JP5186994B2 - Image processing device - Google Patents

Description

  The present invention relates to an image processing apparatus that stores image data, and more particularly to an image processing apparatus that stores image data for an image to be displayed on a display unit.

  An image processing device such as a facsimile device, a scanner device, a printer device, a copying device, or a composite device that combines the functions of these devices, and an image memory that temporarily stores read image data or image data to be output It has. Some image processing apparatuses including the image memory include a display unit including a liquid crystal display for displaying an image temporarily stored in the image memory.

  Many image processing apparatuses equipped with such a display unit have a low resolution in the display unit. Therefore, when a high-resolution image based on image data stored in the image memory is displayed on the display unit, It is necessary to reduce the image based on the target image data. As a reduction process performed on image data, a technique for thinning out image data in rows that are not displayed in the sub-scanning line direction has been proposed (see Patent Document 1). In the image processing apparatus disclosed in Patent Document 1, image data compressed by a compression encoding method for a binary image (monochrome image) such as an MH (Modified Huffman) encoding method or an MR (Modified Read) encoding method is reduced. The target of.

  In addition, as for an image processing apparatus having a facsimile function such as a facsimile apparatus or a composite apparatus having a facsimile function, a scanner unit that can read an image can read a color image. Has been. However, when an image processing apparatus having a facsimile function capable of reading a color image is a transmission side, if the reception side is not compatible with a color image, a binary image is printed on the reception side.

  When such an image processing apparatus confirms that the receiving side does not support color images, it converts the read color image into a binary image, transmits image data based on the converted binary image, and transmits the data to be transmitted. The amount is reduced and the transmission time is shortened. However, in this case, since the color information read by the color image is not transmitted to the receiving side, the receiving side cannot identify the color scheme of the document. On the other hand, there has been proposed a composite apparatus that transmits information about a portion based on designated color information together with image data of an image to be a document (see Patent Document 2).

The composite apparatus disclosed in Patent Document 2 first reads an image serving as a document with a color image, then extracts a portion based on designated color information from the image serving as a document, and creates an image synthesized with text indicating the color information. To do. Then, the composite apparatus converts the image to be a document into image data converted into a binary image, and transmits the image data for the document to the receiving side together with the image data of the image combined with the text based on the color information. As a result, the receiving side outputs an image synthesized with the text based on the color information, and can recognize the color arrangement of the image to be the original.
Japanese Patent Laid-Open No. 06-274612 JP 2004-023539 A

  As described above, the composite apparatus of Patent Document 2 transmits an image indicating a color arrangement in the original document in addition to the read image of the original document itself. Therefore, even if the receiving side outputs only a binary image, the content of the original is recognized from the received original image, and the color arrangement on the original is recognized from the image showing the color arrangement in the original. .

  However, many image processing apparatuses that can read a color image often display the color image as it is when the read image is displayed on the display unit. Therefore, when an image processing apparatus capable of reading a color image transmits image data by the facsimile function, if the image is displayed on the display unit to confirm the image to be transmitted, the read color image is displayed on the display unit. .

  On the other hand, in order to visually recognize the state of the image received on the receiving side where color images cannot be output, the image processing apparatus on the transmitting side displays the image on the display unit as a binary image. It is required to do. At this time, the binary image displayed on the display unit is an image obtained by reducing the read image. As the image reduction process, when the thinning process in the sub-scanning line direction in the image processing apparatus of Patent Document 1 is used, a dropout or the like occurs in the reduced image. Its visibility is lacking.

  In view of such a problem, an object of the present invention is to propose an image processing apparatus capable of providing a highly visible image by converting a monochrome image to be reduced for display on a display unit as a multi-valued monochrome image having a plurality of gradations. And

  In order to achieve the above object, an image processing apparatus according to the present invention converts a first image data based on a color image into second image data that is a monochrome image that is the same magnification as the color image and is a binary image. And a display unit for displaying an image, and in the image processing apparatus for displaying a reduced image corresponding to the first image data on the display unit, the first image data is a color image based on the first image data. A second image conversion unit that converts the image data into third image data that is a multi-valued monochrome image reduced in size, and a memory that stores the second and third image data in association with each other. When the reduced image corresponding to the first image data is displayed, the third image data corresponding to the first image data is given from the memory to the display unit, and a module based on the third image data is displayed. And displaying the chrome images on the display unit.

  In such an image processing device, the second image conversion unit converts the color image based on the first image data into a multi-value monochrome image, and then reduces the image to a resolution suitable for the display unit. Third image data may be acquired. At this time, first, the first image data including the color component and the luminance component is converted into a multi-value monochrome image in which only the luminance component is expressed by a plurality of gradations, and the color image based on the first image data, etc. Obtain a multi-value monochrome image that is doubled. Thereafter, the third image data can be acquired by performing a reduction process on the multi-value monochrome image.

  Conversely, the second image conversion unit reduces the color image based on the first image data to an image that matches the resolution of the display unit, and then converts the image into a multi-value monochrome image, and converts the third image data You may get it. At this time, first, a reduction process is performed for each of the color component and the luminance component of the first image data to obtain a reduced color image. Thereafter, the reduced color image is converted into a multi-value monochrome image in which only the luminance component is expressed by a plurality of gradations, and the third image data can be obtained.

