JP2000251064A - Image formation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image formation system capable of obtaining a high- definition image at all the time by compensating the fluctuation of characteristic information caused by an environmental change. SOLUTION: Concerning the image formation system for forming an image on the basis of inputted images or image data, this system is provided with an image input part 1 for input processing for images or image data, an image output part 3 for outputting an image, a characteristic information recognizing part 4 for recognizing the characteristic information of any one of or both of the image input part 1 and the image output part 3, a correction information generating part 5 for generating characteristic information corrected to be characteristic information defined as a predetermined target from the recognized result of the characteristic information recognizing part 4 and an image processing part 2 for performing image processing on the basis of the corrected characteristic information and the characteristic information to be recognized by the characteristic information recognizing part 4 is characteristic information for which the component of fluctuation caused by the environmental change is compensated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus for performing image processing based on characteristic information of image input means or image output means. It relates to a forming system.

[0002]

2. Description of the Related Art An image forming system in which an original is read by an image input device, the read image data is subjected to image processing by an image processing device, and an image is output by an image output device based on the image processed image data is an entire system. There is a wide variety of forms, from the form in which the system components are housed in one device, to the form in which system components are individually arranged and connected to each other via a network.
The former is an image forming apparatus represented by a copying machine,
The latter is an image forming system to which various devices such as a scanner, a printer, a copying machine, and a personal computer are connected via a network. However, in either case, the quality of an image to be formed greatly changes due to a difference in characteristic information unique to the image input device or the image output device. In particular, in the latter example connected via a network, the characteristics of individual devices such as scanners and printers differ depending on the manufacturer and model.For example, in the case of a system that outputs an image read by a scanner to a printer, the scanner or If you replace the printer with another device,
An output image changes due to a change in device characteristics.
That is, every time the system configuration is changed, an image having a different image quality is obtained due to a difference in device characteristics, or an image with image quality deterioration is often obtained. For this purpose, an image processing apparatus that processes an image previously recognizes characteristic information specific to a scanner or printer to be connected and performs image processing suitable for the recognized characteristic information. Apparatus or image forming systems are becoming conceivable. For example, an image forming system described in JP-A-9-172543 in which appropriate correction characteristic information is set in accordance with the creation process and output mode of individual image data, and an optimum image is obtained by processing the image. Already in the world. Further, an image forming system that separates image data from an image input device for each image area and performs image processing for each separated image area to obtain an optimal image has already been put to practical use.

[0003]

However, even in an image forming system in which the characteristic information inherent in the input / output device of the scanner or the printer is taken into account, the characteristic information changes due to the fluctuation of the characteristic information due to the environmental change of the scanner or the printer. Therefore, even if the image processing is performed only once by incorporating the characteristic information of the scanner or the printer, a high-definition image output has not been obtained forever. Therefore, an object of the present invention is to provide an image forming system capable of always obtaining a high-definition image by compensating for a variation due to an environmental change of characteristic information of an image input device or an image output device. It is in.

[0004]

According to a first aspect of the present invention, there is provided an image processing apparatus, comprising: performing image quality processing on an input image or image data in accordance with image characteristics; In the image forming system, image input means for inputting an image or image data and transmitting it to a subsequent stage, image output means for outputting an image based on the input processed image data, and the image input means or the image output Characteristic information recognizing means for recognizing one or both of the characteristic information, and correction information for generating characteristic information corrected so as to become predetermined target characteristic information from the recognition result of the characteristic information recognizing means. Generating means for processing the image data output from the image input means based on the corrected characteristic information generated by the correction information generating means. And image processing means for transmitting image-processed image data to the image output means, wherein the characteristic information recognized by the characteristic information recognizing means is characteristic information compensated for a variation due to an environmental change. Things. According to a second aspect of the present invention, there is provided an image forming system which performs image quality processing on an input image or image data according to characteristics of the image and forms an image based on the processed image data. Image input means for transmitting to the subsequent stage, image output means for outputting an image based on the input processed image data, and characteristic information for recognizing characteristic information of one or both of the image input means and the image output means Recognizing means, correction information generating means for generating characteristic information corrected to become predetermined target characteristic information from the recognition result of the characteristic information recognizing means, and the correction information generated by the correction information generating means Image processing is performed on the image data output from the image input unit based on the characteristic information, and the image data that has been subjected to the image processing is output to the image output unit. Characteristic information recognized by the characteristic information recognizing means is present at each of a plurality of locations in the same page processed by the image input means or the image output means, and compensates for a variation due to an environmental change. It is characterized by the characteristic information obtained. According to a third aspect of the present invention, in the image forming system according to the first or second aspect, the characteristic information in which the variation due to the environmental change is compensated is compensated for the variation due to a temperature change or a lapse of time after the power is turned on. It is characterized by the characteristic information obtained. According to a fourth aspect of the present invention, in the image forming system according to any one of the first, second, and third aspects, the characteristic information recognized by the characteristic information recognizing means is γ characteristic information, spatial frequency characteristic. Information, color characteristic information, scanner RGB dot displacement characteristic information, or one or more characteristic information among resolution characteristic information.

