JP2008141576A - Image forming method and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform toner save while preventing an image of a picture from being changed by maintaining a saturation. <P>SOLUTION: In a printer 14, toner save can be performed in a mode regarding cost important and a mode regarding saturation important. When the mode regarding saturation important is designated, an occupant color is calculated from image data by an image data analysis unit 42, and a signal value of a maximum saturation of the occupant color is calculated by a maximum color signal calculation unit 44. A data setting unit 46 sets data based on the occupant color, the maximum saturation, a save rate that is inputted in advance and held in a data holding unit for regarding saturation important, a relative ratio of colors of CMYK, and correction characteristics with respect to output characteristics of an image output unit, and a parameter setting unit 32 sets a parameter with which the maximum saturation of the occupant color can be maintained, on the basis of the data. In an image processing unit 24, data conversion is performed on the basis of the set parameter, so that a picture of the image corresponding to the image data can be printed out. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming method and an image forming apparatus for forming a multicolor image on an image forming medium such as recording paper by applying, for example, an electrophotographic process.

  2. Description of the Related Art In recent years, image forming apparatuses such as printers, copiers, facsimiles to which an electrophotographic process is applied, or multifunction peripherals having these functions are widely used. In this image forming apparatus, an electrostatic latent image is formed by scanning and exposing a charged photosensitive drum according to image data to form an electrostatic latent image, and supplying a color material such as toner charged by a developing device. A toner image corresponding to the above is formed. Thereafter, the toner image is transferred to a recording paper or the like, and the toner is melted and fixed by pressurizing and heating, so that an image corresponding to the image data is formed on the recording paper.

  In such an image forming apparatus, it is possible to reduce consumption of color materials such as toner for the purpose of reducing running cost (hereinafter referred to as toner save).

  By the way, as a method for performing toner save, a method of uniformly reducing the number of dots by performing data compression or the like is generally used. However, in such a toner save method, not only a decrease in density but also formation is performed. The image quality of the recorded image may be degraded.

  From this, in Patent Document 1, by selecting and switching between a toner save for character / line drawing and a toner save for photographic images, an optimum toner save according to the properties of the image to be formed becomes possible. Propose to.

Further, in Patent Document 2, output level adjustment, application of a gray screen, and dither for toner saving are performed depending on whether image data to be subjected to image formation processing includes an image or a monochrome background object. It is proposed that the toner save method is switched depending on the object, such as selecting one of the options.
Japanese Patent Laid-Open No. 11-151833 JP 2001-083845 A

  However, if the toner save method is switched for each image, for example, when there are a plurality of different types of images in the same page, each image may be formed properly, but the saturation of the entire page changes. As a result, a printed matter different from the original image data is output. That is, there is a problem in that the original image information of the image data is changed with respect to the color, so that the original image cannot be obtained on the printed matter.

  The present invention has been made in view of the above-described facts, and suppresses the formation of an image having an image different from the original image data due to a visual saturation change on a printed material when toner is saved. An object of the present invention is to provide an image forming method and an image forming apparatus.

  In order to achieve the above object, the image forming method of the present invention is configured such that when an image corresponding to image data input from an image processing apparatus is formed on a recording medium by an image forming device, the density of each color component used for image formation is set. An image forming method for generating print data to be lowered and forming an image based on the generated print data, wherein the density of each color component forming the image is predetermined when the data conversion is performed on the image data Data for generating a parameter to be compressed at a ratio is stored in a storage means, and when the image processing apparatus is designated to form an image with the density of each color component lowered by the predetermined ratio, the storage is performed. Generating the print data to be output to the image forming device by performing data conversion on the image data based on the parameters stored in the means; When the image processing apparatus is designated to place importance on the saturation of the image formed on the recording medium, the image data is analyzed to form an image corresponding to the image data on the recording medium. A dominant color is calculated, and a saturation-oriented parameter that enables the saturation of the dominant color to be maintained and enables correction according to the output characteristics of the image forming device is generated. The print data to be output to the image forming device is generated by performing data conversion on the image data based on the emphasis parameter.