  In any one of the image processing apparatuses described above, a first encoding unit that compresses and encodes the second image data from the first image conversion unit and supplies the second image data to the memory; and the third encoding unit from the second image conversion unit. A second encoding unit that compresses and encodes image data and supplies the image data to the memory. At this time, the first encoding unit performs compression encoding by an MH (Modified Huffman) method, an MR (Modified READ) method, an MMR (Modified Modified READ) method, or a JBIG (Joint Bi-lebel Image experts Group) method. May be performed. On the other hand, the second encoding unit may perform compression encoding by a JPEG (Joint Photographic Experts Group) method or the like.

  In such an image processing device, the display unit includes a display unit memory that temporarily stores the third image data compressed by the second encoding unit read from the memory, When displaying a monochrome image using three image data, the third image data stored in the display unit memory may be expanded.

  In any one of the image processing apparatuses described above, the display unit includes a reduction processing unit that further reduces a monochrome image based on the third image data read from the memory, and the reduction processing unit includes the third image. The monochrome image based on the data may be further reduced in accordance with the size of the area where the image is displayed on the display unit. Thereby, for example, when a plurality of images are displayed on the display unit, the image can be reduced in the display unit in accordance with the area to be displayed on the display unit. The load on the part side is reduced.

  According to the present invention, since the third image data that is a reduced multi-value monochrome image is generated for the second image data that is a binary monochrome image, the display unit multivalues the third image data. Monochrome image can be displayed. A multi-valued monochrome image based on the third image data is generated based on the first image data to be a color image and becomes an image having a plurality of gradations. Can be reduced. Therefore, a reduced image that is a monochrome image displayed on the display unit has a reproducibility close to that of a monochrome image based on the second image data, and is a highly visible image.

<Outline of the present invention>
The basic configuration of the image processing apparatus of the present invention will be described with reference to FIG. FIG. 1 is a block diagram showing the basic configuration of the image processing apparatus of the present invention.

  The image processing apparatus shown in FIG. 1 converts a first image data based on a color image into second image data based on a binary monochrome image (hereinafter referred to as “monochrome binary image”); A first image conversion unit 1b that converts the first image data into third image data based on a multi-valued monochrome image (hereinafter referred to as “grayscale image”). The image processing apparatus is stored in the memory 2 that temporarily stores the second and third image data, the communication unit 3 that transmits the second image data stored in the memory 2, and the memory 2. And a display unit 4 for displaying an image based on the second image data.

  In the image processing apparatus configured as described above, the first image data including the color component and the luminance component is provided to each of the first and second image conversion units 1a and 1b. The first image data may be constituted by, for example, color signals of three primary colors (RGB), or may be constituted by a color difference signal (Cr, Cb) and a luminance signal (Y). Then, the first image conversion unit 1a binarizes the luminance component of the first image data, and acquires second image data that becomes a black and white binary image having the same resolution as the first image data.

  On the other hand, the second image conversion unit 1b converts the resolution of the first image data into the resolution for display on the display unit 4, extracts only the luminance component of the first image data, and reduces the reduced multiple gradation levels. Third image data to be a gray scale image is acquired. At this time, for example, the second image conversion unit 1b can reduce the image by performing a weighting addition on the image data of a plurality of pixels having a fixed distance from the target pixel after the reduction in the image before the reduction. .

  Each of the second and third image data acquired by the first and second image conversion units 1 a and 1 b is written in the memory 2. At this time, the second and third image data having the same first image data as the conversion source are associated and temporarily stored in the memory 2. Thereafter, the second image data stored in the memory 2 is read out by the communication unit 3, and the second image data as a black and white binary image is transmitted to the outside.

  At this time, the third image data corresponding to the second image data to be transmitted is read and given to the display unit 4, and the display unit 4 displays a grayscale image based on the third image data. Thereby, the display unit 4 can display an image obtained by reducing the image of the transmitted second image data, and the operator can check the content of the transmitted image by displaying the display unit 4.

  As described above, the image processing apparatus according to the present invention generates, in the second image conversion unit 1b, the third image data that is a grayscale image that is a reduced image corresponding to the second image data that is a monochrome binary image. The gray scale image reduced by the third image data is displayed on the display unit 4. As a result, the display unit 4 displays a grayscale image that has been reduced using an interpolation process such as a filter process, and thus corresponds to a thin line or a part of a fine character like an image reduced by a thinning process. Data loss can be prevented. Therefore, the visibility of the reduced image displayed on the display unit 4 is improved, so that the operator can confirm an image in a state close to a monochrome image based on the transmitted second image data on the display unit 4.

  Image processing apparatuses in the following embodiments are based on the above-described basic configuration and operation. In the following, details of the features of each embodiment will be described by taking a composite apparatus capable of facsimile communication as an example.

<First Embodiment>
A first embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is a block diagram showing the internal configuration of the image processing apparatus according to this embodiment.

  As shown in FIG. 2, the image processing apparatus 100 according to the present embodiment includes an image conversion unit 11 that converts a color image into a monochrome binary image, an image conversion unit 12 that converts a color image into a grayscale image, An ASIC (Application Specific Integrated Circuit) 10 having an image reduction unit 15 that performs reduction processing is provided. The ASIC 10 includes a memory controller 13 that controls reading and writing of an SDRAM (Synchronous Dynamic Random Access Memory) 20 and a CODEC (Coder and Decoder) 14 that performs compression coding on image data. In the ASIC 10, the image conversion unit 11 operates as the first image conversion unit 1a in the basic configuration in FIG. 1, and the image conversion unit 12 and the image reduction unit 15 are in the second image conversion unit 1b in the basic configuration in FIG. Works as.