[0005]

In the image forming system according to the first aspect of the present invention, when the characteristic information recognizing means recognizes the characteristic information of the image input means or the image output means, a change due to an environmental change is recognized. The compensated characteristic information is recognized, the characteristic information corrected by the correction information generating means so as to become the target characteristic information from the recognition result of the characteristic information recognizing means is generated, and the image is obtained by the characteristic information corrected by the image processing means. Since data is processed, image processing is performed based on characteristic information that takes into account environmental changes, and a stable and high-definition image can always be obtained. Also,
In the image forming system according to the second aspect, when the characteristic information recognizing means recognizes characteristic information corresponding to each of a plurality of locations on the same page of the image input means or the image output means, the variation due to each environmental change. The characteristic information compensated for the characteristic information is recognized, the characteristic information corrected by the correction information generating means so as to become the target characteristic information from the recognition result of the characteristic information recognizing means is generated, and the characteristic information corrected by the image processing means is used. Because image data is processed, image processing is performed based on characteristic information that takes into account environmental changes at multiple locations on the same page, and high-definition images with stability that does not change for each location on the same page Can be obtained. According to a third aspect of the present invention, in addition to the configuration of the image forming system according to the first or second aspect, image processing is performed based on characteristic information in which a variation due to an ambient temperature or a lapse of time after power-on is compensated. Is performed, so
Optimal image processing that compensates for a factor that causes a large variation can always be performed. According to a fourth aspect of the present invention, in addition to the configuration of the image forming system according to the first, second, or third aspect, the characteristic information recognized by the characteristic information recognizing means includes gamma characteristic information, spatial frequency Characteristic information, color characteristic information,
Since one or more pieces of the scanner RGB dot position shift characteristic information or the resolution characteristic information are used, a high-definition image can be always obtained even in black and white and color image processing.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows a configuration example of an image forming system in which various devices are connected on a network 40. This is a form in which each person can connect his / her personal computer to the network 40 and commonly use the database and the input / output device, and it is expected that the personal computer will be used in various fields in the future. In this example, an MF (multifunction) copier 41, scanners 42 and 44, a laptop computer 43, a personal computer 4
5, a laser printer 46, 47, and a modem 48 connected to a fax 49 at a remote value via a public line are connected to the network 40. Here, the scanner 4
The laser printers 2 and 44 have characteristic information unique to an input device called a scanner profile to be described later, and the laser printers 46 and 47 have characteristic information unique to an output device also called a printer profile to be described later. . Further, the MF copier 41 and the facsimile 49 are configured to have a scanner profile and a printer profile. Here, for example, it is assumed that a document is read by the scanner 42, the image data output from the scanner 42 is taken into the personal computer 45, subjected to image processing, and output from the laser printer 47. The data and the scanner profile are fetched, and the printer profile is also fetched from the laser printer 47 at the same time. Further, the personal computer 45 processes the image data captured from the scanner 42 on the basis of the information captured from the scanner profile and the printer profile, and performs processing on the laser printer 47 based on the processed image data.
To output the image. With this configuration, even if there is a difference in the characteristic information between the scanners 42 and 44 and the characteristic information between the laser printers 46 and 47, the selected image input device (scanner 42 or 44) and image output Processing is performed in consideration of individual characteristic information between the devices (laser printers 46 and 47), and a high-quality image suitable for the system can be obtained.

