JP2004221679A - Image processing apparatus, program, and storage medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processing apparatus for realizing proper encoding to searching and management of image data and processing or the like with respect to the image data. <P>SOLUTION: A composite machine being the image processing apparatus for compressing an original image to generate a code stream, divides the original image into a plurality of regions (S2), performs character recognition processing to recognize a character from images of a plurality of divided regions and to generate character recognition information being a result of character recognition as attached information (S3), and embeds the generated attached information to a prescribed embedded position of the code stream (S5). Thus, in the case of searching required image data from a plurality of image data or the like for example, the image data can simply be searched by utilizing the attached information. That is, the searching and management of image data and processing applied to the image data or the like can easily be performed by embedding the attached information to the code stream as required. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image processing device, a program, and a storage medium.
[0002]
[Prior art]
2. Description of the Related Art In recent years, with the spread of image processing apparatuses such as scanners, digital cameras, personal computers, printers, copiers, and multifunction peripherals (MFPs), digital image data has been stored in storage devices such as memories and hard disks, and CD-ROMs and the like. It is easy to save the data on an optical disk or to transmit the data via the Internet or the like. Such image data is usually compressed and stored in a storage device, an optical disk, or the like in many cases.
[0003]
Recently, high-definition images can be easily obtained by various techniques, but the image data size of the high-definition images tends to be large, and handling of high-definition images has become difficult. 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 images. In recent years, DWT (discrete wavelet transform) has been increasingly used as a frequency transform in place of DCT (discrete cosine transform) adopted in JPEG. A representative example is JPEG2000, an image compression / decompression method succeeding JPEG, which became an international standard in 2001.
[0004]
Since such compressed image data is digital data, it can be easily transmitted via the Internet or the like or stored in a storage device. However, on the other hand, there is a high possibility that the image data will be modified without permission of the creator. is there. To prevent this, a method of embedding signature information for specifying a creator as additional information in an original image has been proposed (for example, see Patent Document 1).
[0005]
[Patent Document 1]
JP 2001-42768 A
[0006]
[Problems to be solved by the invention]
However, in the technique of Patent Document 1, although signature information can be embedded as additional information in an original image, the signature information is not additional information relating to the original image. It is difficult to use signature information for secondary use. Further, even when the additional information on the original image is embedded in the original image, the processing time when using the additional information may be long depending on the embedding position.
[0007]
In addition, a user desires to be able to easily retrieve image data having a character area or a photograph area or image data having a similar image from a plurality of image data stored in a storage device. For example, in the related art, a user confirms an image displayed on a display device or the like or an image printed on a sheet or the like based on image data, so that image data having a character area or a photograph area or similar image data can be obtained. In many cases, image data or the like having the searched image is searched.
[0008]
An object of the present invention is to provide an image processing apparatus, a program, and a storage medium that realize encoding suitable for search and management of image data, processing of image data, and the like.
[0009]
[Means for Solving the Problems]
An image processing apparatus for compressing an original image by a procedure of two-dimensional wavelet transform, quantization and encoding to generate a code stream, comprising: an area dividing unit that divides the original image into a plurality of areas; An additional information generating unit configured to generate additional information related to the original image from an image of the plurality of regions divided by the region dividing unit; and an additional unit that embeds the additional information generated by the additional information generating unit into the code stream. Information embedding means.
[0010]
Therefore, by generating additional information related to the original image and embedding the generated additional information in the code stream, the image data of the original image has the additional information. When searching, for example, it is possible to easily search using the additional information. That is, by embedding additional information as needed, it becomes possible to easily perform search and management of image data, processing of image data, and the like.
[0011]
According to a second aspect of the present invention, in the image processing apparatus according to the first aspect, the additional information generation unit generates character recognition information as the additional information by recognizing characters from the images of the plurality of areas. And
[0012]
Therefore, by generating the character recognition information as additional information, the character recognition information is embedded in the code stream. For example, when searching for image data having a character area from a plurality of image data, the character recognition information can be easily obtained. It becomes possible to search. That is, by using the character recognition information, it is possible to easily search and manage image data.
[0013]
According to a third aspect of the present invention, in the image processing apparatus according to the first or second aspect, the additional information generation unit generates area identification information as the additional information by identifying area attributes of the plurality of areas. Features.
[0014]
Therefore, by generating the region identification information as additional information, the region identification information is embedded in the code stream. For example, in a case where image data having a photograph region is searched from a plurality of image data, the region identification information can be more easily obtained. It becomes possible to search. That is, by using the area identification information, it is possible to easily search and manage the image data.
[0015]
According to a fourth aspect of the present invention, in the image processing apparatus according to the first, second or third aspect, the additional information generating unit generates tilt detection information as the additional information by detecting a tilt of an image in the plurality of regions. It is characterized by doing.
[0016]
Therefore, by generating the inclination detection information as additional information, the inclination detection information is embedded in the code stream. For example, when an image is displayed on a display device or printed on paper, the inclination detection information can be more easily used. This makes it possible to correct the inclination of the image. That is, by using the inclination detection information, it is possible to easily perform processing on image data.
[0017]
According to a fifth aspect of the present invention, in the image processing apparatus according to any one of the first to fourth aspects, the additional information embedding unit embeds the additional information in a main header of the code stream.
[0018]
Therefore, by embedding the additional information in the main header of the code stream, for example, when searching for required image data from a plurality of image data, a search is performed using the additional information of the main header at an early stage of reading the main header. As a result, the processing time can be reduced.
[0019]
According to a sixth aspect of the present invention, in the image processing apparatus according to any one of the first to fourth aspects, the additional information embedding unit embeds the additional information in a tile part header of the code stream. .
[0020]
Therefore, by embedding the additional information in the tile part header of the code stream, for example, the additional information for each tile (each area) is embedded in the corresponding tile part header, and the required image data is searched from a plurality of image data. In such cases, it is possible to easily search using the additional information of the tile part header.