  The image forming apparatus of the present invention is used for image formation by performing data conversion on image data when an image corresponding to image data input from the image processing apparatus is formed on a recording medium by an image forming device. An image forming apparatus that generates print data for reducing the density of each color component and enables image formation with a reduced amount of color material used, and forms the image when the data conversion is performed on the image data. A first storage means for storing data for generating parameters for compressing the density of each color component at a predetermined ratio; and a dominant color when an image corresponding to the image data is formed on the recording medium. Image data analysis means for analyzing and calculating, and when performing the data conversion on the image data, correction according to the output characteristics of the image forming device; And setting means for setting data capable of generating a parameter capable of maintaining the saturation of the dominant color calculated by the image data analysis means, and the designation based on the designation for the image data in the image processing apparatus A selection unit that selects data stored in the first storage unit or data set by the setting unit, and the image forming device based on the parameters set according to the data selected by the selection unit Conversion means for performing data conversion on the image data to be output to.

  According to the present invention, by performing data conversion (compression) on image data based on parameters, print data with reduced image density is generated, and an image is formed on a recording medium based on the generated print data. Then, image formation is performed while suppressing the amount of color material used in the image forming device.

  Here, the storage means (first storage means) stores data that can generate parameters for compressing the data for each color material at a predetermined ratio, and image formation with the density of each color lowered at a predetermined ratio. Is specified, the amount of color material used is reduced by a general method for uniformly reducing the image density by performing data conversion using parameters based on data stored in the storage means (first storage means). It is possible to form an image with reduced image quality.

  On the other hand, when it is specified that importance is attached to the saturation of the image, by analyzing the image data, the dominant color having the largest occupation area when formed on a recording medium such as recording paper is calculated, Data (parameters) for decreasing the image density while maintaining the saturation of the calculated dominant color is set.

  By performing data conversion on image data using this parameter, the image of the original image data is maintained in the image of the image formed on the recording medium, and the image formed using the original image data Compared to the above, an image in which the amount of color material used is suppressed is obtained.

  That is, paying attention to the dominant color that affects the color tone of the image formed on the recording medium, by performing data compression while maintaining the color balance of the dominant color, while suppressing the amount of color material used, An image in which the original color of the image is maintained, that is, an image in which the overall color balance is maintained can be formed.

  Here, the dominant color may be a color that occupies the widest area among the colors having the same hue even if the saturation is different. The dominant colors are, for example, the basic category colors white, black, red, green, yellow, blue, brown, orange, purple, peach, and gray, and the most occupied area from these 11 colors. A wide color may be set, and furthermore, the hues of four colors of red, green, yellow and blue, which are basic hues, are applied, and the color having the widest area among these four colors is used as the dominant color. May be.

The image forming method of the present invention includes
When it is set so as to emphasize the saturation of the image formed on the recording medium, the maximum saturation of the dominant color or the maximum saturation and the average saturation of the dominant color are calculated together with the dominant color, and the dominant color is calculated. A parameter for emphasizing saturation that enables the maximum saturation or the maximum saturation and the average saturation of a color to be maintained and enables correction according to the output characteristics of the image forming device is generated, Based on this, the data conversion for generating the print data is performed.

  In the image forming apparatus of the present invention, the image data analysis unit calculates the maximum saturation of the dominant color or the maximum saturation and the average saturation of the dominant color together with the dominant color, and the setting unit calculates the dominant color. The maximum saturation or the maximum saturation of the color and the data capable of maintaining the average saturation are set.

  According to this invention, the maximum saturation or the maximum saturation and the average saturation of the dominant color are calculated together with the dominant color, and the image is designed to reduce the density while maintaining each of the maximum saturation or the maximum saturation and the average saturation. Form. Thereby, it is possible to form an image while maintaining the color balance and color on the printed material.

  Furthermore, the image forming apparatus of the present invention stores an input unit that can input a relative compression ratio for each color component forming the image, and a second that stores the compression ratio of each color component input by the input unit. Storage means, and the setting means includes the dominant color, the maximum saturation or maximum saturation and average saturation, and the relative compression ratio of each color component stored in the second storage means. The data is set based on the above.

  According to the present invention, a relative compression ratio is set between color materials forming an image, and data conversion is performed so that the compression ratio is maintained.

  Thereby, for example, on the image formed on the recording medium, the saturation reproducibility is lowered by setting the compression ratio to be high for a color having little influence on the saturation and hue. The consumption of the corresponding color material can be suppressed with certainty.

  In such an invention, the compression ratio between the color materials may be set so that the density ratio perceived on the recording medium is constant.