FIG. 2 is a block diagram showing an overall configuration of an image forming system that performs an optimization process in consideration of characteristic information of an image input / output device. The whole is composed of an image input device 31, an image processing device 32 and an image output device 33. Further, the above devices may be included in one device as an image forming device, or as shown in FIG. 1, an image forming system including devices that are separately connected on a network. It does not matter. However, in the image forming system of FIG. 1, signal transmission from the image input device 31 to the image processing device 32, from the image processing device 32 to the image output device 33, or from the image output device 33 to the image processing device 32 is performed directly between the devices. rather than,
This is performed via a cable of the network 40. The image input device 31 reads an original image by the image input device 31 such as a scanner, performs input processing such as shading correction and gamma correction, and sends the input image data to the next image processing device 32 as image data. In the case of image data input, the image input unit 1 performs input processing such as noise removal and waveform shaping, and sends the same to the next-stage image processing device 32 as image data. The image input unit 1 includes at least an image input unit 1 serving as an image input unit for inputting an image or image data and transmitting it to a subsequent stage, and a scanner profile 21 serving as unique characteristic information of the image input unit 1. The image output device 33 also has an image output unit 3 that outputs an image based on the image data received from the image processing device 32, and a printer profile 22 that is unique characteristic information of the image output unit 3. And Further, the image processing device 32 receives image data from the image input unit 1 and performs various types of image processing so that the image output unit 3 can perform optimal printing. An optimization control unit 9 for optimizing image processing by taking in characteristic information of one or both of the profile 21 and the printer profile 22. Accordingly, as an overall processing operation, the image input unit 1 receives an image or image data, prepares the image or image data in the next stage, and transfers it to the image processing unit 2. Further, the optimization control unit 9 of the image processing device 32 inputs the scanner profile 21 and the printer profile 22, which are characteristic information specific to the image input unit 1 and the image output unit 3, and obtains the characteristic information of both profiles or one of them. Based on the characteristic information of the profile, a processing condition capable of performing an optimum process is calculated and given to the image processing unit 2. The image processing unit 2 performs image processing based on the optimum processing conditions given from the optimization control unit 9, and transmits the processed image data to the image output unit 3. The image output unit 3 outputs an image based on the image data from the image processing unit 2 to a recording medium.

FIG. 3 is a block diagram showing a main part of the image forming system according to the present invention. In the figure,
The optimization control unit 9 of the image processing device 32 includes a characteristic information recognizing unit 4 that is a characteristic information recognizing unit that recognizes characteristic information of the scanner profile 21 and the printer profile 22, and the characteristic information recognized by the characteristic information recognizing unit 4. And a correction information generating unit 5 that is a correction information generating unit that generates processing conditions that allow the image processing unit 2 to perform optimal processing. Further, the image processing device 32 has an environment change correction unit 6 so that the characteristic information recognized by the characteristic information recognition unit 4 becomes the characteristic information in which the variation due to the environmental change is compensated. The environment change correction unit 6 determines the temperature of a predetermined place of the image processing apparatus 32 or the lapse of time after power-on, and determines how much variation should be compensated for the reference characteristic information value. It is calculated from an arithmetic expression or a setting table given in advance and notified to the characteristic information recognizing unit 4. The characteristic information recognizing unit 4 includes a scanner profile 2
1 or the characteristic information value of the printer profile 22 and the compensation value of the characteristic information notified from the environment change correction unit 6 so as to know the value of the characteristic information in which the variation due to the environmental change is compensated. I have. Here, the whole operation will be briefly described. An image or image data is received by the image input unit 1, arranged into image data which is easy to process, and passed to the image processing unit 2 at the next stage. Further, the characteristic information recognition unit 4 captures a scanner profile 21 or a printer profile 22 which is characteristic information of the input / output device. Next, the correction information generation unit 5 holds target characteristic information 23 for optimally processing the entire system, and always considers the entire system as the target characteristic information while considering the characteristic information of the input / output device. 23. That is, based on the result of recognition of the scanner profile 21 and the printer profile 22 by the characteristic information recognizing unit 4, characteristic information (hereinafter referred to as corrected characteristic information) corrected to become the target characteristic information 23 is generated, and Notify processing unit 2. Therefore,
The image processing unit 2 processes the image data with the correction characteristic information received from the correction information generation unit 5, so that the target characteristic information 23 can be held throughout the entire system.