  The image processing apparatus 100 including the ASIC 10 further includes an SDRAM 20 corresponding to the memory 2 in the basic configuration of FIG. The SDRAM 20 is controlled by the memory controller 13, and the ASIC 10 generates second image data that is a monochrome binary image and third image data that is a grayscale image from the first image data based on a color image. Then, each of the second and third image data acquired from the same first image data is temporarily stored in association with the SDRAM 20. At this time, the memory controller 13 writes the second and third image data compressed and encoded by the CODEC 14 into the SDRAM 20.

  The image processing apparatus 100 also includes a modem 30 that transmits and receives data to and from the ASIC 10 via the local bus 52, and an NCU (Network Control Unit) 31 that is connected to an external public switched telephone network (PSTN). Is provided. The modem 30 and the NCU 31 function as the communication unit 3 in the basic configuration of FIG. In other words, the image processing apparatus 100 performs modulation / demodulation by the modem 30 to mutually convert between a voice signal transmitted and received by the PSTN and a data string based on the image data, and the NCU 31 performs PSTN including outgoing calls or incoming calls. Control the communication used.

  The image processing apparatus 100 includes a subsystem 40 that transmits and receives data via a peripheral component interconnect (PCI) bus 57 and a universal serial bus (USB) interface 58, and a liquid crystal display (LCD) that displays an image. 44 and an operation unit 45 that receives an operation from the operator. The subsystem 40 includes a CODEC 41 that decompresses and decodes image data provided from the ASIC 10, an image reduction unit 42 that performs image reduction processing, and a conversion unit 43 that converts the image data into data in a format that can be displayed on the LCD 44. Have The subsystem 40 and the LCD 44 function as the display unit 4 in the basic configuration of FIG. The operation unit 45 includes buttons, keys, a touch panel integrated with the LCD 44, and the like.

  As described above, the image processing apparatus 100 having the function of each block shown in FIG. 1 includes a scanner unit for reading an image of a document, a main control unit for controlling the main body, and a printing unit for printing on recording paper. And an interface connected to a communication network other than PSTN. First, as a scanner unit, a light source (not shown) that irradiates a document with light, a CCD (Charge Coupled Device) 50 that receives reflected light from the document and converts it into an electrical signal, and an electrical signal from the CCD 50 is converted into digital data. An AFE (Analog Front-End) 51 for converting to image data.

  This scanner unit irradiates light on a document from a light source constituted by a white light such as a cold cathode tube or a light emitting diode, and receives reflected light indicating the density of the document by the CCD 50 to read an image of the document. At this time, the CCD 50 has a line sensor in which light receiving elements each having a color filter that transmits a specific color for each of the three primary colors (RGB) are arranged on one surface. That is, a line sensor provided with a color filter that transmits the R (red) component of the reflected light, a line sensor provided with a color filter that transmits the G (green) component of the reflected light, and a B (blue) component of the reflected light. The CCD 50 is constituted by a line sensor provided with a color filter that transmits light.

  The AFE 51 converts the RGB analog signals output from the three line sensors constituting the CCD 50 into image data that is digital data obtained by synchronizing RGB data at the same pixel position. As a result, image data in RGB format is input from the AFE 51 to the ASIC 10. The RGB image data output from the AFE 51 corresponds to the first image data described above.

  The main control unit includes an MPU (Micro Processing Unit) 53, an SDRAM 54, a flash memory 55, and an SRAM (Static Random Access Memory) 56 connected to the local bus 52. That is, the MPU 53 reads out various programs stored in the flash memory 55 and executes the programs using the SDRAM 54 as a work area for the read programs. By executing the program by the MPU 53, various functions in the composite apparatus are realized. The SRAM 56 stores various user settings typified by speed dials.

The printer controller 58 constituting the printing unit and the network board 60 constituting the interface are connected to the PCI bus 57 together with the USB interface 59, and data is transmitted to and received from the MPU 53 via the ASIC 10. The network board 60 is connected to a LAN (Local Area Network) and is connected to a TCP / IP (Transmission
It communicates with other terminal devices according to the Control Protocol / Internet Protocol) protocol. The printer controller 58 controls the operation of the image forming apparatus in order to perform printing on recording paper by an image forming apparatus (not shown).

  Further, the printer controller 58 can generate raster data using a page description language (PDL) received through the network board 60. That is, when the image processing apparatus 100 receives data transmitted from a terminal device connected to the LAN via the network board 60, the printer controller 58 can process the received data with a not-shown image forming apparatus. Convert to data. As a result, the image processing apparatus 100 shown in FIG. 2 realizes a network print function for printing a document or an image requested to be printed from a terminal device connected via a LAN on a recording sheet.

  The image processing apparatus 100 configured as described above can realize a scan function, a copy function, and a facsimile function in addition to the above-described network print function as a configuration as shown in FIG. Among the functions realized by the image processing apparatus 100, functions other than the network print function already described above will be briefly described below.

  The scan function is realized by operating a scanner unit having a light source (not shown), the CCD 50, and the AFE 51. That is, when the CCD 50 receives reflected light from a document based on light from a light source (not shown), an electrical signal corresponding to the amount of received light is generated for each pixel, and an analog signal that is serially continuous for each color of RGB is generated. Is output. Then, the AFE 51 synchronizes the data at each pixel position of the RGB signal and converts it into digital data to generate digital image data in RGB format and output it to the ASIC 10. In the ASIC 10, the image data from the AFE 51 is written into the SDRAM 20 by the memory controller 13.

