JP3537589B2 - Image processing device - Google Patents

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 digital image processing function and a large-scale buffer memory, for example, an image processing apparatus applied to a digital copying machine, a facsimile apparatus and a printer. The present invention relates to an image processing apparatus capable of effectively utilizing a buffer memory in a multifunction peripheral having a copier, a facsimile, and a printer function.

[0002]

2. Description of the Related Art In a conventional image processing apparatus, particularly a digital multifunction peripheral, processing procedures such as an image processing function and a control function of a storage unit and an external I / F unit are limited. For this reason, sufficient resources have not been effectively utilized.

[0003] The prior art Japanese Patent Laid-Open Publication No.
There is an image processing apparatus disclosed in US Pat. In this image processing device, independent of various image processing functions,
By performing access to the storage unit and input / output control to the external I / F, the image processing resources are effectively utilized.

[0004]

However, even in the above-mentioned conventional image processing apparatus, the storage section has not yet been appropriately and effectively utilized as the entire composite function. Data is converted into various formats on a bus in the middle of the image processing apparatus, and neither format is suitable for source coding. For example, in a data format that does not increase the compression efficiency, data that can be stored in the storage unit is limited. In addition, when converted to an irreversible coded code in order to increase the compression efficiency, a remarkable image quality degradation occurs after decoding,
There is a problem that the subsequent processing may be hindered.

Further, each composite function separately holds a small memory and uses it for similar functions. Except for an extremely local usage mode, there is room for more effective use of memory resources if centralized control is performed at one location.

The present invention has been made in view of such a situation of the prior art, and an object of the present invention is to provide a multifunction peripheral that effectively and appropriately utilizes various processing functions including a memory resource to realize a system. It is to provide an image processing device with improved performance.

[0007] In order to achieve the above object, the image processing apparatus of the present invention compresses the read digital image data.
A plurality of compression / decompression means for decompression, a plurality of compression memories for storing the image data compressed by the plurality of compression means, and a selection means for selecting a required data bus from a plurality of data buses; In an image processing apparatus having an I / F means for transmitting and receiving image data to and from an external unit, the plurality of compression / decompression means and the plurality of compression memories are configured to encode and decode multi-valued digital image data as an information source. First multi-level compression / decompression means for converting
And the multi-level compression memory for storing the image data corresponding to multi-value information compressed by the compression / decompression unit, the selection
Data bus required from multiple data buses by means
A second compression / decompression means for encoding and decoding binary digital image data obtained by selecting
A binary compression memory for storing the image data corresponding to the binary information compressed by the second compression / decompression means is provided independently.

Further, the above-mentioned image processing apparatus is provided with an external I / O
Send data at least with personal computer as F
A first transmitting / receiving means for receiving, a facsimile machine and
Second transmission / reception means for transmitting / receiving data, and a memory storage unit.
Third transmission / reception means for transmitting / receiving data to / from a memory, and a memory
Means for adjusting access to the storage unit.
The first transmitting / receiving means and the second transmitting / receiving means;
Communication means and at least two of the third transmission / reception means.
Simultaneous writing to the same address from two or more transmission / reception means
To avoid addressing the memory storage unit to a predetermined address.
Whether the access is during the reading period or the writing period
Should be monitored.

[0009]

The memory storage unit accessible from a plurality of units preferably has means for controlling the use range of the memory area and means for controlling data in the same area so that they can be accessed mutually.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of an image processing apparatus according to the present invention will be described in detail with reference to the accompanying drawings. FIG.
FIG. 19 to FIG. 19 show an embodiment of the image processing apparatus of the present invention.

FIG. 1 is a block diagram showing the configuration of the image processing apparatus according to the present embodiment. The image processing apparatus shown in FIG. 1 optically reads an image and converts a photoelectrically converted image signal into a digital signal. The reading unit 11 corrects a signal deterioration caused by an imaging element and a reading position of the read image signal. Shading correction unit 12, M of input image
A filter 14 for performing a smoothing process for TF correction or moire removal, an electric scaling unit 16 for enlarging or reducing image data within one line for reading in a main scanning direction by a line sensor, a floor of an input image Γ conversion processing section 17 for performing tone conversion, image quality processing section 19 for performing image quality processing corresponding to the setting mode, smoothing section 22 for performing smoothing / multi-level conversion of a binary image, writing for reproducing image data as electrophotography on paper Unit 24, a multi-level compression memory unit 2 constituting a multi-level compression memory for storing multi-level image data
6. First compression / expansion of data to / from this memory
A multi-level compression / expansion unit 25 constituting the compression / expansion means, and a binary compression memory for storing binary images and code data are configured.
And a second compression / expansion unit 28 which constitutes a second compression / expansion means for compressing / expanding data in / from this memory.