Here, it has been described that the target characteristic information 23 is held in the correction information generating unit 5, but it is not necessarily required that the target characteristic information 23 be present in the correction information generating unit 5;
2 may be set anywhere. Furthermore, it may be outside the image processing device 32. In the example of FIG. 3, the environment change correction unit 6 is provided in the image processing device 32. However, the environment change correction unit 6 is provided in the characteristic information recognition unit 4 of the optimization control unit 9, and the characteristics of the scanner profile 21 and the printer profile 22 are stored. When recognizing information, a change due to an environmental change may be compensated. The environment change correction unit 6 is provided in the image input device 31 or the image output device 33, and the characteristic information recognizing unit 4 always stores the characteristic information value of the scanner profile 21 or the printer profile 22 that compensates for the fluctuation due to the environmental change. It is also possible to adopt a configuration that aims to give. As described above, the image processing unit 2 performs image processing using the correction characteristic information generated by the correction information generation unit 5 and transmits the processed image data to the image output unit 3. Further, the image output unit 3 outputs an image based on the received image data to a storage medium. With such a configuration, even if the characteristic information processed by the image input device 31 or the image output device 33 is different due to an environmental change, the image processing unit 2 can operate until the environmental change of the image input device 31 or the image output device 33. Image processing can be performed based on the considered characteristic information.

FIG. 4 is a block diagram showing the image processing unit 2 in FIG. 3 in detail in the image forming system of the present invention. Here, the image processing unit 2 is roughly divided into a filter processing unit 11, a density conversion processing unit 12, a γ (gamma) conversion processing unit 13, a color conversion processing unit 14, a halftone processing unit 15, and an image area separation unit 16. And so on. First, the image input unit 1 of the image input device 31 inputs image data or an image drawn on a document,
The image data is output in the form of image data that can be easily processed by the image processing unit 2 at the next stage. Further, the image input device 31 has a scanner profile 2 indicating characteristic information unique to the image input processing.
The information is transmitted to the characteristic information recognition unit 4 of the optimization control unit 9 together with the compensation value information for compensating the variation due to the environmental change from the environment change correction unit 6 described above. . Further, the image output device 33 combines the printer profile 22 indicating the characteristic information unique to the image output processing of the image output unit 3 with the compensation value information for compensating the variation due to the environmental change from the environment change correction unit 6. To the characteristic information recognition unit 4. Further, the image data from the image input unit 1 is input to the filter processing unit 11 and the image area separation unit 16 of the image processing unit 2. In the image area separation unit 16, using the input image data, the image attribute of the input image is a character or line drawing area having an edge part, or a picture area such as a photograph having a halftone part or a continuous tone part. Is determined. Each of the filter processing unit 11, the density conversion processing unit 12, the γ (gamma) conversion processing unit 13, the color conversion processing unit 14, the halftone processing unit 15, etc. Different processing is performed by the processing unit.

Further, in the filter processing unit 11, the MTF (Modulation Transfer Fun
ction) The processing of converting the spatial frequency of the image is performed by correcting the characteristics or performing filter processing to reduce the moire generated in the halftone print original. Further, the density conversion processing unit 12 performs resolution conversion processing when there is a difference between the input resolution and the output resolution, or when the input image requires enlargement or reduction magnification processing. Further, the γ conversion processing unit 13 performs a conversion process of the gradation characteristics of the image data so as to obtain a desired gradation characteristic. In the case of a color image, the color conversion processing unit 14 converts an RGB input image from a scanner into CMYK data which is a reproduction color of a printer. Further, the halftone processing unit 15 performs processing such as systematic dither processing and error diffusion processing according to the output characteristics of the printer. The optimization control unit 9
Controls the image processing unit 2 so that optimal image processing can be performed based on the recognition result of the characteristic information recognition unit 4. That is, the characteristic information recognizing unit 4 includes the information of the scanner profile 21 and the printer profile 22 and the correction information generating unit 5
From the received correction characteristic information, the characteristic information of the input / output device in which the variation has been corrected is obtained and transmitted to the correction information generation unit 5. The correction information generating unit 5 generates correction characteristic information based on the characteristic information received from the characteristic information recognizing unit 4 so as to become the target characteristic information 23, and transmits the generated correction characteristic information to the image processing unit 2. The image processing unit 2 processes the image data based on the correction characteristic information received from the correction information generating unit 5 and transmits the processed image data to the image output unit 3. The image output unit 3 outputs the image data on a medium based on the image data received from the image processing unit 2.