  At this time, when the network board 60 receives a request for image data for the read document image from another terminal device via the LAN, the memory controller 13 of the ASIC 10 reads the image data stored in the SDRAM 20. The read image data is given to the network board 60 via the PCI bus 57 and then transmitted to the requested terminal device through the LAN. Thereby, a network scanning function using the network is realized.

  The copy function is realized by operating a scanner unit operated to realize the above-described scanning function and a printing unit by a printer controller 58 that operates an image forming apparatus (not shown). That is, the scanner unit operates in the same manner as when the above-described scanning function is realized, and image data for an image of a document read by the scanner unit is output from the AFE 51 to the ASIC 110. This image data is given to the print controller 58 through the PCI bus 57. The print controller 58 controls printing by the image forming apparatus in accordance with the image data, and the image of the original read by the CCD 50 is printed on the recording paper.

  The transmission operation in the facsimile function is realized by operating the scanner unit operated to realize the above-described scanning function and the communication unit configured by the modem 30 and the NCU 31. That is, first, the scanner unit operates in the same manner as when the above-described scanning function is realized, and image data for an image of a document read by the scanner unit is output from the AFE 51 to the ASIC 10. Further, the NCU 31 establishes a connection with the counterpart facsimile machine via the PSTN. At this time, it is determined whether or not the counterpart facsimile machine can receive image data to be a color image.

  When the facsimile machine on the other side can receive image data to be a color image, the ASIC 10 compresses and encodes the image data input from the AFE 51 with the CODEC 14 and then writes the data into the SDRAM 20 with the memory controller 13. When transmission to the facsimile machine on the other side becomes possible, the compressed and encoded image data stored in the SDRAM 20 is read by the memory controller 13 of the ASIC 10 and given to the modem 30 through the local bus 52. Therefore, the compression-encoded image data is modulated by the modem 30 and transmitted from the NCU 31 to the counterpart facsimile machine.

  If the facsimile machine on the other side cannot receive the image data to be a color image, the ASIC 10 binarizes the image data input from the AFE 51 by the image conversion unit 11 and then compresses it by the CODEC 14. Turn into. That is, the above-described first image data that becomes a color image is converted into the above-described second image data that becomes a monochrome binary image by the image conversion unit 11, and then compression-coded by the CODEC 14. After the compression encoding of the second image data, the second image data subjected to the compression encoding is temporarily stored in the SDRAM 20 and then modulated by the modem 30 as in the case of transmitting the image data to be a color image. , And sent from the NCU 31 to the facsimile machine on the other side.

  In this way, when image data for an image of a document read by the scanner unit is transmitted to the counterpart facsimile machine, the image reducing unit 15 displays the reduced image of the transmitted image on the LCD 44. Then, reduction processing is performed on the read image data. That is, the image reduction unit 15 performs a reduction process on the image data based on the original image read by the scanner unit, and generates a reduced image having a size corresponding to the resolution of the LCD 44.

  The image data to be a reduced image is compressed and encoded by the CODEC 14 and then temporarily stored in the SDRAM 20 through the memory controller 13. When a display on the LCD 44 is requested, image data to be a reduced image is read from the SDRAM 20 by the ASIC 10 and then given to the subsystem 40 via the PCI bus 57 and the USB interface 59. Then, the subsystem 40 converts the image data given through the ASIC 10 into RGB format image data to be displayed on the LCD 44, supplies the image data to the LCD 44, and a reduced image of the transmitted image is displayed on the LCD 44.

  The image processing apparatus according to the present invention is characterized in that the processing of the image data during the transmission operation by the facsimile function is the operation when the second image data is transmitted as a black and white binary image. Detailed operations at the time of data transmission will be described later.

  In addition, when transmitting image data of a color image, the image data given to the modem 30 is compressed and encoded by the JPEG method in the CODEC 14 after the image data in RGB format is converted into image data composed of a luminance signal and a color difference signal. Is done. At this time, for the image data to be a reduced image to be given to the subsystem 40, the image data converted from the RGB format is subjected to filter processing on each of the luminance signal and the color difference signal, and the reduction processing is performed. Thereafter, the CODEC 14 compresses and encodes the reduced image data by the JPEG method.

  On the other hand, the reception operation in the facsimile function is realized by operating a printing unit operated to realize the above-described printer function and a communication unit including the modem 30 and the NCU 31. That is, when the NCU 31 confirms a call from the partner facsimile machine, the NCU 31 establishes a connection with the partner facsimile machine through the PSTN. Thereafter, communication is performed between the modem 32 and the facsimile machine on the other side, and when reception of a signal transmitted from the facsimile machine on the other side is confirmed, the signal received by the modem 30 and the NCU 31 is demodulated, and image data To get.

  The image data acquired at this time is temporarily stored in the SDRAM 20 by the memory controller 13 when given to the ASIC 10 through the local bus 52. Thereafter, when printing of the received image data by the printing unit is requested, the image data temporarily stored in the SDRAM 20 is decompressed by the CODEC 14 and decoded. The decoded image data is given to the printer controller 58 via the PCI bus 57, and an image based on the received image data is printed on a recording sheet.

  When the received image data is stored in the SDRAM 20, the image data is decompressed and decoded by the CODEC 14, then reduced by the image reduction unit 15, and becomes a reduced image to be displayed on the LCD 44, and the SDRAM 20 is received together with the received image data. May be stored. At this time, the generated image data to be a reduced image may be further subjected to compression coding given to the CODEC 14 and may be stored in the SDRAM 20 in association with the received image data.