[0021]
According to a seventh aspect of the present invention, in the image processing apparatus according to any one of the first to fourth aspects, the additional information embedding unit embeds the additional information in a least significant bit of a layer in the code stream. And
[0022]
Therefore, by embedding the additional information in the least significant bit of the layer in the code stream, it is possible to embed the additional information without increasing the image size.
[0023]
An eighth aspect of the present invention is the image processing apparatus according to any one of the first to seventh aspects, further comprising a reading optical system that optically reads the original image from a document.
[0024]
Therefore, the original image can be read from the document, and as a result, various processes such as image processing can be performed on the read original image.
[0025]
According to a ninth aspect of the present invention, in the image processing apparatus according to any one of the first to eighth aspects, the decompression means for decompressing the compressed original image in a sequence of decoding, inverse quantization, and inverse two-dimensional wavelet transform. It is characterized by having.
[0026]
Therefore, by using the decompression means of the JPEG2000 algorithm, an image compressed by the JPEG2000 algorithm can be decompressed by utilizing the characteristics of JPEG2000, and as a result, the decompressed image can be displayed on a display device or a paper Etc. can be executed.
[0027]
According to a tenth aspect of the present invention, there is provided the image processing apparatus according to the ninth aspect, further comprising a printer engine for forming an image decompressed by the decompression means on a recording material.
[0028]
Therefore, it is possible to form an expanded image on a recording material such as paper.
[0029]
The program according to claim 11 is interpreted by a computer provided in an image processing apparatus that generates a code stream by compressing an original image by a procedure of two-dimensional wavelet transform, quantization, and encoding. Divided into a plurality of regions, an additional information generating function of generating additional information related to the original image from the images of the plurality of regions divided by the region dividing unit, and an additional information generating unit that generates the additional information. And an additional information embedding function for embedding the additional information into the code stream.
[0030]
Therefore, by generating additional information related to the original image and embedding the generated additional information in the code stream, the image data of the original image has the additional information. When searching, for example, it is possible to easily search using the additional information. That is, by embedding additional information as needed, it becomes possible to easily perform search and management of image data, processing of image data, and the like.
[0031]
According to a twelfth aspect of the present invention, in the program according to the eleventh aspect, the additional information generation function generates character recognition information as the additional information by recognizing characters from the images of the plurality of areas.
[0032]
Therefore, by generating the character recognition information as additional information, the character recognition information is embedded in the code stream. For example, when searching for image data having a character area from a plurality of image data, the character recognition information can be easily obtained. It becomes possible to search. That is, by using the character recognition information, it is possible to easily search and manage image data.
[0033]
The invention according to claim 13 is the program according to claim 11 or 12, wherein the additional information generation function generates area identification information as the additional information by identifying area attributes of the plurality of areas.
[0034]
Therefore, by generating the region identification information as additional information, the region identification information is embedded in the code stream. For example, in a case where image data having a photograph region is searched from a plurality of image data, the region identification information can be more easily obtained. It becomes possible to search. That is, by using the area identification information, it is possible to easily search and manage the image data.
[0035]
According to a fourteenth aspect of the present invention, in the program according to the eleventh, twelfth, or thirteenth aspect, the additional information generation function generates tilt detection information as the additional information by detecting a tilt of an image in the plurality of regions.
[0036]
Therefore, by generating the inclination detection information as additional information, the inclination detection information is embedded in the code stream. For example, when an image is displayed on a display device or printed on paper, the inclination detection information can be more easily used. This makes it possible to correct the inclination of the image. That is, by using the inclination detection information, it is possible to easily perform processing on image data.
[0037]
The invention according to claim 15 is the program according to any one of claims 11 to 14, wherein the additional information embedding function embeds the additional information in a main header of the code stream.
[0038]
Therefore, by embedding the additional information in the main header of the code stream, for example, when searching for required image data from a plurality of image data, a search is performed using the additional information of the main header at an early stage of reading the main header. As a result, the processing time can be reduced.
[0039]
The invention according to claim 16 is the program according to any one of claims 11 to 14, wherein the additional information embedding function embeds the additional information in a tile part header of the code stream.
[0040]
Therefore, by embedding the additional information in the tile part header of the code stream, for example, the additional information for each tile (each area) is embedded in the corresponding tile part header, and the required image data is searched from a plurality of image data. In such cases, it is possible to easily search using the additional information of the tile part header.
[0041]
The invention according to claim 17 is the program according to any one of claims 11 to 14, wherein the additional information embedding function embeds the additional information in the least significant bit of a layer in the code stream.
[0042]
Therefore, by embedding the additional information in the least significant bit of the layer in the code stream, it is possible to embed the additional information without increasing the image size.
[0043]
A computer readable storage medium according to the invention of claim 18 stores the program according to any one of claims 11 to 17.
[0044]
Therefore, the same operation as the invention according to any one of claims 11 to 17 is achieved.
[0045]
BEST MODE FOR CARRYING OUT THE INVENTION
A first embodiment of the present invention will be described with reference to FIGS.
[0046]
In the present embodiment, the “JPEG2000 algorithm” is used. However, since the JPEG2000 algorithm itself is well known in various documents and gazettes, the details are omitted, and the outline is described.
[0047]
FIG. 1 is a functional block diagram for explaining the outline of the JPEG2000 algorithm.
The JPEG2000 algorithm includes a color space conversion / inverse conversion unit 100, a two-dimensional wavelet conversion / inverse conversion unit 101, a quantization / inverse quantization unit 102, an entropy encoding / decoding unit 103, and a tag processing unit 104. I have.
[0048]
One of the features of JPEG2000 is that a two-dimensional discrete wavelet transform (DWT: Discrete Wavelet Transform) having an advantage of high image quality in a high compression area is used. Another major feature is that a functional block called a tag processing unit 104 for performing code formation is added at the last stage, and a code stream as code string data is generated and interpreted. JPEG2000 can realize various convenient functions by the code stream.