  As described above, according to the present invention, it is possible to form an image while suppressing the amount of color materials used for image formation while maintaining the entire image as well as the individual images formed on the recording medium. As a result, it is possible to obtain an excellent effect that the running cost can be reduced while the image formation in which the original color is maintained is possible.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of an image forming system 10 applied to the present embodiment. The image forming system 10 includes, for example, a plurality of image processing apparatuses 12 such as personal computers and workstations, and a printer 14 that is an image forming apparatus to which the present invention is applied. The network is connected so that data can be exchanged.

  An image processing unit 16 is formed in the image processing apparatus 12, and various processes including image processing such as creation, editing, and processing of an image and a document can be performed using a predetermined program. The image processing apparatus 12 is provided with a printer driver 18, and the image data created by the image processing unit 16 can be output to the printer 14 via the printer driver 18.

  In the image forming system 10, image data such as an image or a document created by the image processing device 12 is transmitted to the printer 14, whereby an image corresponding to the image data is recorded on an image recording medium such as recording paper (hereinafter referred to as recording paper). Print processing to be performed is possible.

  The printer 14 includes an image output unit 20 as an output device that executes image output, performs predetermined image processing on the image data, outputs the image data to the image output unit 20, and controls the operation of the image output unit 20. A controller unit 22 that can execute the printing process is provided. In the printer 14, the image data output from the image processing device 12 is input to the controller unit 22, and print processing based on the image data is executed.

  As a result, the image forming system 10 outputs a printed matter corresponding to the image data. Such an image forming system 10 can apply a general configuration in which a plurality of image processing apparatuses 12 and a printer 14 are connected to a network. The network includes not only the printer 14 but also an input device such as a scanner. Further, the PC 12 may be capable of bidirectional communication with each of the output device and the input device.

  Further, the printer 14 applied to the present embodiment may be a copying machine having a scanner function, and further forms at least an image corresponding to image data on a recording medium, such as a multi-function machine including a facsimile function. Any configuration can be applied as long as it has a function (printing function).

  For example, the image output unit 20 of the printer 14 applied as the image forming apparatus in the present embodiment forms an image by using an electrophotographic process using toners of colors C, M, Y, and K as color materials. . In other words, in the image output unit 20, data of each color component of CMYK is input as print data, and a photosensitive drum as an image carrier is scanned and exposed in accordance with each data, and the electrostatic drum is electrostatically formed on the photosensitive drum. A latent image is formed, and toner development is performed using C, M, Y, and K toners to form toner images of each color.

  Thereafter, the image output unit 20 transfers the toner image onto a recording medium such as recording paper (hereinafter referred to as recording paper) while superimposing it, and heats and pressurizes it to melt and fix the toner image on the recording paper. . As a result, the printer 14 forms and outputs an image corresponding to the image data on the recording paper.

  The controller unit 22 is provided with an image processing unit 24 that performs various data processing on the image data. The image processing unit 24 performs data conversion processing on image data using, for example, a color management system (CMS, not shown).

  The image output unit 20 inputs image data in the CMYK color space (hereinafter referred to as CMYK signal), and performs image formation processing based on the CMYK signal. Further, the image processing device 12 performs various processes on, for example, RGB color space image data (hereinafter referred to as RGB signals), and the image processing unit 24 of the printer 14 includes an RGB signal or other image output unit 20. Image data in a color space different from the device color space signal (CMYK signal) is input.

  From here, the image processing unit 24 converts image data different from device color signals such as RGB signals into data (hereinafter referred to as L * a * b * color space) in a device-independent color space such as CIELAB. L * a * b * signal) and then converted into CMYK signals that are image data in the device color space. For such data conversion, a general method using a multidimensional lookup table (DLUT) or the like can be applied.

  In the CMS of the image processing unit 24, for example, a color conversion profile such as an ICC profile is used to convert an L * a * b * signal into a CMYK signal that is image data in the device color space.

  The image output unit 20 can form an image with a preset gradation such as 256 gradations in which the density of each color of C, M, Y, and K is 0 to 255. Is provided with an LUT for converting each pixel into the number of dots (dot arrangement) corresponding to the density (density value of the image data), and the image processing unit 24 performs data conversion using the conversion parameters of the LUT. As a result, raster data of each color of C, M, Y, and K is generated and output as print data. The image output unit 20 scans and exposes a light beam based on the print data (raster data) to form toner images of C, M, Y, and K colors.

