JP2018019247A - Image processing device, image forming apparatus, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processing device configured to perform proof printing reflected with setting of an exposure that is adjusted in accordance with an output environment or fluctuation with the passage of time, an image forming apparatus and a program.SOLUTION: An image processing device comprises: reception means for receiving from an image forming apparatus exposure information indicating a relationship between an exposure and a dot size; storage means for storing the received exposure information; reception means for receiving proof image data; resolution conversion means for converting the received proof image data into an output resolution of the image forming apparatus; generation means which normalizes the exposure of the exposure information in the storage means, thereby generating a comparative parameter of the exposure to be compared with values at pixel positions after the conversion; dot size determination means for determining the dot size by comparison with the comparative parameter; and transmission means for transmitting to the image forming apparatus output data including pixel information of the determined dot size.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an image processing apparatus, an image forming apparatus, and a program.

  Conventionally, in the printing process of offset printing, there is a process called proof printing in which printing plate data is printed by an electrophotographic machine having a low cost per sheet and the color and image quality thereof are confirmed. In the case of performing proof printing with an electrophotographic machine or the like, it is necessary to devise a technique for maintaining the reproducibility of halftone dots and hues, and there is a document disclosing a technique for maintaining such reproducibility. One technology corrects the area ratio of each halftone dot in the proof printing process for the purpose of reproducing the dot gain generated when ink is pressed against the printing paper, and irradiates the photosensitive material with the corrected exposure amount of light. As a result, a latent image is formed (see Patent Document 1).

  In general, the density characteristics of a printer engine are greatly affected by environmental factors such as temperature and humidity and changes over time. For this reason, the printer engine adjusts the exposure amount related to image formation and adjusts the engine to match the target density characteristic at the timing when the fluctuation of the density characteristic becomes large, such as when starting in the morning or after mass printing. However, if the exposure amount set in the printer engine is uniquely changed for the purpose of reproduction, such as dot gain and color, it will not be possible to reflect the exposure amount setting that is adjusted according to the output environment or temporal variation, There is a problem in that the reproducibility of hue and the like and the stability of image quality are affected.

  The present invention has been made in view of the above, and is an image processing apparatus, an image forming apparatus, and a program that perform proof printing with high reproducibility reflecting the setting of an exposure amount adjusted according to an output environment, a change with time, and the like. The purpose is to provide.

  In order to solve the above-described problems and achieve the object, the present invention provides a receiving unit that receives exposure amount information indicating a relationship between an exposure amount and a dot size from an image forming apparatus, and the reception unit that receives the exposure amount information. A storage unit that stores exposure amount information; a reception unit that receives proof image data; a resolution conversion unit that converts the proof image data received by the reception unit into an output resolution of the image forming apparatus; and a storage unit. Generating means for generating a comparison parameter of an exposure amount to be compared with the value of each pixel position after conversion to the output resolution by normalizing the exposure amount of the stored exposure amount information; The dot size determining means for determining the dot size corresponding to the value of each pixel position by the comparison of the above and the dot size determining means The output data including pixel information of the dot size is characterized by having a transmission means for transmitting to the image forming apparatus.

  According to the present invention, since the dot size of each halftone dot of the proof image data can be adjusted based on the exposure amount setting adjusted according to the output environment and the temporal change, the adjustment is made according to the output environment and the temporal change. It is possible to obtain a proof printed matter with high reproducibility that reflects the setting of the exposure amount.

FIG. 1 is a diagram illustrating an example of an overall configuration of an image generation system including an image processing apparatus according to the first embodiment. FIG. 2 is a diagram illustrating an example of DFE hardware blocks. FIG. 3 is a functional block diagram illustrating an example of main functions related to DFE image processing. FIG. 4 is a diagram illustrating an example of exposure amount information. FIG. 5 is an explanatory diagram of processing in the resolution conversion unit. FIG. 6 is an explanatory diagram of processing in the generation unit. FIG. 7 is an explanatory diagram of processing in the dot size determination unit. FIG. 8 is a diagram illustrating an example of a sequence showing the relationship between engine adjustment performed by the printer and exposure amount information update processing in DFE. FIG. 9 is a diagram illustrating an example of an image processing flow suitable for proof printing performed by the DFE. FIG. 10 is a diagram illustrating an example of an overall configuration of an image generation system including an image forming apparatus according to the second embodiment. FIG. 11 is a diagram illustrating an example of a hardware block of the MFP. FIG. 12 is a functional block diagram showing an example of main functions of the MFP. FIG. 13 is a diagram illustrating an example of an image processing flow suitable for proof printing executed by the MFP.

  Hereinafter, embodiments of an image processing apparatus, an image forming apparatus, and a program will be described in detail with reference to the accompanying drawings.

(First embodiment)
FIG. 1 is a diagram illustrating an example of an overall configuration of an image generation system including an image processing apparatus according to the first embodiment. An image generation system 1 illustrated in FIG. 1 includes a computer 10, a DFE (Digital Front End) 20 as an “image processing apparatus”, and a printer 30 as an “image forming apparatus”.