[0049]
Note that a color space conversion / inversion unit 100 is often provided in the input / output part of the image. The color space conversion / inverse conversion unit 100 includes, for example, an RGB color system including R (red) / G (green) / B (blue) components of a primary color system, and Y (yellow) / M of a complementary color system. This is a part that performs conversion from the YMC color system composed of each component of (magenta) / C (cyan) to YCrCb or the YUV color system or vice versa.
[0050]
Hereinafter, the JPEG2000 algorithm, particularly the wavelet transform, will be described.
[0051]
FIG. 2 is a schematic diagram schematically showing an example of each of the divided components of the original image which is a color image. In a color image, as shown in FIG. 2, each component 110 of the original image is generally separated by, for example, an RGB primary color system. Further, each component 110 of the image is divided by tiles 111, which are rectangular areas (in the example of FIG. 2, each component 110 is divided into a total of 16 rectangular tiles 111, 4 × 4 vertically and horizontally). ). Each of such tiles 111, for example, R00, R01,..., R15 / G00, G01,..., G15 / B00, B01,. . Therefore, the compression / expansion operation of the image data is performed independently for each component 110 and for each tile 111.
[0052]
At the time of encoding image data (see FIG. 1), data of each tile 111 of each component 110 is input to the color space conversion / inverse conversion unit 100, subjected to color space conversion, and then subjected to two-dimensional wavelet conversion / inverse conversion. The unit 101 applies a two-dimensional wavelet transform (forward transform) and spatially divides the frequency band.
[0053]
FIG. 3 is a schematic diagram schematically showing subbands at each decomposition level when the number of decomposition levels is three. The two-dimensional wavelet transform / inverse transform unit 101 performs a two-dimensional wavelet transform on the tile image (decomposition level 0 (120): 0LL) obtained by dividing the image into tiles, and performs a decomposition level 1 (121). (1LL, 1HL, 1LH, 1HH) are separated. Subsequently, the two-dimensional wavelet transform / inverse transform unit 101 performs a two-dimensional wavelet transform on the low-frequency component 1LL in this layer, and outputs the sub-bands (2LL, 2HL, 2LH, 2HH) indicated by the decomposition level 2 (122). ) To separate. Then, similarly, the two-dimensional wavelet transform / inverse transform unit 101 sequentially performs the two-dimensional wavelet transform also on the low-frequency component 2LL, and outputs the sub-bands (3LL, 3HL, 3LH) indicated by the decomposition level 3 (123). , 3HH). In FIG. 3, the subbands to be encoded at each decomposition level are shown in gray. For example, if the number of decomposition levels is 3, the gray subbands (3HL, 3LH, 3HH, 2HL, 2LH, 2HH, 1HL, 1LH, 1HH) are to be encoded, and the 3LL subband is not encoded. .
[0054]
Next, in the quantization / dequantization unit 102 (see FIG. 1), after bits to be encoded are determined in the specified encoding order, a context is generated from bits around the target bits. 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. Here, FIG. 4 is an explanatory diagram showing a precinct. As shown in FIG. 4, one precinct is composed of three rectangular regions that spatially match. Further, each precinct is divided into non-overlapping rectangular "code blocks". This is a basic unit when performing entropy coding.
[0055]
Although the coefficient values after the wavelet transform can be quantized and encoded as they are, in JPEG2000, in order to increase the encoding efficiency, the coefficient values are decomposed into "bit planes", and each pixel or code block is decomposed. The bit planes can be prioritized.
[0056]
Here, FIG. 5 is an explanatory diagram showing an example of a procedure for prioritizing bit planes. As shown in FIG. 5, in this example, the original image (32 × 32 pixels) is divided into four 16 × 16 pixel tiles, and the size of the precinct at the decomposition level 1 and the size of the code block are each 8 × 8 pixels and 4 × 4 pixels. The numbers of the precincts and code blocks are assigned in raster order. In this example, the precincts are assigned numbers 0 to 3 and the code blocks are assigned numbers 0 to 3. 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.
[0057]
FIG. 5 also shows an explanatory diagram illustrating an example of a typical “layer” configuration concept for tile 0 / precinct 3 / code block 3. The converted code block is divided into subbands (1LL, 1HL, 1LH, 1HH), and each subband is assigned a wavelet coefficient value.
[0058]
The layer structure is easy to understand when the wavelet coefficient value is 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 are made up of 1, 3, 1, and 3 bit planes, respectively. A layer including a bit plane closer to LSB (Least Significant Bit: Least Significant Bit) is subject to quantization first, and conversely, a layer closer to MSB (Most Significant Bit: Most Significant Bit) is quantized to the end. It will remain without being. A method of discarding from a layer close to the LSB is called truncation, and it is possible to finely control the quantization rate.
[0059]
The entropy coding / decoding unit 103 (see FIG. 1) performs coding on each tile 111 of each component 110 by probability estimation from the context and the target bit. Thus, the encoding process is performed on all the components 110 of the image in units of the tiles 111.
[0060]
Finally, the tag processing unit 104 (see FIG. 1) combines all coded data from the entropy coding / decoding unit 103 into one code stream (code string data) and adds a tag to the code stream. I do. Here, FIG. 6 is a schematic diagram schematically showing an example of the structure of the code stream. Tag information called a header (main header (Main header), tile part header) is added to the beginning of the code stream and the beginning of the partial tiles constituting each tile 111. Coded data (bit stream). Then, at the end of the code stream, tag information (end of codestream) is added again.
