JP2004088307A - Image processing apparatus, image forming apparatus, program, and storage medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily put together images and divide the images that have been put together without repeating a process for expanding all images for expanding to a memory. <P>SOLUTION: In an image processing apparatus, a header/code data division processing section 55 divides a plurality of images to one or a plurality of tiles each and performs the discrete wavelet conversion of pixel values for each tile, and divides a plurality of code streams that are hierarchically compressed and coded to a header section and a code data section each. A header processing section 56 performs editing so that each image in data of the header section after the division is put together into one image. Then, a code stream synthesis section 57 generates a new, single code stream where each image is put together into one image by connecting the data of the edited header section to each code data section. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image processing apparatus, an image forming apparatus, a program, and a storage medium that combine images or divide the combined images.
[0002]
[Prior art]
The demand for high performance or multifunctional image compression / decompression technology that facilitates the handling of high-definition still images is likely to become stronger and stronger in the future. At present, JPEG (Joint Photographic Experts Group) is most widely used as an image compression / decompression algorithm for facilitating the handling of such high-definition still images. In addition, JPEG2000, which has become certain to become an international standard in 2001, has not only more sophisticated algorithms than JPEG, but also a large number of functions and flexibility for various applications. As a result of its expandability, it is expected as a next-generation high-definition still image compression / decompression format succeeding JPEG.
[0003]
By the way, in recent years, when printing or displaying an image in the background of the improvement of image accuracy and image quality of a printer or the like, consideration for the environment, etc., opportunities for displaying and printing a plurality of pages in a smaller number of pages have been increased. ing. In addition, it is often performed to display and print an index with an easier accuracy. In such a case, in order to create an image, the image is developed one by one, and if necessary, the procedure of changing the size to a predetermined size and developing the image in the memory is repeated to create an aggregated image.
[0004]
Such means requires several times the processing time as compared with the processing of a single image, and also requires a large amount of memory, requiring a memory exceeding the amount of memory provided, or a memory capable of high-speed processing. For example, it takes much longer time for processing than printing a single image, and it causes a great deal of pain to the user.
[0005]
To solve such a problem, the technique disclosed in Japanese Patent Application Laid-Open No. 2000-156829 attempts to reduce the amount of memory used by generating an aggregated image in a small unit such as a line when creating an index image. . Also, the technique disclosed in Japanese Patent Application Laid-Open No. 2000-156830 discloses a technique for preparing an extra buffer to increase the speed.
[0006]
Japanese Patent Application Laid-Open No. 2001-148774 discloses a technique for performing image aggregation by designating the number of images to be aggregated. A number of re-aggregation techniques are disclosed.
[0007]
[Problems to be solved by the invention]
However, even in the techniques disclosed in JP-A-2000-156829 and JP-A-2000-156830, since the process of expanding all the images and expanding them in the memory is repeated, generation of the aggregated image requires It still takes many times longer than a single image. This is the same in the technology disclosed in JP-A-2001-148774 and JP-A-10-322542.
[0008]
SUMMARY OF THE INVENTION It is an object of the present invention to enable easy aggregation of images and division of aggregated images without repeating the process of expanding all images and expanding them in a memory.
[0009]
[Means for Solving the Problems]
The first aspect of the present invention is directed to a plurality of code streams obtained by dividing a plurality of images into one or a plurality of rectangular regions, and performing discrete wavelet transform of pixel values for each of the rectangular regions and performing hierarchical compression encoding. A header / code data division processing means for dividing the data into a header portion and a code data portion, and a header processing means for editing the data of the divided header portion in order to combine the images into one image. Code stream synthesizing means for combining the data of the edited header portion and the respective code data portions to generate a single new code stream in which the images are aggregated into one image. An image processing device.
[0010]
Therefore, the images can be easily aggregated without repeating the process of expanding all the images and expanding them in the memory.
[0011]
According to a second aspect of the present invention, in the image processing apparatus according to the first aspect, the image processing apparatus further includes an aggregation setting unit configured to set the number of images that aggregates the plurality of images into one image, and the header processing unit includes: The editing is performed according to the setting of the aggregation setting means.
[0012]
Therefore, it is possible to obtain a desired aggregated image by setting the number of images to be aggregated.
[0013]
According to a third aspect of the present invention, in the image processing apparatus according to the second aspect, the aggregation setting unit sets the number of images to be aggregated in at least one of a horizontal direction and a vertical direction of the images.
[0014]
Therefore, it is possible to obtain a desired aggregated image by setting the number of images to be aggregated in the horizontal and vertical directions.
