JP4194373B2 - Image processing apparatus, program, and storage medium - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image processing apparatus, a program, and a storage medium.
[0002]
[Prior 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 is stored in a storage device such as a memory or a hard disk, or a CD-ROM or the like. It is familiar to store on an optical disc of this type, or to transmit 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 high-definition images tends to increase, and handling of high-definition images has become difficult. Currently, JPEG (Joint Photographic Experts Group) is most widely used as an image compression / decompression algorithm that facilitates handling of such high-definition images. In recent years, the use of DWT (Discrete Wavelet Transform) is increasing 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 facilitates transmission over the Internet or the like, storage in a storage device, etc. On the other hand, it is highly likely to be altered without permission from the creator. is there. In order to prevent this, a method has been proposed in which signature information for identifying a creator is embedded as additional information in an original image (see, for example, 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, signature information can be embedded as additional information in the original image. However, since the signature information is not additional information related to the original image, other than for specifying the creator, for example, image data search or the like It is difficult to use signature information for secondary use. Even when the additional information related to the original image is embedded in the original image, the processing time for using the additional information may be longer depending on the embedded position.
[0007]
Further, the user desires that image data having a character area or a photographic area or image data having a similar image can be easily searched from a plurality of image data stored in the storage device. For example, in the conventional technology, a user confirms an image displayed on a display device or the like based on image data, an image printed on a sheet, etc. In many cases, image data or the like having the processed 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 image data search and management, processing on image data, and the like.
[0009]
[Means for Solving the Problems]
The image processing apparatus of the present invention The original image Divided into rectangular areas, and for each rectangular area Compress by the procedure of 2D wavelet transform, quantization and encoding , Having encoded data for each rectangular area In an image processing apparatus for generating a code stream, a plurality of the original images are Rectangle An area dividing unit that divides into areas and the area dividing unit For each rectangular area, the image of the rectangular area Related For search Additional information generating means for generating additional information, and additional information generated by the additional information generating means as the code stream In the encoded data of the rectangular area corresponding to the additional information in And additional information embedding means for embedding.
[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 additional information. For example, necessary image data is obtained from a plurality of image data. It becomes possible to easily search using additional information when searching. Generate codestream . In other words, by embedding additional information as necessary, it is possible to easily search and manage image data, process image data, and so on. A simple codestream .
[0045]
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of the present invention will be described with reference to FIGS.
[0046]
Although the present embodiment uses the “JPEG2000 algorithm”, the JPEG2000 algorithm itself is well known from various documents, publications, and the like, so the details will be omitted and the outline will be 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 transform / inverse conversion unit 101, a quantization / inverse quantization unit 102, an entropy encoding / decoding unit 103, and a tag processing unit 104. Yes.
[0048]
One of the features of JPEG2000 is that it uses two-dimensional discrete wavelet transform (DWT), which has the advantage of good image quality in the high-compression region. Another major feature is that a function block called a tag processing unit 104 for performing code formation is added to the final stage, and a code stream that is code string data is generated and interpreted. And JPEG2000 can realize various convenient functions by the code stream.
[0049]
Note that a color space conversion / inverse conversion unit 100 is often prepared for an input / output portion of an image. This color space conversion / inverse conversion unit 100 is, for example, an RGB color system composed of R (red) / G (green) / B (blue) components of the primary color system, or Y (yellow) / M of the complementary color system. This is a part that performs conversion from the YMC color system composed of the components of (magenta) / C (cyan) to the YCrCb or 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 component obtained by dividing an original image which is a color image. In the color image, generally, as shown in FIG. 2, each component 110 of the original image is separated by, for example, an RGB primary color system. Furthermore, each component 110 of the image is divided by a tile 111 that is a rectangular area (in the example of FIG. 2, each component 110 is divided into 4 × 4 vertical and horizontal 16 tiles 111 in total. ). Such individual tiles 111, for example, R00, R01,..., R15 / G00, G01,..., G15 / B00, B01,..., B15 are basic units for executing the image data compression / decompression process. . Therefore, the compression / decompression operation of the image data is performed independently for each component 110 and for each tile 111.
[0052]
When encoding image data (see FIG. 1), the data of each tile 111 of each component 110 is input to the color space conversion / inverse conversion unit 100, and after color space conversion is performed, two-dimensional wavelet conversion / inverse conversion is performed. The unit 101 applies a two-dimensional wavelet transform (forward transform) to divide the space into frequency bands.
