is input from the scanner, but it may be applied to the printer driver operating on the host computer.
When applied to a printer driver, when data to be printed is received from a higher-level process (application, etc.), it is of course possible to determine at that point whether the data is a halftone image or a character / line drawing. It is possible to omit the configuration related to the region information generation processing or to simplify the configuration.

The present invention can also be applied to a combination of a computer program and appropriate hardware (encoding circuit etc.).

As described above, according to the first and second embodiments, the decoding means for decoding losslessly encoded image area information and the information entropy of the image area information are reduced. Image area information converting means for rewriting or deleting a part of the image area information, and the image area information obtained by converting the image area information decoded by the decoding means by the image area information converting means again with a reversible code. Re-encoding means for encoding, lossless encoding means having the information converting means, and storage means capable of storing data obtained by encoding image area information associated with at least one page of image data. 1 page by controlling both the image area information conversion means provided in the lossless conversion means and the image area information conversion means in the preceding stage of the re-encoding means according to the amount of the encoded data. Image area information for the desired encoding data It can be accommodated on the amount.

<Third Embodiment> The third embodiment will be described. The third embodiment performs almost the same operation as the first embodiment described above, but the structure is different. FIG. 22 is a block configuration diagram thereof. Operations of components having the same reference numerals as those in FIG. 1 (image data encoding processing)
Are the same, the description thereof will be omitted, and the coding portion of the image area information in the third embodiment will be described below.

Image data (multi-valued color image data) input via the input unit 101 from an image scanner, page description language rendering, or the like is supplied to the encoding unit 102 and also to the image area information generation unit 2201. It
As described above, the coding unit 102 and the subsequent components are the same as those in FIG.

The image area information generator 2201 generates image area information from the input image data. When the input target is a scanner, the same processing as that of the image area information generation unit 1701 in the first embodiment described above may be performed.
In the case of the L rendering, the image area information is known for each pixel when the image is developed by the PDL rendering, so that information may be used.

The generated image area information has a data size to be collectively coded by the blocking unit 2202,
For example, it is divided into blocks of size M × N.

Since multi-valued lossy compression such as JPEG used for compression of image data is inconvenient for use in compression of image area information which is a collection of binary data, it is a lossless compression of JBIG or PackBits. The lossless encoding unit 2203 performs lossless encoding using run length encoding such as.

The reversibly encoded image area information is stored in the memory controller 2
It is stored in the first memory 104 via 204.

FIG. 27 shows the state of the memory in the initial state of encoding. The difference from FIG. 4 is that a storage area for image area information is provided as shown in the figure.
The encoded image area information is sequentially stored in this storage area via the memory control unit 2204.

As described above, the coding sequence control unit 108 detects whether or not the count value of the first counter 107 has reached a certain set value, and when it is detected that the set value has been reached, a predetermined value is determined. Is output to control the encoding unit 102 to encode image data at a higher compression rate than before.

In the third embodiment, at the same time, the encoding sequence control unit 108 encodes the instruction to re-encode the image area information in synchronization with the re-encoding timing of the image data described above. Instruct the control unit 2205.

The encoding control unit 2205 is connected to the first memory 1
The encoded image area data is read from 04, and a control signal is output to the memory control unit 2204 so as to send the data to the lossless code re-encoding unit 2206.

Upon receiving the encoded data, the lossless code re-encoding unit 2206 decodes the encoded data, discards some of the plurality of attribute flag data or replaces them with fixed values, and then performs lossless encoding again. Even when a part of the attribute flag is replaced with a fixed value, the information entropy is reduced, so that the amount of data after run-length encoding is reduced. The re-encoded attribute data is stored again in the first memory 104.

On the other hand, the encoding control unit 2205 has an image provided in the lossless encoding unit 2203 so as to encode the attribute flag data of which the information amount is reduced in the lossless code re-encoding unit 2206 and the attribute flag data of the same information. A control signal is sent to the area information conversion processing unit so as to discard a part of the attribute flag or replace it with a fixed value, and the encoding process is continued.

This process is repeated until the image area flag data to be re-encoded is used up and the re-encoding process is completed.

The encoding sequence control unit 108 detects whether or not the count value of the counter 107 has reached a certain set value, and every time the target value is exceeded, the image data is re-encoded and synchronized with it. By increasing the number of attribute flags to be discarded in the image area flag, the code amount of the image area data can be gradually reduced, and the code amount of the image area data can be kept within the target value.

Next, the processing contents (image area information coding processing) of the third embodiment will be described with reference to the flowchart of FIG. The process of the third embodiment is roughly divided into two processes as described above. One is lossless encoding processing and the other is re-encoding processing.

The encoding process is realized by the image area information conversion process of step S2305 and the lossless encoding process of step S2307. Also, the re-encoding process is performed in step S2315.
Of the image area information conversion process of step S2317 and the re-encoding process of step S2319.

The other steps are the conditional branch and the start and end steps, except for the change in the image area information changing process in S2313.

First, from step S2301, the image area information encoding process is started. In the next step S2303,
It is detected whether or not the input of the image area information for one page of the image is completed, and if it is completed, step S232
If it is not completed, that is, if the image area information is input, the image area information conversion process of step S2305 is performed.

In the initial state in which the re-encoding processing has not been activated yet, nothing is processed in the image area conversion processing, and the input image area information is encoded as it is by the lossless encoding processing in the next step S2307. To do.

In the next step S2309, it is determined whether or not the re-encoding process is in progress. If the re-encoding process is in progress, the re-encoding process of steps S2315 to S2319 is executed, but the re-encoding process is in progress. If not, the process proceeds to step S2311, and it is determined whether the image data is re-encoded.

If the control signal indicating that the encoded data has exceeded the predetermined target value has not been received from the encoding sequence control unit 108, the flow returns to step S2303 to repeat the encoding process, and to output the control signal indicating that it has exceeded. If received, the processing content in the image area information conversion processing is changed. Due to this change, steps S2305 and S231
The contents of the image area conversion processing in 7 are changed. In particular,
In the initial state, all the input image area information has been encoded without invalidating even one bit. That is, although nothing was done in the image area conversion processing, after changing the processing content,
At least one bit in the image area information is discarded or replaced with a fixed value in the image area conversion processing. For example, all the bits indicating the character line drawing are converted into the bits indicating the halftone. After that, each time the processing content is changed, the number of bits of the image area flag to be discarded or replaced with a fixed value is increased (in a state where the run length tends to be long).

After changing the contents of the image area information conversion processing, re-encoding processing is performed. In the re-encoding process, step S23
At 15, the encoded image area information is decoded to restore the data before encoding. In the next step S2317, the image area information conversion process is performed, and a part of the image area information is discarded or replaced with a fixed value. Then, the next step S231
At 9, the converted image area information is losslessly encoded again.

When the re-encoding process is completed, the process returns to step S2303, and if the image area information is input, it is encoded. If the code amount of image data exceeds the set value even once and re-encoding is started, in conjunction with that,
The image area information conversion processing content is changed, and step S2305
After a part of the image area flag data is discarded or replaced with a fixed value in the image area information conversion processing of step S23,
At 07, lossless encoding is performed.

If the re-encoding process is still in progress even after all the image area information has been input, the process moves from step S2303 to step S2321, where it is determined that the re-encoding process is in progress, and Steps S2315 to S2319
Re-encoding process consisting of

If all the input of the image area information is completed and the re-encoding processing has not been performed, step S2323 is entered and the encoding processing of the image area information is completed.

If the code amount of the image data exceeds the set value even once, this time, all the bits indicating the chromatic color / achromatic color in the image area information are changed to the chromatic color.

Next, 6-bit data "000000" is added to the image area information of 2 bits per pixel to make it into 8 bits, and then Pa c kbits coding is performed as a reversible code. Specific processing contents in the embodiment will be described in more detail with reference to FIG.