[0061]
On the other hand, at the time of decoding, image data is generated from the code stream of each tile 111 of each component 110, contrary to the time of encoding. In this case, as shown in FIG. 1, the tag processing unit 104 interprets the tag information added to the code stream (code string data) input from the outside, and converts the code stream into the code of each tile 111 of each component 110. The stream is decomposed into streams, and a decoding process (decompression process) is performed for each code stream of each tile 111 of each component 110. At this time, the position of the bit to be decoded is determined in the order based on the tag information in the code stream, and the quantization / inverse quantization unit 102 determines the peripheral bits of the target bit position (decoding has already been performed. Is generated from the sequence of Then, the entropy coding / decoding unit 103 generates a target bit by performing decoding by probability estimation from the context and the code stream, and writes the target bit at the position of the target bit. Since the data decoded in this manner is spatially divided for each frequency band, the two-dimensional wavelet transform / inverse transform unit 101 performs an inverse two-dimensional wavelet transform on each of the components, thereby obtaining each component in the image data. Each tile 111 at 110 is restored. The restored data is converted by the color space conversion / inversion unit 100 into the original color system data. Here, the extension means is executed.
[0062]
Next, a configuration example of the multifunction peripheral 1 which is the image processing apparatus of the present embodiment will be described. The multifunction device 1 according to the present embodiment has a multifunction such as a copy function, a printer function, a scanner function, a facsimile function, and an image server function.
[0063]
FIG. 7 is a longitudinal sectional view schematically showing the multifunction peripheral 1 of the present embodiment. The MFP 1 includes a scanner 2 that is an image reading unit that reads a document image from a document, and a printer 3 that is an image forming unit that forms an image read by the scanner 2 on a recording material such as paper.
[0064]
A contact glass 5 on which a document (not shown) is placed is provided on the upper surface of the main body case 4 of the scanner 2. The original is placed with the original surface facing the contact glass 5. On the upper side of the contact glass 5, a document pressure plate 6 (which may be a so-called ADF) for pressing a document placed on the contact glass 5 is provided.
[0065]
Below the contact glass 5, a reading optical system 7 for optically reading a document image is provided. The reading optical system 7 includes a first traveling body 10 on which a light source 8 for emitting light and a mirror 9 are mounted, a second traveling body 13 on which two mirrors 11 and 12 are mounted, and a mirror 9 via an imaging lens 14. , 11, and 12 are configured by a CCD (Charge Coupled Device) image sensor 15 and the like that receive the light guided by the light. The CCD image sensor 15 functions as a photoelectric conversion element that generates photoelectric conversion data by photoelectrically converting reflected light from a document imaged on the CCD image sensor 15. 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 10 and 13 are provided so as to be able to reciprocate along the contact glass 5, and at the time of reading an original image, which will be described later, have a 2: 1 speed by a moving device such as a motor (not shown). Scanning travel in the sub-scanning direction by the ratio. As a result, exposure scanning of the document reading area by the reading optical system 7 is performed. In the present embodiment, the reading optical system 7 side is shown as a fixed document type that performs scanning, but the reading optical system 7 side may be a document moving type in which the position is fixed and the document side moves.
[0066]
The printer 3 includes a recording material path 20 from a recording material holding unit 16 for holding a recording material such as a sheet of paper to an output unit 19 via an electrophotographic printer engine 17 and a fixing unit 18.
[0067]
The printer engine 17 uses a photoconductor 21, a charger 22, an exposure unit 23, a developing unit 24, a transfer unit 25, a cleaner 26, and the like to form a toner image formed around the photoconductor 21 by electrophotography on a recording material. The transferred and transferred toner image is fixed on the recording material by the fixing device 18. In the present embodiment, the printer engine 17 forms an image by an electrophotographic method. However, the present invention is not limited to this. For example, 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. May be used to form an image.
[0068]
The MFP 1 is controlled by a control system including a plurality of microcomputers. FIG. 8 is a block diagram schematically showing an electrical connection of a control system related to image processing among these control systems. The control system includes a CPU 30, a ROM 31, a RAM 32, an operation panel 33, an IPU (Image Processing Unit) 34, an I / O port 35, a communication control unit 36, and the like, which are connected by a bus 37. The CPU 30 performs various calculations and centrally controls processing such as image processing. The ROM 31 stores various programs and fixed data related to processing executed by the CPU 30. The RAM 32 functions as a work area for the CPU 30 and also functions as a memory for temporarily storing image data (for example, image files). The operation panel 33 is provided with a display such as an LCD (Liquid Crystal Display), a plurality of operation keys including a hard key, a touch panel, and the like (all not shown). Functions as an operation unit. The IPU 34 includes hardware related to various types of image processing, and the ROM 31 includes a nonvolatile memory such as an EEPROM or a flash memory. Here, the program stored in the ROM 31 can be rewritten as a program downloaded from an external device (not shown) via the I / O port 35 under the control of the CPU 30. In the present embodiment, the ROM 31 functions as a storage medium for storing a program. The communication control unit 36 has a function of transmitting and receiving data between the multifunction device 1 and an external device (not shown) via a network or the like, and is used to connect to a facsimile modem function and a public telephone line network. Network control function, LAN (Local Area Network) control function, and the like.
[0069]
Next, an outline of image processing in the multifunction peripheral 1 of the present embodiment will be described with reference to FIG. FIG. 9 is a functional block diagram for explaining an outline of image processing in the multifunction peripheral 1. In the image processing of the multifunction peripheral 1, the area dividing unit 40 that divides the original image read by the scanner 2 into a plurality of areas, performs an area identification process for identifying the plurality of divided areas based on an area attribute, , An additional information generation unit 41 that performs a character recognition process for recognizing characters from an image, a compression unit 42 having each of the functional blocks described with reference to FIG. 1, and region identification information generated by the region identification process. And an additional information embedding unit 43 that embeds character recognition information or the like generated by character recognition processing as additional information at a predetermined embedding position of a code stream that is compressed data.
[0070]
As a character recognition process for recognizing characters from an image, for example, an OCR (Optical Character Recognition) process is used. Further, the additional information generation unit 41 may execute a tilt detection process for detecting a tilt angle of the original image read by the scanner 2. As a result, tilt detection information such as tilt angle correction information, which is a tilt detection result, is obtained. Therefore, the additional information embedding section 43 may embed the inclination detection information as additional information.