  Image data to be a reduced image is given to the subsystem 40 by the ASIC 10 via the PCI bus 57 and the USB interface 59, and a reduced image based on the received image data can be displayed on the LCD 44. Therefore, the user of the image processing apparatus 100 can recognize the image of the image data received from the facsimile apparatus as the counterpart by the reduced image displayed on the LCD 44, and can determine whether or not to print on the recording paper.

  In the facsimile function realized in this way, the network facsimile function can be realized by using the interface by the network board 60 instead of the scanner unit by the CCD 50 and the AFE 51. That is, when image data transmitted from another terminal device connected to the LAN is given to the ASIC 10 via the PCI bus 57 by the network board 60, this image data is given to the modem 30 via the local bus 52 and externally. Sent.

  At this time, as in the case of the transmission operation using the facsimile function described above, if the destination facsimile apparatus can receive color image data, the image data given to the ASIC 10 is directly compressed and encoded by the CODEC 14. If the destination facsimile machine cannot receive color image data, the image data given to the ASIC 10 is directly converted into second image data that becomes a black and white binary image by the image conversion unit 11 and then directly. It is compressed and encoded by the CODEC 14.

  Then, other operations including the operation of the image reduction unit 15 to display a reduced image corresponding to the image data transmitted to the facsimile machine of the other party on the LCD 44 are the same as those described above. Therefore, except for the operation of generating image data for transmission using the image data received by the network board 60, the transmission operation by the above-described facsimile function is referred to and detailed description thereof is omitted.

  The details of the monochrome binary image transmission operation using the facsimile function in the image processing apparatus 100 that implements each function in this way will be described below.

(First operation example)
First, a first example of the monochrome binary image transmission operation will be described with reference to the block diagram of FIG. 3 is a block diagram showing an operation flow of each unit in the image processing apparatus of FIG. 2, and each block of the image processing apparatus of FIG. 2 according to the order of operation when transmitting a monochrome binary image. Are sorted.

  When transmitting image data based on a monochrome binary image using the facsimile function, as described above, the first image data based on a color image is transferred from the AFE 51 (see FIG. 2) or the network board 60 (see FIG. 2) to the ASIC 10. Entered. The first image data is written in the SDRAM 20 by the memory controller 13 (see FIG. 2) and temporarily stored in the SDRAM 20 in order to perform arithmetic processing in each part of the ASIC 10.

  As described above, when the first image data based on the color image based on the document to be transmitted is stored in the SDRAM 20, the first image data is read from the SDRAM 20 by the memory controller 13, and as shown in FIG. It is given to each of the conversion units 11 and 12. Then, the image conversion unit 11 extracts only the luminance component of the first image data, performs binarization based on the luminance value serving as a threshold value, and generates second image data that becomes a monochrome binary image.

  At this time, if the first image data is RGB format image data, the luminance signal obtained by weighted addition of the RGB color signals is binarized. When the first image data is composed of a luminance signal and a color difference signal, the luminance signal is binarized to obtain second image data as a monochrome binary image. The second image data is obtained by removing the color component of the first image data and setting the luminance component to two gradations, and the resolution that is the size of the image is the same as that of the first image data.

  On the other hand, the image conversion unit 12 to which the first image data similar to the image conversion unit 11 is given acquires image data based on a grayscale image reflecting only the luminance component from the first image data. That is, when the first image data is RGB format image data, a luminance signal obtained by weighted addition of RGB color signals is calculated and converted into image data based on the luminance signal. If the first image data is composed of a luminance signal and a color difference signal, only the luminance signal is extracted and converted to image data.

  Therefore, the image conversion unit 12 is a multi-grayscale grayscale image in which the color component of the first image data is removed and only the luminance component is obtained, and the image data has the same resolution as the resolution of the first image data. Is acquired. Image data based on such a grayscale image is given from the image conversion unit 12 to the image reduction unit 15 and subjected to reduction processing, and converted into third image data that becomes a reduced grayscale image.

  In the image reduction unit 15, the image data obtained by the image conversion unit 12 is subjected to interpolation processing using a filter, and converted into third image data that becomes a reduced grayscale image. That is, a filter for weighted addition of data of a plurality of pixels at positions within a predetermined distance from the target pixel after reduction is provided in the image reduction unit 15, and this filter is used. An interpolation process for reducing the image is performed by the weighted addition.

  Therefore, in the image based on the image data obtained by the image conversion unit 12, when a pixel having data is present at the same position as the target pixel, the data of the target pixel and its surrounding pixels are weighted and added by this filter. Thus, the pixel data of interest after reduction is obtained. As described above, since the grayscale image of a plurality of gradations obtained by the image conversion unit 12 is reduced by the interpolation processing in the image reduction unit 15, the data of each pixel of the reduced image is obtained by converting the data of its surrounding pixels. The value is taken into account. Therefore, the grayscale image reduced by the third image data is an image having better visibility than the monochrome binary image reduced by the thinning process.

  When weighted addition using this filter is performed, the weighting factor based on the value of the filter can be changed according to the surrounding state of the target pixel, and a reduced image with better visibility may be obtained. . That is, for example, when the value of the filter is changed at the edge portion, the weighting coefficient for multiplying each data is changed so that the edge is emphasized. Therefore, in the example in which the filter value is changed in correspondence with the edge portion, the image after reduction is an edge-enhanced image, which is an image with better visibility.