P a c k bit s 8 before encoding
In the bit data, as shown in FIG. 24 (a), the upper 6 bits are all 0, and the upper 2 bits of the lower 2 bits have corresponding pixel data in the character line drawing area, the halftone or the flag bit, and the lower side has A flag bit is assigned to represent a chromatic color or an achromatic color. Therefore, the value that the 8-bit data can take is a value of 0 or more and 3 or less.

It is assumed that the image area information generator 2201 outputs the above 8-bit data in pixel units. As concrete output data, consider the data shown in FIG.

When this is encoded with packbits, it is compressed into the data shown in FIG. In the compressed data, the negative value represents the number of continuous data, and the number of discontinuous data is the positive value. These are called length information, and it is possible to determine from the sign bit of the length information whether continuous data or non-continuous data continues. Each data after compression is 8 bits (1 byte) as in FIG. With 1-byte length information, the maximum value that can be represented is about one half of 255.
28, and if the length information is shorter than that, it can be encoded by one set of length information and the following image area flag data group, and if it exceeds it, a plurality of sets of length information + image area flag data It is encoded by being divided into groups.

Let us take a closer look at the compressed data of FIG. 24 (c). Since the first length information “−4” is a negative value, it represents the number of continuous pieces of continuous data as described above, and indicates that four pieces of image area flag data “1” immediately after the length information continue.

The next data "4" is also length information, but since it is a positive value this time, it indicates that four pieces of non-continuous data continue. Therefore, the four data "2, 3, 2, 3" following the "4" represent discontinuous data. In FIG. 7C, only the positive length information is underlined so that the length information and the image area flag data can be easily distinguished.

"-5" next to the non-continuous data is also length information of continuous data, which means that five pieces of image area flag data "2" immediately after the length information continue. The next underlined data "3" is the length information of the non-continuous data, the following three data "1, 0, 1" are the image area flag data, and the next "-6, 0" is This indicates that 6 pieces of data “0” continue.

The lossless code re-encoding unit 17 converts the compressed data.
FIG. 2 shows what happens when the re-encoding process is performed in 15.
4 (d) (e) will be described. Here, an example will be described in which, in the re-encoding process, the chromatic / achromatic color flag is fixed to "1" to make all chromatic colors.

The encoded image area data is once decoded,
After the data is returned to the data shown in FIG. 9B, the flag data is replaced and converted into the data shown in FIG. Then, convert the converted data into Packbits again.
By encoding, the encoded data shown in FIG. 7E can be obtained. It can be seen that the encoded data of 15 bytes before re-encoding is reduced to 6 bytes after re-encoding.

Even after performing the above re-encoding processing, in the case of re-encoding the image data by re-encoding the target value in which the count value of the total code amount is set in the encoding of the image data again. A control signal for re-encoding the image area data is also received from the encoding sequence control unit 108, and if the re-encoding process is completed, the next new re-encoding process is immediately started. If the re-encoding process is not completed, the next new re-encoding process is started immediately after the re-encoding process is completed.

In the new re-encoding process, the remaining 1-bit image area flag is also replaced with "1". As a result, the value of all image area flag data (8 bits) becomes "3", and assuming that the number of data bytes is N, the amount of data after encoding is approximately (2N / 128) +2 bytes.

This is because every time the number of continuous data exceeds 128, a new set of encoded data of 2 bytes (length information and continuous data) increases.

Since the Packbits encoding circuit, decoding circuit, and data conversion circuit are well-known techniques, the description of the separate path configuration is omitted.

In the above description, the image area flag of each pixel is described as 2 bits for simplification, but as described above, there are some other information as the image area flag. In the re-encoding process, re-encoding can be performed up to 2 times for 2-bit image area flag data and up to 4 times for 4-bit image area flag data. The larger the number, the more the number of re-encoding processes can be increased, and the code amount can be controlled in multiple stages.

As described above, the lossless encoding process of the image area flag data is controlled independently of the compression encoding process of the image data, and each is stored in the data within the target code amount.

The two types of encoded data are multiplexed when being output to an externally connected network device, image output device, mass storage device, or the like. In consideration of the multiplexing, the units for encoding the two types of data are set to the same size, and the encoded data generated by encoding one unit is managed and stored as one packet or file. . At the time of multiplexing, two types of packet data having the same image position are concatenated, for example, in the order of image data / image area data to form one packet and output to the outside.

Since the two encoding processes are independently controlled, the image data compression encoding processing unit may have another configuration. Therefore, even if the units 2201 to 2206 for losslessly encoding the image area flag data are added to the configuration of FIG. 2, the same processing can be performed. The structure is shown in FIG.
The operations of 01 to 2206 are exactly the same as those in FIG.
The operation of the image data compression part is exactly the same as the operation of FIG.

<Fourth Embodiment> In the fourth embodiment,
A processing method will be described in which the number of re-encoding processes can be increased and the code amount can be finely controlled even if the number of bits of image area information is the same as in the third embodiment. The configuration of the present embodiment is also the same as that of the first embodiment, except for the method of reducing the image area flag data in the lossless coding unit 1703 and the lossless code recoding unit 1706.

In the first embodiment, the image area flag data is replaced with a fixed value bit by bit, that is, the data is degenerated one bit at a time, but in the present embodiment, the number of states is degenerated. For example, a 2-bit image area flag can represent 4 states, but
By degenerating into three states in the second re-encoding process and degenerating into two states in the second re-encoding process, the information entropy before encoding is reduced, and the data amount after encoding (code amount)
Is to be reduced finely.

Expressing the third embodiment by using the term number of states, it can be said that the number of states is reduced to half each time the image area flag data is re-encoded.

While the number of states is reduced by half in the third embodiment by one re-encoding process, the number of states is reduced by one in the present embodiment, so the code amount can be finely reduced. It is natural.

The processing result of this embodiment is shown in FIG.
(C), (d), and (e) are shown and described.

FIG. 26 (a) is the same data as the image area flag data shown in FIG. 24 (b), in which all of the two 2-bit states are present. To enumerate the four states again,
It looks like this:

(1) Chromatic character part (corresponding to data “3”) (2) Achromatic character part (corresponding to data “2”) (3) Chromatic non-character part (corresponding to data “1”) Correspondence, also referred to as chromatic image portion) (4) Achromatic non-character portion (corresponding to data "0", also referred to as achromatic image portion) In the present embodiment, in the first re-encoding process, Among the four states, two states of (3) chromatic non-character part and (4) achromatic non-character part are combined to be reduced to one state (3 ′) non-character part. This results in the following three states.

(1) Chromatic character part (2) Achromatic character part, (3 ') Non-character part Specifically, by replacing the data "0" with "1", the above-mentioned degeneracy is reduced. To do. The data after the state degeneration changes to the data shown in FIG. This is packbi
When ts encoded, the encoded data shown in FIG. 26 (c) is obtained. It can be seen that the code amount is slightly smaller than that of the coded data before re-encoding in FIG. 24 (c).

In the second re-encoding process, the two states of (1) the chromatic color character portion and (2) the achromatic color character portion are combined to be reduced to one state (1 ') character portion. This allows
There are the following two states.

(1 ') Character part (3') Non-character part This time, the data "2" is replaced with "3" to reduce the above state. The data after state degeneration is shown in FIG.
The data is changed to that shown in (d). This data is shown in Figure 24.
This is the same as the data in (d). This is Pa c kbit
The encoded data s-encoded is shown in FIG.
It becomes the same encoded data as (e).

In the third embodiment, the 15-byte data before re-encoding is reduced to 6 bytes in one re-encoding, but in the fourth embodiment, 11 bytes are re-encoded in the first re-encoding. The number of bytes is reduced to 6 bytes by the second re-encoding. After all, in the fourth embodiment, it is possible to obtain a code amount that changes and decreases finely, which is not obtained in the third embodiment, so that compressed data of the image area flag close to the target code amount can be obtained.