[0071]
The image processing of the multifunction device 1 basically performs OCR processing on image data corresponding to an area divided from the image data of the original image read by the scanner 2, and further converts the image data by the JPEG2000 algorithm. A code stream is generated by compression encoding. That is, the image is divided into one or a plurality of rectangular regions (tiles 111), and the pixel values are discrete wavelet-transformed for each of the rectangular regions and compression-coded hierarchically. At this time, the area identification information, character recognition information, inclination detection information, and the like are embedded at predetermined embedding positions in the code stream. The functions of the area dividing unit 40, the additional information generating unit 41, the compressing unit 42, the additional information embedding unit 43, and the like are executed by image processing performed by the CPU 30 based on a program stored in the ROM 31. However, the present invention is not limited to this, and may be executed, for example, by image processing performed by hardware by the IPU 34 or the like.
[0072]
Here, examples of the area attribute include various area attributes such as a character area, a photograph area, a figure area, a table area, a solid black area, and a background area. Note that the background area is a margin area corresponding to a margin of a document, but is not limited to this, and may be, for example, an area obtained by adding a space between lines to the margin area.
[0073]
On the other hand, the additional information includes, for example, character recognition information (character recognition result information) generated by the OCR process, and region identification information region (region identification result information) such as coordinate information and region attribute information generated by the region identification process. And tilt detection information (tilt detection result information) such as tilt angle correction information generated by the tilt detection processing. The character recognition information includes a character code, a character color, a font size, font information, character coordinate position information, certainty information (certainty information), and a title (character code). The title is a character code obtained by extracting the title area by the area identification processing and performing OCR processing on the title area. For example, a title such as “2002 meeting minutes.j2k” is embedded in a predetermined embedding position by a character code.
[0074]
Examples of the predetermined embedding position include headers such as a main header and a tile part header (see FIG. 6), the least significant bit of the image (embedding can be performed without increasing the image size), and a character area of the image. , There is a least significant bit, etc. In addition, when the image size is not an integral multiple of the tile, information is added to form an image of an integral multiple of the tile, but it is also possible to embed the image in the information portion to be added.
[0075]
Next, image processing executed by the CPU 30 of the MFP 1 based on a program will be described. Here, for example, image processing for accumulating image data in order to use the MFP 1 as an image server will be described with reference to FIGS. 10 and 11. FIG. 10 is a flowchart schematically showing the flow of image processing according to the present embodiment, and FIG. 11 is an explanatory diagram schematically showing the embedding position of additional information by the image processing.
[0076]
As shown in FIG. 10, first, the process waits for reading of a document image by the scanner 2 (N in step S1). When the operator opens the document pressing plate 6 of the scanner 2 and sets a document on the contact glass 5, closes the document pressing plate 6 and presses a copy start key on the operation panel 33, the scanner 2 performs a scanning operation of the reading optical system 7. To read the original image from the original set on the contact glass 5.
[0077]
When an original image is read from a document by the scanner 2 (Y in S1), the read original image is divided into a plurality of regions, and based on region attributes such as a character region, a photograph region, a drawing region, a table region, and a background region. Then, attributes of a plurality of areas mixed in the original image are identified (S2). Here, the area dividing means or the area dividing function is executed, and the additional information generating means or the additional information generating function is executed. As a method of area identification, a conventional method, for example, an area identification method using the density of black runs is sufficient, and the method is well-known, so that the description thereof will be omitted. Here, by identifying a plurality of areas, area identification information such as coordinate information and area attribute information can be obtained for each of the plurality of areas. Note that the image processing of the present embodiment is performed on the original image read by the scanner 2, but the present invention is not limited to this. For example, the image processing of the present embodiment is performed on the original image received via the network. Image processing may be performed.
[0078]
Next, an OCR process is performed on the plurality of divided areas (S3). That is, characters are recognized from the image of each of the plurality of regions. Here, the additional information generating means or the additional information generating function is executed. Note that the OCR processing includes a pattern matching method, a structure analysis method, and the like. These methods are known, and thus description thereof is omitted. Here, by performing the OCR process for each of the plurality of regions, the character recognition information such as the character code, the character color, the font size, the font information, the coordinate position information of the character, and the certainty information (reliability information) is obtained for each of the plurality of regions. Is obtained.
[0079]
Next, the original image is compressed based on the JPEG2000 algorithm (S4). As a result, a code stream is generated from the original image based on the JPEG2000 algorithm. Then, the area identification information and the character recognition information are embedded as additional information at a predetermined embedding position of the code stream (S5). Here, additional information embedding means or additional information embedding function is executed. For example, as shown in FIG. 11, the additional information is embedded in the least significant bit of the layer in the code stream. As a result, embedding can be performed without increasing the image size. The area R in which the additional information is embedded is an area corresponding to the character area of the original image.
[0080]
Here, the data is embedded in the least significant bit of the area R corresponding to the character area of the image. However, the present invention is not limited to this. For example, the data may be simply embedded in the least significant bit. Further, although the area identification information and the character recognition information are embedded as additional information at a predetermined embedding position, the present invention is not limited to this. For example, only one of the area identification information and the character recognition information is embedded at a predetermined embedding position. When the inclination detection processing is executed, the inclination detection information such as the inclination angle correction information of the inclination detection result may be embedded at a predetermined embedding position. Alternatively, the original image may be compressed while embedding the additional information by simultaneously executing steps S4 and S5. Here, since the original image is compressed at a plurality of resolutions based on the JPEG2000 algorithm, OCR processing may be performed for each resolution to embed character recognition information at a predetermined embedding position.
[0081]
Finally, the image data (compressed data) in which the additional information is embedded is stored in the RAM 32 as an image file (S6). Here, when there are a plurality of originals, the processing from steps S1 to S6 is repeated for each original, and a plurality of image files are stored in the RAM 32 for each original.