  The computer 10 is a computer such as a general-purpose PC (Personal Computer) that transmits image data that is normally printed, such as 8-bit color image data, to the DFE 20. The 8-bit color image data is an example of “normal image data”. In the present embodiment, in addition to the image data, the proof image data Q printed in the proof printing process is read from an external device (for example, an offset printing machine) or a portable storage medium, and the proof image data Q to the DFE 20 is read. Also send. The proof image data Q is TIFF (Tagged Image File Format) image data having a color depth of 1 bit that has already been subjected to color conversion, halftone processing, and the like in an external device such as an offset printer. In the present embodiment, the proof image data Q will be described as plate data of C (Cyan) M (Magenta) Y (Yellow) K (Black).

  The DFE 20 transmits various image data to the printer 30 by performing image processing. For example, when receiving 8-bit color image data from the computer 10, the DFE 20 performs data processing such as color conversion and halftone processing on the image data and outputs the image data to the printer 30. When the proof image data Q is received from the computer 10, the DFE 20 performs image processing suitable for proof printing on the proof image data Q and outputs the proof image data Q to the printer 30. In image processing suitable for proof printing, the DFE 20 receives exposure amount information R from the printer 30 and performs processing for determining the dot size of the proof image data Q based on the exposure amount information R. The exposure amount information R is information indicating the exposure amount for each dot size of each color of CMYK of the printer 30.

  A printer 30 shown as an “image forming apparatus” in the first embodiment is a general-purpose electrophotographic printer having CMYK color toners. The printer 30 transmits exposure amount information R indicating the adjusted exposure amount to the DFE 20 every time the exposure amount related to image formation is adjusted. The printer 30 has a function of adjusting the exposure amount, and adjusts the exposure amount to an optimum value by performing engine adjustment at a timing when the density characteristics of the printer engine greatly fluctuate, such as when starting in the morning or after mass printing. In addition to this, the timing for adjusting the exposure amount includes, for example, after a long period of time with the power on and after an instruction for manual adjustment by the user. The printer 30 prints the print data T transmitted from the DFE 20 with the exposure amount adjusted when the print data T is received. The print data T is an example of “output data” that the DFE 20 transmits to the printer 30.

  With the image processing technique suitable for proof printing described above, the proof image data Q can be printed out in the image data image generation system 1.

  Hereinafter, the configuration of the image processing apparatus suitable for proof printing and the processing flow of image processing will be described in more detail.

  FIG. 2 is a diagram illustrating an example of hardware blocks of the DFE 20. 2 includes a CPU (Central Processing Unit) 200, a ROM (Read Only Memory) 201, a RAM (Random Access Memory) 202, an HDD (Hard Disk Drive) 203, a device I / F 204, a first communication I / O. F205 and a second communication I / F 206, which are connected to each other via a bus 209. In addition, an LCD (Liquid Crystal Display) 207 and a keyboard 208 are connected to the device I / F 204.

  The CPU 200 is a central processing unit and comprehensively controls the operation of the entire DFE 20. The ROM 201 is a read-only nonvolatile storage medium that stores a fixed program. The RAM 202 is a readable / writable volatile storage medium used as a work area when the CPU 200 processes information. The HDD 203 is a readable / writable nonvolatile storage medium that stores various programs and data. The HDD 203 stores programs relating to image processing as the various programs. The HDD 203 also has a storage area for storing exposure amount information R (see FIG. 1) transmitted from the printer 30.

  The device I / F 204 is an interface that connects the LCD 207 and the keyboard 208 to the bus 209.

  The LCD 207 is a liquid crystal display for displaying information generated by the CPU 200.

  The keyboard 208 is an input device that notifies the CPU 200 of a key signal of a pressed key.

  The first communication I / F 205 is a communication interface such as RS232C or USB (Universal Serial Bus) for communicating with the computer 10.

  The second communication I / F 206 is a communication interface such as RS232C or USB for communicating with the printer 30.

  Next, the functional configuration of the DFE 20 will be described. The DFE 20 exhibits various functions when the CPU 200 loads various programs such as the ROM 201 and the HDD 203 to the RAM 202 and executes them.

  FIG. 3 is a functional block diagram illustrating an example of main functions related to the image processing of the DFE 20. The DFE 20 illustrated in FIG. 3 includes a first communication control unit 21, a second communication control unit 22, a storage control unit 23, an operation reception unit 24, a display control unit 25, and the like as functional units related to image processing. The image determination unit 26, the proof image processing unit 27, the normal image processing unit 28, the print data transmission instruction unit 29, and the like.

  The first communication control unit 21 communicates with the computer 10 via the first communication I / F 205 and receives various image data transmitted from the computer 10.

  The second communication control unit 22 communicates with the printer 30 via the second communication I / F 206, receives exposure amount information R from the printer 30, and transmits print data T to the printer 30. I do.

  The storage control unit 23 accesses the ROM 201, the RAM 202, the HDD 203, and the like, and instructs writing and reading of programs and data according to the access area.

  The operation receiving unit 24 receives an operation signal (key signal or the like) from the keyboard 208.

  The display control unit 25 controls the display on the LCD 207.

  The image determination unit 26 determines whether the image data received by the first communication control unit 21 is image data P for normal printing or proof image data Q for proof printing.