As described above, according to the third and fourth embodiments, like the first and second embodiments described above,
The image area information for one page can be stored in a desired encoded data amount.

<Fifth Embodiment> The fifth embodiment will be described. The fifth embodiment performs almost the same operation as the first embodiment described above, but the structure is different. FIG. 28 is a block configuration diagram thereof. Operations of components having the same reference numerals as those in FIG. 1 (image data encoding processing)
Are the same, the description thereof will be omitted, and the coding portion of the image area information in the fifth embodiment will be described below.

Image data (multi-valued color image data) input via the input unit 101 from an image scanner or page description language rendering is supplied to the encoding unit 102 and also to the image area information generation unit 2801. It
As described above, the coding unit 102 and the subsequent components are the same as those in FIG.

The image area information generator 2801 generates image area information from the input image data. When the input target is a scanner, the same processing as that of the image area information generation unit 1701 in the first embodiment described above may be performed.
In the case of the L rendering, the image area information is known for each pixel when the image is developed by the PDL rendering, so that information may be used.

The generated image area information has a data size to be collectively coded by the blocking unit 2803,
For example, it is divided into blocks of size M × N.

Multi-valued lossy compression such as JPEG used for compression of image data is inconvenient to use for compression of image castle information, which is a collection of binary data, and is reversible compression such as JBIG or PackBits. The image area information is losslessly encoded by the lossless encoding unit 2805 using run length encoding such as.

The encoded image area information is stored in the first memory 104 via the third memory control unit 2807. At the same time, the amount of code data output from the lossless encoding unit is cumulatively counted by the fourth counter 2811, and the count value is sent to the encoding control unit 2813.

FIG. 33 shows the state of the memory in the initial state of encoding. The difference from FIG. 4 is that a storage area for image area information is provided. Basically, the encoded image area information is sequentially held in this storage area, but it is also possible to store the encoded image data in this storage area, as will be described later. Even if the image area data after encoding does not fit in this storage area, if there is a surplus in the storage area for the image data, it is of course possible to hold it in the storage area for the surplus. is there.

The coding control unit 2813 and the coding sequence control unit 108 respectively include a fourth counter 2811.
Then, the count value from the first counter 107 is sent to the sixth counter 2809.

The sixth counter encodes image data,
The encoding counts of the image castle information are summed, and the count value is sent to the image / image area encoding control unit 2819.

A total target value of image data and image area data is set in a register in the image / image area encoding control unit 2819, and the total count value of the code amounts of the image data and image area data is When the target value is exceeded, a control signal is output to the encoding control unit 2813 and the encoding sequence control unit 108 so as to perform re-encoding processing.

[0230] The encoding control unit 2813 uses the first memory 1
The encoded image area data is read from 04, and a control signal is output to the memory control unit 2807 so as to send the image area data to the lossless code re-encoding unit 2815.

The coding sequence control unit 108 outputs a control signal to the first memory control unit 103 so as to discard the data stored in the first memory 104. The first memory control unit 103 discards the stored data by clearing the memory address counter or the encoded data management table based on the control signal. Then, the encoding sequence control unit 108
Controls the encoding unit 102 to perform encoding at a higher compression rate than before, and performs re-encoding processing.

That is, even if the count value of the first counter 107 exceeds the target value of the code amount of the image data stored in the register in the encoding sequence control unit 108, or the fourth counter Even if the count value of 2811 exceeds the target value of the code amount of the image area data stored in the register in the encoding control unit 2813, the target value of the code amount of the image data and the code amount of the image area data If the sum of the code amounts of the image data and the image area data does not exceed the sum of the daily standard values of, the encoding process is continued.

As a result, for example, the image data slightly exceeds the target value of the image data, but since the code amount of the corresponding image area information is small, the image area data in the first memory 104 is By allocating the allocated storage area to the image data, if the total code amount of the image data and the image castle information falls within the target value of the code amount of the image data and the image area data, the image data is re-created. No need to encode. It eliminates the need for high compression, which improves image quality and performance.

The image data re-encoding process is performed by the image / image area encoding control unit 2819 to the encoding sequence control unit 10
When the control signal for the re-encoding process is output to 8, the encoding sequence control unit 108 performs the control for performing the re-encoding process as described above in the description of FIG.

In the re-encoding process of the image castle information, when the control signal of the re-encoding process is output from the image / image area encoding control unit 2819 to the encoding control unit 2813, the encoding control unit 2813 , The encoded image area data is read from the first memory 104, and the data is reversible code re-encoding unit 281.
A control signal is output to the memory control unit 2807 so as to send to the memory controller 5.

Upon receiving the encoded data, the lossless code re-encoding unit 2815 decodes the encoded data, discards a part of the plurality of attribute information or replaces it with a fixed value, and then performs lossless encoding again. Even if some of the attribute flags are replaced with fixed values, the information entropy is reduced, and the amount of data after run-length encoding is reduced. The re-encoded attribute data is stored again in the first memory 104, and the code amount thereof is counted by the fifth counter 2817.

On the other hand, like the lossless code re-encoding unit 2815, the encoding control unit 2813 causes the lossless encoding unit 2805 to discard a part of the attribute information input thereafter or replace it with a fixed value. Send a control signal to continue the encoding process. At the same time, the fourth counter 2811
A control signal is also sent to reset the value that has been counted and held until then, and discards part of the attribute information or replaces it with a fixed value and then newly counts the code amount generated by encoding processing. .

When the image area information to be re-encoded is lost and the re-encoding process is completed, the count value of the fifth counter 2817 is transferred to the fourth counter 2811 and added. As a result, the counter 2811 counts the total code amount of the lossless encoded data after the attribute information is partially discarded or replaced with a fixed value.

Each time the image data and the image area information are re-encoded, the respective code amounts are counted, and the total value of the image data and the image area information code amounts is calculated by the image / image area encoding control unit 2.
Every time the total of the image data and the target value of the image area information set in the register in 819 is exceeded, the image data re-encoding processing and the image area information re-encoding processing are performed.
The re-encoding of the image area information can reduce the code amount of the image area data by increasing the number of attribute flags to be discarded, and the code amount of the image area information can be kept within the target value. Becomes

Next, the processing contents of this embodiment will be described with reference to the flowchart of FIG. The processing of this embodiment is
As described above, it is roughly divided into two processes. One is lossless encoding processing and the other is re-encoding processing.

The encoding process is composed of the image area information conversion process of step S2905 and the lossless encoding process of step S2907. Also, the re-encoding process is performed in step S291.
5, the image area information conversion process of step S2917, and the re-encoding process of step S2919. The other steps are the conditional branch and the start and end steps, except for the change in the image area information changing process in S2913.

First, from step 2901, the encoding process of the image area information is started. In the next step 2903, it is detected whether or not the input of the image area information for one page of the image (one image) is completed, and if completed, the process proceeds to step S2921, and if not completed, that is,
If the image area information is input, the image area information conversion process of step S2905 is performed.

In the initial state in which the re-encoding process has not been activated yet, nothing is processed in the image area conversion processing, and the input image area information is directly encoded by the reversible encoding processing in step S2907. To do.

In the next step S2909, it is determined whether or not the re-encoding process is in progress. If the re-encoding process is in progress, the re-encoding process consisting of steps S2915 to S2919 is executed. If not, the process proceeds to step S2911, and it is determined whether the total data amount (total code amount) of the image data and the image region information encoded by the image / image region encoding control unit exceeds the set value.