  In such an image processing unit 24 provided in the printer 14, a color conversion profile used by the CMS is set based on the maximum density that can be output by the image output unit 20. In the printer 14, the color conversion profile is updated and the image output unit 20 performs a calibration process at a preset timing or the like, or a setup process for returning the image output unit 20 to the initial state at the time of installation. Image formation is possible in the maximum density range that can be output.

  As the basic configuration of the printer 14, a known configuration is applied, and detailed description thereof is omitted.

  Incidentally, the image output unit 20 provided in the printer 14 has unique gradation characteristics. FIG. 3A shows an example of the gradation characteristics. In general, the gradation characteristics are not linear but curved. FIG. 3A shows the ratio of the maximum density to 1.0 when the maximum density is 1.0 with respect to a signal of 256 gradations (0 to 255) (output signal to the image output unit 20). ing.

  The gradation change (density change) of the image formed on the recording paper or the like is preferably linear with respect to the gradation characteristics of the image output unit 20. From here, correction characteristics for gradation characteristics are generally set so that the gradation change of the image on the recording paper is linear, and data conversion (gradation signal correction) is performed based on the correction characteristics.

  FIG. 3B shows an example of correction characteristics for the gradation characteristics shown in FIG. In FIG. 3B, the signal value (density value) of the output signal with respect to the input signal is shown. This correction characteristic is set based on the gradation characteristic of the image output unit 20, and the gradation change of the image output from the image output unit 20 is performed by performing data conversion on the image data based on this correction characteristic. (Tone change of each color of C, M, Y, K) becomes linear.

  As shown in FIG. 2, the controller unit 22 of the printer 14 includes a normal processing data holding unit 30 that stores correction data based on the gradation characteristics of the image output unit 20, and various types of data. A parameter setting unit 32 for setting conversion parameters for image data is provided.

  Normally, the printer 14 performs data conversion processing on image data using parameters set based on data held in the normal processing data holding unit 30. As a result, the printer 14 can form an image with an appropriate gradation change according to the image data.

  On the other hand, the printer 14 consumes toner by performing image formation. In the printer 14, the toner consumption (use amount) increases as the density of the image formed on the recording paper increases, and the running cost of the apparatus increases. On the other hand, when toner save is performed, the image density decreases, but the toner consumption (running cost of the apparatus) can be suppressed.

  From here, the printer 14 is set with a toner save mode for suppressing toner consumption. In the printer 14, a cost-oriented mode that uniformly reduces the toner consumption amount is set as the toner save mode.

  As shown in FIG. 2, the controller unit 22 of the printer 14 is provided with a cost-oriented data holding unit 34 and a process selection unit 36. Data used for setting parameters for performing data conversion on image data in the cost-oriented mode is stored in the cost-oriented data holding unit 34, and the processing selection unit 36 selects the toner save mode or the normal mode.

  FIG. 4 shows an outline of correction of the output signal with respect to the input signal in the cost-oriented mode. In the cost-oriented mode, by setting the toner save rate, the output signal corresponding to the input signal is uniformly compressed according to the set save rate.

  The cost-oriented data holding unit 34 stores data corresponding to the save rate, and the processing selection unit 36 sets the cost-oriented data to the save rate when the cost-oriented toner save mode and the save rate are set. Read from the data storage unit 34.

  As a result, the parameter setting unit 32 sets parameters for uniformly compressing the input signal according to the save rate, based on the data selected and read by the process selection unit 36.

  The image processing unit 24 performs data conversion on the input signal based on this parameter, thereby generating and outputting an output signal that uniformly saves toner of each color of C, M, Y, and K according to the save rate. .

  On the other hand, if the density of each color of CMYK is uniformly suppressed by performing toner save, the saturation of the image formed and output on the recording paper changes, and the image of the entire recording paper has the original image data. May be different. From this point, in the printer 14, as the toner save mode, a saturation importance mode that suppresses toner consumption while setting the saturation reproducibility of the image is set, and the cost importance mode and the saturation importance mode can be selected as the toner save mode. It is trying to become.

  As shown in FIG. 2, the controller unit 22 of the printer 14 has a data input unit 38 for inputting data as a condition for toner saving in the saturation priority mode, and a chroma input from the data input unit 38. A saturation emphasizing data holding unit 40 for storing the emphasis emphasizing data is provided.

  The change in the visual saturation of the image formed and output on the recording paper is caused by a change in the density or gradation of each color of CMYK. In addition, changing the balance of each color of CMYK causes not only visual saturation but also a change in hue.