FIGS. 5 and 6 show information of the scanner profile 21 and the printer profile 22 for explaining the optimization processing in the optimization control unit 9. FIG. FIGS. 5A, 5B, and 5C are diagrams showing spatial frequency characteristics. FIG. 5A shows an example of input MTF characteristic information of a scanner which is a typical example of the image input apparatus 31.
4B is an example showing output MTF characteristic information of a printer which is a representative example of the image output device 33. These pieces of property information are recognized by the property information recognition unit 4. For example, when an original is read by a scanner having input MTF characteristic information as shown in FIG. 5A and output to a printer having output MTF characteristic information as shown in FIG. The information is obtained by multiplying the MTF characteristics shown in FIGS. 5A and 5B. Accordingly, the MTF characteristics of the obtained output image are considerably degraded in frequency characteristics. Therefore, for example, the MTF characteristic of the output image can be obtained without deterioration of the original as shown in FIG.
The F characteristic is stored in advance in the correction information generating unit 5 as a target (target) MTF characteristic. That is,
The scanner profile 21 described above describes input MTF characteristic information of the scanner as shown in FIG.
The printer profile 22 describes output MTF characteristic information of the printer as shown in FIG. Therefore,
The characteristic information recognizing unit 4 of the optimization control unit 9 obtains a characteristic obtained by multiplying the MTF characteristic. Further, the correction information generating unit 5 obtains what kind of filter coefficient processing is required to make the target MTF characteristic from the MTF characteristic obtained from the characteristic information recognizing unit 4, and notifies the image processing unit 2.
The filter processing unit 11 of the image processing unit 2 performs the filter processing using the filter coefficient characteristics given from the correction information generation unit 5, so that the entire system from the input to the output is processed by the target MTF characteristics. Be effective.

FIGS. 6A, 6B, 6C, and 6D show γ.
This is an example for optimizing the characteristics. FIG.
(A) shows the γ characteristic information of the scanner fetched from the scanner profile 21. The horizontal axis is the reading density of the original, and the vertical axis is the output gradation level from the scanner. FIG. 6B shows the γ characteristic information of the printer taken from the printer profile 22, which is indicated by the paper print density with respect to the gradation level input to the printer. Further, FIG. 6C shows the γ characteristic information of the target (target) in the whole system as in the optimization example of the spatial frequency characteristic, and is indicated by the γ characteristic information to be the target of the output with respect to the input. ing. Therefore, based on the γ characteristic information obtained by multiplying FIG. 5 (A) and FIG. 5 (B) from the characteristic information recognizing unit 4, the correction information generating unit 5 becomes such that the entire system becomes as shown in FIG. 5 (C). 5 (D) is generated. Further, the γ conversion processing section 13 of the image quality processing section 2 performs image processing with γ correction characteristics as shown in FIG. Although the description of the other processing units is omitted, the density conversion processing unit 12, the color conversion processing unit 14, or the halftone processing unit 15
A similar correction process is performed as necessary.

In the description of the characteristic information in FIGS. 5 and 6, it has been assumed that the characteristic information of the input / output device does not change due to an environmental change. However, most of the actual characteristic information of the input / output device changes due to environmental changes due to the temperature of the device or the lapse of time after the power is turned on. FIG. 7 shows the relationship between the lapse of time after the power of the scanner is turned on and the MTF characteristic of the scanner at 0.5 times the Nyquist frequency. The relationship between the time elapsed since the power of the scanner was turned on and the variation in the MTF characteristic of the scanner is measured in advance and stored in the environment change correction unit 6. Further, the environment change correction unit 6 constantly measures the time elapsed after the power is turned on and the temperature of a predetermined place of the apparatus, and recognizes the data of the fluctuation of the characteristic information value from the characteristic information upon request. It can be transmitted to the section 4. Therefore, for example, when a document is read 30 minutes after the power is turned on, the MTF characteristic value of the scanner at 0.5 times the Nyquist frequency described in the scanner profile 21 is 36.6% from FIG.

Table 1 shows how the MTF changes (%) with the passage of time with respect to the reading frequency (lines / mm) of the scanner. The scanning frequency (read / mm) of the scanner is 1 read / mm, 2 read / mm
mm, 3 wires / mm, 4 wires / mm, 5 wires / mm, 6 wires / m
m, and the elapsed time is 10 minutes, 30 minutes, 50 minutes,
They are represented at intervals of 70 minutes, 90 minutes and 20 minutes. In addition, a reading frequency of zero (0 lines /
mm) is set to 100 (%). Here, the variation when the scanner is read 20 minutes after the power is turned on can be obtained as shown in Table 2 by taking an intermediate value between 10 minutes and 30 minutes from this table.