[0015]
The invention according to claim 4 is a single code stream obtained by dividing an image into a plurality of rectangular regions, and performing discrete wavelet transform of pixel values for each of the rectangular regions and hierarchically compression-encoding the rectangular region. A header / code data division processing unit that divides a header portion and a coded data portion into one or a plurality of which are each a single image, and divides the data of the header portion after the division for each image. Header processing means for editing to generate a plurality of new code streams; and code for combining the data of the edited header portion and each of the code data portions to generate a plurality of new code streams for each of the images And a stream synthesis processing unit.
[0016]
Therefore, it is possible to easily divide the aggregated image without repeating the process of expanding all the images and expanding them in the memory.
[0017]
According to a fifth aspect of the present invention, there is provided a scanner for reading an image of a document, and the read image is divided into one or a plurality of rectangular areas, and pixel values are discrete wavelet-transformed for each of the rectangular areas to hierarchically compress and encode. 5. An image compression encoding means for generating a single code stream, the image processing apparatus according to claim 1, wherein the code stream is used as the target, and the code stream of the image processing apparatus. And a printer engine for forming an image on a sheet based on each code stream synthesized by the synthesizing means.
[0018]
Therefore, images can be easily aggregated and the aggregated image can be divided without repeating the process of expanding all images and expanding them in the memory.
[0019]
The invention according to claim 6 is an aggregation setting process for setting the number of images to aggregate a plurality of images into one image, dividing the plurality of images into one or a plurality of rectangular regions, and dividing the plurality of images into one or a plurality of rectangular regions. A header / code data division process of dividing a plurality of code streams, which are subjected to discrete wavelet transform of pixel values and hierarchically compression-encoded, into a header portion and a code data portion, and data of the header portion after the division. A header process for editing the data according to the setting of the aggregation setting means, and combining the data of the edited header portion with each of the code data portions to aggregate each image into one image. A computer-readable program that causes a computer to execute a code stream synthesis process that generates a code stream.
[0020]
Therefore, the images can be easily aggregated without repeating the process of expanding all the images and expanding them in the memory.
[0021]
The invention according to claim 7 is the program according to claim 6, wherein the aggregation setting process sets the number of images to be aggregated in the horizontal direction.
[0022]
Therefore, a desired aggregated image can be obtained by setting the number of images to be aggregated in the horizontal direction.
[0023]
The invention according to claim 8 is the program according to claim 6 or 7, wherein the aggregation setting process sets the number of images to be aggregated in the vertical direction.
[0024]
Therefore, a desired aggregated image can be obtained by setting the number of images to be aggregated in the vertical direction.
[0025]
The invention according to claim 9 is a single code stream obtained by dividing an image into a plurality of rectangular areas, and performing discrete wavelet transform on pixel values for each of the rectangular areas and hierarchically compression-encoding the code area. A header / code data division process of dividing one or a plurality of each into a single image into a header portion and a code data portion, and a header process of editing data of the header portion after the division. A code stream synthesizing process of combining the edited data of the header portion and each of the code data portions to generate a plurality of new code streams for each of the images. is there.
[0026]
Therefore, it is possible to easily divide the aggregated image without repeating the process of expanding all the images and expanding them in the memory.
[0027]
According to a tenth aspect, there is provided a storage medium storing the program according to any one of the sixth to ninth aspects.
[0028]
Therefore, the same operation and effect as the invention according to any one of claims 6 to 9 are exerted by the stored program.
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
[Overview of JPEG2000 algorithm]
First, an outline of the JPEG2000 algorithm related to the present embodiment will be described.
[0030]
FIG. 1 is a block diagram for explaining the outline of the JPEG algorithm. The JPEG algorithm includes a color space conversion / inverse conversion unit 100, a discrete cosine conversion / inverse conversion unit 101, a quantization / inverse quantization unit 102, and an entropy coding / decoding unit 103. Usually, lossy encoding is used to obtain a high compression ratio, and thus, in most cases, complete compression / decompression of original image data, so-called lossless compression, is not performed. However, this irreversible (lossy) compression rarely causes problems in practical use. Therefore, the JPEG system greatly contributes to reducing the memory capacity required for compression and decompression processing or storing image data after compression, and to shorten the time spent for data transmission and reception. Because of these advantages, JPEG has become the most widespread still image compression and decompression algorithm.
[0031]
FIG. 2 is a block diagram for explaining the outline of the JPEG2000 algorithm. The JPEG2000 algorithm includes a color space conversion / inverse conversion unit 110, a two-dimensional wavelet conversion / inverse conversion unit 111, a quantization / inverse quantization unit 112, an entropy encoding / decoding unit 113, and a tag processing unit 114. I have.