  The proof image processing unit 27 performs image processing suitable for proof printing on the proof image data Q received by the first communication control unit 21. Specifically, the proof image processing unit 27 includes an exposure amount information update instruction unit 27-1, a resolution conversion unit 27-2, a generation unit 27-3, and a dot size determination unit 27-4.

  The exposure amount information update instruction unit 27-1 instructs the storage control unit 23 to update the exposure amount information R of the HDD 203 with the latest exposure amount information R received by the second communication control unit 22.

  The resolution conversion unit 27-2 converts the proof image data Q into the output resolution of the printer 30.

  The generation unit 27-3 normalizes the exposure amount information R of the HDD 203. Specifically, the generation unit 27-3 includes an exposure amount information read instruction unit 27-3A and an exposure amount ratio information generation unit 27-3B. The exposure amount information reading instruction unit 27-3A instructs the storage control unit 23 to read the exposure amount information R stored in the HDD 203 for the output sheet specified in the output sheet type information. The exposure amount ratio information generation unit 27-3B can compare the read exposure amount information R with the value indicated by each pixel position of the proof image data after the resolution conversion by the resolution conversion unit 27-2. Normalize.

  The dot size determination unit 27-4 has a value indicating each pixel position of the proof image data after resolution conversion and each value of the exposure amount for the dot size indicated by the exposure amount information after normalization (as a “comparison parameter”). And the dot size at each pixel position of the proof image data after resolution conversion is determined.

  The normal image processing unit 28 performs existing image processing on the image data P received by the first communication control unit 21. For example, the normal image processing unit 28 is a color conversion processing unit 28-1, a total amount regulating unit 28-2, a gamma conversion unit 28-3, or a halftone processing unit 28- as a processing unit that performs existing image processing. 4 etc.

  The color conversion processing unit 28-1 converts the 8-bit color image data P from various input formats into CMYK 8-bit color image data.

  The total amount regulating unit 28-2 adjusts the toner amount for pixels in which the total toner amount of CMYK exceeds the regulation value according to the total amount regulation value of the printer 30.

  The gamma conversion unit 28-3 corrects the CMYK density characteristics according to the density characteristics of the printer 30.

  The halftone processing unit 28-4 performs halftone processing and generates image data that matches the color depth of the printer 30.

  The print data transmission instruction unit 29 instructs the second communication control unit 22 to transmit the print data T (see FIG. 1) to the printer 30. The print data T is obtained by storing image data generated by image processing of either the proof image processing unit 27 or the normal image processing unit 28 in a data unit and adding header information such as print settings.

  FIG. 4 is a diagram showing an example of exposure amount information R (see FIG. 1). FIG. 4 shows exposure amount information of three types of paper as an example. The exposure amount information R1 shown in FIG. 4A is the exposure amount information of plain paper. The exposure amount information R2 shown in FIG. 4B is gloss amount exposure amount information. The exposure amount information R3 shown in FIG. 4C is the exposure amount information of the matte paper.

  Each exposure amount information R1 to R3 includes dot size information indicating the dot size of the printer 30 and CMYK information indicating the toner color (matching the process color) of the printer as information for classifying the exposure amount. In this example, the dot size information includes three types of 3/3 dots, 2/3 dots, and 1/3 dots, and 3/3 dots of these indicate the largest dot size.

  In each exposure amount information R1 to R3, a value indicating the exposure amount is set at a position corresponding to any of the dot size information and any of the CMYK information. For example, in the exposure amount information R1 for plain paper in FIG. 4A, the value “5.” indicating the exposure amount is displayed at the corresponding position of “3/3 dots” in the dot size information and “K” in the CMYK information. 49 (unit is nanosecond “ns” indicating exposure time) ”is set. These values differ depending on the engine characteristics of the printer 30 and are updated as appropriate according to the timing of engine adjustment.

  Next, each process of the proof image processing unit 27 will be described in detail. Here, as an example of the proof image data Q, plate data of the process color “M” having a color depth of 1 bit and a resolution of 2400 dpi is used. Further, a printer having a color depth of 2 bits and a resolution of 1200 dpi is used as the proof image output destination printer 30.

  FIG. 5 is an explanatory diagram of processing in the resolution conversion unit 27-2. The plate data d1 shown in FIG. 5 is one in which each of the matrix-like rectangular areas is one pixel, and each pixel is divided into patterns according to pixel values. In this example, since the color depth of the printing plate data d1 is 1 bit, each pixel takes either a pixel value “1” where a dot is formed or a pixel value “0” where a dot is not formed. In the plate data d1 shown in FIG. 5, pixels where dots are formed are indicated by hatching, and pixels where dots are not formed are indicated by blanks.

  In this example, the resolution conversion unit 27-2 performs conversion from 2400 dpi of the printing plate data d1 to low resolution of 1200 dpi of the printer 30. Therefore, in this case, the low resolution data of 1200 dpi is obtained by converting the pixel value of the four pixels into information indicating the ratio of one pixel in units of four pixels of the plate data d1 (that is, “unit pixel region”). What gives d2 is shown. A rectangular frame X0 shown in FIG. 5 indicates one processing unit (a unit pixel region including four pixels).