[Table 1]

[Table 2]

In the above description of the characteristic information in FIGS. 5 and 6, it is assumed that the characteristic information of the input / output device does not change depending on the processing location. However, in an actual input / output device, the characteristic information changes depending on the processing location. For example, one of the causes is that the light amount of the light source and the characteristics of the photoelectric conversion elements in the scanner differ depending on the processing location, and the temperature temporarily decreases when cold paper is inserted into the reading unit. I have. Further, it has been observed that in a general printer without a seam, there is a difference in the γ characteristic which is always determined above and below the paper. For example, FIG. 8A shows the MT of the scanner.
This is an example in which the F characteristic is divided for each place in the same page. At a certain frequency, the MTF characteristic values registered in the scanner profile 21 are A = 0.4, B = 0.5, C =
0.4, D = 0.45, E = 0.5, F = 0.35. FIG. 8B shows an example in which the MTF characteristics of the printer are divided for each place in the same page. At a certain frequency, the MTF registered in the printer profile 22 is displayed.
The characteristic values are a = 0.3, b = 0.35, and c = 0.35.

Here, the target characteristic information 23 is set to 0.5 as the MTF characteristic value at any frequency, and the region to which the target pixel to be processed belongs is the same as the region to which the target pixel in the pre-processing belongs. In this case, for example, A
Further, when the part a is processed and the part A and the part a are processed again, the same processing as the previous time is performed because the processing is not switched. Accordingly, since the MTF characteristic values of the scanner and the printer are A = 0.4 and a = 0.3, the correction information generating unit 5 sets the correction characteristic information value to the target characteristic information value of 0.5. Generated as 0.42. When the region to which the target pixel being processed belongs is different from the region to which the target pixel at the time of the preprocessing belongs, for example,
At the time of the preprocessing, the parts A and a are processed, and when the parts B and b are processed this time, the optimization processing according to the cases B and b is performed again. At this time, since the MTF characteristic values of the scanner and the printer are B = 0.5 and b = 0.35, the correction information generating unit 5 sets the correction characteristic information unit 5 to the target characteristic information value of 0.5. Generate the value as 0.29. Further, the image processing unit 2 outputs the MTF correction characteristic information generated by the correction information generation unit 5, that is, the MTF correction characteristic information of the MTF correction information.
42. In the latter case, if MTF processing is performed with 0.29,
The target MTF characteristic information value 0.5 is obtained. According to the characteristic information of each place to be processed as described above, the MTF with respect to the lapse of time after the power is turned on as shown in FIG.
An image input device 31 is prepared by preparing in advance a variation of the MTF characteristic value with respect to a characteristic variation or a temperature change (not shown), and compensating the MTF characteristic information value by the variation according to the temperature change or the lapse of time after power-on. And fine-grained correction corresponding to the characteristic information for each location to be processed by the image output device 33. Further, in the above example, the compensation for the variation of the MTF characteristic information of the image input device has been described. However, the variation of the MTF characteristic information of the image output device, the γ characteristic information of the image input output device, the spatial frequency characteristic information, The variation of one or more of the color characteristic information, the scanner RGB dot position deviation characteristic information, or the resolution characteristic information may be compensated. Claim 3
In the above, the variation of the characteristic information due to the environmental change is based on the lapse of time after the temperature or the power is turned on. However, the variation of the characteristic information due to the number of times of use or the humidity change may be compensated.

[0018]

As described above, according to the first aspect of the present invention, the characteristic corrected by the correction information generating means so as to become the target characteristic information from the recognition result of the characteristic information compensated for the variation due to the environmental change. Since the information is generated and the image data is processed with the corrected characteristic information, the image processing is performed based on the characteristic information in consideration of the environmental change.
An image forming system that can always obtain a stable and high-definition image can be provided. According to the second aspect of the present invention, the correction information generating means converts the characteristic information obtained by compensating for the variation due to the environmental change at each of a plurality of locations in the same page into the target characteristic information so that the target characteristic information is obtained. Since a plurality of corrected characteristic information is generated and the image data is processed for each location using the plurality of corrected characteristic information for each location, the characteristic information taking into account environmental changes at a plurality of locations within the same page And an image forming system capable of obtaining a high-definition image with stability that does not change at each location on the same page. According to the third aspect of the present invention, in the image forming system according to the first or second aspect, image processing can be performed based on characteristic information in which a variation due to an ambient temperature or a lapse of time after power-on is compensated. Therefore, it is possible to perform optimal image processing that compensates for a factor that causes a large variation. According to the fourth aspect of the invention, in the image forming system according to the first, second, or third aspect, a high-definition image can be obtained even in monochrome and color image processing.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating an example of an image forming system in which an image input device, an image processing device, and an image output device are connected on a network.