  Further, when the toner save ratio is increased, desired saturation reproducibility cannot be obtained. However, for example, Y color has little influence on visual saturation change and hue. For such colors, even if the toner save ratio is larger than other colors (C, M, K colors), there is little influence on the saturation and hue. The toner save ratio can be set larger than that of other colors.

  From here, the data for emphasizing saturation input from the data input unit 38 is set for each color of C, M, Y, and K in consideration of the influence on the hue as well as the saturation. As a result, in the saturation priority mode of the printer 14, a save rate for visually suppressing the change in saturation is set, and C, M, Y, and K can be set within a range in which the change in saturation and hue is not felt. The relative ratio between them is set.

  As such a relative ratio, for example, C: M: Y: K can be set as 1: 1: 10: 1. In this case, for example, when the save rate is 5%, the save rate for each color of C, M, and K is 5%, and the save rate for Y color is 50%.

  When these data are input from the data input unit 38, they are stored in the chroma emphasis data holding unit 40 as chroma emphasis data. Note that an operation panel (not shown) or the like provided in the printer 14 can be used as the data input unit 38 used for such data input.

  On the other hand, the controller unit 22 of the printer 14 is provided with an image data analysis unit 42 that analyzes image data input to the printer 14, a maximum saturation signal value calculation unit 44, and a data setting unit 46.

  The image data analysis unit 42 analyzes the image data input to the printer 14 to calculate the color with the highest area ratio, and sets the calculated color as the dominant color for the corresponding image data. That is, the area of each color is calculated by analyzing the image data for one page of recording paper, and the color with the largest occupied area is set as the dominant color of the corresponding image data. When the dominant color is calculated, the area (occupied area) is calculated with the same hue as the same color even if the saturation is different.

  The maximum color signal value calculation unit 44 calculates a signal value that is the maximum saturation for the dominant color obtained by analyzing the image data by the image data analysis unit 42. In addition to the data stored in the dominant color of the image data, the signal value for maximum saturation, and the data stored in the saturation emphasizing data storage unit 40, the data setting unit 46 includes data stored in the normal processing data storage unit 30. Based on the above, data for obtaining parameters used for image data conversion is set.

  That is, the printer 14 calculates the dominant color and the maximum saturation signal value of the dominant color from the image data when performing the saturation priority mode and the toner saving.

  Further, in the printer 14, a save rate and a ratio of each color of C, M, Y, and K when performing toner save in the saturation priority mode are set, and data conversion based on these data is performed. At this time, the printer 14 performs data conversion in accordance with the gradation characteristics of the image output unit 20.

  In order to retain the hue when toner save is performed, it is necessary to make the gradation change of each color linear, and at the same time, maintain the ratio of each color, at least the ratio of the color that has a large visual impact. There is a need to. From here, the data setting unit 46 sets data for setting parameters based on the data (correction characteristics) held by the normal processing data holding unit 30, so that when toner is saved. Also, the gradation change of each color is made to be linear.

  FIG. 5 shows an example of a relative value of saturation with respect to an input signal when toner saving is performed in the saturation priority mode. The saturation is shown as a relative value C with respect to the input signal, with the maximum saturation (maximum density) being 1.0.

  The broken line shown in FIG. 5 is the correction characteristic of the input signal in the normal processing mode, and in the saturation priority mode, the correction characteristic is compressed based on the save rate α set for the corresponding color. An example of the correction characteristic at this time is indicated by a solid line.

In the normal processing mode, for example, when the input signal of the maximum saturation value for the dominant color is the signal value Imax and the relative value C ₀ , the correction characteristic applied to the saturation priority mode with the save rate α is , saturation is the relative value C ₁ when a signal value Imax.

Here, when performing toner saving in saturation-oriented mode, when the input signal is a signal value Imax, performs data conversion so that the relative value C ₁ of the saturation is ensured. That is, the printer 14 performs data conversion on the signal value Imax so that the output signal is set to the signal value Iomax.

  The dominant colors are formed by C, M, Y, and K colors, and when data conversion is performed, the ratios of the C, M, Y, and K colors are stored in the saturation emphasizing data holding unit 40. It is set according to the stored data.

  The parameter setting unit 32 of the controller unit 22 sets parameters for performing this data conversion based on the data set by the data setting unit 46. As a result, the image processing unit 24 performs data conversion on the image data based on the set parameters, thereby enabling toner saving while suppressing a change in visual hue while maintaining a desired saturation. Image data (CMYK signal) is generated.

