Patent Application
20120008171
This application is based upon and claims priority under 35 USC 119 from Japanese Patent Application No. 2010-157076, filed Jul. 9, 2010.
1. Technical Field
The present invention relates to an image processing apparatus, an image forming apparatus, and a computer readable medium.
2. Related Art
In the case where documents having high confidentiality such as documents for internal use only is to be printed, in order to suppress unauthorized copying and forgery of the documents, conventionally, a print process is performed on a dedicated sheet called ‘sakura gami’ or the like in which, when a copy process is performed on the sheet by a copier, characters or the like appear on the surface of the copied sheet.
A technique of printing a ground tint pattern is known in which, when a copier performs a copy process on a plain sheet, characters or the like appear on the surface of the copied sheet in a similar manner as the case of ‘sakura gami’. In the ground tint pattern printing technique, “hidden character portion” which appears as a result of a copy process is output in a low-density pattern, and “ground portion” which is formed as a white portion as a result of a copy process is output in a high-density pattern.
According to an aspect of the invention, an image processing apparatus includes a combining module that respectively combine a plurality of first patterns and a plurality of second patterns each corresponding to the first patterns. Respective densities of the first patterns are different from each other. At least one of the second patterns include a plurality of regions where respective coverages are different in a main scanning direction.
Exemplary embodiments of the invention will be described in detail based on the following figures, wherein:
Hereinafter, exemplary embodiments which are examples of the invention will be described in detail with reference to the accompanying drawings. In the drawings illustrating the exemplary embodiments, the identical components are denoted by the same reference numerals, and repeated description will be omitted.
An image processing apparatus of a first exemplary embodiment will be described.
The image processing apparatus produces a plurality of second patterns to be combined with a plurality of first patterns which are related to a ground tint pattern image, and the densities of which are different from each other, respectively, and performs a process of combining the plurality of second patterns with the first patterns corresponding to the second pattern. The image processing apparatus further performs a process of combining together the first patterns which are combined with the second patterns, a process of forming the plurality of first patterns into one pattern, i.e., a process of producing a ground tint pattern image.
For example, assuming that there are a high density pattern, a medium density pattern, and a low density pattern, the plurality of first patterns may be configured by three patterns which are the high density pattern, the medium density pattern, and the low density pattern, or two patterns which are the high density pattern and the low density pattern. These numbers of patterns are provided mere examples, and the numbers are not limited to them. The high density pattern may have large screen line number. The medium density pattern may have medium screen line number. The low density pattern may have small screen line number.
In the first exemplary embodiment, it is assumed that the plurality of first patterns are configured by two patterns of a pattern of a high density (hereinafter, referred to as “high-density pattern”), and a pattern of a low density (hereinafter, referred to as “low-density pattern”).
A high-density pattern is formed as a white portion when an image of the high-density pattern is copied with a copier, and indicates a background portion (hereinafter, referred to as “background pattern”). A low-density pattern remains (appears) when an image of the low-density pattern is copied with a copier, and indicates a hidden character portion (hereinafter, referred to as “hidden character pattern”) which is an example of a latent image portion. The latent image portion is not limited to a hidden character pattern (hidden character portion), and may be, for example, a hidden figure portion (hidden figure pattern) or hidden symbol portion (hidden symbol pattern) which indicates a figure or a symbol. Namely, the latent image portion may be any kind of pattern (such as characters, a figure, or a symbol) which represses or suppresses unauthorized copying and leakage of information of a printed matter (a recording medium on which a print process is performed).
The plurality of second patterns are patterns which are to be combined with the plurality of first patterns (such as a background pattern and a hidden character pattern), respectively, and which indicate a ground tint pattern such as in ‘sakura gami’ (hereinafter, such a pattern is referred to as “combination pattern”).
In the first exemplary embodiment, with respect to at least one of the plurality of second patterns (combination patterns), i.e., a combination pattern which corresponds to the background pattern, a pattern having a plurality of regions where their coverages are different in the main scanning direction in accordance with the output characteristics related to the density of the image forming apparatus is produced.
The output characteristics related to the density mean output characteristics related to the in-plane evenness or the density stability. Specifically, the output characteristics are information related to the output density.
The in-plane evenness means an index for evaluating whether the density in the plane (in the page) is even or not. For example, the case where the in-plane evenness is high or good means a state where the in-plane density is even and the density unevenness is eliminated or suppressed.
The density stability means an index for evaluating whether the density of an output image corresponding to a designated density value is obtained or not. The density stability is varied depending on the environment (the temperature, the humidity, and the like) of the place where the image forming apparatus is located, and deteriorations of components (particularly, an image carrier such as a photosensitive drum, an optical system including an optical scanning system, and the like) constituting the image forming apparatus. For example, the case where the density stability is high or good means a state where the density of an output image matching a designated density value is obtained.