  The second image data from the image conversion unit 11 and the third image data from the image reduction unit 15 are respectively supplied to the CODEC 14 and subjected to compression encoding corresponding to the respective images. That is, the CODEC 14 compresses and encodes the second image data that is a black and white binary image by the MH method, the MR method, the MMR method, the JBIG method, or the like, while the third image data that becomes a grayscale image. On the other hand, compression encoding by the JPEG method or the like is performed.

  The second and third image data compressed and encoded by the CODEC 14 in this way are associated with each other as generated from the same first image data by the memory controller 13 (see FIG. 2), and then written into the SDRAM 20. . In this way, when the second and third image data stored in the SDRAM 20 are read by the memory controller 13 (see FIG. 2), the second image data is sent via the local bus 52 (see FIG. 2). It is given to the modem 30. On the other hand, the third image data is given to the USB interface 59 via the PCI bus 57 (see FIG. 2).

  Therefore, after the modem 30 to which the second image data is given modulates the second image data, the NCU 31 transmits the modulated second image data to the facsimile apparatus that is the counterpart through the PSTN. As a result, the second image data to be a black and white binary image can be transmitted to a facsimile apparatus that cannot receive image data as a color image.

  Further, the third image data is given to the USB interface 59, and the third image data is transferred to the subsystem 40 connected to the USB interface 59. In this subsystem 40, the third image data transferred by the USB interface 59 is first given to the CODEC 41, and the third image data is decompressed and decoded based on the compression method described above.

  The third image data decompressed and decoded in this way is provided to the image reduction unit 42 and converted into an image having a size corresponding to the display area when displayed on the LCD 44. That is, when the image based on the third image data is displayed on the entire LCD 44, the image reduction unit 42 does not perform the reduction process. Further, for example, when displaying an image for two pages on the LCD 44, the display area on the LCD 44 is ½ of the entire area, so the image reduction unit 42 displays an image based on the third image data for one page. Reduce processing to halve.

  The third image data that has been processed by the image reduction unit 42 is further supplied to the conversion unit 43 and converted into image data in a data format that can be processed by the LCD 44. At this time, the image data based only on the luminance signal in which the third image data becomes a grayscale image is converted into image data in RGB format. Furthermore, when images of a plurality of pages are displayed on the LCD 44 at a time, the third image data for a plurality of pages reduced by the image reduction unit 42 is combined with image data of one image, and then an RGB format image is displayed. Converted to data.

  In this way, the third image data converted into RGB format image data is applied to the LCD 44, and an image based on the second image data transmitted by the modem 30 and the NCU 31 is displayed on the LCD 44. As a result, the operator can confirm the image displayed on the LCD 44 and recognize the image of the original received by the partner facsimile machine.

(Second operation example)
Next, a second example of the monochrome binary image transmission operation different from the first example will be described with reference to the block diagram of FIG. 4 is also a block diagram illustrating an operation flow of each unit in the image processing apparatus of FIG. 2, similar to the block diagram of FIG. 3, according to the order of operation when transmitting a monochrome binary image. The blocks of the image processing apparatus in FIG. 2 are rearranged.

  In the present operation example, unlike the first operation example, when the first image data temporarily stored in the SDRAM 20 is read by the memory controller 13 (see FIG. 2), the image conversion unit 11 and the image reduction unit 15 receive the first image data. Given. That is, in this operation example, when generating the third image data to be a reduced grayscale image, first, after the reduction process in the image reduction unit 15 is performed, the image conversion unit 12 converts the color image from the color image. Converted to a grayscale image.

  Since the operations other than the generation operation of the third image data by the image conversion unit 12 and the image reduction unit 15 are the same as those in the first operation example, the first operation example is referred to as that. Details are omitted. Therefore, hereinafter, the operation of generating the third image data by the image conversion unit 12 and the image reduction unit 15 will be described in detail.

  In this operation example, the image reduction unit 15 performs the interpolation processing by the filter described in the first operation example for each color signal constituting the first image data, or each of the luminance signal and the color difference signal. That is, when the first image data is image data in RGB format, the image reduction unit 15 has a filter for each color signal in RGB and performs interpolation processing for each color signal in parallel. On the other hand, when the first image data is composed of a color difference signal and a luminance signal, the image reduction unit 15 includes a filter for each of the luminance signal and the plurality of color difference signals, and the luminance signal and the plurality of color differences are included. Interpolation processing for each of the signals is performed in parallel.

  The image reduction unit 15 performs the reduction process by the interpolation process on the first image data, so that image data of a reduced color image is obtained. When the first image data is image data in the RGB format, reduced image data in the RGB format can be obtained. On the other hand, when the first image data is composed of a color difference signal and a luminance signal, the color difference signal is obtained. And reduced image data based on the luminance signal are obtained.

  The image data based on the reduced color image obtained by the image reduction unit 15 is supplied to the image conversion unit 12 and converted into image data based on the gray scale image from which only the luminance component is extracted. In this way, when the third image data that is a reduced grayscale image is output from the image conversion unit 12, the third image is output by the memory controller 13 (see FIG. 2), as in the first operation example. Data is written to the SDRAM 20.

  In the image conversion unit 12, the operation of converting the image data of the color image reduced by the image reduction unit 15 into the third image data is the same as in the first operation example. That is, when the image data of the color image reduced by the image reduction unit 15 is image data in the RGB format, the image data is converted into the third image data using the luminance signal obtained by weighted addition of each color signal. On the other hand, when the image data based on the color image reduced by the image reduction unit 15 is composed of the luminance signal and the color difference signal, only the luminance signal is extracted and converted into the third image data.