  For the purpose of explanation, the plate data d1 shown in FIG. 5 is provided with dot forming portions E1 to E4 having four different dot forming portions for forming dots. The dot formation unit E1 has all four pixels of the four pixels that are processing units as the dot formation unit. The dot formation part E2 has 3 pixels as a dot formation part. The dot formation part E3 has 2 pixels as a dot formation part. The dot formation part E4 has 1 pixel as a dot formation part.

  Here, as an example, the maximum dot size is set to “1”, and a value (pixel occupation ratio) obtained by dividing “1” by the number of pixels of the dot forming unit is set to the coordinates (pixel position) indicated by one pixel of the conversion destination. Set. That is, the resolution is reduced by allocating the average value of the pixel values of the dot formation portion in the original region (in this example, the region for four pixels) to one pixel. The arrow line X1 shown in FIG. 5 represents the coordinate E14 which is the conversion destination of the dot formation part E4 with an arrow as an example of the said conversion destination.

  In the case of this example, since the dot forming unit E1 has all four pixels among the four pixels as the processing unit as the dot forming unit, “1” is set to the coordinate E11 of one pixel to which the four pixels are converted. Since the dot forming unit E2 has 3 pixels as the dot forming unit, “0.75” is set to the coordinate E12 of one pixel of the conversion destination of the 4 pixels including the dot forming unit E2. Since the dot forming unit E3 has two pixels as the dot forming unit, “0.50” is set to the coordinate E13 of one pixel to which the four pixels including the dot forming unit E3 are converted. Since the dot forming unit E4 has one pixel as the dot forming unit, “0.25” is set to the coordinate E14 of one pixel to which the four pixels including the dot forming unit E4 are converted. For each of the four pixels that do not include other dot formation portions, “0” is set to the coordinates of one pixel of each conversion destination.

  FIG. 6 is an explanatory diagram of processing in the generation unit 27-3. The exposure amount information R10 shown in FIG. 6A shows the exposure amount information of plain paper among the three types of paper as an example. It should be noted that the values of the exposure amounts in the exposure amount information R10 shown in FIG. 6A and the exposure amount information R1 shown in FIG.

  Here, as an example, a process for normalizing the exposure value of each dot size in each CMYK color so that all of the exposure values of 3/3 dots, which are the maximum dot size in each CMYK color, are equal to “1”. Show. Although all the exposure values of 3/3 dots are set to “1”, this “1” is the value of each coordinate of the low resolution data d2 after the conversion processing of the resolution conversion unit 27-2. The comparison is possible, and corresponds to “1” set to the maximum dot size in the resolution conversion, that is, the upper limit value of the pixel occupation ratio.

  For each CMYK color, the generation unit 27-3 multiplies the value of the exposure amount of each dot size by a value that makes the maximum dot size 3/3 dot exposure amount value the upper limit value of the pixel occupation ratio. Match. Here, as an example, the value of the exposure amount of each dot size is divided by the value of the exposure amount of 3/3 dots, which is the maximum dot size, and the figures after the decimal point are rounded off or rounded off. In addition, since the value of each pixel of the low resolution data d2 after the resolution conversion is up to two decimal places, it shows that the significant figures after the decimal place are obtained up to two digits.

  For example, in the “M” color of the exposure amount information R10, the value of the exposure amount of 3/3 dots is set to “0.90”. Accordingly, the generation unit 27-3 sets the exposure amount value “0.30” of “M” color 1/3 dots, the exposure amount value “0.60” of “M” color 2/3 dots, “ The exposure value “0.90” of 3/3 dots of “M” color is divided by the exposure value “0.90” of the maximum dot size of “M” color, and the value up to a significant figure is obtained as the value. Ask for. For other colors, values up to significant figures are obtained by the same procedure.

  As another example, in the “Y” color of the exposure amount information R10, the value of the exposure amount of 3/3 dots is set to “0.80”. Accordingly, the generation unit 27-3 exposes the exposure amount value of each dot size, that is, the exposure amount value “0.20” of 1/3 dot of “Y” color, and 2/3 dot exposure of “Y” color. The amount value “0.50” and the exposure amount value “0.80” of 3/3 dots of “Y” color are respectively set to the exposure amount value “0.80” of the maximum dot size of “Y” color. Divide and calculate up to significant figures.

  The exposure amount information R100 shown in FIG. 6B indicates the exposure amount information after normalization of the exposure amount information R10 in FIG. As is clear from the values set in the exposure amount information R100, the exposure values of 3/3 dots of CMYK colors are all converted to “1”. In addition, by this normalization, the exposure value of each dot size of each CMYK color is converted to a ratio having a maximum value of “1” (comparable to “pixel occupation ratio”), and the dot for each CMYK color is changed. It can be used as a conversion parameter for size.

  FIG. 7 is an explanatory diagram of processing in the dot size determination unit 27-4. FIG. 7 shows the state of the coordinate setting values indicating each pixel of the low resolution data d2 before and after the determination of the dot size determined by the dot size determination unit 27-4.

  For each coordinate indicating each pixel of the low resolution data d2, the dot size determination unit 27-4 obtains a set value and a conversion parameter for the corresponding color in the exposure amount information R100 after normalization (see FIG. 6B). By comparing, the dot size of each coordinate is determined.