Further, selectors 20a to 20h for selecting a plurality of data buses, an operation unit 30 for specifying a processing mode, a control unit 31 for controlling each bus and processing contents, and an external unit for accessing an external application (not shown) It has an APL terminal 32 having an I / F section.

In the configuration shown in FIG. 1, the storage unit has two systems, one for multivalued data and the other for binary data. Although the multifunction device system has both storage units in the full equipment, there may be various combinations in some cases. These combinations are selected according to the composite function and the required image quality. Basically, the multi-value storage unit stores read image data after shading correction as original data without performing gradation processing, image quality processing, and the like, and responds to a request for a high-quality image.

With respect to the image data once fetched, the image data is used for changing the image quality processing and outputting the same image, or performing the processing of changing the magnification, etc. Data writing is not permitted directly from an external device. However, the captured raw image data is transferred to the APL terminal 32. For example, when a personal computer (hereinafter, also referred to as a PC) is connected as an external application and multi-valued image data is required for a certain kind of application software, the multi-valued image data is transferred. Data reading from the value storage unit is permitted. It is used as a storage unit for storing image data in the reading unit for a composite function specialized for the reading device.

The storage unit for binary data includes encoded binary data of an image, font data of PC and FAX, FA
Used for X reception data and the like. In this case, binary data such as codes and fonts may be used, and the data must be located at a position accessible from an external unit. If the original is mainly composed of characters and the image quality does not matter, the binary storage unit can be used for image storage, electronic sorting, image rotation, and image synthesis. The system can be configured at a lower cost than the multi-value storage unit, and can be released to a function using a plurality of binary data. The multivalued and binary storage units may be either an electric medium or a magnetic medium, or may be mixed. One method is to configure the storage unit with an electric medium as the primary option and configure the storage unit with a magnetic medium as the extension option.

In the configuration of FIG. 1, several selectors 20 are inserted on the image bus. The switching will be described. First, if the image (raw) data after shading correction is accumulated and used many times in the image processing of the copy function,
The read data is subjected to shading correction and information source coding of multi-valued image data is performed. Thereby, the encoded image data from which the redundant data is deleted is generated and stored in the multi-value storage unit. When the stored image information is printed out many times, the reading unit 11 does not operate, takes out the encoded data in the storage unit, and returns it to the video bus after decoding. Here, the selector transfers the image data from the storage unit to the filter 14, performs electrical scaling (16) on the data after MTF correction or smoothing processing in the main scanning direction, performs γ conversion (17), and performs image quality processing (19). ), The data is transferred to the writing unit 24 as it is and printed out.

When transferring the once fetched data to an external application unit such as a personal computer instead of image processing of the copying function, the reading unit 11 is not operated, the coded image data in the storage unit is taken out, and the decoded video data is output. Return to the bus. On the video bus, the filter block is passed through (no filtering is performed), and in the scaling block, main scanning scaling is performed if requested. The gamma conversion and gradation processing are also performed, and data is transferred from an external unit terminal to a PC. As a result, it is possible to supply raw data to be read for performing arbitrary processing by application software on a personal computer. Since the scaling process can be handled by software, the processing block may be particularly skipped. However, if it is necessary to perform high-speed processing in hardware, a scaling function may be used.

The stored image processing is performed on the image data after the image quality processing by using a binary storage unit. The image data subjected to the multi-value processing is binarized in the image quality processing unit 19. As the binarization method, there are fixed binarization by threshold processing, binary dither processing, and binary error diffusion processing. The generated binary image data is transferred to the binary storage unit through the selector 20. Information source coding is performed on the binary signal, and the code data is stored in the memory 29 for the binary code.
In printing out the stored image information a plurality of times, the reading section 11 and the image processing function for the copying function are not operated, the stored binary code information is taken out, and after being decoded, it is returned to the video bus.

The binary image is subjected to a binary / multilevel conversion in a smoothing block, and is subjected to a correction process so that a series of pixels in an edge portion and a contour portion of the image continuously changes. With respect to the converted multi-valued image data, the writing unit 24 controls the power modulation and the phase modulation of the writing laser to reproduce the image on the paper.

When used as a buffer function for printout data from an external unit, binary image data for output is received from a terminal 32 for external application, and encoded data is stored in a binary code memory 29 after information source encoding. I do. If the amount of data is large, coding and storage are repeated, while the stored data is read out and decoded and transferred to the video bus. The binary image data on the video bus is subjected to binary / multi-value conversion in the smoothing block 22, and then the image is reproduced on the paper through the writing unit 24.

When the binary code memory 29 is shared between a plurality of external application units, for example, when font data is stored and shared, font data is stored in a binary storage unit from an external application through an external unit terminal. When the data amount is large, data compression is performed once, and after reducing the data amount, the data is stored in the memory. If the data is small, the font data is directly downloaded to the memory. When another application uses this font data, it reads the data stored in the memory, expands the data if it is a compressed code,
Transfer font data to the required external unit through the external application terminal.