  On the other hand, as shown in FIG. 1, the PC 12 is provided with a UI unit 50 so that various print settings can be performed while a predetermined UI (user interface) is displayed on a monitor (not shown). It has become.

  Further, the printer driver 18 displays a predetermined UI set by the UI unit 50, and when performing print processing using the printer 14, whether or not to perform print processing in the toner save mode and toner save. When performing printing processing in the mode, it is possible to set whether to set the cost priority mode or the saturation priority mode.

  FIG. 6 shows an outline of a toner save setting window 52 as an example of a UI applied to the setting at this time. The toner save setting window 52 is provided with a radio box 54A that is marked when the normal mode is set and a radio box 54B that is marked when the toner save mode is set.

  In addition, the toner save setting window 52 is provided with radio boxes 56A and 56B that can be marked by marking the radio box 54B, and an input box 58 that allows a save rate to be entered by marking the radio box 56A. It has been.

  In the toner save setting window 52, the toner save mode is selected by marking the radio box 54B, whereby the radio boxes 56A and 56B can be marked. By marking the radio box 56A, the cost-oriented mode is selected. The In the toner save setting window 52, by marking the radio box 56A, a numerical value within a predetermined range can be input to the input box 58. In addition, the input box 58 may be capable of increasing or decreasing the displayed numerical value by using the up key 60A and the down key 60B.

  Thus, the radio box 54A is marked and the OK button 62 is operated to set the image forming process in the normal mode. The radio box 54B is marked, the radio box 56A is marked, and the input box 58 is marked. By inputting a desired numerical value and operating the OK button 62, toner saving in the cost-oriented mode is set.

  In the toner save setting window 52, the toner save in the saturation priority mode is set by marking the radio box 56B instead of the radio box 56A.

  The toner save mode setting window 52 does not limit the UI used when the toner save setting is performed, and any configuration can be applied as long as the information can be input.

  Hereinafter, a printing process in the image forming system 10 will be described as an operation of the present embodiment.

  The image processing apparatus 12 provided in the image forming system 10 creates, processes, and edits images and documents using various applications, and stores the data (image data). Further, the image processing apparatus 12 is provided with a printer driver 18, and the image data using the printer 14 is transmitted by transmitting image data having various print settings using the printer driver 18 to the printer 14. Print output for data is possible.

  In the printer 14, when the image data output from the image processing device 12 is input to the controller unit 22, the image processing unit 24 provided in the controller unit 22 performs predetermined data processing on the image data and performs processing. Is output to the image output unit 20.

  In the image output unit 20, when image data is input from the controller unit 22, a toner image of each color of C, M, Y, and K is formed based on the corresponding image data, and the formed toner image is superimposed on the recording paper. Transcription and output. As a result, an image corresponding to the image data output from the image processing device 12 is formed on the recording paper.

  By the way, the printer 14 can select the toner save mode. By selecting the toner save mode, an image corresponding to the image data is formed on the recording paper while suppressing the amount of toner used. As a result, the running cost of the printer 14 can be reduced.

  Here, the toner save process in the printer 14 will be described with reference to FIG. In the image forming system 10, whether to save toner or to perform image forming processing in the normal mode is set in the image processing device 12, and the printer 14 performs processing based on the setting on the image processing device 12. I do. In the printer 14, data such as a save rate and a ratio of each color is input from the data input unit 38 as data for emphasizing saturation, and is stored in the data storage unit 40 for emphasizing saturation.

  In the flowchart of FIG. 7, the process is executed as image data is input to the image processing unit 24. In the first step 100, whether or not the toner save mode is set in the print setting in the image processing apparatus 12 is determined. Check.

  If the normal mode is set instead of the toner save mode, a negative determination is made in step 100 and the process proceeds to step 102 to set parameters to be applied to the normal mode. In this parameter setting, data held in the normal processing data holding unit 30 is read, and parameter setting is performed so that correction based on the gradation characteristics of the image output unit 20 is performed.

  Thereafter, in step 104, data conversion is performed on the image data based on the set parameters. In step 106, the converted data is output to the image output unit 20. Thus, when print output is executed by the image output unit 20, an image corresponding to the image data is formed on the recording paper and output.

  On the other hand, when the toner save mode is set, an affirmative determination is made in step 100, and the process proceeds to step 108. In this step 108, it is confirmed whether or not the gradation emphasis mode is set.