  Here, since the “M” color plate data is taken as an example, the dot size determination unit 27-4 compares the “M” color conversion parameter of the exposure amount information R100 with the conversion parameter for each dot size. Based on the set value, for example, the dot size is determined under the following conditions. For the “M” color, a value from 0 to 0.32 is determined as no dot, and for a value from 0.33 to 1.00, the closer dot size is determined. . Here, the dots from 0 to 0.32 are assumed to have no dots. However, those having a range from 0 to 0.32 are less than the minimum dot size of the printer 30, and the minimum dot size or less depends on the dot size. This is because it cannot be expressed. In addition, since the conditions shown here are examples, you may change suitably. For example, only a pixel having a value of “1” may be determined to be 3/3 dots, and may be modified so as to include a part that does not have a range.

  The converted image data d3 shown in FIG. 7 is image data in which the corresponding pixels are expressed in gradation by the dot size determined by the dot size determination unit 27-4. The correspondence relationship between the low resolution data d2 and the converted image data d3 is as follows. Since the value of the coordinate E11 of the low resolution data d2 is “1”, gradation information indicating 3/3 dots is set in the corresponding pixel E21 of the converted image data d3.

  Further, since the pixel value E12 of the low resolution data d2 is “0.75”, gradation information indicating 2/3 dots is set in the corresponding pixel E22 of the converted image data d3.

  Further, since the pixel value E13 of the low resolution data d2 is “0.50”, gradation information indicating 2/3 dots is set in the corresponding pixel E23 of the converted image data d3.

  Further, since the pixel value E14 of the low resolution data d2 is “0.25”, gradation information indicating no dot is set in the corresponding pixel E24 of the converted image data d3.

  For the other pixels of the converted image data d3, the pixel value of the low resolution data d2 is “0”, so that gradation information indicating no dot is set.

  Next, processing of the image generation system 1 will be described. First, a process in which the DFE 20 receives the exposure amount information R (see FIG. 1) from the printer 30 will be described. The printer 30 adjusts the exposure amount by adjusting the engine when the printer is activated, after a large amount of printing, after being left for a long time with the power on, or when the user manually instructs adjustment.

  FIG. 8 is a diagram illustrating an example of a sequence showing a relationship between engine adjustment performed by the printer 30 and update processing of the exposure amount information R in the DFE 20. First, the printer 30 executes an engine adjustment process to determine an optimum exposure amount (S1). Specifically, the printer 30 approaches the target density characteristic while adjusting the exposure amount related to image formation to the optimum solution at each moment, and the exposure amount when the target density characteristic is reached is used as the exposure quantity to be used thereafter. Save as the value of. The printer 30 determines the exposure value for each paper type, each CMYK color, and each dot size.

  Then, the printer 30 transmits the exposure value determined for each paper type, each CMYK color, and each dot size, that is, exposure amount information R to the DFE 20 (S2). The printer 30 performs the transmission process in step S2 every time the engine adjustment process is executed.

  When the DFE 20 receives the exposure amount information R from the printer 30, the DFE 20 updates the exposure amount information R in the HDD 203 with the received exposure amount information R (S3).

  FIG. 9 is a diagram illustrating an example of an image processing flow suitable for proof printing executed by the CPU 200 of the DFE 20. First, the CPU 200 (exposure amount information update instruction unit 27-1) acquires the latest exposure amount information R (see FIG. 3) transmitted from the printer 30 from the second communication control unit 22, and the exposure amount of the HDD 203. The storage controller 23 is instructed to update the information R (see FIG. 3) (S10).

  Subsequently, the CPU 200 (image determination unit 26) acquires image data for which a print instruction has been issued from the first communication control unit 21, and the image data is either proof image data P for normal printing (see FIG. 3) or a proof. It is determined whether the image data Q (see FIG. 3) (S11).

  In the following, processing in the case of proof printing will be described. First, the CPU 200 (resolution conversion unit 27-2) converts the proof image data Q to the output resolution of the printer 30 (S12).

  Subsequently, the CPU 200 (exposure amount reading instruction unit 27-3A) instructs the storage control unit 23 to acquire the latest exposure amount information R stored in the HDD 203 (S13).

  Subsequently, the CPU 200 (exposure amount ratio information generation unit 27-3B) normalizes the exposure amount information R acquired in step S13 (S14).

  Subsequently, the CPU 200 (dot size determining unit 27-4) compares the value indicated by each pixel position of the proof image data after resolution conversion with the conversion parameter indicated by the exposure amount information after normalization, and after the resolution conversion. The dot size at each pixel position of the proof image data is determined (S15).

  Then, the CPU 200 (print data transmission instruction unit 29) instructs the second communication control unit 22 to transmit the print data T (see FIG. 3) to the printer 30 (S16). The print data T is obtained by storing the image data generated by the image processing up to step S15 in the data portion and adding header information such as print settings.