[0082]
After that, the image data stored in the RAM 32 as an image file may be transmitted to an external device via a network by the communication control unit 36 at a predetermined timing, for example. At this time, for example, when searching for image data of an image having a character area from a plurality of image data stored as image files in the RAM 32 to transmit only image data of an image having a character area, the CPU 30 What is necessary is just to detect the character code in image data, and it can search easily.
In order to transmit only image data having a similar image, when searching for image data having a similar image from a plurality of image data stored as image files in the RAM 32, the CPU 30 determines the area within the image data. It is possible to easily search by detecting the identification information and determining whether or not the area attributes match other image data for each area.
[0083]
The image of the image data may be subjected to image processing such as scaling (enlargement and reduction), rotation, and black-and-white inversion. In such image processing, the character image in the character area M is scaled by changing the font size of the character area M, and the image is held as images of various resolutions by the compression means of the JPEG2000 algorithm. The image can be freely changed from high image quality to low image quality. Further, when the original image is displayed on a display device or the like, the image can be expanded according to the resolution of the display device or the like.
[0084]
As described above, in the present embodiment, the original image is divided into a plurality of regions, the attributes of the plurality of regions are identified, the region identification information is generated (S2), and the OCR process is performed on the divided plurality of regions to perform the character By generating recognition information (S3) and embedding the generated area identification information and character recognition information at predetermined embedding positions of the code stream (S5), for example, image data required from a plurality of image data (compressed data) is obtained. It is possible to easily search using additional information, for example, when searching for. That is, by embedding the additional information as needed, search and management of image data, processing of image data, and the like can be easily performed. In addition, since additional information corresponding to each of a plurality of regions of the original image, such as region identification information and character recognition information, can be obtained, a necessary region, such as a character region or a photograph region, can be easily searched from the image. Can be extracted. Further, by using the compression means and the decompression means of the JPEG2000 algorithm, it is possible to execute various image processing utilizing the characteristics of JPEG2000.
[0085]
A second embodiment of the present invention will be described with reference to FIG. FIG. 12 is a flowchart schematically showing the flow of image processing according to the present embodiment. The same parts as those described above are denoted by the same reference numerals.
[0086]
The basic configuration of this embodiment is the same as that of the first embodiment, but the difference from the first embodiment is that the image processing executed by the CPU 30 of the MFP 1 based on the program is different. Is a point.
[0087]
Image processing executed by the CPU 30 of the MFP 1 according to the present embodiment based on a program will be described. Here, for example, image processing for accumulating image data in order to use the MFP 1 as an image server will be described.
[0088]
As shown in FIG. 12, first, the process waits for reading of a document image by the scanner 2 (N in step S11). When the operator opens the document pressing plate 6 of the scanner 2 and sets a document on the contact glass 5, closes the document pressing plate 6 and presses a copy start key on the operation panel 33, the scanner 2 performs a scanning operation of the reading optical system 7. To read the original image from the original set on the contact glass 5.
[0089]
When an original image is read from a document by the scanner 2 (Y in S11), the read original image is divided into a plurality of tiles 111 (a plurality of areas: see FIG. 1) by tiling processing (S12). Here, the area dividing means or the area dividing function is executed.
Thereby, the original image is divided into a plurality of tiles 111 (a plurality of areas). This tiling process is performed based on the JPEG2000 algorithm.
[0090]
Next, an OCR process is performed on the plurality of divided tiles 111 (S13). That is, characters are recognized from the image of each of the plurality of tiles 111. Here, the additional information generating means or the additional information generating function is executed. Note that the OCR processing includes a pattern matching method, a structure analysis method, and the like. These methods are known, and thus description thereof is omitted. Here, by executing the OCR process, character recognition information such as a character code, a character color, a font size, font information, character coordinate position information, and certainty information (reliability information) can be obtained for each tile 111.
[0091]
Next, the original image is compressed based on the JPEG2000 algorithm (S14). As a result, a code stream is generated from the original image based on the JPEG2000 algorithm. Then, character recognition information is embedded as additional information at a predetermined embedding position of the code stream (S15). Here, additional information embedding means or additional information embedding function is executed. For example, additional information for each tile 111 is embedded in a corresponding tile part header. Since the tiling process is executed in step S12, it is not necessary to execute the tiling process in step S14.
[0092]
Here, the character recognition information is embedded at a predetermined embedding position as additional information. However, the present invention is not limited to this. For example, when the inclination detection processing is executed, the inclination detection information such as the inclination angle correction information of the inclination detection result is executed. The detection information may be embedded at a predetermined embedding position. Alternatively, the image may be compressed while embedding the additional information by executing Step S14 and Step S15 simultaneously.
[0093]
Finally, the image data (compressed data) in which the additional information is embedded is stored as an image file in the RAM 32 (S16). Here, when there are a plurality of originals, the processing from steps S11 to S16 is repeated for each original, and a plurality of image files are stored in the RAM 32 for each original.
[0094]
After that, the image data stored in the RAM 32 as an image file may be transmitted to an external device via a network by the communication control unit 36 at a predetermined timing, for example. At this time, for example, when searching for image data of an image having a character area from a plurality of image data stored as image files in the RAM 32 to transmit only image data of an image having a character area, the CPU 30 What is necessary is just to detect the character code in image data, and it can search easily.
[0095]
As described above, in the present embodiment, the original image is divided into a plurality of tiles 111 (a plurality of areas) by performing tiling processing (S12), and the OCR processing is performed on the plurality of divided tiles 111 to perform character recognition. By generating information (S13) and embedding the generated character recognition information in a predetermined embedding position of the code stream (S15), for example, when searching for required image data from a plurality of image data (compressed data), etc. It is possible to easily search using the additional information. That is, by embedding the additional information as needed, search and management of image data, processing of image data, and the like can be easily performed. Further, since additional information corresponding to each tile 11 of the original image, for example, character recognition information or the like is obtained, a necessary area, for example, a character area can be easily searched and extracted from the image. Further, by using the compression means and the decompression means of the JPEG2000 algorithm, it is possible to execute various image processing utilizing the characteristics of JPEG2000.