In the configuration shown in FIG. 2, the external storage unit is integrated at one place. A reading unit 41 that optically reads a document and converts an electric signal after photoelectric conversion into a digital signal, and an image processing unit that processes image data for a copying function.
A PU unit 42, a writing control unit 43 for performing binary-to-multi-value conversion of image data for output on paper, a writing unit 44 for controlling power modulation, phase modulation and the like to generate an image on paper, I
A data bus is configured between the PU 42 and the write control unit 43 for transferring image data, and the control unit 48 controls the bus. With respect to the data bus, data transfer between external units is performed, and data processing is performed between the units as a composite function.

External units connected to the data bus include a PC 45 and a FAX 46, and a memory (also called a storage unit) 47 is connected to them as well. The data bus seen from the write control unit 43 includes IPU42, P
C45, FAX 46, and storage unit 47 are connected, and transmit and receive image and code data among each other.
The image data to be reproduced on the paper is transferred to the writing control unit 48.

FIG. 3 shows the internal configuration of the IPU 42. Image data read by the reading unit 41 is corrected by a shading correction unit 51 such as uneven reading. Regarding the shading correction data, the filter 52
Performs smoothing processing for MTF correction or moire removal of the optical system. With respect to the data after the filtering process, the main scanning electrical scaling process of the read line image is performed. Electric scaling unit 5
After 3, a selector 54 is provided to control the image bus.
The image signal selected by the selector 54 is subjected to γ conversion (55) for gradation control of the multi-valued image. The image data after the γ conversion is subjected to image quality processing (56) corresponding to the image reproduction mode, and any one of multi-value processing, binary processing, dither processing, and error diffusion processing is selected.

The control of the selector 54 will be described. IPU
The image data flowing from 42 to the data bus is data after electrical scaling or data after image quality processing. The data after the electrical scaling is not subjected to any particular processing in the filter 14, but is set to a mode in which the input raw data is passed through as it is, and a selector is set to supply the read original data to an application that requires it. There is a case where scanner data is supplied to a PC, a case where raw data to be read is stored in a storage unit as multi-value data, or the like. When selecting the data after the image quality processing, the MFP is used as a copy function, and when the image data is transferred to the writing control unit so as to reproduce the reproduced image on paper, similarly when the reproduced image is transmitted to the FAX. is there.

The selector 54 before the γ conversion selects either the processed image from the reading unit 41 or the multi-valued image data stored in the storage unit. The selection of read data is a bus setting for normal real-time image processing, but when processing the same read image multiple times or when releasing the reading unit to another functional unit Select the image data stored in the storage unit I do.

An example of image bus control using a storage unit will be described. When a multivalued image requiring halftone reproduction is read and a large number of copies (for example, 999) are generated for one document, the read document is electrically scaled and then stored in a storage unit as a multivalued image. That is, the reading unit 41 is activated only once, and thereafter the reading system does not need to be activated while reproducing the copy image. After reading out the stored image and performing image processing for gamma conversion and halftone,
The image data is transferred to the data bus again, and a signal for image reproduction on paper is output from the writing control unit 43. At this time, the control unit 4 avoids data collision on the data bus.
In step 8, bus control and arbitration are performed.

The writing unit 44 is always in use while generating 999 copies, but the reading unit 41 is in a quiescent state for 998 copies once used. During this time PC4
5, another image can be read and supplied as an image. Although it is necessary to adjust data on the bus, in the image processing apparatus as a multifunction peripheral, the reading unit 41 and the writing unit 4
4 are operated in parallel without making a rest state.

Similarly to the multi-valued image, in the parallel operation of the system, when the capacity of the storage unit is small and halftone cannot be stored, or when there is no problem in reproducing the image with binary information in a character document, the storage in the IPU 42 is performed. The output image bus to the unit 47 is switched. Instead of multi-valued raw data after electrical scaling, a "binary" image that has been subjected to fixed binarization, binary error diffusion processing, or binary dither processing in the image quality processing block is transferred to the data bus Then, the data is stored in the storage unit as binary data.

The stored data is read out as it is, or the image is read out by rotating the image. The stored binary image data is developed on the data bus, and the data is reproduced on the paper by the writing control unit. Even in this case, the writing unit 44
Since the usage rate of the reading unit 41 is low,
Multi-valued image data for PC is transferred from the bus after electrical scaling
It can be supplied to C45. As in the case of the multi-valued storage data, the arbitration and control of the data bus are performed by the control unit 48.