<Second Embodiment>
A second embodiment of the present invention will be described below with reference to the drawings. FIG. 5 is a block diagram showing the internal configuration of the image processing apparatus according to this embodiment. In the configuration of FIG. 5, the same parts as those of the configuration of FIG. 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 5, the image processing apparatus 101 according to the present embodiment includes a memory controller 46 in the subsystem 40 in addition to the configuration of the image processing apparatus 100 (see FIG. 2) according to the first embodiment. In addition, an SDRAM 47 controlled by the memory controller 46 is added. That is, the SDRAM 47 whose data writing and reading are controlled by the memory controller 46 in the subsystem 40 is provided in a component corresponding to the display unit 4 (see FIG. 1) in the image processing apparatus 101. Since the configuration other than the memory controller 46 and the SDRAM 47 is the same as that in the image processing apparatus 100 of the first embodiment, detailed description thereof is omitted.

  As described above, when the image processing apparatus 101 includes the SDRAM 47, when image data to be displayed on the LCD 44 is transferred to the subsystem 40 through the USB interface 59, the image data can be temporarily stored in the SDRAM 47. . As a result, the image processing apparatus 101 according to the present embodiment can cope with the display of images by the subsystem 40 and the LCD 44 even when the scanning unit including the CCD 50 continuously reads an image of a document of a plurality of pages.

  That is, when the scan function, the copy function, or the facsimile function is executed, a feeder that continuously supplies a plurality of pages of documents to the image processing apparatus 101 is installed, and a plurality of pages of documents are continuously detected by the scanning unit. The image is read. Therefore, in the scanning unit, the CCD 50 and the AFE 51 operate to obtain a plurality of image data corresponding to a plurality of pages of the document. When a plurality of image data output from the AFE 51 is given to the ASIC 10, it is written into the SDRAM 20 by the memory controller 13 in the ASIC 10 and temporarily stored.

  Thereafter, a plurality of image data temporarily stored in the SDRAM 20 is read from the SDRAM 20 for each data corresponding to one page of the document. Similarly to the first embodiment, conversion processing to a monochrome image, image reduction processing, compression coding processing, or the like is performed in the ASIC 10 corresponding to each function. The operation of each function in the image processing apparatus 101 of the present embodiment is the same as that of the image processing apparatus 100 in the first embodiment, except for the transmission operation in the facsimile function. Therefore, hereinafter, the transmission operation in the facsimile function, which is a feature of the present embodiment, will be described with a focus on the case of transmitting image data of a monochrome binary image.

  A monochrome binary image transmission operation in the facsimile function by the image processing apparatus 101 will be described with reference to the block diagram of FIG. The block diagram of FIG. 6 is a block diagram showing an operation flow of each unit in the image processing apparatus of FIG. 5, and each block of the image processing apparatus of FIG. 5 according to the order of operation when transmitting a monochrome binary image. Are sorted.

  As described above, when a plurality of first image data corresponding to a plurality of pages of originals are output from the AFE 51 (see FIG. 5), they are stored in the SDRAM 20 by the memory controller 13 (see FIG. 5) in the ASIC 10. As shown in FIG. 6, when the plurality of first image data is read from the SDRAM 20 for each piece of data corresponding to one page of the document, it is given to the image conversion units 11 and 12.

  The image conversion units 11 and 12 perform the same operation as in the first embodiment (see FIG. 3). Therefore, the image conversion unit 11 converts the first image data into second image data that becomes a black and white binary image, while the image conversion unit 12 converts the first image data into image data that becomes a grayscale image. Is done. Further, the image data obtained by the image conversion unit 12 is given to the image reduction unit 15, and third image data that becomes a reduced grayscale image is acquired as in the first embodiment (see FIG. 3). The

  The second image data output from the image conversion unit 11 and the third image data output from the image reduction unit 15 are further compressed and encoded by the CODEC 14 on the basis of the corresponding methods, and then again. , Stored in the SDRAM 20. Of the second image data and the third image data stored in the SDRAM 20, the second image data is a modem via the local bus 52 (see FIG. 5) by the ASIC 10 as in the first embodiment (see FIG. 3). 30. Thereafter, the modem 30 and the NCU 31 transmit the second image data for each piece of data corresponding to one page of the document to the counterpart facsimile machine.

  On the other hand, the third image data stored in the SDRAM 20 is given to the USB interface 59 through the PCI bus 57 (see FIG. 5) by the ASIC 10 as in the first embodiment (see FIG. 3). As a result, the third image data stored in the SDRAM 20 is transferred to the subsystem 40 connected to the USB interface 59 through the USB interface 59.

  Then, the subsystem 40 operates the memory controller 46 (see FIG. 5) to write the third image data transferred through the USB interface 59 into the SDRAM 47. As a result, a plurality of third image data corresponding to a plurality of pages of documents is first temporarily stored in the SDRAM 47. Therefore, the SDRAM 47 not only functions as a buffer in subsequent processing to be displayed on the LCD 44, but also functions as a memory that stores data until display is requested by operating the operation unit 45.