[0096]
In each of the embodiments, the MFP 1 is used as an image processing apparatus. However, the present invention is not limited to this. For example, a personal computer or the like may be used. In this case, the personal computer includes a CPU, a ROM, a RAM, an HDD (Hard Disk Drive) storing various programs, a CD-ROM drive, a scanner, and communication control for transmitting information by communication with an external device via a network. The apparatus is provided with a device, a display device for displaying the progress and results of processing to the operator, and an input device such as a keyboard and a mouse. Here, the HDD functions as a storage medium for storing a program related to the image processing as described above.
[0097]
Generally, a program installed in the HDD of a personal computer is recorded on an optical information recording medium such as a CD-ROM or a DVD-ROM, or a magnetic medium such as an FD, and the recorded program is stored in the HDD. Installed. Therefore, a portable storage medium such as an optical information recording medium such as a CD-ROM or a magnetic medium such as an FD can also be a storage medium for storing the above-described program related to image processing. Further, such a program may be fetched from outside via a communication control device, for example, and installed in the HDD.
[0098]
【The invention's effect】
According to the first aspect of the present invention, in an image processing apparatus that generates a code stream by compressing an original image in a procedure of two-dimensional wavelet transform, quantization, and encoding, a region division that divides the original image into a plurality of regions Means, additional information generating means for generating additional information related to the original image from the images of the plurality of areas divided by the area dividing means, and additional information generated by the additional information generating means in the code stream. And additional information embedding means for embedding, the image data of the original image has additional information, for example, when searching for required image data from a plurality of image data. , It is possible to easily search. That is, by embedding the additional information as needed, search and management of image data, processing of image data, and the like can be easily performed.
[0099]
According to the second aspect of the present invention, in the image processing apparatus according to the first aspect, the additional information generating unit generates character recognition information as the additional information by recognizing a character from the images of the plurality of regions. Since the character recognition information is embedded in the code stream, for example, when searching for image data having a character area from a plurality of image data, the character recognition information can be easily searched. . That is, by using the character recognition information, search and management of image data can be easily performed.
[0100]
According to the third aspect of the present invention, in the image processing apparatus according to the first or second aspect, the additional information generation unit generates area identification information as the additional information by identifying area attributes of the plurality of areas. Because of this feature, the area identification information is embedded in the code stream, and, for example, when searching for image data having a photo area from a plurality of image data, it is possible to easily search using the area identification information. Become. That is, by using the area identification information, it is possible to easily search and manage the image data.
[0101]
According to a fourth aspect of the present invention, in the image processing apparatus according to the first, second or third aspect, the additional information generating unit detects the inclination of the image of the plurality of regions to detect the inclination detection information as the additional information. Since the tilt detection information is embedded in the code stream, for example, when the image is displayed on a display device or printed on paper, the image can be easily detected based on the tilt detection information. The inclination can be corrected. That is, by using the inclination detection information, it is possible to easily perform processing on image data.
[0102]
According to a fifth aspect of the present invention, in the image processing apparatus according to any one of the first to fourth aspects, the additional information embedding unit embeds the additional information in a main header of the code stream. Therefore, for example, when searching for required image data from a plurality of image data, it is possible to search using the additional information of the main header at an early stage of reading the main header. Time can be reduced.
[0103]
According to the invention described in claim 6, in the image processing apparatus according to any one of claims 1 to 4, the additional information embedding unit embeds the additional information in a tile part header of the code stream. Therefore, for example, the additional information of each tile (each area) is embedded in the corresponding tile part header, and the additional information of the tile part header is used in a case where necessary image data is searched from a plurality of image data. Then you can easily search.
[0104]
According to a seventh aspect of the present invention, in the image processing apparatus according to any one of the first to fourth aspects, the additional information embedding unit embeds the additional information in a least significant bit of a layer in the code stream. , Additional information can be embedded without increasing the image size.
[0105]
According to an eighth aspect of the present invention, the image processing apparatus according to any one of the first to seventh aspects further comprises a reading optical system for optically reading the original image from the original. It is possible to read the original image from the computer, and as a result, it is possible to execute various processes such as image processing on the read original image.
[0106]
According to a ninth aspect of the present invention, in the image processing apparatus according to any one of the first to eighth aspects, the compressed original image is decompressed in a procedure of decoding, inverse quantization, and inverse two-dimensional wavelet transform. By using the decompression means of the JPEG2000 algorithm, it is possible to decompress an image compressed by the JPEG2000 algorithm by utilizing the characteristics of JPEG2000. Display of an image on a display device or the like, printing on paper or the like can be executed.
[0107]
According to a tenth aspect of the present invention, in the image processing apparatus of the ninth aspect, a printer engine for forming an image expanded by the expansion means on a recording material is provided. An image can be formed on a recording material such as paper.
[0108]
The program according to claim 11 is interpreted by a computer provided in an image processing apparatus that generates a code stream by compressing an original image by a procedure of two-dimensional wavelet transform, quantization, and encoding. Divided into a plurality of regions, an additional information generating function of generating additional information related to the original image from the images of the plurality of regions divided by the region dividing unit, and an additional information generating unit that generates the additional information. And the additional information embedding function of embedding the additional information into the code stream, the image data of the original image has the additional information, for example, when searching for necessary image data from a plurality of image data , Etc., can be easily searched using additional information. That is, by embedding the additional information as needed, search and management of image data, processing of image data, and the like can be easily performed.
[0109]
According to the twelfth aspect of the present invention, in the program according to the eleventh aspect, the additional information generation function generates character recognition information as the additional information by recognizing characters from the images of the plurality of regions. This character recognition information is embedded in the code stream. For example, when searching for image data having a character area from a plurality of image data, it is possible to easily search using the character recognition information. That is, by using the character recognition information, search and management of image data can be easily performed.