[0032]
As described above, JPEG is currently the most widely used still image compression / expansion method. However, the demand for higher definition still images has not stopped, and the technical limits of the JPEG system are beginning to appear. For example, block noise and mosquito noise, which were not so noticeable until now, have become remarkable as the definition of the original image has increased, and the image quality degradation of the JPEG file has become a level that cannot be ignored. As a result, the improvement of image quality in a low bit rate, that is, in a high compression rate region has been recognized as the most important issue in technical development. JPEG2000 was born as an algorithm that could solve these problems. In the near future, it is expected to be used together with the currently mainstream JPEG format.
[0033]
One of the biggest differences between FIG. 1 and FIG. 2 described above is the conversion method. JPEG uses Discrete Cosine Transform (DCT), and JPEG2000 uses Discrete Wavelet Transform (DWT). The advantage that DWT has better image quality in a high compression area than DCT is a major reason for adoption. Another major difference is that, in the latter case, a functional block called a tag processing unit 114 is added in order to perform code formation in the last stage. Here, a code stream is generated and interpreted. The code stream has enabled JPEG2000 to realize various convenient functions. For example, FIG. 3 is a diagram showing an example of subbands at each decomposition level when the decomposition level is 3, and an arbitrary hierarchy corresponding to the octave division hierarchy in the block-based DWT shown in FIG. Thus, the compression / decompression processing of the still image can be stopped.
[0034]
Note that color space conversion / inverse conversion units 100 and 110 are often provided in the input / output portion of the original image in FIGS. For example, an RGB color system composed of R (red) / G (green) / B (blue) components of a primary color system, and Y (yellow) / M (magenta) / C (cyan) components of a complementary color system The conversion from the YMC color system to the YCrCb or YUV color system or the reverse conversion corresponds to this.
[0035]
Hereinafter, the JPEG2000 algorithm will be described.
[0036]
Here, the definition of terms relating to JPEG2000 is based on JPEG2000 Part I FDIS (Final Draft International Standard). Hereinafter, definitions of typical terms are shown.
[0037]
1. code-block: A rectangular grouping of coefficients from the same subband of a tile-component.
2. decomposition level: A collection of wavelet subbands there each co-efficient has the same spatial impact as a part of the company's representatives. The include the HL, LH, and HH subbands of the same two dimensional subband decomposition. For the last decomposition level the LL subband is also included.
3. precinct: A one rectangular region of a transformed tile-component, with each search resolution level, used for limiting the size of packets.
4. layer: A collection of compressed image data from coding passes of one, or more, code-blocks of a tile component. Layers have an order for encoding and decoding that must be preserved.
5. region of interest (ROI): A collection of coefficients that are considered of a partial relevance by some user defined measure.
The above is the definition of typical terms.
[0038]
FIG. 4 is a diagram illustrating an example of each component of the tiled color image. As shown in FIG. 4, a color image generally includes a rectangular area (tile) 130 in which each of the components 130, 131, and 132 (in this example, the RGB primary color system) of the original image is formed. _t , 131 _t , 132 _t Divided by Each of the tiles, for example, R00, R01, ..., R15 / G00, G01, ..., G15 / B00, B01, ..., B15 is a basic unit when executing the compression / decompression process. Therefore, the compression / expansion operation is performed independently for each component and for each tile.
[0039]
At the time of encoding, the data of each tile of each component is input to the color space conversion unit 110 shown in FIG. 2 and subjected to color space conversion, and then the two-dimensional wavelet conversion unit 111 performs two-dimensional wavelet conversion (forward conversion). ) Is applied to perform spatial division into frequency bands.
[0040]
FIG. 3 described above shows subbands at each decomposition level when the decomposition level is 3. That is, a two-dimensional wavelet transform is performed on the tile original image (0LL) (decomposition level 0 (reference numeral 120)) obtained by the tile division of the original image, and the subband indicated by the decomposition level 1 (reference numeral 121) is obtained. (1LL, 1HL, 1LH, 1HH). Subsequently, a two-dimensional wavelet transform is performed on the low-frequency component 1LL in this layer to separate the subbands (2LL, 2HL, 2LH, 2HH) indicated by the decomposition level 2 (reference numeral 122). Similarly, two-dimensional wavelet transform is performed on the low-frequency component 2LL to separate the sub-bands (3LL, 3HL, 3LH, 3HH) indicated by the decomposition level 3 (123).