  In the first embodiment, the second communication I / F 206 and the second communication control unit 22 mainly correspond to “reception means”. In addition, the exposure amount information update instruction unit 27-1, the storage control unit 23, and the HDD 203 mainly correspond to a “storage unit”. The first communication I / F 205, the first communication control unit 21, and the image determination unit 26 mainly correspond to “accepting means”. Also, the resolution conversion unit 27-2 mainly corresponds to “resolution conversion means”. In addition, the generation unit 27-3 mainly corresponds to a “generation unit”. The dot size determination unit 27-4 mainly corresponds to “dot size determination means”. Also, the print data transmission instruction unit 29, the second communication control unit 22, and the second communication I / F 206 mainly correspond to “transmission means”. The image determination unit 26 mainly corresponds to “determination means”. The normal image processing unit 28 mainly corresponds to “normal image processing means”.

  In the first embodiment, the system configuration in which the exposure information R transmitted by the printer 30 every time the engine is adjusted is received on the DFE 20 side. However, when the DFE 20 performs the image processing of the proof image data Q. In addition, the system configuration may be modified such that the latest exposure amount information is acquired from the printer 30.

(Second Embodiment)
FIG. 10 is a diagram illustrating an example of an overall configuration of an image generation system including an image forming apparatus according to the second embodiment. The image generation system 2 illustrated in FIG. 10 includes a computer 10 and an MFP (Multi Function Peripheral) 40 as an “image forming apparatus”. In the present embodiment, it is assumed that the computer 10 and the MFP 40 are connected via a network such as a LAN (Local Area Network) or a VPN (Virtual Private Network). The computer 10 is the same as that shown in the first embodiment, except that it communicates with the MFP 40 via a network. Accordingly, the configuration of the MFP 40 will be described in detail below.

  The MFP 40 is an MFP equipped with the function of the DFE 20 (see FIG. 3) shown in the first embodiment.

  FIG. 11 is a diagram illustrating an example of hardware blocks of the MFP 40. The MFP 40 shown in FIG. 11 includes a CPU 400, an ASIC (Application Specific Integrated Circuit) 401, a system memory 402 including a ROM 402a and a RAM 402b, an interface 403 including an SD memory card slot 403a, a USB interface 403b, and a network interface 403c. An auxiliary storage device 404, a touch display 405, an engine 406, and a scanner 407 are included.

  The CPU 400 performs various processes in cooperation with various control programs stored in advance in the ROM 402a or the auxiliary storage device 404 using the predetermined area of the RAM 402b as a work area, and controls the overall operation of the MFP 40.

  The ASIC 401 is an image processing application IC (Integrated Circuit) having hardware elements for image processing, and has a function as a bridge for connecting each part to the CPU 400.

  The ROM 402a is a read-only memory that stores fixed programs and fixed data. The RAM 402b is a volatile memory that is freely writable and readable, used for developing programs and data, drawing for a printer, and the like.

  The interface 403 is an interface that detachably connects the own apparatus and an external device. An SD memory card slot 403a shown as an example in FIG. 11 is detachably connected to an SD (registered trademark) memory card as an external storage device. The USB interface 403b removably connects a USB flash memory as an external storage device.

  The interface 403 includes an interface for connecting the own apparatus to the network. A network interface 403c shown in FIG. 4 is a network card or the like, and connects its own apparatus to the network.

  In this embodiment, an SD memory card, a USB flash memory, or the like is illustrated as an external storage device, but the external storage device is not limited to these.

  The auxiliary storage device 404 has a storage medium for magnetically, electrically, or optically writing and reading. For example, an HDD or the like has a magnetic recording medium. The auxiliary storage device 404 stores rewritable setting information such as programs relating to various controls of the MFP 40 (including a program relating to image processing suitable for proof printing) and device capability information. The auxiliary storage device 404 stores image data input by the scanner 407, image data input via the interface 403, and the like.

  The touch display 405 is an interface for the user to operate the MFP 40 in an interactive manner, and includes a display device such as a liquid crystal and an input device having a touch panel, a key switch group, and the like. The touch display 405 displays the operation and settings of the MFP 40, the operation method, and the like on the display device screen under the control of the CPU 400. Further, when the touch display display 405 detects an input by the user via the touch panel or the key switch group, the touch display display 405 outputs the input information to the CPU 400.

  The engine 406 is a printer engine, such as a monochrome plotter, a one-drum color plotter, or a four-drum color plotter. The engine 406 includes an image processing portion of proof image data in addition to a so-called engine portion such as a plotter.

  The scanner 407 includes a line sensor including a CCD (Charge Coupled Device) photoelectric conversion element, an A / D converter that converts an analog read signal into a digital signal, and a drive circuit thereof.

  Next, a functional configuration of the MFP 40 will be described. The MFP 40 exhibits various functions when the CPU 400 loads various programs such as the ROM 402a and the auxiliary storage device 404 to the RAM 402b and executes them.

  FIG. 12 is a functional block diagram illustrating an example of main functions of the MFP 40. 12 includes a communication control unit 41, a storage control unit 42, an operation reception unit 43, a display control unit 44, an engine adjustment unit 45, an image determination unit 46, and the like as functional units related to image processing. A proof image processing unit 47, a normal image processing unit 48, a print execution unit 49, and the like.

  The communication control unit 41 communicates with the computer 10 via the network interface 223c and accepts various image data transmitted from the computer 10.

  The storage control unit 42 accesses the ROM 402a, the RAM 402b, the auxiliary storage device 404, and the like, and instructs writing and reading of programs and data according to the access area.