Regarding the data flow on the data bus,
3 is shown. First, regarding the use of the storage unit of the FAX function, when data is received and an image is output on paper, or when the received data is transferred to a PC instead of paper, an I / F unit to the writing unit 44 or the PC 45 is used. Is already occupied by another data transfer, the storage unit 47 is used as a save location for the received / reproduced data. The data is stored in the storage unit until each function is released, and the data is output based on the priority designation from the control unit 48.

In order not to wait in the order of the writing section 44 but to align the image with the output paper, the data is temporarily stored, and when the data is read out again, the data is rotated to align the image with the transfer paper. Alternatively, various types of image data are synthesized on the storage unit, and the data is transferred to the subsequent functional unit. The image information read by the reading unit 41 and binary-processed or multi-valued original data is combined with FAX reception data and text data created by the PC 45 in a memory, and are reproduced as integrated data, for example, on paper.

The first page of the output printed matter is, for example, a PC
Then, after forming a copy of the contents by several pages, a text sentence is printed by the PC 45 at the end of the FAX reception document, and a series of documents is created. Performs addressing control of the storage unit together with the bus control,
It manages which unit function has data at which address of the storage unit and controls the order of page generation to the writing unit 44.

FIGS. 4 to 8 show the outline of the individual functions of the IPU 42. FIG. An outline of shading correction of the signal in FIG. 5 will be described with reference to the circuit configuration block in FIG. When an original is read by the line sensor, unevenness in data depending on the main scanning reading position occurs in the density distribution due to uneven illumination of the lamp, dust and dirt on the CCD light receiving surface, and the reflection mirror even on the same line. Shading correction is a process for preserving the data non-uniformity depending on the reading position and performing correction of the read data when the original is read by the line sensor.

Prior to reading the original, the reference white plate is read. The reference white plate is a reference “white” with uniform spectral characteristics over the entire surface
Is stored in the line memory 62 as one line image data at the time of reading. In this case, since there is a possibility that the reference data 61 includes random noise just by reading one line at a moment, a plurality of lines are read and OR processing is performed to remove the influence of random noise. The read document image is normalized 63 with the stored reference data 61 to remove data non-uniformity due to illuminance unevenness, and as reflection data faithful to the document,
The image is taken into the image processing apparatus.

FIG. 6 shows an outline of the processing contents of the filter unit. The shading-corrected data is corrected for illumination unevenness, but there are still points to be corrected for input data. When an image is read optically, MT
F deteriorates. The input image is dull compared to the original, and the sharpness is deteriorated. This applies to the main and sub directions, and the correction is performed in the IPU. MTF deterioration is corrected for the data after the shading correction by the two-dimensional enhancement filter. A process of superimposing an edge emphasizing component on a pixel region forming an edge in data with a configuration of coefficients having differential characteristics is performed.

On the other hand, in this image processing apparatus, the input data is converted into discrete signals at a certain sampling interval after A / D conversion. Furthermore, when performing dither processing in image quality processing, when converting into a dither pattern at a certain pixel interval, if resampling is performed within the maximum frequency of the input image signal, a moiré image due to aliasing is generated. In particular, this is remarkable in a print original using halftone dots. In order to correct this problem, the input digital image is subjected to a smoothing process to remove a frequency component higher than half the resampling frequency. High frequency removal included in the input signal is performed in the smoothing.

The processing of the filter 14 is closely related to the mode setting of the reproduced image. The copying function generally includes a character mode, a photo mode, and a character / photo mode. The character mode has an aim of sharply reproducing a character original, and an MTF correction filter is used for this aim. In the photo mode, when reproducing halftones by dither processing on a printed document, it is necessary to remove moiré. For this reason, the high-frequency component of the halftone dot generation in the read original is attenuated by the smoothing filter. In the text / photo mode, various variations are conceivable depending on the purpose, but a weak MTF correction is performed mainly for characters, and a weak smoothing process is performed for mainly a picture portion.

FIG. 7 shows an outline of the electric zooming in the main scanning direction. For example, storing input image data in a line memory,
The address of the line memory at the storage destination is skipped every other pixel, and 1/2 of the pixel is thinned out (one pixel is thinned out for every two pixels). Thus, an image reduced by 50% is generated. When a reduced image is not generated by simple thinning, data is configured by weighting the distance to the rearranged position with respect to the input pixel value by ratio distribution or convolution of two pixels.

In the case of enlargement, interpolation between input pixels is performed. In the case of enlargement to 200%, the same input pixels are successively arranged two by two on the line memory to form an enlarged image. When an enlarged image cannot be formed by the continuous arrangement, the rearranged pixel value is complemented by interpolation complementation by weight at an arrangement position between two pixels or by convolution with peripheral pixels.

Regarding reduction and enlargement, when the relocated image is stored again in another memory and the read timing when reading the stored data is controlled, the image shift in the main scanning direction is executed. In the case of the left shift, the relocation data in the line memory is read out earlier by the pixel clock corresponding to the required shift amount than the main scanning start timing. In the case of right shift, on the other hand, reading is performed later than the main scanning start timing.