[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 a tile image (decomposition level 0 (120): 0LL) obtained by tile division of the image, and obtains a composition level 1 (121). Are separated (1LL, 1HL, 1LH, 1HH). Subsequently, the two-dimensional wavelet transform / inverse transform unit 101 performs two-dimensional wavelet transform on the low-frequency component 1LL in this hierarchy, and displays subbands (2LL, 2HL, 2LH, 2HH) indicated by the decomposition level 2 (122). ). Then, the two-dimensional wavelet transform / inverse transform unit 101 sequentially performs the two-dimensional wavelet transform on the low frequency component 2LL in the same manner, and displays subbands (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, when the number of decomposition levels is 3, the subbands shown in gray (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 / inverse quantization unit 102 (see FIG. 1), after the bits to be encoded are determined in the designated encoding order, a context is generated from the bits around the target bits. The wavelet coefficients that have undergone the quantization process are divided into non-overlapping rectangles called “precincts” for each subband. This was introduced to use memory efficiently in implementation. Here, FIG. 4 is an explanatory view showing a precinct. As shown in FIG. 4, one precinct consists of three rectangular regions that are spatially matched. Furthermore, each precinct is divided into rectangular “code blocks” that do not overlap. This is a basic unit for entropy coding.
[0055]
The coefficient values after wavelet transform can be quantized and encoded as they are. However, in JPEG2000, in order to increase the encoding efficiency, the coefficient values are decomposed into “bit plane” units, and each pixel or code block is divided. The bit planes can be prioritized.
[0056]
Here, FIG. 5 is an explanatory diagram showing an example of a procedure for ranking the 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 and the code block at the composition level 1 is 8 respectively. X8 pixels and 4x4 pixels. The numbers of the precinct and the code block are assigned in raster order, and in this example, the numbers are assigned from 0 to 3 for the preamble and from 0 to 3 for the code block. A mirroring method is used for pixel expansion outside the tile boundary, wavelet transform is performed with a reversible (5, 3) filter, and a wavelet coefficient value of decomposition level 1 is obtained.
[0057]
An explanatory diagram showing an example of the concept of a typical “layer” configuration for tile 0 / precinct 3 / code block 3 is also shown in FIG. The converted code block is divided into subbands (1LL, 1HL, 1LH, 1HH), and wavelet coefficient values are assigned to the subbands.
[0058]
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 are made up of bit planes of 1, 3, 1, and 3, respectively. A layer including a bit plane closer to LSB (Least Significant Bit) is subject to quantization first. Conversely, a layer closer to MSB (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 the quantization rate can be finely controlled.
[0059]
The entropy encoding / decoding unit 103 (see FIG. 1) performs encoding on each tile 111 of each component 110 by probability estimation from the context and the target bit. In this way, the encoding process is performed in units of tiles 111 for all the components 110 of the image.
[0060]
Finally, in the tag processing unit 104 (see FIG. 1), all encoded data from the entropy encoding / decoding unit 103 is combined into one code stream (code string data) and a tag is added 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 (tile header), tile part header (tile header)) is added to the top of the code stream and the top of the partial tiles constituting each tile 111, and then each tile 111 Followed by the encoded data (bit stream). Then, tag information (end of codestream) is added to the end of the codestream again.
[0061]
On the other hand, at the time of decoding, contrary to the time of encoding, image data is generated from the code stream of each tile 111 of each component 110. In this case, as shown in FIG. 1, the tag processing unit 104 interprets tag information added to a code stream (code string data) input from the outside, and converts the code stream to the code of each tile 111 of each component 110. The data is decomposed into streams, and decoding processing (decompression processing) 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 completed). )) To generate a context. Then, the entropy encoding / decoding unit 103 performs decoding by probability estimation from the context and the code stream, generates a target bit, and writes it in the position of the target bit. Since the data decoded in this way is spatially divided for each frequency band, each component in the image data is obtained by performing a two-dimensional wavelet inverse transform in the two-dimensional wavelet transform / inverse transform unit 101. Each tile 111 at 110 is restored. The restored data is converted into original color system data by the color space conversion / inverse conversion unit 100. Here, decompression means is executed.