[0041]
Further, in FIG. 3, the subbands to be encoded at each decomposition level are shown in gray. For example, when the decomposition level is 3, the subbands (3HL, 3LH, 3HH, 2HL, 2LH, 2HH, 1HL, 1LH, 1HH) shown in gray are to be encoded, and the 3LL subband is not encoded.
[0042]
Next, bits to be encoded are determined in the specified encoding order, and a context is generated from bits around the target bit by the quantization unit 112 shown in FIG. The wavelet coefficients after the quantization process are divided into non-overlapping rectangles called precincts for each subband. This was introduced to make efficient use of memory in the implementation.
[0043]
FIG. 5 is a view for explaining an example of the relationship between a precinct and a code block. _t0 , 140 _t1 , 140 _t2 , 140 _t3 Are divided into four tiles. As shown in FIG. 5, for example, the precinct 140 _p4 Consists of three spatially matched rectangular areas, and the precinct 140 _p6 The same is true for Here, precinct numbers are assigned from 0 to 8 in raster order. Further, each precinct is divided into non-overlapping rectangular code blocks. In this example, it is divided into twelve code blocks from 0 to 11, for example, code block 140 _b1 Indicates code block number 1. This code block is a basic unit when performing entropy coding.
[0044]
The coefficient value after wavelet transform can be quantized and encoded as it is. However, in JPEG2000, in order to increase the encoding efficiency, the coefficient value is decomposed into “bit plane” units, and each pixel or code block is decomposed. "Bit planes" can be ranked. FIG. 6 briefly explains the procedure. In this example, the original image (32 × 32 pixels) is divided by four tiles of 16 × 16 pixels, and the size of the precinct and the code block at the decomposition level 1 are 8 × 8 pixels and 4 pixels, respectively. × 4 pixels. Precincts and code blocks are numbered in raster order. The pixel expansion outside the tile boundary is performed by using a mirroring method, performing a wavelet transform using a reversible (5, 3) filter, and obtaining a wavelet coefficient value of decomposition level 1. In addition, a conceptual diagram of a representative “layer” for tile 0 / precinct 3 / code block 3 is also shown. The layer structure is easy to understand when the wavelet coefficient values are viewed from the horizontal direction (bit plane direction). One layer is composed of an arbitrary number of bit planes. In this example, layers 0, 1, 2, and 3 consist of 1, 3, 1, and 3 bit planes, respectively. Then, a layer including a bit plane closer to the LSB is subject to quantization first, and conversely, a layer closer to the MSB remains unquantized to the end. A method of discarding from a layer close to the LSB is called truncation, and it is possible to finely control the quantization rate.
[0045]
The above-described entropy coding unit 113 shown in FIG. 2 performs coding for each component tile by probability estimation from the context and the target bit. In this way, the encoding process is performed on all the components of the original image in tile units. Lastly, the tag processing unit 114 combines all the encoded data from the entropy coder unit into one code stream and performs a process of adding a tag to it. FIG. 7 is a diagram simply showing an example of the structure of a code stream. A tag called a header (a main header 150 and a tile part header 151, respectively) is placed at the head of the code stream and the head of a partial tile constituting each tile. Information is added, followed by encoded data (bitstream 152) for each tile. Then, at the end of the code stream, a tag (End of codestream) 153 is placed again.
[0046]
On the other hand, at the time of decoding, image data is generated from the code stream of each tile of each component, contrary to the time of encoding. This will be briefly described with reference to FIG. In this case, the tag processing unit 114 interprets the tag information added to the code stream input from the outside, decomposes the code stream into a code stream of each tile of each component, and Is subjected to a decoding process. The positions of the bits to be decoded are determined in the order based on the tag information in the code stream, and the inverse quantization unit 112 calculates the order of the neighboring bits (already decoded) at the target bit position. A context is created. The entropy decoding unit 113 decodes the context and the code stream by probability estimation to generate a target bit, and writes the target bit at the position of the target bit.
[0047]
Since the data decoded in this way is spatially divided for each frequency band, the two-dimensional wavelet inverse transform unit 111 performs an inverse two-dimensional wavelet transform on each of the tiles of each component of the image data. Will be restored. The restored data is converted by the color space inverse converter 110 into the original color system data.
[0048]
Further, in the case of the conventional JPEG compression / decompression format, the tile described in JPEG2000 above may be read as a square block having eight pixels on one side, which is subjected to two-dimensional discrete cosine transform.
[0049]
Up to this point, the description has been given of a general still image. However, this technique can be extended to a moving image. In other words, each frame of a moving image is composed of one still image, and the moving image data is created (encoded) or displayed (decoded) at a frame rate optimal for the application. it can. This is a function called motion compression / expansion processing of a still image. Since this method has a function not available in the MPEG format video file currently widely used for moving images, that is, it has the advantage that it can handle high-quality still images in frame units, It is starting to attract attention in the field. Eventually, it is likely to spread to general consumers.