  The operation accepting unit 43 accepts an operation signal (key signal or the like) from the touch panel of the touch display display 405 or a key switch group.

  The display control unit 44 controls display on the display device of the touch display display 405.

  The engine adjustment unit 45 adjusts the exposure amount related to the image formation of the engine 406 to the target density characteristic while adjusting it to the optimum solution at each moment, and the exposure amount when the target density characteristic is reached is adjusted most recently. The value is stored in the auxiliary storage device 404 as an amount value.

  The image determination unit 46 determines whether the image data received by the communication control unit 41 is image data P for normal printing or proof image data Q for proof printing.

  The proof image processing unit 47 includes a resolution conversion unit 47-1, a generation unit 47-2, and a dot size determination unit 47-3. The resolution converter 47-1 converts the proof image data Q into the output resolution of the present apparatus.

  The generation unit 47-2 normalizes the exposure amount information R updated by the most recently adjusted exposure amount value in the auxiliary storage device 404. Note that the normalization method is the same as that in the first embodiment, and a description thereof will be omitted.

  The dot size determination unit 47-3 determines the dot size at each pixel position of the proof image data after resolution conversion. Note that the method for determining the dot size is the same as that in the first embodiment, and a description thereof will be omitted.

  The normal image processing unit 48 corresponds to the normal image processing unit 28 (see FIG. 3), and performs existing image processing on the image data P received by the communication control unit 41. The further description will be repeated from the description of the first embodiment, and will be omitted.

  The print execution unit 49 controls the engine 406 to print the print data T.

  FIG. 13 is a diagram illustrating an example of an image processing flow suitable for proof printing executed by the CPU 400 of the MFP 40. First, the CPU 400 (engine adjustment unit 45) executes engine adjustment processing at a predetermined timing, and the storage control unit 42 updates the exposure amount information R of the auxiliary storage device 404 with the latest exposure amount information R obtained by the execution. (S20).

  The subsequent processing from step S21 to step S25 corresponds to the processing from step S11 (see FIG. 9) to step S15 (see FIG. 9) in the DFE 20 shown in the first embodiment. To do.

  Subsequent to step S25, the CPU 400 (print execution unit 49) controls the engine 406 to execute printing of the print data T (S26).

  In the second embodiment, the engine adjustment unit 45 mainly corresponds to “adjustment means”. The print execution unit 49 and the engine 406 mainly correspond to “image forming unit”.

  A part or all of the functional units shown in each embodiment may be configured by hardware such as ASIC.

  In each embodiment, since the resolution conversion from 2400 dpi to 1200 dpi is taken as an example, the processing unit (unit pixel area) of the conversion source of the resolution conversion is set to 4 pixels, but this processing unit is the resolution of the proof image data. You may change suitably according to the output resolution of a printer or MFP.

  In addition, as an example, the color depth of a printer or MFP is set to 2 bits, and three types of dot sizes of 1/3 dot, 2/3 dot, and 3/3 dot are shown. It may be increased or decreased as appropriate according to the color depth of the MFP.

  As described above, in each embodiment and each modification, the dot size of each halftone dot of the proof image data can be adjusted based on the setting of the exposure amount adjusted according to the output environment and the variation with time. For this reason, the exposure setting adjusted according to the output environment and changes over time is reflected, and the effect of obtaining a proof printed matter with high reproducibility such as color tone and stability of image quality in the highlight area can be obtained. Play.

  Further, by using exposure amount information corresponding to the paper type, it is possible to cope with different fixing conditions depending on the output paper type on the printer or MFP side.

  Further, by replacing the pixel occupation ratio with a numerical value instead of a pixel value at the time of resolution conversion, it becomes possible to apply a conversion parameter to proof image data of an arbitrary resolution.

  The program executed in each embodiment and each modified example is provided in advance in a memory unit such as a ROM or HDD, but is not limited to this. The program executed in each embodiment and each modification may be recorded on a computer-readable recording medium such as DFE or MFP and provided as a computer program product. For example, a file in an installable format or an executable format may be provided by being recorded on a recording medium such as a flexible disk, a CD-R, a DVD (Digital Versatile Disk), a Blu-ray Disc (registered trademark), or a semiconductor memory. Good.

  Further, the program executed in each embodiment and each modification may be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network. The program executed in each embodiment and each modification may be configured to be provided or distributed via a network such as the Internet.

20 DFE
DESCRIPTION OF SYMBOLS 21 1st communication control part 22 2nd communication control part 23 Memory | storage control part 24 Operation reception part 25 Display control part 26 Image determination part 27 Image processing part for proof 27-1 Exposure amount information update instruction | indication part 27-2 Resolution conversion Unit 27-3 generation unit 27-3A exposure amount information read instruction unit 27-3B exposure amount ratio information generation unit 27-4 dot size determination unit 28 normal image processing unit 28-1 color conversion processing unit 28-2 total amount regulation unit 28 -3 Gamma conversion unit 28-4 Halftone processing unit 29 Print data transmission instruction unit P Image data Q Proof image data R Exposure amount information T Print data

JP 2006-030277 A

Claims (10)