[0062]
Next, a configuration example of the multifunction machine 1 that is the image processing apparatus according to the present embodiment will be described. The multifunction device 1 of the present embodiment has complex functions such as a copying 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 machine 1 according to the present embodiment. The multifunction machine 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 document is placed with the document 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 that emits 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, 12 and the like, and a CCD (Charge Coupled Device) image sensor 15 that receives the light is configured. The CCD image sensor 15 functions as a photoelectric conversion element that generates photoelectric conversion data by photoelectrically converting reflected light from an original image formed on the CCD image sensor 15. The photoelectric conversion data is a voltage value having a magnitude corresponding to the intensity of reflected light from the document. The first and second traveling bodies 10 and 13 are provided so as to freely reciprocate along the contact glass 5, and at a speed of 2: 1 by a moving device such as a motor (not shown) during a document image reading operation described later. Scanning is performed in the sub-scanning direction at a ratio. Thereby, exposure scanning of the original reading area is performed by the reading optical system 7. In the present embodiment, the reading optical system 7 side is shown as a document fixing type that performs scanning 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 that extends from a recording material holding unit 16 that holds a recording material such as sheet-like paper to a discharge unit 19 via an electrophotographic printer engine 17 and a fixing device 18.
[0067]
The printer engine 17 uses a photosensitive member 21, a charger 22, an exposure unit 23, a developing unit 24, a transfer unit 25, a cleaner 26, and the like as a recording material on a toner image formed around the photosensitive member 21 by electrophotography. The transferred toner image is fixed on the recording material by the fixing device 18. In this embodiment, the printer engine 17 forms an image by an electrophotographic method, but 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, a direct thermal recording method, etc. Alternatively, image formation may be performed.
[0068]
Such a multifunction machine 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 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, in addition, functions as a memory that temporarily stores image data (for example, image files). The operation panel 33 is provided with a plurality of operation keys (all not shown) including a display device such as an LCD (Liquid Crystal Display), hard keys, a touch panel, and the like. Functions as an operation unit. The IPU 34 includes hardware related to various 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 into 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 the program. The communication control unit 36 has a function of transmitting / receiving data between the multifunction device 1 and an external device (not shown) via a network or the like, and is connected to a facsimile modem function or a public telephone line network. Network control function, LAN (Local Area Network) control function, and the like.
[0069]
Next, an overview of image processing in the multifunction machine 1 of the present embodiment will be described with reference to FIG. FIG. 9 is a functional block diagram for explaining an overview of image processing in the multifunction machine 1. The image processing of the multifunction machine 1 includes an area dividing unit 40 that divides an original image read by the scanner 2 into a plurality of areas, an area identification process that identifies the divided areas based on area attributes, and a plurality of areas An additional information generation unit 41 that executes character recognition processing for recognizing characters from an image, a compression unit 42 having each functional block described with reference to FIG. 1, and region identification information generated by region identification processing And an additional information embedding unit 43 that embeds character recognition information generated by character recognition processing or the like as additional information in a predetermined embedding position of a code stream that is compressed data.
[0070]
As character recognition processing for recognizing characters from an image, for example, OCR (Optical Character Recognition) processing is used. Further, the additional information generation unit 41 may execute an inclination detection process for detecting the inclination angle of the original image read by the scanner 2. Thereby, tilt detection information such as tilt angle correction information, which is a tilt detection result, is obtained. Therefore, the additional information embedding unit 43 may embed the inclination detection information as additional information.
[0071]
The image processing of the multifunction device 1 basically performs OCR processing on the image data corresponding to the area divided from the image data of the original image read by the scanner 2, and further, the image data is processed by the JPEG2000 algorithm. A code stream is generated by compression encoding. That is, an image is divided into one or a plurality of rectangular areas (tiles 111), and pixel values are discretely wavelet transformed for each rectangular area and hierarchically encoded. At this time, area identification information, character recognition information, inclination detection information, and the like are embedded at a predetermined embedding position of 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 by image processing performed by hardware using the IPU 34 or the like.
[0072]
Here, the area attributes include various area attributes such as a character area, a photograph area, a figure area, a table area, a black solid area, a background area, and the like. The background area is a margin area corresponding to the margin of the document. However, the background area is not limited to this. For example, the background area may be an area obtained by adding an inter-line area corresponding to a line.