[0050]
[Overall configuration of copier]
An embodiment of the present invention will be described.
[0051]
FIG. 8 is a longitudinal sectional view schematically showing a copying machine according to the present embodiment. The copier 1 implements the image forming apparatus of the present invention, and includes a scanner 2 and a printer 21 that forms an image based on read image data output from the scanner 2 on a recording medium such as paper.
[0052]
A contact glass 3 on which an original (not shown) is placed is provided on the upper surface of the main body case of the scanner 2. The original is placed with the original surface facing the contact glass 3. Above the contact glass 3, there is provided a platen cover 4 for holding down an original placed on the contact glass 3.
[0053]
Below the contact glass 3, a first traveling body 7 on which a light source 5 for emitting light and a mirror 6 are mounted, a second traveling body 10 on which two mirrors 8, 9 are mounted, and mirrors 6, 8, 9 A reading optical system 13 including a CCD (Charge Coupled Device) image sensor 12 and the like that receives the light guided by the imaging lens 11 through the imaging lens 11 is provided. The CCD image sensor 12 functions as a photoelectric conversion element that generates photoelectric conversion data obtained by photoelectrically converting reflected light from a document imaged on the CCD image sensor 12. The photoelectric conversion data is a voltage value having a magnitude corresponding to the intensity of light reflected from the document. The first and second traveling bodies 7 and 10 are provided so as to be reciprocally movable along the contact glass 3, and at the time of image reading processing described later, at a speed ratio of 2: 1 by a moving device such as a motor (not shown). To run. As a result, exposure scanning of the document reading area by the reading optical system 13 is performed.
[0054]
The printer 21 includes a medium path 26 from a medium holding unit 22 for holding a recording medium such as a sheet of paper to an output unit 25 via an electrophotographic printer engine 23 and a fixing unit 24.
[0055]
The printer engine 23 transfers the toner image formed around the photoreceptor 32 to the recording material by an electrophotographic method using a charger 27, an exposure device 28, a developing device 29, a transfer device 30, a cleaner 31, and the like, and transfers the toner image. The toner image is fixed on the recording material by the fixing device 24. In this example, the printer engine 23 forms an image by an electrophotographic method. However, the present invention is not limited to this, and various image forming methods such as an ink jet method, a sublimation type thermal transfer method, and a direct thermal recording method may be used. Can be.
[0056]
Such a copying machine 1 is controlled by a control system including a plurality of microcomputers. FIG. 9 is a block diagram showing an electrical connection of a control system related to image processing among these control systems. In this control system, a CPU 41, a ROM 42, and a RAM 43 are connected by a bus 44. The CPU 41 performs various calculations and centrally controls processing such as image processing. The ROM 42 stores various programs and fixed data related to the processing executed by the CPU 41. The RAM 43 is a work area for the CPU 41. The IPU (Image Processing Unit) 45 includes hardware related to various image processing. The ROM 42 serving as a storage medium includes a non-volatile memory such as a flash memory, and a program stored in the ROM 42 is a program downloaded from an external device (not shown) through the I / O port 46 under the control of the CPU 41. Can be rewritten.
[0057]
FIG. 10 is a functional block diagram of the image processing device 51. The image processing device 51 includes an image compression encoding unit 52 and an aggregate image unit 53. The image compression encoding unit 52 implements image compression encoding means, and converts digital image data of a plurality of images read by the scanner 2 and subjected to various image processing such as white shading correction by the IPU 45 into JPEG2000. A compression encoding is performed by an algorithm to generate a code stream of each image. That is, the image is divided into one or a plurality of rectangular regions (tiles), and pixel values are discrete wavelet-transformed for each of the rectangular regions and hierarchically compression-encoded. The aggregated image unit 53 performs an aggregation process of integrating the code streams of the respective images into one image and a division process of dividing the code stream of an image already aggregated into one image into a plurality of images. .
[0058]
Therefore, the image compression encoding unit 52 includes the respective functional blocks described with reference to FIG. 2, and performs the compression encoding of the image data by the JPEG2000 algorithm as described above. The function of the image compression encoding unit 52 may be performed by processing performed by hardware by the IPU 45, or may be performed by processing performed by the CPU 41 based on a program stored in the ROM 42. The function of the aggregated image unit 53 is actually realized by processing performed by the CPU 41 based on a program stored in the ROM 42.