If it is not over, step S29.
Returning to 03, the encoding process is repeated, and if the encoding process is over, the process content in the image area information conversion process is changed. The contents of the image area conversion processing in steps S2905 and S2917 are changed by the change. Specifically, in the initial state, all the input image area flag data has been encoded without invalidating even one bit. That is, although nothing was done in the image area conversion processing, after the processing content is changed, at least the 1-bit flag data in the image area information is discarded or replaced with a fixed value by the image area conversion processing. To do. After that, each time the processing content is changed, the number of bits of the image area flag to be discarded or replaced with a fixed value is increased.

After changing the contents of the image area information conversion processing, re-encoding processing is performed. In the re-encoding process, step S29
At 15, the already encoded image area information is subjected to a decoding process to be returned to the data before encoding. Then, the next step S291
At 7, image area information conversion processing is performed, and part of the image area information is discarded or replaced with a fixed value. Then, in the next step S2919, the converted image area information is reversibly encoded.

When the re-encoding process is completed, the process returns to step S2903, and if the image area information is input, it is encoded. In the image / image area coding control unit, if the sum of the code amounts of the image data and the image area data exceeds the set value even once, the content of the image area information conversion process is changed, and the image area information conversion process of step S2905 is performed. After part of the image area flag data has been replaced with the abolished drug or a fixed value, lossless encoding is performed in step S2907.

If the re-encoding process is still in progress even after all the image area information has been input, the process moves from step S2903 to step S2921, where it is determined that the re-encoding process is in progress, and Steps S2915 and S2919
Re-encoding process consisting of

If all the input of the image area information has been completed and the re-encoding processing has not been carried out, the flow advances to step S2923 to end the image area information encoding processing.

Next, 6-bit data "000000" is added to the image area flag data of 2 bits per pixel to obtain 8 bits.
Specific processing contents in the present embodiment in the case where Packbits coding is performed as a reversible code after bit conversion will be described in more detail with reference to FIG.

As shown in FIG. 30 (a), the upper 6 bits of the 8-bit data before the Packbits encoding are all 0, and whether the corresponding pixel data is the character part or not on the upper side of the lower 2 bits. , And flag data representing a chromatic color or an achromatic color is contained in the lower side. Therefore, the value that the 8-bit data can take is a value of 0 or more and 3 or less.

It is assumed that the image area information generating section 2801 outputs the above 8-bit data in pixel units. As concrete output data, consider the data shown in FIG.

If this is encoded with Packbits, it is compressed into the data shown in FIG. In the compressed data, the negative value represents the number of continuous data, and the number of discontinuous data is the positive value. These are called length information, and it is possible to determine from the sign bit (MSB) of the length information whether continuous data or non-continuous data continues. Each data after compression is 8 bits (1 byte) as in FIG. With 1-byte length information, the maximum value that can be represented is about 128, which is half of 255, and is 1 if the length information is less than that.
It is possible to encode with a set of length information and a flag data group of image area information that follows, and if it exceeds, it is encoded separately into a plurality of sets of length information + image area flag data group.

Let us take a closer look at the compressed data of FIG. 30 (c). Since the first length information “−4” is a negative value, it represents the number of continuous pieces of continuous data as described above, and indicates that four pieces of image area flag data “1” immediately after the length information continue.

The next data "4" is also length information, but since it is a positive value this time, it indicates that four pieces of non-continuous data continue. Therefore, the four data "2, 3, 2, 3" following the "4" represent discontinuous data. In FIG. 7C, only the positive length information is underlined so that the length information and the image area flag data can be easily distinguished.

"-5" next to the non-continuous data is also length information of continuous data, which means that five pieces of image area flag data "2" immediately after the length information continue. The next underlined data "3" is the length information of the non-continuous data, the following three data "1, 0, 1" are the image area flag data, and the next "-6, 0" is This indicates that 6 pieces of data “0” continue.

The lossless code re-encoding unit 28 converts the compressed data.
What happens when the re-encoding process is performed in 15 will be described with reference to FIGS. Here, in the re-encoding process, an example in which the chromatic / achromatic color flag is fixed to "1" to make all chromatic colors is shown.

The encoded image area data is once decoded,
After being returned to the data of FIG. 30 (b), the flag data is replaced and converted into the data of FIG. 30 (d). Then, convert the converted data into Packbits again.
By encoding, the encoded data shown in FIG. 7E can be obtained. It can be seen that the encoded data of 15 bytes before re-encoding is reduced to 6 bytes after re-encoding.

Despite the above re-encoding processing, the count value of the total code amount, which is the sum of the code amounts of the image data and the image area data, is stored in the register in the image / image area encoding control unit 2819. When the total target value of the code amounts of the set image data and image area data is again exceeded, the next new re-encoding process is immediately started if the re-encoding process is completed. If the re-encoding process is not completed, the next new re-encoding process is started immediately after the re-encoding process is completed.

In the new re-encoding process, the remaining 1-bit image area flag is also replaced with "1". As a result, the value of all image area flag data (8 bits) becomes "3", and assuming that the number of data bytes is N, the amount of data after encoding is approximately (2N / 128) +2 bytes.

This is because every time the number of continuous data exceeds 128, a new set of 2-byte encoded data (length information and continuous data) increases.

The Packbits encoding circuit, decoding circuit, and data conversion circuit are well-known techniques, and therefore description of individual circuit configurations will be omitted.

In the above description, for the sake of simplification, the significant number of bits of the image area information of each pixel has been described as 2 bits, but as described above, there are some other information as the image area flag. In the re-encoding process, re-encoding can be performed up to 2 times for 2-bit image area flag data and up to 4 times for 4-bit image area flag data. The larger the number, the more the number of re-encoding processes can be increased, and the code amount can be controlled in multiple stages.

As described above, the lossless encoding process of the image area flag data is controlled independently of the compression encoding process of the image data, and each is stored in the data within the target code amount.

The two types of encoded data are multiplexed when being output to a network lateral device, an image output device, a mass storage device or the like connected to the outside. In consideration of the multiplexing, the units for encoding the two types of data are set to the same size, and the encoded data generated by encoding one unit is managed and stored as one packet or file. . At the time of multiplexing, two types of packet data having the same image position are concatenated, for example, in the order of image data / image area data to form one packet and output to the outside.

Since the two encoding processes are independently controlled, the image data compression encoding processing unit may have another configuration. Therefore, even if the units 2801 and 2819 for losslessly encoding the image area flag data are added to the configuration of FIG. 2, the same processing can be performed. The configuration is shown in FIG.
The operations of 01 to 2819 are exactly the same as those of FIG.
The operation of the image data compression portion is also the same as the operation of FIG.

<Sixth Embodiment> In the second embodiment,
Even if the number of bits of image area information is the same as in the first embodiment,
A processing method capable of finely controlling the code amount by increasing the number of times of re-encoding processing will be described. The configuration of this embodiment is also the same as that of the fifth embodiment, except that the reversible coding unit 2805 and the reversible code recoding unit 281 are different.
5 is a method of degenerating image area flag data in FIG.

In the first embodiment, the image area information is replaced with a fixed value bit by bit, that is, the data is degenerated one bit at a time.
Reduce the number of states. For example, a 2-bit image area flag can represent four states, but by degenerating this into three states in the first re-encoding process and degenerating it into two states in the second re-encoding process. The information entropy before encoding is reduced, and the data amount after encoding (code amount) is finely reduced.

If the fifth embodiment is expressed using the term number of states, it can be said that the number of states is reduced to half each time image area information is re-encoded.

In the fifth embodiment, the number of states is reduced to half by one re-encoding process, whereas in the sixth embodiment, the number of states is reduced by one. It is natural to be able to reduce finely.

FIG. 32B shows the processing result of this embodiment.
(C), (d), and (e) are shown and described.

FIG. 30A shows the same data as the image area flag data shown in FIG. 30B, in which all of the two 2-bit states are present. The four states are listed again as follows.