Receiving means for receiving exposure amount information indicating a relationship between the exposure amount and the dot size from the image forming apparatus;
Storage means for storing the exposure amount information received by the receiving means;
Receiving means for receiving proof image data;
Resolution converting means for converting the proof image data received by the receiving means into an output resolution of the image forming apparatus;
Generating means for generating a comparison parameter of an exposure amount to be compared with a value of each pixel position after conversion to the output resolution by normalizing the exposure amount of the exposure amount information stored in the storage unit;
Dot size determining means for determining a dot size corresponding to the value of each pixel position by comparison with the comparison parameter;
Transmitting means for transmitting output data including pixel information of the dot size determined by the dot size determining means to the image forming apparatus;
An image processing apparatus comprising: The receiving unit receives information indicating the updated exposure amount from the image forming apparatus as the exposure amount information every time the exposure amount is updated in the image forming apparatus.
The image processing apparatus according to claim 1. The receiving means receives exposure amount information of each color of toner,
The storage means stores exposure amount information of each color of the toner received by the receiving means,
The accepting means accepts proof image data for each process color as the proof image data,
The generating unit normalizes the exposure amount of the exposure amount information stored in the storage unit for each process color, and compares the exposure amount with the value of each pixel position after conversion to the output resolution. Are generated for each process color,
The dot size determining means determines a dot size corresponding to the value of each pixel position by comparison with a comparison parameter corresponding to a process color of proof image data received by the receiving means among the comparison parameters.
The image processing apparatus according to claim 1. The receiving means receives exposure amount information of each type of paper,
The storage means stores exposure amount information of each type of the paper received by the receiving means,
The receiving unit receives the proof image data and information indicating a type of output paper;
The generation unit compares the exposure amount of the exposure amount information stored in the storage unit with the value of each pixel position after conversion to the output resolution by normalizing the exposure amount for each type of the output paper. Generate exposure comparison parameters for each type of output paper,
The dot size determining unit determines a dot size corresponding to the value of each pixel position by comparison with a comparison parameter corresponding to information indicating the type of output paper received by the receiving unit among the comparison parameters. ,
The image processing apparatus according to claim 1. The resolution conversion unit associates, as the value of each pixel position after the conversion, a pixel occupation ratio representing a ratio of the number of pixels in which the pixel value occupies 1 with respect to the total number of pixels in the unit pixel area of the conversion source,
In the normalization, the generation means multiplies the value of the exposure amount of each dot size by a value that makes the value of the exposure amount of the maximum dot size of the exposure amount information the upper limit value of the pixel occupation ratio.
The image processing apparatus according to claim 1. The dot size determination means uses the information indicating the ratio of the dot sizes obtained by the multiplication as the comparison parameter to determine the dot size corresponding to the value of each pixel position based on the information indicating the ratio of the dot sizes. decide,
The image processing apparatus according to claim 5. Furthermore,
The accepting unit includes a determining unit that determines whether the image data is normal image data or proof image data.
Normal image processing means for performing image processing on normal image data when the receiving means determines that the image data is normal image data;
The transmission unit transmits the image data image-processed by the normal image processing unit to the image forming apparatus;
The image processing apparatus according to claim 1. Adjusting means for adjusting the exposure amount of the apparatus;
Storage means for storing exposure amount information indicating a relationship between the exposure amount and the dot size most recently adjusted by the adjustment unit;
Receiving means for receiving proof image data;
Resolution conversion means for converting the proof image data received by the reception means into the output resolution of the device itself;
Generating means for generating a comparison parameter of an exposure amount to be compared with a value of each pixel position after conversion to the output resolution by normalizing the exposure amount of the exposure amount information stored in the storage unit;
Dot size determining means for determining a dot size corresponding to the value of each pixel position by comparison with the comparison parameter;
Image forming means for forming an image of the dot size determined by the dot size determining means;
An image forming apparatus comprising: A computer of an image processing apparatus having a storage unit,
Receiving means for receiving exposure amount information indicating a relationship between the exposure amount and the dot size from the image forming apparatus;
Storage means for storing the exposure amount information received by the receiving means in the storage unit;
Receiving means for receiving proof image data;
Resolution converting means for converting the proof image data received by the receiving means into an output resolution of the image forming apparatus;
Generating means for generating a comparison parameter of an exposure amount to be compared with a value of each pixel position after conversion to the output resolution by normalizing the exposure amount of the exposure amount information stored in the storage unit;
Dot size determining means for determining a dot size corresponding to the value of each pixel position by comparison with the comparison parameter;
Transmitting means for transmitting output data including pixel information of the dot size determined by the dot size determining means to the image forming apparatus;
Program to make it function. A computer of an image forming apparatus having a function of adjusting an exposure amount and storing exposure amount information indicating a relationship between a recently adjusted exposure amount and a dot size in a storage unit;
Receiving means for receiving proof image data;
Resolution conversion means for converting the proof image data received by the reception means into the output resolution of the device itself;
Generating means for generating a comparison parameter of an exposure amount to be compared with a value of each pixel position after conversion to the output resolution by normalizing the exposure amount of the exposure amount information stored in the storage unit;
Dot size determining means for determining a dot size corresponding to the value of each pixel position by comparison with the comparison parameter;
Image formation instruction means for instructing the formation of an image of the dot size determined by the dot size determination means;
Program to make it function.

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