FIG. 8 shows a configuration example of the image quality processing units 19 and 56 described with reference to FIGS. The image quality processing corresponding to the mode is selected for the multi-valued image data whose gradation characteristics have been matched by the γ conversion. In this processing block, density information DEN and phase information PH are generated. The phase relating to the binary processing is the right phase of the leading pixel and the central phase of all other black pixels. Regarding the multi-value processing 71, in the case of one-dot processing, three phase states of left, center, and right are controlled. In the case of two-dot processing, the even-numbered pixels are controlled to the right phase and the odd-numbered pixels are controlled to the left phase to form a vertical line based image.

The multi-value processing 71 directly outputs the gradation processing data of γ conversion with respect to the density. For the phase, corresponding phase information is generated for the one-dot and two-dot processing. In the fixed binarization 72, the gradation processing data after the γ conversion is binarized based on a fixed threshold. Regarding the phase, the leading pixel that changes from white to black is set to the right phase, and the others are set to the center phase.

Regarding the dither processing 73, the multi-value dither processing generates density data and phase information using a multi-value dither matrix. Threshold order right phase in dither sub-matrix,
It is arranged in the center phase and the left phase. Binary dither is generated in the same manner, but does not have a sub-matrix and one pixel constitutes dither with one threshold. As for the phase, a right phase and a center phase are generated.

The error diffusion process 74 controls the quantization step at the time of error generation by using a multi-value level or a binary value.
The error generation and the error superposition for the redundant component from the peripheral pixels are performed. Regarding the error diffusion processing, a table for both 1 dot and 2 dots is created at the time of quantization of the generated signal, and the density data refers to the table value. Control the state of the two phases.

These processes are performed in parallel, and are selected by the selector 75 in accordance with the input of the processing mode from the operation unit. The density data and the phase data are generated and selected at the same time with the same processing as a pair. Since these gradation processes are premised on image reproduction in electrophotography, CR
It does not have data in the depth direction corresponding to the luminance on T.
In order to reproduce the halftone with the area gradation, to express the density information indicating the size of the dot shape and the density of the dot group,
Generate and output phase information.

When supplying image data for electrophotographic reproduction to a storage unit and an external function, it is necessary to output density data and phase data together. When storing a multi-valued processed image after gradation processing for a storage unit, density data and phase data are stored. Since the density data has a strong correlation, high-efficiency coding can be expected when performing information source coding. The phase is artificially added unlike the density data, and the correlation is not so strong, so that high-efficiency encoding cannot be expected as much as the density data. On the other hand, when the input raw data is stored in the storage unit, there is no phase data but only density change data of the document. Therefore, both the required storage capacity and the data content are different between the input raw data and the data after the image quality processing. The most suitable data content is bus-selected by the subsequent use unit of the stored image.

FIGS. 9 and 10 show an outline of the smoothing (binary / multi-value conversion) process. In the gradation processing unit, it has been described that the right phase and the center phase are generated in the binarization processing,
Such data is not always generated in an external unit such as a PC or a facsimile. In addition, since the phase information is generated again at the time of multi-level conversion, binary data is input to the smoothing unit as the central phase. From this input binary data, multi-value density information and phase information are generated in order to eliminate jaggies on the steps. A two-dimensional image array is created for the input data to generate a pattern 81. Pattern matching 83 is performed between the input pattern and a geometrically characteristic pattern code 82 stored in advance to create data that complements the jaggedness. With respect to the created complementary data, a multi-value code is generated 84, and density data and phase data are output to perform smooth image reproduction on paper.

FIG. 10A shows input binary data.
When the image is reproduced as it is, a jagged image is reproduced in the reproduction of an oblique line or the like. FIG.
In (B), the change area can be smoothly complemented by adding new fine dots based on the density data and the phase data. However, depending on the angle of the oblique line, the reproduced pattern becomes thicker than the input pattern around the pixel where the fine dot is added, and the undulation may be noticeable instead of removing the jaggedness. In such a case, smoother diagonal lines can be reproduced by changing the two-dimensional arrangement of the input image as shown in FIG. 10C without adding fine pixels. Which pattern to take depends on the pattern generated from the input data, and is selected at the time of matching with the pattern code. Means for limiting to only one of the patterns can be arbitrarily controlled by modifying the stored pattern code.

FIG. 11 shows a processing flow of the binary-to-multivalue conversion. The structure of the image data is 1 for both multi-valued data and binary data.
The data is organized in data groups in line units. Therefore, a line memory required to generate a two-dimensional pattern is combined to expand (widen) the pattern area in the sub-scanning direction (9).
Perform 1). For example, nine line memories are used to store an image area of nine lines. In the area of these nine lines, expansion (widening) in the main scanning direction for a two-dimensional pattern
For (92), flip-flops (FF) are combined for each line by the required number of pixels. For example, 1
Binary image data in the main scanning direction is secured by three pixel FFs.