(1) Chromatic character line drawing part (corresponding to data “3”) (2) Achromatic character line drawing part (corresponding to data “2”) (3) Chromatic color non-character line drawing part (halftone) Part) (corresponding to data "1", also called chromatic image part) (4) achromatic non-character line drawing part (halftone part) (corresponding to data "0", also called achromatic image part) In the embodiment, in the first re-encoding process, two states of (3) chromatic non-character portion and (4) achromatic non-character portion are combined into one state ( 3 ') Degenerate to non-character part.

This results in the following three states.

(1) Chromatic color character part (2) Achromatic color character part, (3 ') Non-character part Specifically, by replacing the data "0" with "1", the above-mentioned degeneracy is reduced. To do. The data after the state degeneration changes to the data shown in FIG. This is Packbi
When the ts encoding is performed, the encoded data shown in FIG. It can be seen that the encoded data before re-encoding has a code amount slightly smaller than that in FIG.

In the second re-encoding process, the two states of (1) the chromatic color character part and (2) the achromatic color character part are combined to be reduced to one state (1 ') character part. This allows
There are the following two states.

(1 ') Character part (3') Non-character part This time, the data "2" is replaced with "3" to reduce the above state. The data after state degeneration is shown in FIG.
The data is changed to that shown in (d). This data is shown in Figure 30.
This is the same as the data in (d). This is Pa c kbit
32 (e) which is s-coded coded data is naturally the same coded data as FIG. 30 (e).

In the fifth embodiment, the data of 15 bytes before re-encoding is reduced to 6 bytes in one re-encoding, but in the sixth embodiment, 11 bytes are re-encoded in the first re-encoding. The number of bytes is reduced to 6 bytes by the second re-encoding. In the end, in the sixth modification, it is possible to obtain a code amount that changes finely and that cannot be obtained in the fifth embodiment, so that compressed data of an image area flag close to the target code amount can be obtained. .

<Seventh Embodiment> In the fifth embodiment,
Encoding control unit 2813 and encoding sequence control unit 10
8 from the fourth counter 2811 and the count value from the first counter 107 from the sixth counter 28
09, the sixth counter 2809 sums up the counts of the coding of the image data and the coding of the image area data, and sends the count value to the image / image area coding control unit 2819. Then, with respect to the total target value of the image data and the image area data held in the register in the image / image area encoding control unit 2819, the total count value of the code amounts of the image data and the image area data is It is determined whether or not the target value is exceeded, and when the target value is exceeded, the encoding control unit 17
13. The configuration has been described in which the control signal is output to the encoding sequence control unit 108 so as to perform the re-encoding process.

In the seventh embodiment, the fourth counter 28
11, the first counter 107, and the sixth counter 28
An embodiment in which the re-encoding processing of the image data and the image area data is independently performed with reference to the respective count values of No. 09 will be described.

A register in the image / image area coding control unit 1719 holds a total target value (target code amount) of image data and image area information, and a sixth counter 2809
From the above, the total count value of the code amount of the image data and the image castle information is sent. When the total code amount exceeds the target value in the register, the image / image area coding control unit 28
19 outputs a control signal to the encoding control unit 2813 and the encoding sequence control unit 108 so as to perform re-encoding processing.

When the target value in the image / image area coding control unit 2819 is exceeded, it means that the target code of the image data held in each register in the coding sequence control unit 108 and the coding control unit 2813. This means that at least one of the image data and the image area information has exceeded the target code amount of the amount and the image area information (both cases may exist).

The encoding control unit 2813 and the encoding sequence control unit 108, which have received the re-encoding control signal from the image / image area encoding control unit 2819, the count values of the first counter 107 and the fourth counter 2811. However, the encoding control unit 2
813, by referring to the target value of the code amount of the image data and the target value of the code amount of the image area data, which are held in the register in the encoding sequence control unit 108, it is determined whether or not it is exceeded, and If so, the control signal for the re-encoding process described above is output and the re-encoding process is performed.

For example, the code amount of image area data does not exceed the target value in the encoding control unit 2813, and the code amount of image data does not exceed the target value in the encoding sequence control unit 108. If it exceeds the target value of the image / image area coding control unit 1719 as a result, the coding control unit 1713 does not output the re-coding control signal for the image area data, Sequence control unit 10
Reference numeral 8 outputs a control signal for re-encoding the image data.

As a result, even if the total target value of the image data and the image area data is exceeded and the re-encoding process is performed, only the data that is dominant as a factor that exceeds the target value is re-encoded. By performing the above, it is not necessary to re-encode the image area data that does not exceed the respective target values, for example, in the above example, it is possible to avoid unnecessary image quality deterioration.

<Eighth Embodiment> In the fifth embodiment,
Encoding control unit 2813 and encoding sequence control unit 10
8 from the fourth counter 2811 and the count value from the first counter 107 from the sixth counter 28
Send to 09. The sixth counter 2809 sums the code amounts (count values) of the coding of the image data and the coding of the image area information, and the total value is the image / image area coding control unit 171.
Sent to 9. Then, the image / image area coding control unit 2819
For the total target value of the image data and image area information held in the register inside, it is judged whether the total value of the code amount of the image data and image area information exceeds this target value. In this case, the configuration has been described in which the control signal for performing the re-encoding process is output to the encoding unit 2813 (resultingly includes the lossless code re-encoding unit 2807) and the encoding sequence control unit 108.

In such a configuration, the image / image area coding control unit 2819 may alternately output control signals for re-coding processing to the coding control unit 2813 and the coding sequence control unit 108.

If the target value held in the register in the image / image area coding control unit 2819 is exceeded,
First, an instruction request for a luxury purse process is issued to the encoding sequence control unit 108, and re-encoding is performed. Even if this re-encoding is performed, the image area encoding control unit 1719 still remains.
If the target value held in the register inside is exceeded, next, the encoding control unit 2813 (reversible encoding unit 2
The request signal is output to the re-encoding unit 805 and the reversible code re-encoding unit 2807) to perform the re-encoding process.

Hereinafter, every time it is determined that the target value is exceeded, the compression rate for re-encoding is alternately increased.

As a result of the above, it becomes possible to suppress the encoding by excessively increasing the compression rate.

The processing of the first to eighth embodiments described above may be executed by a computer program executed by a general-purpose information processing apparatus (for example, a personal computer) equipped with a multitasking OS, including the basic part described at the beginning. realizable. Therefore, the present invention can also be applied to such a computer program. In this case,
Those skilled in the art can easily understand that each unit in the block configuration diagrams shown in the first to eighth embodiments can be realized by a module of a computer program or a function program. Therefore, the present invention may be applied to a computer program.

In general, when a computer program is installed in a general-purpose information processing device such as a personal computer, a storage medium (floppy (registered trademark) disk, CDROM,
Since the present invention can be realized by setting (MO etc.) and installing or copying, the present invention also includes such a storage medium in its category.

[0293]

As described above, according to the present invention, it is possible to perform encoding within a target size without re-inputting image area information of a multivalued image.

[Brief description of drawings]

FIG. 1 is a diagram showing a first basic configuration of an image processing apparatus to which the present invention is applied.

FIG. 2 is a diagram showing a second basic configuration of an image processing apparatus to which the present invention is applied.

3 is a flowchart showing a simplified process in the configuration of FIG.

FIG. 4 is a diagram showing a data flow and a memory content in an encoding phase in an initial state.

FIG. 5 is a diagram showing a data flow and a memory content in an encoding / re-encoding phase.

FIG. 6 is a diagram showing a data flow and a memory content in a transfer phase.

FIG. 7 is a diagram showing a data flow and a memory content in an encoding phase after a transfer phase.

FIG. 8 is a flowchart showing details of processing in the configuration of FIG.

9 is a diagram showing a data flow and a memory content in an encoding / re-encoding phase in the modified example of the configuration of FIG.