[0110]
According to a thirteenth aspect of the present invention, in the program according to the eleventh or twelfth aspect, the additional information generation function generates area identification information as the additional information by identifying area attributes of the plurality of areas. The area identification information is embedded in the code stream. For example, when searching for image data having a photographic area from a plurality of pieces of image data, it is possible to easily search using the area identification information. That is, by using the area identification information, search and management of image data can be easily performed.
[0111]
According to a fourteenth aspect of the present invention, in the program according to the eleventh, twelfth or thirteenth aspect, the additional information generation function generates tilt detection information as the additional information by detecting a tilt of an image in the plurality of regions. Therefore, the inclination detection information is embedded in the code stream, and the inclination of the image can be easily corrected by the inclination detection information, for example, when the image is displayed on a display device or printed on paper. It becomes. That is, by using the inclination detection information, it is possible to easily perform processing on image data.
[0112]
According to the invention described in claim 15, in the program according to any one of claims 11 to 14, the additional information embedding function embeds the additional information in a main header of the code stream. For example, when searching for required image data from the image data, it is possible to search using the additional information of the main header at an early stage of reading the main header. As a result, the processing time can be reduced. .
[0113]
According to the invention of claim 16, in the program according to any one of claims 11 to 14, the additional information embedding function embeds the additional information in a tile part header of the code stream. The additional information of each tile (each area) is embedded in the corresponding tile part header, and it is easy to search using the additional information of the tile part header when searching for required image data from a plurality of image data. Can be.
[0114]
According to the invention described in claim 17, in the program according to any one of claims 11 to 14, the additional information embedding function embeds the additional information in a least significant bit of a layer in the code stream. Additional information can be embedded without increasing the image size.
[0115]
According to the computer-readable storage medium of the invention of claim 18, since the program of any one of claims 11 to 17 is stored, the program of any one of claims 11 to 17 is stored. A similar effect is achieved.
[Brief description of the drawings]
FIG. 1 is a functional block diagram for explaining an outline of a JPEG2000 algorithm.
FIG. 2 is a schematic diagram schematically showing an example of each divided component of an original image that is a color image.
FIG. 3 is a schematic diagram schematically showing subbands at each decomposition level when the number of decomposition levels is three.
FIG. 4 is an explanatory diagram showing a precinct.
FIG. 5 is an explanatory diagram showing an example of a procedure for ranking bit planes.
FIG. 6 is a schematic diagram schematically showing an example of a structure of a code stream.
FIG. 7 is a longitudinal sectional view schematically showing the multifunction peripheral according to the first embodiment of the present invention.
FIG. 8 is a block diagram schematically showing an electrical connection of a control system related to image processing in a control system of the multifunction peripheral.
FIG. 9 is a functional block diagram for describing an outline of image processing in the multifunction peripheral.
FIG. 10 is a flowchart schematically showing a flow of image processing according to the first embodiment of the present invention.
FIG. 11 is an explanatory diagram schematically showing an embedding position of additional information by image processing according to the first embodiment of the present invention.
FIG. 12 is a flowchart schematically showing a flow of image processing according to the second embodiment of the present invention.
[Explanation of symbols]
1 Image processing device (compound machine)
7 Reading optical system
17 Printer Engine
30 Computer (CPU)
31 Storage media (ROM)

Claims (18)

In an image processing apparatus that generates a code stream by compressing an original image by a procedure of two-dimensional wavelet transform, quantization, and encoding,
Area dividing means for dividing the original image into a plurality of areas,
Additional information generating means for generating additional information related to the original image from the image of the plurality of areas divided by the area dividing means,
An image processing apparatus, comprising: additional information embedding means for embedding the additional information generated by the additional information generating means in the code stream. 2. The image processing apparatus according to claim 1, wherein the additional information generation unit generates character recognition information as the additional information by recognizing characters from the images of the plurality of areas. The image processing apparatus according to claim 1, wherein the additional information generation unit generates area identification information as the additional information by identifying area attributes of the plurality of areas. 4. The image processing apparatus according to claim 1, wherein the additional information generation unit generates tilt detection information as the additional information by detecting a tilt of an image in the plurality of regions. The image processing apparatus according to claim 1, wherein the additional information embedding unit embeds the additional information in a main header of the code stream. The image processing device according to claim 1, wherein the additional information embedding unit embeds the additional information in a tile part header of the code stream. The image processing apparatus according to claim 1, wherein the additional information embedding unit embeds the additional information in a least significant bit of a layer in the code stream. The image processing apparatus according to claim 1, further comprising a reading optical system that optically reads the original image from a document. The image processing apparatus according to claim 1, further comprising an expansion unit configured to expand the compressed original image in a sequence of decoding, inverse quantization, and two-dimensional inverse wavelet transform. The image processing apparatus according to claim 9, further comprising a printer engine configured to form an image expanded by the expansion unit on a recording material. The original image is interpreted by a computer provided with an image processing apparatus that generates a code stream by compressing the original image in a procedure of two-dimensional wavelet transform, quantization, and encoding.
An area division function for dividing an original image into a plurality of areas,
An additional information generation function of generating additional information related to the original image from an image of the plurality of regions divided by the region dividing unit;
A program for executing an additional information embedding function of embedding the additional information generated by the additional information generating means in the code stream. 12. The program according to claim 11, wherein the additional information generation function generates character recognition information as the additional information by recognizing characters from the images of the plurality of regions. 13. The program according to claim 11, wherein the additional information generation function generates area identification information as the additional information by identifying area attributes of the plurality of areas. 14. The program according to claim 11, wherein the additional information generation function generates tilt detection information as the additional information by detecting a tilt of an image in the plurality of regions. 15. The program according to claim 11, wherein the additional information embedding function embeds the additional information in a main header of the code stream. 15. The program according to claim 11, wherein the additional information embedding function embeds the additional information in a tile part header of the code stream. 15. The program according to claim 11, wherein the additional information embedding function embeds the additional information in a least significant bit of a layer in the code stream. A computer-readable storage medium storing the program according to any one of claims 11 to 17.

Images