FIG. 2 is a block diagram illustrating a main part of an image forming system that performs an optimization process.

FIG. 3 is a block diagram showing a main part of the image forming system of the present invention.

FIG. 4 is a block diagram showing an image processing unit of the image forming system in FIG. 3 in more detail;

5A is an explanatory diagram illustrating MTF characteristic information of an image input device, FIG. 5B is an explanatory diagram illustrating MTF characteristic information of an image output device, and FIG. 5C is a diagram illustrating target MTF characteristic information. FIG.

6A is an explanatory diagram illustrating γ characteristic information of an image input device, FIG. 6B is an explanatory diagram illustrating γ characteristic information of an image output device, and FIG. 6C is an example of target γ characteristic information; FIG. 3D is an explanatory diagram illustrating γ correction characteristic information for processing image data.

FIG. 7 is an explanatory diagram showing a relationship between a lapse of time after power-on of the scanner and an MTF characteristic of the scanner at 0.5 times the Nyquist frequency.

FIG. 8A is an explanatory diagram showing an example of characteristic information existing at a plurality of locations in the same page, and FIG. 8B is another example of characteristic information existing at a plurality of locations in the same page. FIG.

[Explanation of symbols]

 Reference Signs List 1 image input unit (image input unit) 2 image processing unit (image processing unit) 3 image output unit (image output unit) 4 characteristic information recognition unit (characteristic information recognition unit) 5 correction information generation unit (correction information generation unit) 6 Environment change correction unit 9 Optimization control unit 11 Filter processing unit 12 Density conversion processing unit 13 γ conversion processing unit 14 Color conversion processing unit 15 Halftone processing unit 16 Image area separation unit 21 Scanner profile 22 Printer profile 23 Target characteristic information 31 Image input device 32 Image processing device 33 Image output device

Continued on the front page F term (reference) 5B057 BA02 BA11 CA01 CA08 CA16 CB01 CB08 CB16 CD05 CE01 CE06 CE11 CE16 CH18 5C077 PP01 PP05 PP31 PP43 TT02

Claims (4)

[Claims] 1. An image forming system that performs image quality processing on an input image or image data in accordance with characteristics of the image and forms an image based on the processed image data, and transmits the image or image data to a subsequent stage. An image input unit, an image output unit that outputs an image based on the input processed image data, a characteristic information recognition unit that recognizes characteristic information of one or both of the image input unit and the image output unit, Correction information generating means for generating characteristic information corrected to become predetermined target characteristic information from the recognition result of the characteristic information recognition means,
Image processing means for performing image processing on image data output from the image input means based on the corrected characteristic information generated by the correction information generating means, and transmitting the image-processed image data to the image output means, An image forming system, wherein the characteristic information recognized by the characteristic information recognizing means is characteristic information in which a variation due to an environmental change is compensated. 2. An image forming system for performing image quality processing on an input image or image data in accordance with characteristics of the image and forming an image based on the processed image data, and transmitting the image or image data to a subsequent stage. An image input unit, an image output unit that outputs an image based on the input processed image data, a characteristic information recognition unit that recognizes characteristic information of one or both of the image input unit and the image output unit, Correction information generating means for generating characteristic information corrected to become predetermined target characteristic information from the recognition result of the characteristic information recognition means,
Image processing means for performing image processing on image data output from the image input means based on the corrected characteristic information generated by the correction information generating means, and transmitting the image-processed image data to the image output means, The characteristic information recognized by the characteristic information recognizing means is characteristic information which exists at each of a plurality of places in the same page processed by the image input means or the image output means, and compensates for a variation due to an environmental change. Image forming system. 3. The image forming system according to claim 1, wherein the characteristic information in which a variation due to an environmental change is compensated is characteristic information in which a variation due to a time change after a temperature change or power-on is compensated. An image forming system, characterized in that: 4. The image forming system according to claim 1, wherein the characteristic information recognized by the characteristic information recognizing means includes gamma characteristic information, spatial frequency characteristic information, and color characteristic information. An image forming system comprising: one or a plurality of pieces of scanner RGB dot position shift characteristic information or resolution characteristic information.