  Here, if it is set to the cost emphasis mode instead of the saturation emphasis mode, a negative determination is made at step 108 and the routine proceeds to step 110. In this step 110, the save rate set in the print settings is read. In the next step 112, the data held in the cost-oriented data holding unit 34 is read, and the cost is determined from the read data and the save rate setting. Set the parameters for saving toner in the priority mode.

  Thereby, the image output unit 20 outputs an image in which the toner consumption of each color of C, M, Y, and K is uniformly suppressed according to the save rate.

  On the other hand, when the saturation emphasis mode is set, an affirmative determination is made at step 108 to set parameters for toner saving in the saturation emphasis mode.

  In this process, first, in step 114, the dominant color of the image data is calculated by analyzing the image data. Here, the dominant color is a color that occupies the widest area on the formed image when an image is formed on one sheet of recording paper. For example, the area of each color is calculated by analyzing image data, The color with the maximum is set as the dominant color of the corresponding image data. In addition, even if the dominant color is a color with different saturation, the area having the same hue is calculated as the same color.

  In the next step 116, the maximum saturation is calculated from the dominant color, and the color signal of the maximum saturation (for example, signals of each color of C, M, Y, K) is obtained.

  Thereafter, in step 118, the dominant color of the image data, the signal value of the maximum saturation, the data held in the saturation importance data holding unit 40, and the data held in the normal processing data holding unit 30. Based on the above, data for obtaining the parameter is set, and in step 120, the parameter is set based on this data.

  Data conversion (compression) is performed on the image data using the parameters set in this way, and print processing based on the converted data is executed.

  Thus, in the printer 14, even when toner is saved in the saturation priority mode, the amount of toner used is suppressed according to the save rate, and the running cost can be reduced.

  At this time, the printer 14 calculates the dominant color of the image formed on the recording paper and the maximum saturation of the dominant color from the image data, and performs data conversion by using the parameters set based on the calculation result. It is possible to prevent the saturation reproducibility from being lowered on the image formed on the recording paper and to prevent the hue from changing.

  Therefore, an image maintaining the color and image of the original image data is formed.

  In the printer 14, the color hue that has little influence on the saturation and hue is set to be small in place of the other colors, thereby changing the visual hue on the recording paper (printed material). As a result, the amount of toner used for the corresponding color can be further reduced.

  As described above, the printer 14 applied to the present embodiment can perform high-quality image formation in which saturation reproducibility is ensured while performing toner saving.

  In the present embodiment, the occupied area is calculated for each color having the same hue in the image of one sheet of recording paper, and the color having the largest occupied area is applied as the dominant color. However, the present invention is not limited to this. For example, 11 basic colors such as white, black, green, yellow, blue, brown, orange, purple, peach and gray are applied, and the occupied area of each of these 11 colors is calculated to obtain the most occupied area. May be applied as a dominant color, or may be applied by setting four colors of red, green, yellow, and blue, which are basic hues, and setting a dominant color from these four colors. Thereby, the process when calculating a dominant color can be simplified.

  In this embodiment, the maximum saturation of the dominant color is calculated. However, the present invention is not limited to this, and the maximum saturation and the average saturation are calculated by calculating the maximum saturation and the average saturation of the dominant color. This may be maintained, and this enables more reliable color and the original image (look) to be maintained.

  Further, the present embodiment described above does not limit the configuration of the present invention. For example, in this embodiment, a relative ratio is set for each color of CMYK. However, the present invention is not limited to this, and a non-device color space such as data in the RGB color space or L * a * b * color space. For each color signal, a save rate, a relative ratio, etc. may be set.

  In the present embodiment, the data input unit 38 is provided in the printer 14 and the conditions for performing toner saving in the saturation priority mode are input. However, the present invention is not limited to this. For example, from the image processing apparatus 12, Conditions for performing toner save in the saturation priority mode may be transmitted to the printer 14 and held in the saturation priority data holding unit 40, and the printing process is executed in the saturation priority mode. When the image data to be transmitted is transmitted, the corresponding condition may be transmitted to the printer 14 in addition to the print setting.

  Furthermore, although the printer 14 has been described as an example in the present embodiment, the present invention can be applied to an image forming apparatus having an arbitrary configuration to which an electrophotographic process is applied. The present invention is not limited to an image forming apparatus to which an electrophotographic process is applied, but is applied to an image forming apparatus having various configurations that forms a color image according to image data using an arbitrary color material such as an inkjet method. As a result, it is possible to form an image with a desired saturation reproducibility while reducing the consumption of the color material used for the image formation.