[0073]
On the other hand, as additional information, for example, character recognition information (character recognition result information) generated by OCR processing, region identification information regions (region identification result information) such as coordinate information and region attribute information generated by region identification processing, etc. And tilt detection information (tilt detection result information) such as tilt angle correction information generated by the tilt detection process. Character recognition information includes character code, character color, font size, font information, character coordinate position information, certainty information (probability information), title (character code), and the like. The title is a character code obtained by extracting a title area by area identification processing and performing OCR processing on the title area. For example, a title such as “2002 meeting minutes. J2k” is embedded at a predetermined embedding position with a character code.
[0074]
The predetermined embedding position includes, for example, a header such as a main header and tile part header (see FIG. 6), the least significant bit of the image (embedding is possible without increasing the image size), and a character area of the image. And the least significant bit corresponding to. In addition, if the image size is not an integral multiple of the tile, information is added to form an image that is an integral multiple of the tile, but it is also possible to embed in the information portion to be added.
[0075]
Next, image processing executed by the CPU 30 of the multifunction device 1 based on a program will be described. Here, for example, image processing for storing image data in order to use the multifunction device 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 embedded position of additional information by the image processing.
[0076]
As shown in FIG. 10, first, the scanner 2 waits for reading of a document image (N in step S1). When the operator opens the document pressure plate 6 of the scanner 2 and sets a document on the contact glass 5, closes the document pressure plate 6 and presses the copy start key on the operation panel 33, the scanner 2 scans the reading optical system 7. The original image is read from the original set on the contact glass 5.
[0077]
When the original image is read from the document by the scanner 2 (Y in S1), the read original image is divided into a plurality of areas, and based on area attributes such as a character area, a photo area, a figure area, a table area, and a background area. 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 for region identification, a conventional method, for example, a region identification method using the density of black runs is sufficient, and since the method is known, the description thereof is omitted. Here, by identifying a plurality of regions, region identification information such as coordinate information and region attribute information is obtained for each of the plurality of regions. Note that the image processing of the present embodiment is performed on the document 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 an original image received via a network. Image processing may be executed.
[0078]
Next, OCR processing is executed for the plurality of areas identified and divided (S3). That is, a character is recognized from an image for each of a plurality of areas. Here, the additional information generating means or the additional information generating function is executed. The OCR process includes a pattern matching method, a structure analysis method, and the like. Since these methods are publicly known, description thereof is omitted. Here, the character recognition information such as the character code, the character color, the font size, the font information, the character coordinate position information, the certainty degree information (the certainty information), etc. 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, the additional information embedding means or the 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. Thereby, it is possible to embed without increasing the image size. The region R in which the additional information is embedded is a region corresponding to the character region of the original image.
[0080]
Here, although embedded in the least significant bit of the region R corresponding to the character region of the image, the present invention is not limited to this. For example, it may be simply embedded in the least significant bit. In addition, the area identification information and the character recognition information are embedded in the predetermined embedding position as additional information, but the present invention is not limited to this. For example, only one of the area identification information and the character recognition information is included in the predetermined embedding position. Alternatively, when tilt detection processing is executed, tilt detection information such as tilt angle correction information as a tilt detection result may be embedded at a predetermined embedding position. Further, the original image may be compressed while embedding 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, the character recognition information may be embedded at a predetermined embedding position by executing OCR processing for each resolution.
[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 documents, the processing from steps S1 to S6 is repeated for each document, and a plurality of image files are stored in the RAM 32 for each document.
[0082]
Thereafter, the image data stored as an image file in the RAM 32 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 in order to transmit only the image data of the image having a character area, the CPU 30 It is sufficient to detect a character code in the image data, and the search can be easily performed. In addition, in order to transmit only image data having similar images, when searching for image data having similar images from a plurality of image data stored as image files in the RAM 32, the CPU 30 uses an area in the image data. The identification information can be detected, and it can be easily searched by determining whether or not the region attribute matches each other image data.
[0083]
Note that the image of the image data may be subjected to image processing such as scaling (enlargement / reduction), rotation, and black / white reversal. In such image processing, the character image in the character area M is scaled by changing the font size in the character area M, and the image is held as an image 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. Furthermore, when an original image is displayed on a display device or the like, the image can be expanded in accordance with the resolution or the like of the display device.