  As described above, when the third image data is stored in the SDRAM 47, first, the third image data corresponding to the first page of the document is read from the SDRAM 47 in order to display the image of the first page of the document on the LCD 44. Issued to the CODEC 41. Thereafter, the CODEC 41, the image reduction unit 42, and the conversion unit 43 operate in the same manner as in the first embodiment (see FIG. 3), and the image of the first page of the document is displayed on the LCD 44 as a grayscale image. The

  At this time, when the LCD 44 displays the image of a plurality of pages of the document including the first page of the document, the third image data corresponding to the number of pages to be displayed is read from the SDRAM 47. Then, the CODEC 41, the image reduction unit 42, and the conversion unit 43 perform the same processing as in the first embodiment (see FIG. 3), and images of a plurality of pages including the first page are displayed on the LCD 44. Is done.

  Further, when the SDRAM 47 functions as a memory, when the page requested to be displayed on the LCD 44 and the display mode on the LCD 44 are recognized based on the operation of the operation unit 45, the third image data of the requested page is displayed. Are extracted from the SDRAM 47 and read out. When a plurality of pages are displayed at a time, the third image data decompressed and decoded by the CODEC 41 so as to correspond to the display area on the LCD 44 of each page to be displayed according to the set display mode on the LCD 44. In contrast, the image reduction unit 42 performs a reduction process.

  Thereafter, the conversion unit 43 converts the data format of the third image data into a format for display on the LCD 44, and outputs it to the LCD 44. Thereby, the image processing apparatus 101 displays the image of the page requested by the operator on the LCD 44 in the requested display mode when transmitted by the facsimile function.

  When a color image is transmitted by this facsimile function, image data to be a color image for transmission and image data to be a color image reduced for display are stored in the SDRAM 20 as in the first embodiment. The data is compressed and encoded by the CODEC 14 and stored. Therefore, in the subsystem 40, a plurality of pieces of image data to be a color image reduced for display are transferred to the read document of a plurality of pages, and the plurality of pieces of image data to be a color image are stored in the SDRAM 47. Is done. Then, an operation similar to the operation based on the block diagram of FIG. 6 is performed, and the image of the page requested by the operator is displayed on the LCD 44 in the requested display mode.

  In the present embodiment, the operation for generating the third image based on the grayscale image is the same as the first operation example (see FIG. 3) in the first embodiment, but the second operation in the first embodiment is performed. It is good also as operation | movement similar to an example (refer FIG. 3). That is, first, the first image data is input to the image reduction unit 15 to generate image data based on the reduced color image, and then the image conversion unit 12 generates the third image data based on the reduced grayscale image. May be.

  The present invention is not limited to a facsimile apparatus, as long as it is an image processing apparatus having a configuration that displays an image obtained by reducing an actual image, and functions of a printer apparatus, an image scanner apparatus, a copying apparatus, or each apparatus. The present invention can be applied to various image processing apparatuses such as a composite apparatus including a combination of

These are block diagrams which show the basic composition of the image processing apparatus of this invention. FIG. 2 is a block diagram illustrating an internal configuration of the image processing apparatus according to the first embodiment. These are block diagrams which show the operation | movement flow of each part in the image processing apparatus of FIG. These are block diagrams which show another operation | movement flow of each part in the image processing apparatus of FIG. These are block diagrams which show the internal structure of the image processing apparatus in 2nd Embodiment. FIG. 6 is a block diagram illustrating an operation flow of each unit in the image processing apparatus of FIG. 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a 1st image conversion part 1b 2nd image conversion part 2 Memory 3 Communication part 4 Display part 10 ASIC
11, 12 Image conversion unit 13, 46 Memory controller 14, 41 CODEC
15, 42 Image reduction unit 20, 47, 54 SDRAM
30 Modem 31 NCU
40 Subsystem 43 Converter 44 LCD
45 Operation unit 50 CCD
51 AFE
52 Local bus 53 MPU
55 Flash memory 56 SRAM
57 PCI bus 58 Printer controller 59 USB interface 60 Network board

Claims (5)

A first image conversion unit that converts first image data of a color image into second image data that is a monochrome image that is the same magnification as the color image, and a display unit that displays the image; In the image processing apparatus that displays the reduced image corresponding to the image data on the display unit,
A second image conversion unit that converts the first image data into third image data that is a multivalued monochrome image in which a color image based on the first image data is reduced;
A memory for storing the second and third image data in association with each other;
With
When the reduced image corresponding to the first image data is displayed on the display unit, the third image data corresponding to the first image data is given from the memory to the display unit, and the third image data is included in the third image data. An image processing apparatus for displaying a monochrome image based on the display unit. In claim 1,
The second image conversion unit converts the color image based on the first image data into a multi-valued monochrome image, and then reduces the image to an image suitable for the resolution of the display unit to obtain the third image data. An image processing apparatus. In claim 1 or claim 2,
A first encoding unit that compresses and encodes the second image data from the first image conversion unit and supplies the second image data to the memory;
A second encoding unit that compresses and encodes the third image data from the second image conversion unit and supplies the third image data to the memory;
An image processing apparatus comprising: In claim 3,
The display unit includes a display unit memory for temporarily storing the third image data compressed by the second encoding unit read from the memory,
An image processing apparatus that expands the third image data stored in the display unit memory when displaying a monochrome image based on the third image data. In any one of Claims 1 thru | or 4,
The display unit is
A reduction processing unit for further reducing the monochrome image by the third image data read from the memory;
The image processing apparatus, wherein the reduction processing unit further reduces the monochrome image based on the third image data in accordance with a size of a region for displaying an image on the display unit.

Images