10 is a diagram showing a data flow and a memory content in a transfer phase in the modified example of FIG.

11 is a diagram showing a data flow and a memory content in an encoding phase after a transfer phase in the modified example of FIG.

12 is a flowchart showing a processing procedure in the configuration of FIG.

13 is a diagram showing a data flow and a memory content in an encoding phase in an initial state in the configuration of FIG.

14 is a diagram showing a data flow and a memory content in a transfer phase in the configuration of FIG.

15 is a diagram showing a data flow and a memory content in an encoding / re-encoding phase in the configuration of FIG.

16 is a diagram showing a data flow and a memory content in the encoding phase after the encoding / re-encoding phase in the configuration of FIG.

FIG. 17 is a block configuration diagram of an apparatus according to the first embodiment of the present invention.

FIG. 18 is a flowchart showing a processing procedure in the first embodiment.

FIG. 19 is a diagram showing encoded data of lossless encoding and encoded data after re-encoding in the first embodiment.

FIG. 20 is a diagram showing another configuration of the first embodiment.

FIG. 21 is a diagram illustrating coded data after re-encoding of lossless code and coded data after re-encoding in the second embodiment.

FIG. 22 is a block configuration diagram of an apparatus according to a third embodiment.

FIG. 23 is a flowchart showing a processing procedure according to the third embodiment.

FIG. 24 is a diagram showing encoded data of lossless encoding and encoded data after re-encoding in the third embodiment.

FIG. 25 is a diagram showing another configuration of the third embodiment.

FIG. 26 is a diagram illustrating encoded data after re-encoding of lossless code and encoded data after re-encoding in the fourth embodiment.

FIG. 27 is a diagram showing a data flow and a memory content in a coding phase in an initial state in the third embodiment.

FIG. 28 is a block configuration diagram of an apparatus according to a fifth embodiment.

FIG. 29 is a flowchart showing a processing procedure in the fifth embodiment.

FIG. 30 is a diagram showing encoded data of lossless encoding and encoded data after re-encoding in the fifth embodiment.

FIG. 31 is a diagram showing another configuration of the fifth embodiment.

[Fig. 32] Fig. 32 is a diagram illustrating coded data after re-encoding of lossless codes and coded data after re-encoding in the sixth embodiment.

FIG. 33 is a diagram showing a data flow and a memory content in a coding phase in an initial state according to the fifth embodiment.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Naoki Ito             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation (72) Inventor Shinichi Kato             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation (72) Inventor Hidefumi Osawa             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation F term (reference) 5C059 KK41 MA00 MA23 MA45 MC11                       ME02 PP20 SS20 TA00 TC38                       UA02 UA34 UA35 UA39                 5C077 LL20 MP01 MP08 PP27 PQ12                       RR21                 5C078 BA57 CA27 DA01 DA07

Claims (27)