[0084]
As described above, in this embodiment, the original image is divided into a plurality of regions, the attributes of the plurality of regions are identified to generate region identification information (S2), and the character is obtained by executing the OCR process on the divided regions By generating recognition information (S3) and embedding the generated area identification information and character recognition information in a predetermined embedding position of the code stream (S5), for example, required image data from a plurality of image data (compressed data) For example, it is possible to easily search using additional information. That is, by embedding additional information as required, image data search and management, processing for image data, and the like can be easily performed. Further, since additional information corresponding to each of a plurality of areas of the original image, such as area identification information and character recognition information, can be obtained, a necessary area such as a character area or a photo area can be easily searched from the image. Can be extracted. Furthermore, by using the compression means and decompression means of the JPEG2000 algorithm, various image processing utilizing the characteristics of JPEG2000 can be executed.
[0085]
A second embodiment of the present invention will be described with reference to FIG. FIG. 12 is a flowchart schematically showing a flow of image processing according to the present embodiment. In addition, the same part as the part demonstrated above is shown with the same code | symbol.
[0086]
The basic configuration of the present embodiment is the same as that of the first embodiment, but the difference from the first embodiment is the image processing that the CPU 30 of the multifunction device 1 executes based on the program. Is a point.
[0087]
Image processing executed by the CPU 30 of the multifunction machine 1 according to the present embodiment based on a program will be described. Here, for example, image processing for storing image data in order to use the multifunction device 1 as an image server will be described.
[0088]
As shown in FIG. 12, first, the scanner 2 waits for reading of an original image (N in step S11). When the operator opens the document pressure plate 6 of the scanner 2 and sets a document on the contact glass 5, closes the document pressure plate 6 and presses the copy start key on the operation panel 33, the scanner 2 scans the reading optical system 7. The original image is read from the original set on the contact glass 5.
[0089]
When the original image is read from the document by the scanner 2 (Y in S11), the read original image is tiling processed and divided into a plurality of tiles 111 (a plurality of areas: see FIG. 1) (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 regions). This tiling process is executed based on the JPEG2000 algorithm.
[0090]
Next, OCR processing is executed for the plurality of divided tiles 111 (S13). That is, a character is recognized from the image for each of the plurality of tiles 111. Here, the additional information generating means or the additional information generating function is executed. The OCR process includes a pattern matching method, a structure analysis method, and the like. Since these methods are publicly known, 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 (certainty information) is 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, the additional information embedding means or the additional information embedding function is executed. For example, the additional information for each tile 111 is embedded in the 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 as the additional information at a predetermined embedding position, but the present invention is not limited to this. For example, when the inclination detection process is executed, the inclination of the inclination detection result such as the inclination angle correction information, etc. The detection information may be embedded at a predetermined embedding position. Further, step S14 and step S15 may be executed simultaneously, and the image may be compressed while embedding additional information.
[0093]
Finally, the image data (compressed data) in which the additional information is embedded is stored in the RAM 32 as an image file (S16). Here, when there are a plurality of documents, the processing from steps S11 to S16 is repeated for each document, and a plurality of image files are stored in the RAM 32 for each document.
[0094]
Thereafter, the image data stored as an image file in the RAM 32 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 in order to transmit only the image data of the image having a character area, the CPU 30 It is sufficient to detect a character code in the image data, and the search can be easily performed.
[0095]
As described above, in the present embodiment, the original image is tiled and divided into a plurality of tiles 111 (a plurality of areas) (S12), and the character recognition is performed by executing the OCR process on the divided tiles 111. Information is generated (S13), and the generated character recognition information is embedded in a predetermined embedding position of the code stream (S15), for example, when searching for necessary image data from a plurality of image data (compressed data), etc. This makes it possible to easily search using additional information. That is, by embedding additional information as required, image data search and management, processing for image data, and the like can be easily performed. Further, since additional information corresponding to each tile 11 of the original image, such as character recognition information, can be obtained, a necessary region, for example, a character region can be easily searched and extracted from the image. Furthermore, by using the compression means and decompression means of the JPEG2000 algorithm, various image processing utilizing the characteristics of JPEG2000 can be executed.