[0059]
FIG. 11 is a functional block diagram of the integrated image unit 53. The integrated image unit 53 includes an image reading unit 54, a header / code data division processing unit 55, a header processing unit 56, a code stream synthesizing unit 57, and an aggregation setting unit 58.
[0060]
Hereinafter, a case where the aggregated image is combined by the aggregated image unit 53 will be described. Note that, for convenience, the description will be made on the assumption that all code streams input to the aggregated image unit 53 have a single-tile configuration of the same size.
[0061]
First, when the user operates an operation panel (not shown) of the copier 1 to instruct execution of copying accompanied by synthesis of an aggregated image, the scanner 2 reads images of a plurality of originals, and the IPU 45 performs white shading correction and the like. The plurality of digital image data subjected to various image processes are output to the aggregation setting unit 58 as a plurality of code streams compression-encoded by the image compression encoding unit 52, respectively.
[0062]
First, in the aggregation setting unit 58 that implements the aggregation setting means, the user operates an operation panel (not shown) to determine how many images are to be aggregated into one, and the horizontal direction for generating the aggregated image is determined. , Set the number of images in the vertical direction. For example, when four images are combined into one image, the horizontal and vertical directions are 2 × 2. Further, the image reading unit 54 sequentially reads each code stream for performing the aggregation process. The read first code stream 61 is divided into a header part and a code data part by a header / code data division processing unit 55 that implements a header / code data division processing unit. Subsequently, in the header processing unit 56 that implements the header processing unit, the image size of the divided main header is changed to the image size after aggregation according to the setting of the aggregation setting unit 58. Also, a new tile part header is generated. A tile index is added to this tile part header.
[0063]
Are read by the image reading unit 54, the header / code data dividing unit 55 divides the header and the coded data, and the header processing unit 56 converts the main header into a tile part header. change. At that time, a tile index is sequentially added. When all the headers of the image data have been processed, a code stream synthesizing unit 57 that realizes a code stream generating unit synthesizes the image stream into a code stream conforming to JPEG2000, and a code stream 61 of an image obtained by integrating a plurality of images into one image. 'Is completed.
[0064]
FIG. 12 is a diagram for explaining the data configuration of a plurality of code streams before aggregation by the aggregation image unit 53. The main header, tile part header, bit stream, EOC marker, The main header, tile part header, bit stream, EOC marker of the second code stream 62,..., The main header, tile part header, bit stream, and EOC marker of the Nth code stream 6N are shown.
[0065]
FIG. 13 is a view for explaining the data configuration of the code stream after aggregation by the aggregated image unit 53. The main header, tile part header, bit stream, tile part header, bit stream, A tile part header, a bit stream, and an EOC marker are shown.
[0066]
12 and 13, the 1, 2,..., Nth code streams 61, 62,..., 6N read by the image reading unit 54 are divided into a header portion and a code data portion. The main header 1 and the tile part header 1 of the code stream are edited by the header processing unit 56, and the main header 2 and the tile part header 2 of the second code stream are added to the main header 1 ′ and the tile part header 1 ′. The header processing unit 56 edits the tile part header 2 ′, and the main header N and the tile part header N of the Nth code stream are edited into the tile part header N ′ by the header processing unit 56, as shown in FIG. The combined image code stream 61 'is generated.
[0067]
FIG. 14 is a flowchart illustrating an example of an image aggregation process performed by the copying machine 1. First, when the user instructs to execute the copy (Y in step S1), it is determined whether the user instructs to execute the aggregation process (step S2). If it is determined that no instruction has been given (N in step S2), a series of processing ends.
[0068]
When the execution of the aggregation process is instructed (Y in step S2), it is determined whether or not all the code streams to be aggregated have been read by the image reading unit 54 (step S3), and all the code streams have been read. When (Y in step S3), the process proceeds to step S10. If not read (N in step S3), the image is read continuously (step S4), and the header / code data division processing section 55 divides the header section and the code data section (step S5). Step S5 implements a header / code data division process.
[0069]
Subsequently, it is determined whether the read code stream is the first code stream (step S6). If the read code stream is the first code stream (Y in step S6), the main header and the tile part header of the aggregated code stream are determined. Is generated from the main header and the tile part header of the original code stream by the header processing unit 56 (step S7). If it is not the first code stream (N in step S6), a tile part header of the aggregated code stream is generated from the main header and tile part header of the original code stream by the header processing unit 56 (step S8). . Header processing is realized by steps S7 and S8. A counter for counting the number of original code streams is incremented (step S9), and the process returns to step S3. Hereinafter, the processing from step S3 to step S9 is repeated until the processing is completed for all the code streams to be subjected to the aggregation processing, and the processing is completed for all the code streams to be aggregated (Y in step S3). A new code stream is generated (step S10), and a series of processing ends. The code stream synthesis processing is realized by step S10.