[Claims] 1. Inputting image area information composed of plural kinds of image area component data for each pixel of multi-valued image data,
An image processing apparatus for compression-encoding the image area information, comprising: first encoding means for losslessly encoding the input image area information; and code data losslessly encoded by the first encoding means. And a second encoding means for decompressing the code data stored in the storage means, reversibly encoding the encoded data again and storing the encoded data in the storage means, and encoding by the first encoding means. Monitoring means for monitoring the data amount and determining whether or not the target data amount is exceeded, and image area information to be encoded by the first encoding means when the monitoring means determines that the target data amount is exceeded. And a control means for requesting conversion of image area component data in each of the image area information obtained by decompressing by the second encoding means according to a predetermined condition, the predetermined image by the control means. Of domain component data conversion When there is a request, the first encoding means converts the requested image area component data in the image area information that is subsequently input, encodes it, and stores it in the storage means, The second encoding means converts the requested image area component data in the image area information obtained by expanding the encoded data already stored in the storage means, re-encodes the converted image area component data, and then re-encodes the storage means. An image processing device, characterized in that it is stored in. 2. The image processing apparatus according to claim 1, wherein the control unit converts the image area component data to be converted each time it determines that the target data amount is exceeded. 3. The image area component data includes data indicating whether the pixel of interest is a character / line drawing area or a halftone area, and data indicating whether the pixel of interest is a chromatic color or an achromatic color. Claim 1 or 2 characterized in that it is included
The image processing device according to item. 4. When the monitoring means first determines that the coded data amount exceeds the target data amount, the control means sets the attribute information of the pixel in the halftone region, which is achromatic, to chromatic color. If the monitoring unit determines that the code data amount exceeds the target data amount for the second time, the control unit determines that the attribute information of the pixel in the character line drawing is achromatic color. 4. The image processing apparatus according to claim 3, wherein the image processing apparatus requests to change the image processing method. 5. Further, by inputting multi-valued image data and analyzing the input multi-valued image data,
Attribute information generating means for outputting, as the attribute information, attribute component data indicating whether it is a character / line drawing region or a halftone region, and attribute component data indicating whether it is a chromatic color or an achromatic color The image processing apparatus according to claim 3. 6. An input means for inputting the multi-valued image data, a first image compression means capable of changing a parameter for determining a compression rate, and a parameter for determining a compression rate, A second image compression unit that has a compression rate higher than that of the first image compression unit and that decodes code data compressed by the first image compression unit and recompresses; and the first image compression unit, The second monitoring means for monitoring the code data amount during compression of the image data being input and determining whether the code data amount has reached a predetermined amount, and the second monitoring means. When it is determined that the predetermined amount has been reached, a setting unit that sets a parameter for increasing the compression rate in the first and second image compression units, and a second unit when the parameter is changed by the setting unit
The image compression means re-encodes the code data previously generated by the first compression means, and the re-encoded code data is stored as code data after the parameter of the first compression means is changed. 6. The control means for storing the coded data generated by the first compression means after the parameter change as the subsequent coded data. The image processing device according to item 1. 7. For each pixel of multi-valued image data, image area information composed of a plurality of types of image area component data is input,
A method of controlling an image processing apparatus for compression-encoding the image area information, comprising: a first encoding step of reversibly encoding the input image area information and storing the image area information in a predetermined storage means; A second encoding step of decompressing the encoded data, reversibly encoding it again, and storing it again in the storage means; and monitoring the amount of data encoded in the first encoding step to determine the target amount of data. A monitoring step of determining whether or not the image data exceeds the target data amount, and if the monitoring step determines that the target data amount is exceeded, the image area information to be encoded in the first encoding step and the second encoding step And a control step of requesting conversion processing of the image area component data in each of the image area information obtained by decompression according to a predetermined condition, and there is a request for conversion processing of the predetermined image area component data by the control step. When the above In the first encoding step, the requested image area component data in the image area information that is subsequently input is converted, encoded, and stored in the storage means, and the second encoding step is performed. Is characterized in that the requested image area component data in the image area information obtained by decompressing the code data already stored in the storage means is changed, then re-encoded and stored in the storage means. Method for controlling image processing device. 8. For each pixel of multi-valued image data, image area information composed of a plurality of types of image area component data is input,
A computer program functioning as an image processing device for compression-encoding the image area information, the program code of a first encoding step of reversibly encoding the input image area information, and storing the image area information in a predetermined storage means, A program code of a second encoding step of decompressing the code data stored in the storage means, reversibly encoding it again, and storing it again in the storage means, and the amount of data encoded in the first encoding step. And a program code of a monitoring process for monitoring whether the target data amount is exceeded, and image area information to be encoded in the first encoding process when the monitoring process determines that the target data amount is exceeded. And a progress of the control step for requesting conversion processing of the image area component data in each of the image area information obtained by decompressing in the second encoding step according to a predetermined condition. When there is a request for conversion processing of the predetermined image area component data by the control step, the first encoding step includes a request of image area information that is input subsequently. The second encoding step includes a program code for converting the existing image region component data, encoding the same, and storing the encoded image data in the storage means, and the second encoding step is an image obtained by expanding the encoded data already stored in the storage means. A computer program comprising a program code for changing the requested image area component data in the area information and then re-encoding and storing it in the storage means. 9. A storage medium on which the computer program according to claim 8 is stored. 10. An image processing apparatus for inputting multi-valued image data and image area information of each pixel and performing compression encoding, wherein a parameter for determining a compression rate of the multi-valued image data is changeable. An image data compression unit, a second image data compression unit that can change a parameter for determining a compression rate, decodes code data compressed by the first image data compression unit, and re-compresses the image data; A parameter for determining the compression ratio of the region information is changeable, a first image region information compression unit for lossless encoding, and a parameter for determining the compression ratio is changeable, the first image region information compression unit A second image area information compression means of lossless encoding for decoding and re-compressing the code data compressed in 1., and a code in the middle of compressing the image data being input by the first image data compression means. Monitor the amount of data In both cases, a monitoring unit that determines whether or not the code data amount has reached a predetermined amount, and if the monitoring unit determines that the predetermined amount has been reached, the first and second image data compression units and the first and second image data compression units. Setting means for setting a parameter for increasing the compression ratio of the first and second image area information compression means, and a case where the parameter is changed by the setting means
The code data previously generated by the image data compression means is re-encoded by the second image data compression means, and the code data previously generated by the first image area information compression means is converted into the second data. Re-encoding by the image area information compressing means, and the coded data after the re-encoding is used as coded data after the parameters of the first image data compressing means and the first image area information compressing means are changed. Control means for storing the coded data generated by the first image data compression means after the parameter change and the first image area information compression means while being saved as subsequent code data. Image processing device. 11. The control unit changes the image area component information forming the image area information to a predetermined state each time it determines that the target data amount is exceeded. Image processing device. 12. The image area component information includes data indicating whether the pixel of interest is a character / line drawing area or a halftone area, and data indicating whether the pixel of interest is a chromatic color or an achromatic color. The image processing device according to claim 10, wherein the image processing device is included. 13. An image processing method for inputting multi-valued image data and image area information of each pixel and compression-encoding, wherein a parameter for determining a compression rate of the multi-valued image data is changeable. An image data compression step, a second image data compression step in which a parameter for determining a compression rate is changeable, the code data compressed in the first image data compression step is decoded and recompressed, A parameter for determining the compression ratio of the region information is changeable, and a first image region information compression step of lossless encoding, and a parameter for determining the compression ratio is changeable, the first image region information compression process Second image area information compression means for lossless encoding, which decodes and re-compresses the code data compressed in 1., and a code which is compressing the image data being input by the first image data compression step. Monitor the amount of data In both cases, a monitoring step of determining whether or not the code data amount has reached a predetermined amount, and the first and second image data compression steps and the first and second image data compression steps when the monitoring step determines that the predetermined amount has been reached A setting step of setting a parameter for increasing the compression rate in the first and second image area information compression steps, and a case where the parameter is changed in the setting step, the first step
The code data previously generated in the image data compression step is re-encoded in the second image data compression step, and the code data previously generated in the first image area information compression step is converted into the second code data. Is re-encoded by the image area information compression step of, and the respective code data after the re-encoding is used as code data after the parameter change of the first image data compression step and the first image area information compression step. And a control step of storing the encoded data generated in the first image data compression step after the parameter change and the first image area information compression step after the parameter is changed, as subsequent encoded data. Image processing method. 14. A computer program which functions as an image processing device for inputting multi-valued image data and image area information of each pixel and performing compression encoding, wherein a parameter for determining a compression rate of the multi-valued image data is changed. A program code of a possible first image data compression step and a parameter for determining a compression rate are changeable, and a second code for decoding and recompressing the code data compressed in the first image data compression step. The program code of the image data compression step and the parameter for determining the compression rate of the image area information can be changed, and the program code of the first image area information compression step of lossless encoding and the parameter for determining the compression rate can be changed. A program coordinator of a second image area information compression means of lossless encoding, which is possible and which decodes and recompresses the code data compressed in the first image area information compression step. And monitoring the code data amount while the image data being input is being compressed by the first image data compression step and monitoring whether the code data amount has reached a predetermined amount. When it is determined that the predetermined amount has been reached by the program code of the process and the monitoring process, the compression rates of the first and second image data compression processes and the first and second image area information compression processes are increased. The program code of the setting step for setting the parameter to be set and the first code when the parameter is changed by the setting step.
The code data previously generated in the image data compression step is re-encoded in the second image data compression step, and the code data previously generated in the first image area information compression step is converted into the second code data. Is re-encoded by the image area information compression step of, and the respective code data after the re-encoding is used as code data after the parameter change of the first image data compression step and the first image area information compression step. And a program code of a control step of storing the coded data generated in the first image data compression step after the parameter change and the first image area information compression step after the parameter is changed, as subsequent code data. A computer program characterized by. 15. A storage medium on which the computer program according to claim 14 is stored. 16. An image processing device for inputting multi-valued image data and image area information of each pixel and performing compression encoding, wherein a parameter for determining a compression rate of the multi-valued image data is changeable. An image data compression unit, a second image data compression unit that can change a parameter for determining a compression rate, decodes code data compressed by the first image data compression unit, and re-compresses the image data; A parameter for determining the compression ratio of the region information is changeable, a first image region information compression unit for lossless encoding, and a parameter for determining the compression ratio is changeable, the first image region information compression unit The image being input by the losslessly encoded second image area information compressing means for decoding and re-compressing the code data compressed in 1., and the first image data compressing means and the first image area information compressing means. Data and image area information Monitoring means for monitoring the total code data amount of the respective code data amounts being compressed, and for determining whether or not the total code data amount reaches a predetermined amount, and the monitoring means for setting the predetermined amount to the predetermined amount. When it is determined that the value has been reached, setting means for setting a parameter for increasing the compression rate of the first and second image data compression means and the first and second image area information compression means, and a parameter by the setting means If you change the first