[0096]
In each embodiment, the multifunction device 1 is used as the 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 communicates with the external device via a CPU, ROM, RAM, HDD (Hard Disk Drive) storing various programs, a CD-ROM drive, a scanner, and a network to communicate information. It includes a device, a display device that displays processing progress and results to the operator, an input device such as a keyboard and a mouse, and the like. Here, the HDD functions as a storage medium for storing a program related to 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 DVD-ROM, 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 that stores a program related to image processing as described above. Furthermore, such a program may be taken in from outside via a communication control device, for example, and installed in the HDD.
This embodiment In the image processing apparatus for generating a code stream by compressing an original image by a procedure of two-dimensional wavelet transform, quantization, and encoding, an area dividing unit that divides the original image into a plurality of areas, and the area division Additional information generating means for generating additional information related to the original image from the images of the plurality of regions divided by the means, and additional information embedding means for embedding the additional information generated by the additional information generating means in the code stream Therefore, 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 easy to use the additional information. It becomes possible to search. That is, by embedding additional information as required, image data search and management, processing for image data, and the like can be easily performed.
This embodiment In the image processing apparatus, the additional information generation unit generates character recognition information as the additional information by recognizing characters from the images of the plurality of regions. For example, when searching for image data having a character area from a plurality of image data, it is possible to easily search using character recognition information. That is, by using the character recognition information, it is possible to easily search and manage image data.
This embodiment In the image processing apparatus, the additional information generation unit generates region identification information as the additional information by identifying region attributes of the plurality of regions. For example, when searching for image data having a photo area from a plurality of image data, it is possible to easily search by area identification information. That is, by using the area identification information, it is possible to easily search and manage image data.
This embodiment In the image processing apparatus, the additional information generation unit generates inclination detection information as the additional information by detecting inclinations of the images of the plurality of regions. For example, when the image is displayed on a display device or printed on paper, the inclination of the image can be easily corrected by the inclination detection information. That is, by using the tilt detection information, it is possible to easily process the image data.
This embodiment In the image processing apparatus, since the additional information embedding unit embeds the additional information in the main header of the code stream, for example, when searching for necessary image data from a plurality of image data Thus, it becomes possible to search using the additional information of the main header at an early stage of reading the main header, and as a result, the processing time can be shortened.
This embodiment In the image processing apparatus, the additional information embedding unit embeds the additional information in the tile part header of the code stream. For example, the tile corresponding to the additional information for each tile (for each region) corresponds to When searching for necessary image data from a plurality of image data embedded in the part header, it can be easily searched using additional information of the tile part header.
This embodiment In the image processing apparatus, the additional information embedding unit embeds the additional information in the least significant bit of the layer in the code stream, so that the additional information can be embedded without increasing the image size. it can.
This embodiment The image processing apparatus of the present invention is provided with a reading optical system that optically reads the original image from the original, so that the original image can be read from the original. Various processes such as image processing can be executed.
This embodiment In the image processing apparatus according to the present invention, it is provided with decompression means for decompressing the compressed original image by the procedures of decoding, inverse quantization, and two-dimensional wavelet inverse transform, and therefore using the decompression means of the JPEG2000 algorithm Thus, an image compressed by the JPEG2000 algorithm can be expanded utilizing the characteristics of JPEG2000, and as a result, display of the expanded image on a display device or the like, printing on paper, or the like can be executed. it can.
This embodiment The image processing apparatus includes a printer engine that forms an image expanded by the expansion unit on a recording material. Therefore, the expanded image can be formed on a recording material such as paper.
This embodiment This program is interpreted by a computer included 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, and divides the original image into a plurality of regions. An area dividing function; an additional information generating function for generating additional information related to the original image from the images of the plurality of areas divided by the area dividing means; and the additional information generated by the additional information generating means as the code. Since the additional information embedding function embedded in the stream is executed, the image data of the original image has additional information, and the additional information is used, for example, when searching required image data from a plurality of image data. And can be easily searched. That is, by embedding additional information as required, image data search and management, processing for image data, and the like can be easily performed.
This embodiment In the above program, the additional information generation function generates character recognition information as the additional information by recognizing characters from the images of the plurality of regions. For example, when searching for image data having a character area from the image data, it is possible to easily search using the character recognition information. That is, by using the character recognition information, it is possible to easily search and manage image data.
This embodiment In this program, the additional information generation function generates region identification information as the additional information by identifying region attributes of the plurality of regions. Therefore, the region identification information is embedded in a code stream, for example, a plurality of regions For example, when searching for image data having a photo area from image data, it is possible to easily search based on area identification information. That is, by using the area identification information, it is possible to easily search and manage image data.