1 is a schematic configuration diagram of an image forming system applied to the present embodiment. It is a schematic block diagram of the principal part of a printer. (A) is a diagram showing an example of output characteristics of the image output unit, (B) is a diagram showing an example of correction characteristics for the output characteristics of (A). It is a diagram which shows the outline of the conversion of the output signal with respect to the input signal applied to cost priority mode. It is a diagram which shows an example of the relative value of the saturation with respect to the input signal applied to a saturation priority mode. FIG. 3 is a schematic diagram illustrating an example of a UI used for print setting when image data is transmitted from an image processing apparatus. 7 is a flowchart illustrating an example of an image forming process based on the print setting in FIG. 6.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image forming system 12 Image processing apparatus 14 Printer (image forming apparatus)
18 Printer Driver 20 Image Output Unit (Image Forming Device)
22 Controller unit 24 Image processing unit (conversion means)
30 Data processing unit for normal processing 32 Parameter setting unit (conversion means)
34 Cost-oriented data holding unit (first storage means)
36 Process selection part (selection means)
38 Data input section (input means)
40 Saturation-oriented data holding unit (second storage unit)
42 Image data analysis unit (image data analysis means)
44 Maximum color signal calculation unit (image data analysis means)
46 Data setting part (setting means)

Claims (5)

Based on the generated print data, print data that reduces the density of each color component used for image formation when an image according to image data input from the image processing apparatus is formed on a recording medium by an image forming device. An image forming method for forming an image, comprising:
Data for generating parameters for compressing the density of each color component forming the image at a predetermined ratio when the data conversion is performed on the image data is stored in a storage unit,
When the image processing apparatus is designated to form an image in which the density of each color component is reduced by the predetermined ratio,
Generating the print data to be output to the image forming device by performing data conversion on the image data based on the parameters stored in the storage unit;
When the image processing apparatus is designated to place importance on the saturation of the image formed on the recording medium,
By analyzing the image data, a dominant color when an image corresponding to the image data is formed on the recording medium is calculated,
A saturation-oriented parameter that enables the saturation of the dominant color to be maintained and enables correction according to the output characteristics of the image forming device;
Generating the print data to be output to the image forming device by performing data conversion on the image data based on the saturation-oriented parameter;
An image forming method. When setting to emphasize the saturation of the image formed on the recording medium, the maximum saturation of the dominant color or the maximum saturation and the average saturation of the dominant color are calculated together with the dominant color,
Generating a saturation-oriented parameter that enables the maximum saturation or the maximum saturation and the average saturation of the dominant color to be maintained and enables correction according to output characteristics of the image forming device; Performing the data conversion to generate the print data based on a parameter;
The image forming method according to claim 1. When an image corresponding to image data input from the image processing device is formed on a recording medium by an image forming device, print data that reduces the density of each color component used for image formation is generated by performing data conversion on the image data An image forming apparatus that enables image formation with a reduced amount of color material used,
First storage means for storing data for generating parameters for compressing the density of each color component forming the image at a predetermined ratio when the data conversion is performed on the image data;
Image data analysis means for calculating a dominant color when an image corresponding to the image data is formed on the recording medium by analyzing the image data;
When performing the data conversion on the image data, it is possible to generate a parameter capable of maintaining the saturation of the dominant color calculated by the image data analysis unit, along with correction according to the output characteristics of the image forming device Setting means for setting data;
Selection means for selecting data stored in the first storage means or data set by the setting means based on designation for the image data in the image processing apparatus;
Conversion means for performing data conversion on image data to be output to the image forming device based on the parameters set according to the data selected by the selection means;
An image forming apparatus comprising: The image data analysis means calculates the maximum saturation of the dominant color or the maximum saturation and the average saturation of the dominant color together with the dominant color,
The image forming apparatus according to claim 3, wherein the setting unit sets data capable of maintaining the maximum saturation or the maximum saturation and the average saturation of the dominant color. An input means capable of inputting a relative compression ratio for each color component forming the image;
Second storage means for storing the compression ratio of each color component input by the input means;
The setting means includes the data based on the dominant color, the maximum saturation or the maximum saturation and the average saturation, and the relative compression ratio of each color component stored in the second storage means. The image forming apparatus according to claim 3, wherein the image forming apparatus is set.

Images