The coverage means an area ratio of an input image in the pulse-surface-area modulation, so-called halftone dot area ratio.
As shown in
The image processing portion 100 has a density optimum number acquiring portion 110, a combination pattern optimum coverage calculating portion 120, a combination pattern producing portion 130, a ground tint pattern image producing portion 140, and a combining portion 150.
The density optimum number acquiring portion 110 serves as a function of acquiring module, and acquires the density optimum number which is given through a user interface such as an input/output device or operation panel that is not shown.
The density optimum number indicates information that, in an output image in which ground tint pattern image patches each including a background pattern and a hidden character pattern (latent image pattern) are two-dimensionally formed at a plurality of positions in the main and sub scanning directions, and the plurality of background patterns in the sub scanning direction are formed respectively based on different density parameters, indicates a ground tint pattern image patch in which the difference between the density of the background pattern and that of the latent image pattern is minimum, at each of a plurality of positions in the main scanning direction. The density optimum number will be described later in detail.
The combination pattern optimum coverage calculating portion 120 calculates the optimum coverage of a combination pattern, i.e., the coverage of the optimum combination pattern which is used for optimizing the output characteristics related to the density of the image forming apparatus (hereinafter, referred to as “combination pattern optimum coverage”), based on the density optimum number acquired by the density optimum number acquiring portion 110. The combination pattern optimum coverage calculating portion 120 stores the calculated combination pattern optimum coverage in the combination pattern optimum coverage storage portion 101.
The combination pattern producing portion 130 reads out the combination pattern optimum coverage from the combination pattern optimum coverage storage portion 101, and, based on this, produces a pattern (combination pattern) which is to be combined with the background pattern, and also a pattern (combination pattern) which is to be combined with the hidden character pattern.
Here, a combination pattern which corresponds to the background pattern is defined as “background combination pattern”, and a combination pattern which corresponds to the hidden character pattern is defined as “hidden character combination pattern”.
In the first exemplary embodiment, the combination pattern optimum coverage calculating portion 120 and the combination pattern producing portion 130 serve as a function of a producing unit.
The ground tint pattern image producing portion 140 reads out the background pattern and the hidden character pattern from the background/hidden character pattern storage portion 102, and combines the read out background pattern with the background combination pattern, and the read out hidden character pattern with the hidden character combination pattern.
Here, the result of the combination of the background pattern with the background combination pattern is defined as “background tint pattern”, and the result of the combination of the hidden character pattern with the hidden character combination pattern is defined as “hidden character tint pattern”.
Furthermore, the ground tint pattern image producing portion 140 combines the background tint pattern with the hidden character tint pattern to produce a ground tint pattern image.
The combining portion 150 combines the print data of a received print object with the ground tint pattern image (ground tint pattern image data) which is produced by the ground tint pattern image producing portion 140. The data (image data) obtained by the combination are output to the image forming apparatus which is not shown.
The combination pattern optimum coverage storage portion 101 stores the calculated combination pattern optimum coverage.
The background/hidden character pattern storage portion 102 stores the background pattern and the hidden character pattern.
Next, the density optimum number acquired by the density optimum number acquiring portion 110 will be described.
The description will be made exemplifying an image (hereinafter, referred to as “ground tint pattern image density check chart image”) in which, as shown in
In the example shown in
In the example shown in
In both the examples of
In the fifteen ground tint pattern image patches, the same number is allocated to ground tint pattern image patches belonging to the identical group (ground tint pattern image patches on the identical line), and different numbers are allocated to ground tint pattern image patches belonging to different groups.
In
In the examples shown in
In the examples shown in
By contrast, background tint patterns of ground tint pattern image patches (those to which the same number is allocated) of the identical group are formed by the same density parameter, but background tint patterns of ground tint pattern image patches of different groups in the sub scanning direction are formed by different density parameters.
In the example, for example, the background tint patterns of the ground tint pattern image patches L1, C1, R1 are set so as to have the same density (the same density parameter). Moreover, the background tint patterns are set so that, as the value of the number allocated to the corresponding ground tint pattern image patch is larger, the density is larger (the value of the density parameter is larger). In the case where the five ground tint pattern image patches located in the left portion L are considered, for example, the density parameters of the background tint patterns have the relationships of “L1<L2<L3<L4<L5”.
Under the preconditions, among the fifteen ground tint pattern image patches in 3 columns by 5 rows, the ground tint pattern image patch in which the difference between the density of the background tint pattern and that of the hidden character tint pattern is minimum is selected in each column. The information indicating the ground tint pattern image patch which is selected in each column, i.e., the number is the density optimum number. In the example, three density optimum numbers are selected.
As the density optimum number in the examples shown in
In the selection of the density optimum number in this case, the above-described density optimum number is selected while the user views an output image (printed matter on which the ground tint pattern image density check chart image is printed) in which, for example, the fifteen ground tint pattern image patches and the numbers allocated to the ground tint pattern image patches are formed. Alternatively, an image reading apparatus such as a scanner may scan an output image (printed matter), and the image processing apparatus may select the above-described density optimum number based on the result of the scan.