This embodiment In the above program, the additional information generation function generates inclination detection information as the additional information by detecting the inclination of the image of the plurality of areas. Therefore, the inclination detection information is embedded in a code stream, for example, an image When the image is displayed on a display device or printed on paper, the tilt of the image can be easily corrected by the tilt detection information. That is, by using the tilt detection information, it is possible to easily process the image data.
This embodiment In this program, since the additional information embedding function embeds the additional information in the main header of the code stream, the main header is quickly read, for example, when searching required image data from a plurality of image data. It is possible to search using the additional information of the main header at a stage, and as a result, the processing time can be shortened.
This embodiment In this program, since the additional information embedding function embeds the additional information in the tile part header of the code stream, for example, additional information for each tile (for each area) is embedded in the corresponding tile part header, When searching for necessary image data from the image data, it is possible to easily search using additional information of the tile part header.
This embodiment In this program, since the additional information embedding function embeds the additional information in the least significant bit of the layer in the code stream, the additional information can be embedded without increasing the image size.
Of this embodiment According to the storage medium This embodiment Because I remember the program of Program of this embodiment Has the same effect as
[0098]
【The invention's effect】
According to the present invention, 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 additional information. For example, when searching for required image data from a plurality of image data, it is possible to easily search using the additional information. Generate codestream . In other words, by embedding additional information as necessary, it is possible to easily search and manage image data, process image data, and so on. A simple codestream .
[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 component obtained by dividing 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 3. FIG.
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 the structure of a code stream.
FIG. 7 is a longitudinal sectional view schematically showing the multifunction machine 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 the control system of the multifunction peripheral.
FIG. 9 is a functional block diagram for explaining an overview of image processing in a 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 a position where additional information is embedded by image processing according to the first embodiment of this 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 (12)

In an image processing apparatus that divides an original image into rectangular areas and compresses each rectangular area by a procedure of two-dimensional wavelet transform, quantization, and encoding to generate a code stream having encoded data for each rectangular area ,
Area dividing means for dividing the original image into a plurality of rectangular areas;
Additional information generating means for generating additional information for searching related to the image of the rectangular area for each rectangular area divided by the area dividing means;
An image processing apparatus comprising: additional information embedding means for embedding additional information generated by the additional information generating means in encoded data of a rectangular area corresponding to the additional information in the code stream.   The image processing apparatus according to claim 1, wherein the additional information generation unit generates character recognition information as the additional information by recognizing a character from an image of each rectangular area.   The image processing apparatus according to claim 1, wherein the additional information generation unit generates area identification information as the additional information by identifying an area attribute for each rectangular area. The image processing apparatus as claimed in 3 claims 1, characterized in that it comprises a reading optical system reads the original image from an original optically. Image processing comprising means for searching for and extracting a required rectangular area from the code stream generated by the image processing device according to any one of claims 1 to 4 , based on the additional information for the search apparatus. Decoding the compressed the original image, the image processing apparatus as claimed in claims 1, characterized in that it comprises an extension means for extending the procedure of inverse quantization and two-dimensional wavelet inverse transformation 5. The image processing apparatus according to claim 6, further comprising a printer engine that forms an image on the recording material, the image expanded by the expansion unit. An image processing apparatus that divides an original image into rectangular areas and compresses each rectangular area by a procedure of two-dimensional wavelet transform, quantization, and encoding to generate a code stream having encoded data for each rectangular area. Comprising a computer, said computer having
An area dividing function for dividing an original image into a plurality of rectangular areas;
An additional information generating function for generating additional information for searching related to the image of the rectangular area for each rectangular area divided by the area dividing means;
A program for executing an additional information embedding function for embedding additional information generated by the additional information generating means in encoded data of a rectangular area corresponding to the additional information in the code stream. The program according to claim 8, wherein the additional information generation function generates character recognition information as the additional information by recognizing a character from an image for each rectangular area. The program according to claim 8 or 9, wherein the additional information generation function generates area identification information as the additional information by identifying an area attribute for each rectangular area. A necessary rectangular area is searched and extracted from a code stream generated by executing the program according to any one of claims 8 to 10 on the computer based on the additional information for the search. A program that causes a computer to execute functions A computer-readable storage medium storing the program according to any one of claims 8 to 11 .

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