The code data previously generated by the image data compression means is re-encoded by the second image data compression means, and the code data previously generated by the first image area information compression means is converted into the second data. Re-encoding by the image area information compressing means, and the coded data after the re-encoding is used as coded data after the parameters of the first image data compressing means and the first image area information compressing means are changed. Control means for storing the coded data generated by the first image data compression means after the parameter change and the first image area information compression means while being saved as subsequent code data. Image processing device. 17. The control unit changes the image area component information forming the image area information to a predetermined state each time it determines that the target data amount is exceeded. Image processing device. 18. The image area component information includes data indicating whether the pixel of interest is a character / line drawing area or a halftone area, and data indicating whether the pixel of interest is chromatic or achromatic. The image processing device according to claim 16, wherein the image processing device is included. 19. An image processing method for inputting multi-valued image data and image area information of each pixel and compression-encoding, wherein a parameter for determining a compression rate of the multi-valued image data is changeable. An image data compression step, a second image data compression step in which a parameter for determining a compression rate is changeable, the code data compressed in the first image data compression step is decoded and recompressed, A parameter for determining the compression ratio of the region information is changeable, and a first image region information compression step of lossless encoding, and a parameter for determining the compression ratio is changeable, the first image region information compression process The image being input by the second image area information compression step of lossless encoding, which decodes and re-compresses the code data that has been compressed in step 1, and the first image data compression step and the first image area information compression step. Data and image area information A monitoring step of monitoring the total code data amount of each code data amount being compressed and determining whether or not the total code data amount reaches a predetermined amount; If it is determined that the parameter has been reached, a setting step of setting a parameter for increasing the compression rate in the first and second image data compression steps and the first and second image area information compression steps, and a parameter by the setting step If you change the first
The code data previously generated in the image data compression step is re-encoded in the second image data compression step, and the code data previously generated in the first image area information compression step is converted into the second code data. Is re-encoded by the image area information compression step of, and the respective code data after the re-encoding is used as code data after the parameter change of the first image data compression step and the first image area information compression step. And a control step of storing the encoded data generated in the first image data compression step after the parameter change and the first image area information compression step after the parameter is changed, as subsequent encoded data. Image processing method. 20. A computer program which functions as an image processing device for inputting multi-valued image data and image area information of each pixel and performing compression encoding, wherein a parameter for determining a compression rate of the multi-valued image data is changed. A program code of a possible first image data compression step and a parameter for determining a compression rate are changeable, and a second code for decoding and recompressing the code data compressed in the first image data compression step. The program code of the image data compression step and the parameter for determining the compression rate of the image area information can be changed, and the program code of the first image area information compression step of lossless encoding and the parameter for determining the compression rate can be changed. A program code of a second image area information compression step of lossless encoding which is possible and which decodes and recompresses the code data compressed in the first image area information compression step. And the total coded data amount of the respective coded data amounts during the compression of the image data and the image region information being input by the first image data compression step and the first image area information compression step. And a program code of a monitoring process for determining whether or not the total code data amount has reached a predetermined amount, and when it is determined that the predetermined amount has been reached by the monitoring process, the first and second Program code of a setting process for setting a parameter for increasing the compression rate of the image data compression process and the first and second image area information compression processes, and the first code when the parameter is changed by the setting process.
The code data previously generated in the image data compression step is re-encoded in the second image data compression step, and the code data previously generated in the first image area information compression step is converted into the second code data. Is re-encoded by the image area information compression step of, and the respective code data after the re-encoding is used as code data after the parameter change of the first image data compression step and the first image area information compression step. And a program code of a control step of storing the coded data generated in the first image data compression step after the parameter change and the first image area information compression step after the parameter is changed, as subsequent code data. A computer program characterized by. 21. A storage medium storing the computer program according to claim 20. 22. An image processing apparatus for inputting multi-valued image data and image area information of each pixel and performing compression encoding, wherein a parameter for determining a compression rate of the multi-valued image data is changeable. An image data compression unit, a second image data compression unit that can change a parameter for determining a compression rate, decodes code data compressed by the first image data compression unit, and re-compresses the image data; A parameter for determining the compression ratio of the region information is changeable, a first image region information compression unit for lossless encoding, and a parameter for determining the compression ratio is changeable, the first image region information compression unit The image being input by the losslessly encoded second image area information compressing means for decoding and re-compressing the code data compressed in 1., and the first image data compressing means and the first image area information compressing means. Data and image area information Monitoring means for observing the respective code data amounts during compression and determining whether or not the respective code data amounts have reached the predetermined amounts set respectively, and the monitoring means for monitoring the image data of the image data. When it is determined that the code amount has reached a predetermined amount, a first setting unit that sets a parameter for increasing the compression rate of the first and second image data compression units, and a parameter is set by the first setting unit. When changed, the code data previously generated by the first image data compression means is re-encoded by the second image data compression means, and the respective code data after the re-encoding is converted into the first code data. Of the image data compression means is stored as coded data after parameter change, and the coded data generated by the first image data compression means after parameter change When it is determined by the monitoring means that the code amount of the image area information has reached a predetermined amount, the compression ratios of the first and second image area information compressing means are stored. Second setting means for setting a parameter to be increased, and when the parameter is changed by the second setting means, the code data previously generated by the first image area information compressing means is changed to the second image area. The data is re-encoded by the information compression means, and the respective re-encoded code data are stored as the code data after the parameter change of the first image area information compression means, and the first data after the parameter change is performed. An image processing apparatus, comprising: second control means for storing the encoded data generated by the image area information compression means as subsequent encoded data. 23. The second control means changes the image area component information constituting the image area information to a predetermined state each time it is determined that the target data amount is exceeded. The image processing device according to item. 24. The image area component information includes data indicating whether the pixel of interest is a character / line drawing area or a halftone area, and data indicating whether the pixel of interest is a chromatic color or an achromatic color. The image processing device according to claim 22, wherein the image processing device is included. 25. An image processing method for inputting multi-valued image data and image area information of each pixel and compression-encoding, wherein a parameter for determining a compression rate of the multi-valued image data is changeable. An image data compression step, a second image data compression step in which a parameter for determining a compression rate is changeable, the code data compressed in the first image data compression step is decoded and recompressed, A parameter for determining the compression ratio of the region information is changeable, and a first image region information compression step of lossless encoding, and a parameter for determining the compression ratio is changeable, the first image region information compression process The image being input by the second image area information compression step of lossless encoding, which decodes and re-compresses the code data that has been compressed in step 1, and the first image data compression step and the first image area information compression step. Data and image area information A monitoring step of monitoring each code data amount during compression and determining whether or not each code data amount has reached a predetermined amount set for each, and a step of monitoring the image data by the monitoring step. When it is determined that the code amount has reached a predetermined amount, a first setting step of setting a parameter for increasing the compression rate in the first and second image data compression steps, and a parameter setting by the first setting step When changed, the code data previously generated in the first image data compression step is re-encoded by the second image data compression step, and the respective code data after the re-encoding is converted into the first code data. Of the image data compression process, the coded data generated in the first image data compression process after the parameter change is stored as the coded data after the parameter change. When it is determined by the monitoring step that the code amount of the image area information has reached a predetermined amount, the compression ratios of the first and second image area information compression steps are stored. A second setting step of setting a parameter to be increased, and when the parameter is changed by the second setting step, the code data previously generated in the first image area information compression step is converted into the second image area. The data is re-encoded by the information compression step, and the respective code data after the re-encoding is stored as the code data after the parameter change in the first image area information compression step, and the first data after the parameter change is performed. A second control step of storing the coded data generated in the image area information compression step as subsequent coded data. 26. A computer program which functions as an image processing apparatus for inputting multi-valued image data and image area information of each pixel and performing compression encoding, wherein a parameter for determining a compression rate of the multi-valued image data is changed. A program code of a possible first image data compression step and a parameter for determining a compression rate are changeable, and a second code for decoding and recompressing the code data compressed in the first image data compression step. The program code of the image data compression step and the parameter for determining the compression rate of the image area information can be changed, and the program code of the first image area information compression step of lossless encoding and the parameter for determining the compression rate can be changed. A program code of a second image area information compression step of lossless encoding which is possible and which decodes and recompresses the code data compressed in the first image area information compression step. And, by the first image data compressing step and the first image area information compressing step, monitoring the respective coded data amounts during the compression of the image data and the image area information being input, The program code of the monitoring process for determining whether or not the code data amount has reached the predetermined amount set for each, and when it is determined that the code amount of the image data has reached the predetermined amount by the monitoring process, The program code of the first setting step for setting a parameter for increasing the compression rate of the first and second image data compression steps, and the first image data compression when the parameter is changed by the first setting step. The code data previously generated in the step is re-encoded by the second image data compression step, and the respective code data after the re-encoding are converted into the first image data. A program of a first control step for storing the encoded data generated in the first image data compression step after the parameter change as the encoded data after the parameter change in the data compression step And a second code for setting a parameter for increasing the compression rate in the first and second image area information compression steps when it is determined that the code amount of the image area information has reached a predetermined amount by the monitoring step. When the program code of the setting step and the parameters are changed in the second setting step, the code data previously generated in the first image area information compressing step is re-coded by the second image area information compressing step. And each of the re-encoded coded data is stored as coded data after the parameter change of the first image area information compression step, and A computer program comprising: the coded data generated in the first image area information compression step after the change, and the program code of the second control step of storing the coded data as subsequent coded data. 27. A storage medium storing the computer program according to claim 26.