The 13 × 9 pixel area is divided into five areas. The central 5 × 5 region is the core region, the 2 × 5 region above it is the upper peripheral region, the 2 × 5 region below the core region is the lower peripheral region, and the 5 × 4 region on the left of the core region is The left peripheral region and the 5 × 4 region on the right of the core region are defined as a right peripheral region,
The pattern shape of each area is independently recognized (93).

By comprehensively judging the information of each area, the shape of the line segment and the position information of the pixel of interest in the line segment are generated (94) as code information and output. The code information is converted into multi-value density data and phase data by referring to an LUT (look-up table), and data for reproducing an image as an electrophotograph is generated. Each pixel of interest is converted into multi-value data from the peripheral area (95).

FIGS. 12 and 13 show the configuration of the storage unit. FIG. 12 shows the configuration of the multi-value storage unit, and FIG. 13 shows the configuration of the binary storage unit. First, FIG. 12 will be described. As described above, the storage memory may be an electric memory, a magnetic memory, or a mixture of both. With regard to multi-valued data, a line memory 101 is provided and data expansion (104) in the sub-scanning direction is performed in order to use peripheral pixels for information source coding. Redundant correlation data between the target pixel and peripheral pixels is deleted from these buffer data. The source-encoded image information is addressed to the storage memory 103 and stored (102).
I do.

When outputting image information from the stored code data, continuous code information is extracted from the memory by addressing control. A decoding process is performed on the code data group for the inverse conversion to reproduce image data. As for the binary image and the code information, the information source encoding (111) is performed in the image area of one line. Therefore, unlike the multi-value system, no line memory is required. The run-length information is encoded, the address of the binary data storage memory 112 is controlled, and the data is stored. The decoding process retrieves the code data corresponding to the storage address from the memory,
Perform image restoration. Basically, only a data conversion point is used as extraction information for a binary image, so that a storage unit can be configured without using a buffer memory or the like.

FIG. 14 shows an outline of binary and multi-level memory access control and area control (121). Is the storage unit 122 constitute a first transmitting and receiving means PC 124, the
FAX 125 constituting the second transmitting / receiving means, third transmitting / receiving
It is accessed from the IPU 126 that constitutes the means . By performing access control so as to access the respective storage areas of the storage units allocated to each functional unit, simultaneous writing from the two functional units to the same address is avoided. On the other hand, access to a predetermined address to the storage unit 122 is performed during a reading period or during a writing period so that data can be shared with already-written data, and reading access to the same address can be performed from a plurality of functional units. Is monitored by the memory access control unit 123.

When no write access is performed from any of the functional units to the memory section of the storage unit, read access to that address is permitted to any unit. On the other hand, in the write access, a functional unit having write permission is associated with each memory partition, and writing is not performed on units other than the unit having permission. When writing and reading occur at the same time, priority is given to writing. The priority of access to a functional unit having write permission for the partition is set higher than other units.

Regarding the area control of the memory, there are a method of statically dividing the capacity used in each functional unit in advance by a fixed area partition, and a method of dynamically changing the capacity according to the used amount. In the fixed area method, a font storage area for a PC, a reception data storage area for a facsimile, and an image processing data storage area for an IPU are determined in advance, and the functional units allocated in the areas write / read data. Each area range is set artificially by inputting a command from the operation unit in setting the system mode or the like.

If there is no FAX due to the system configuration, F
Since it is not necessary to secure an area for storing the received data for AX, the storage unit is not allocated to the FAX unit in the system mode setting. Efficient use of storage units for existing systems. Thereafter, when the FAX unit is expanded by system expansion, the process returns to the system mode setting to secure a storage capacity for FAX reception. In order to allocate a storage unit for facsimile, when the used capacity of another unit is reduced and a problem occurs, the storage unit is expanded electrically or magnetically so that the allocated capacity of the existing functional unit is not reduced.

When dynamically changing the storage capacity, the ID of the connected functional unit is checked. It detects which functional units are connected as many as external units. The addressing of the memory is performed from the functional unit that actually has the write access to the storage unit. Next, in allocating the capacity to the functional unit that has been accessed for writing, data is written from the end address of the area used in the first unit. Fill the memory sequentially as the number of external units increases.

For example, when the PC first uses the memory for writing fonts and then the FAX accesses for receiving data, the receiving data area is secured next to the font area. Further, when the IPU requests to secure an area for reading original data, an area is secured next to the FAX reception area.