[0070]
FIG. 15 is a flowchart when the copier 1 divides an aggregated code stream and performs a division process of generating a plurality of code streams. First, when the user instructs to execute copying (Y in step S11), it is determined whether or not the user instructs to execute the dividing process using an operation panel (not shown) (step S12). When the user has not instructed the execution of the division processing (N in step S12), the series of processing ends. If it is determined that the code stream is necessary (Y in step S12), the image reading unit 54 reads the code stream to be subjected to the division processing (step S13), and the header / code data division processing unit 55 encodes the header and the code. The data section is divided (step S14). Step S14 implements a header / code data division process.
[0071]
It is determined whether all the division processes have been completed (step S15). If it is determined that all the division processes have been completed (Y in step S15), a series of processes is terminated. If the processing has not been completed (N in step S15), the data of the divided header section is edited by the header processing section 56, and the code stream synthesizing section 57 adds a new header section to the single code data section. Generation of a divided image is performed by generating a new code stream (step S16). Step S16 implements header processing and code stream synthesis processing. Then, a counter for counting the number of divisions is increased (step S17), and the process returns to step S15. Hereinafter, the processing of steps S15 and S16 is repeated until the division processing ends, and the processing ends when the division processing ends.
[0072]
Therefore, for example, when there is a document in which four images are vertically and horizontally aggregated and copied into four images, the user instructs on the operation panel (not shown) that the image is divided into four images by dividing the image vertically and horizontally into two. , And instruct the execution of the copy. Then, the image compression encoding unit 52 divides one image into two tiles and divides them into four tiles as shown in FIG. 13 for the digital image data of the original of the aggregated image read by the scanner 2. Create a stream. Then, for this code stream, the header part and the code data part are divided (step S14), and four code streams as shown in FIG. 12 in which each tile is a code data part are generated (step S16). The image is formed by the printer 21 for each code stream, so that four copies obtained by dividing the aggregated image are generated.
[0073]
Note that the image processing apparatus 51 can execute both the aggregation processing and the division processing, but may be configured to be able to perform only one of the processing. In addition, in the above description, the aggregation process has been described assuming that the code stream to be aggregated is formed of a single tile for convenience. However, even when the code stream to be aggregated is divided into a plurality of tiles, a tile index is added. Although some operations are required at the point, the aggregated image can be generated by generally the same processing. In the division processing, for convenience, each grouped image has been described as forming a single tile. However, the grouping may be performed so that a plurality of tiles form a single image. In this case, a code stream is generated for each of a plurality of tiles forming a single image.
[0074]
Further, in the above-described example, the example in which the image processing device 51 is mounted on the copying machine 1 has been described. However, the image processing device 51 can be used in various electronic devices that handle image data. For example, an image processing apparatus such as a personal computer is loaded with an application program for executing the function of the image processing apparatus 51, and various types of image data are aggregated on the information processing apparatus, or the aggregated image data is divided. Can be performed. Further, it is possible to provide a storage medium such as an optical disk, a magneto-optical disk, or a flexible disk in which such an application program is stored.
[0075]
【The invention's effect】
According to the first and sixth aspects of the present invention, the images can be easily aggregated without repeating the process of expanding all the images and expanding them to the memory.
[0076]
According to the second and seventh aspects of the present invention, in the first and sixth aspects, a desired aggregated image can be obtained by setting the number of images to be aggregated.
[0077]
According to a third aspect of the present invention, in the first, second, sixth, and seventh aspects, a desired aggregated image is obtained by setting the number of images to be aggregated in the horizontal and vertical directions. Can be.
[0078]
According to the fourth and ninth aspects of the present invention, it is possible to easily divide the aggregated image without repeating the process of expanding all the images and expanding them in the memory.
[0079]
According to the fifth aspect of the present invention, it is possible to easily aggregate images and divide the aggregated images without repeating the process of expanding all images and expanding them in the memory.
[0080]
According to a tenth aspect of the present invention, the same effect as the one of the sixth to ninth aspects of the invention is exerted by the stored program.
[Brief description of the drawings]
FIG. 1 is a block diagram for explaining an outline of a JPEG algorithm.
FIG. 2 is a block diagram for explaining an outline of a JPEG2000 algorithm.
FIG. 3 is a diagram showing an example of subbands at each decomposition level when the decomposition level is 3.
FIG. 4 is a diagram illustrating an example of each component of a tiled color image.