When a facsimile area becomes more necessary, F
The area is extended so that the AX area is a continuous address, and the start of the area for the next succeeding IPU is shifted and delayed. When the entire system enters a long standby state, the number of accesses to the storage unit is verified, the storage area for functional units that are hardly accessed releases the used memory for other units, and the area setting and addressing are redone. . Memory relocation is not performed while the system is running. A memory unit is preferentially assigned to a functional unit frequently used by memory relocation. Even in the initial area allocation, when the storage capacity becomes insufficient, the storage capacity of the memory unit for the infrequently used unit is released to the functional unit that newly issued the write request.

FIGS. 15 to 18 show the flow of the video signal. FIG. 15 stores the read original data in a multi-valued memory,
In this mode, the IPU function is used a plurality of times. FIG.
The print data from C is stored in the binary memory, and the writing unit is occupied for print output. In these cases, a multi-valued memory and a two-valued memory are owned and used depending on the functional unit.

In FIG. 17 and FIG. 18, the storage units are integrated in one place, and the multi-value storage and the binary storage are functionally used selectively. FIG. 17 shows an example in which the read multivalued original data is stored and the IPU
After the image processing in step (1), the writing unit is output with priority. FIG.
Numeral 8 stores binary data output from the PC as binary data in a storage unit, and transmits the data by facsimile. This is an example in which data created on a PC is used instead of a read image for FAX.

In addition to the storage unit, the external unit is connected to a personal computer, a printer, a facsimile or the like. FIG.
The configuration in the case of functioning as an I / F of an X transmitting / receiving section is shown.
The facsimile transmission / reception unit 200 converts the image data into a communication format and transmits it to an external line, and converts external data into image data and stores and outputs the data to the writing unit via the external I / F unit 300 and the data bus. I do. FAX transceiver 2
00 is a fax image processing unit 201, an image memory 201,
Memory control unit 203, facsimile control unit 204, image compression / decompression unit 205, modem 206, and network control device 207
Consists of Among them, regarding the FAX image processing, the binary smoothing processing for the received image is performed by a processing block that performs write control. As for the image memory 202, part of the output buffer function is transferred to a binary storage unit.

The facsimile transmission / reception unit 20 thus configured
In the case of 0, when the transmission of the image information is started, the facsimile control unit 204 instructs the memory control unit 203 to sequentially read the stored image information from the image memory 202. The read image information is stored in the FAX image processing unit 201.
The signal is restored to the original signal, density conversion processing and scaling processing are performed, and the result is applied to the facsimile control unit 204. The image signal applied to the facsimile control unit 204 is code-compressed by the image compression / decompression unit 205,
After being modulated by the modem 206, the network controller 207
And sent to the destination. Then, the image information whose transmission has been completed is deleted from the image memory 202.

At the time of reception, the received image is temporarily stored in the image memory 2.
02, and if the received image can be recorded and output at that time, it is recorded and output when the reception of one image is completed. When a call is made during the copying operation and reception is started, the usage rate of the image memory 202 becomes a predetermined value, for example, 80%.
Is stored in the image memory 202 until the usage rate reaches 80%. When the usage rate of the image memory 202 reaches 80%, the writing operation being executed at that time is forcibly interrupted, and the received image is read from the image memory 202. Record output.

At this time, the received image read from the image memory 202 is deleted from the image memory 202 and
When the usage rate of 02 has dropped to a predetermined value, for example, 10%, the interrupted writing operation is resumed, and when all the writing operations have been completed, the remaining received images are recorded and output. Further, after the write operation is interrupted, various parameters for the write operation at the time of the interruption are internally saved so that the write operation can be resumed, and the parameters are internally restored at the time of restart.

According to the above-described embodiment, the source coding and decoding of the multi-level digital image signal and the source coding and decoding of the binary digital image signal can be performed independently. The required data bus can be selected from among a plurality of data buses. This makes it possible to achieve both high-quality image reproduction using the memory and effective use of the buffer memory between external units.

The memory unit can be connected to the data bus, and the memory unit can be freely accessed from other functional units by executing the flow control of the bus. As a result, high-quality reproduction of a multi-valued image and effective use as a buffer memory for a binary image and binary data can be achieved with one memory unit. Furthermore, the memory functions of the multifunction peripheral are integrated to effectively use resources, and area control and access control of the memory unit are performed, so that the memory can be used effectively. Further, the same area can be accessed by a plurality of units, and data can be effectively used.

[0071]

As is apparent from the above description, the image processing apparatus of the present invention comprises a plurality of compression / expansion means for compressing / expanding read digital image data, and the plurality of compression / expansion means compressed by the plurality of compression means. An image processing apparatus comprising: a plurality of compression memories for storing image data; a selecting unit for selecting a required data bus from the plurality of data buses; and an I / F unit for transmitting and receiving image data to and from an external unit. A plurality of compression / decompression means and a plurality of compression memories, the first multi-value compression / decompression means for encoding and decoding multi-valued digital image data as an information source; and the first compression / decompression means. and the multi-level compression memory for storing the image data corresponding to multi-value information compressed by means, said election
Select the required data bus from multiple data buses by selecting
Compression / decompression means for encoding and decoding the binary digital image data obtained by selecting the source data, and corresponds to the binary information compressed by the second compression / decompression means. that Yusuke independently a binary compression memory for storing the image data.

Therefore, the source coding and decoding of the multilevel digital image signal and the source coding and decoding of the binary digital image signal can be performed independently, and a plurality of data buses are connected to the binary memory unit. The required data bus can be selected from This makes it possible to achieve both high-quality image reproduction using the memory and effective use of the buffer memory between external units.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an overall configuration of an image processing apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating an overall configuration of an image processing apparatus according to a second embodiment.

FIG. 3 is a block diagram illustrating a detailed configuration of an image processing unit according to a second embodiment.

FIG. 4 is a block diagram illustrating a shading correction unit of FIG. 1;

FIG. 5 shows an example of an input signal for explaining the operation of the shading correction unit.

FIG. 6 is a schematic diagram showing the function of the filter of FIG.

FIG. 7 is a schematic diagram showing the function of the electric zoom of FIG. 1;

FIG. 8 is a block diagram illustrating an image quality processing unit of FIG. 1;

FIG. 9 is a block diagram illustrating a smoothing unit of FIG. 1;

FIG. 10 is a diagram for explaining an operation of a smoothing unit.

FIG. 11 is a diagram showing a processing flow of the block diagram of FIG. 9;

12 is a block diagram illustrating a configuration example 1 of a memory unit illustrated in FIG. 1;

13 is a block diagram illustrating a configuration example 2 of the memory unit illustrated in FIG. 1. FIG.

FIG. 14 is a block diagram illustrating control of a memory unit.

FIG. 15 is a block diagram illustrating a video flow of the image processing apparatus.

FIG. 16 is a block diagram illustrating a video flow of the image processing apparatus.

FIG. 17 is a block diagram illustrating a video flow of the image processing apparatus.

FIG. 18 is a block diagram illustrating a video flow of the image processing apparatus.

FIG. 19 is a block diagram illustrating details of an external I / F unit and a facsimile transmission / reception unit of FIG. 2;

[Explanation of symbols]

11, 41 Reading unit 12 Shading correction unit 14 Filter 16 Electric scaling unit 17 Gamma conversion processing unit 19 Image quality processing unit 20 Selector 22 Smoothing units 24, 44 Writing unit 25 Multi-value compression / expansion unit (first compression / expansion means) 26 ) Multi-level compression memory section (multi-level compression memory) 28 binary compression / expansion section (second compression / expansion means) 29 binary code memory (binary compression memory) 30 operation sections 31, 48 Control unit 32 APL terminal 42 IP 43 Write control unit 45 PC 46 FAX 47 Memory

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N 1/00-1/00 108 H04N 1/32-1/36 H04N 1/42-1/44

Claims (3)

(57) [Claims] A plurality of compression / expansion means for compressing / expanding the read digital image data; a plurality of compression memories for storing the image data compressed by the plurality of compression means; and a plurality of data buses. An image processing apparatus comprising: a selection unit for selecting a necessary data bus from among them; and an I / F unit for transmitting and receiving image data to and from an external unit, wherein the plurality of compression / decompression units and the plurality of compression memories are A first multi-level compression / expansion means for encoding and decoding multi-value digital image data as an information source; and storing the image data corresponding to the multi-value information compressed by the first compression / expansion means. Necessary data from a plurality of data buses by the multi-value compression memory and the selection means.
And a second compression / expansion means for encoding and decoding binary digital image data obtained by selecting the data bus , and the binary information corresponding to the binary information compressed by the second compression / expansion means. An image processing apparatus having an independent binary compression memory for storing the image data. 2. An external I / F as at least a personal
First transmitting / receiving means for transmitting / receiving data to / from a computer
And a second transmission / reception for transmitting / receiving data to / from the facsimile machine
Communication means and a second unit for transmitting / receiving data to / from the memory storage unit.
3 and the access control to the memory storage unit.
Means for controlling the first transmission.
Receiving means, said second transmitting / receiving means, and said third transmitting / receiving
Same from at least two transmission / reception means among communication means
Avoid simultaneous writing to addresses, and
Access to the specified address is in the reading period
And monitoring during the writing period.
The image processing apparatus according to claim 1. 3. A memo accessible from a plurality of units.
The storage unit is a means for controlling the range of use of the memory area.
So that data in the same area can be accessed mutually
And means for controlling.
3. The image processing apparatus according to claim 2, wherein