FIG. 5 is a diagram illustrating an example of a relationship between a precinct and a code block.
FIG. 6 is an explanatory diagram of a procedure of decomposing a coefficient value into “bit planes” and ranking the “bit planes” for each pixel or code block.
FIG. 7 is a diagram schematically illustrating an example of a structure of a code stream.
FIG. 8 is a longitudinal sectional view schematically showing a copying machine according to an embodiment of the present invention.
FIG. 9 is a block diagram showing an electrical connection of a control system related to image processing of the copying machine.
FIG. 10 is a functional block diagram of the image processing apparatus of the copying machine.
FIG. 11 is a functional block diagram of an integrated image unit of the image processing apparatus.
FIG. 12 is a diagram for describing a data configuration of a plurality of code streams before aggregation in an aggregate image unit.
FIG. 13 is a diagram for describing a data configuration of a code stream that has been aggregated by an aggregated image unit.
FIG. 14 is a flowchart illustrating an example of image aggregation processing performed by a copying machine.
FIG. 15 is a flowchart illustrating an example of an image division process performed by a copying machine.
[Explanation of symbols]
1 Image forming apparatus
2 Scanner
23 Printer Engine
51 Image processing device
52 image compression encoding means
55 Header / code data division processing means
56 Header processing means
57 Codestream Synthesis Means
58 Aggregation setting means
61-6N code stream
61 'code stream

Claims (10)

Each of a plurality of images is divided into one or a plurality of rectangular areas, and pixel values of each of the rectangular areas are subjected to discrete wavelet transform, and a plurality of code streams are hierarchically compression-encoded. Header / code data division processing means for dividing into
A header processing means for editing the data of the header portion after the division in order to combine the images into one image;
Code stream synthesizing means for combining the data of the edited header portion and the respective code data portions to generate a single new code stream in which the images are aggregated into one image;
An image processing apparatus comprising: An aggregation setting unit configured to set the number of images that aggregate the plurality of images into one image;
The image processing apparatus according to claim 1, wherein the header processing unit performs the editing according to a setting of the aggregation setting unit. The image processing apparatus according to claim 2, wherein the aggregation setting unit sets the number of images to be aggregated in at least one of a horizontal direction and a vertical direction of the image. A single code stream obtained by dividing an image into a plurality of rectangular areas, discretely performing a discrete wavelet transform on pixel values for each of the rectangular areas, and hierarchically compressing and encoding the code streams, wherein one or more of the rectangular areas are each a single A header / code data division processing unit that divides the target image into a header portion and a code data portion;
Header processing means for editing the data of the divided header portion to generate a plurality of new code streams for each image;
Code stream synthesis processing means for combining the data of the edited header portion and the respective code data portions to generate a plurality of new code streams for each image;
An image processing apparatus comprising: A scanner for reading the image of the original,
Image compression encoding means for dividing the read image into one or a plurality of rectangular areas, and generating a single code stream hierarchically compression-encoded by discrete wavelet transform of pixel values for each of the rectangular areas;
An image processing device according to any one of claims 1 to 4, wherein the code stream is the object.
A printer engine for forming an image on paper based on each code stream synthesized by the code stream synthesizing means of the image processing apparatus;
An image forming apparatus comprising: Each of a plurality of images is divided into one or a plurality of rectangular areas, and pixel values of each of the rectangular areas are subjected to discrete wavelet transform, and a plurality of code streams are hierarchically compression-encoded. A header / code data dividing process for dividing into
A header process of editing the data of the header portion after the division in order to combine the images into one image;
A code stream synthesizing process of combining the data of the edited header portion and the code data portions to generate a single new code stream in which the images are aggregated into one image;
Computer-readable program that causes a computer to execute the program. Causing the computer to further execute an aggregation setting process of setting the number of images in which the plurality of images are aggregated into one image;
The header processing performs the editing according to the setting of the aggregation setting unit,
The program according to claim 6. The program according to claim 7, wherein the aggregation setting process sets the number of images to be aggregated in at least one of a horizontal direction and a vertical direction of the image. A single code stream obtained by dividing an image into a plurality of rectangular areas, discretely performing a discrete wavelet transform on pixel values for each of the rectangular areas, and hierarchically compressing and encoding the code streams, wherein one or more of the rectangular areas are each a single A header / code data division process of dividing the image into a header portion and a code data portion,
Header processing for editing the data of the header part after this division,
A code stream synthesizing process for combining the data of the edited header portion and the respective code data portions to generate a plurality of new code streams for each image;
Computer-readable program that causes a computer to execute the program. A storage medium storing the program according to any one of claims 6 to 9.

Images