The technique of printing a ground tint pattern is configured by the following three factors 1 to 3.
(1) High-density pattern. A high-density pattern is formed as a white portion as a result of a copy process.
(2) Low-density pattern. A low-density pattern remains as a result of a copy process.
(3) Combination process (ground tint pattern processing). The density difference between patterns is made less prominent by forming a ground tint pattern such as in ‘sakura gami’. As a result of the combination process (ground tint pattern process), for example, density differences between a background pattern as a high-density pattern and a hidden character pattern as a low-density pattern are made less prominent as shown in
Here, conditions for obtaining a high image quality in the print image quality and the copy image quality will be described.
With respect to the print image quality, there are following conditions A and B.
(A) The pattern density of the background is lowered. This is performed in order that influences of the density stability (density variation) and in-plane evenness (in-plane density unevenness) of means (image forming unit=print engine) for performing image formation in the image forming apparatus are suppressed to the minimum degree.
(B) The combination process is performed on the hidden character pattern (hidden character portion) and the background pattern (background portion). This is performed in order that the pattern density step difference between the above-described two patterns (the hidden character pattern and the background pattern) is made less prominent.
By contrast, with the copy image quality, there are following conditions C and D.
(C) The pattern density of the background is heightened. This is performed in order that the background easily disappears as a result of a copy process.
(D) The combination process is performed only on the background pattern (background portion). This is performed in order that the hidden characters easily remain as a result of a copy process.
As described above, the print image quality and the copy image quality are in a trade-off relationship.
In the first exemplary embodiment, therefore, a high-density pattern (for example, error diffusion) is used as the background pattern in order to ensure the copy image quality. Furthermore, in order to ensure the copy image quality, a function of suppressing (or absorbing) influences of the density stability (density variation) and in-plane evenness (in-plane density unevenness) is added to “combination process (ground tint pattern process)” in addition to a function of making the density step difference between two patterns (the hidden character pattern and the background pattern) less prominent.
For example, combination patterns shown in
In the above-described fifteen ground tint pattern image patches shown in
By contrast, the background combination patterns of the background tint patterns of the ground tint pattern image patches to which numbers 1 to 5 are allocated are those to which the combination pattern (Cin=40%) shown in
In
As shown in
In the first exemplary embodiment, the density stability (density variation) and in-plane evenness (in-plane density unevenness), i.e., the density variation of the above-described image forming unit (print engine) are corrected by using the relationship. This means that the output characteristics related to the density of the image forming apparatus is corrected to predetermined output characteristics related to a density.
In the example shown in
Next, a ground tint pattern image production process performed by the image processing apparatus will be described with reference to
First, preconditions will be described. It is assumed that a ground tint pattern image density check chart image which is a print object, and which is printed by the image forming apparatus has the contents (output image in which the in-plane density unevenness occurs) shown in
Under the preconditions, the user operates an inputting portion of the user interface (not shown) such as the operation panel of the image processing apparatus 10 to input corresponding density optimum numbers in setting columns of “Nleft=”, “Ncent=”, and “Nright=” of an input screen which is displayed on a displaying portion of the operation panel, and which is used for inputting density optimum numbers. Nleft indicates the density optimum number corresponding to the ground tint pattern image patch which is placed in the left portion L.
Ncent indicates the density optimum number corresponding to the ground tint pattern image patch which is placed in the center portion C.
Nright indicates the density optimum number corresponding to the ground tint pattern image patch which is placed in the right portion R.
The user interface outputs Nleft=5, Ncent=3, and Nright=5 as the density optimum numbers to the density optimum number acquiring portion 110.
When the density optimum number acquiring portion 110 receives the density optimum numbers from the user interface (step S101), the portion outputs the density optimum numbers (Nleft=5, Ncent=3, and Nright=5) to the combination pattern optimum coverage calculating portion 120.
The combination pattern optimum coverage calculating portion 120 calculates the combination pattern optimum coverage (the optimum coverage of the combination pattern) based on the received density optimum numbers (Nleft=5, Ncent=3, and Nright=5).
Namely, the combination pattern optimum coverage calculating portion 120 calculates the coverage (Cin) of the whole region of the background combination pattern based on the received density optimum numbers “Nleft=5”, “Ncent=3”, and “Nright=5” (step S102), and further calculates the coverage (Cin) of the whole region of the hidden character combination pattern based on one of the received density optimum numbers, such as “Ncent=3” (step S103).
Here, the process of calculating the combination pattern optimum coverage by the combination pattern optimum coverage calculating portion 120 will be described with reference to
As shown in
A background dot pattern is configured by combination patterns which function as a plurality of elements. In the first exemplary embodiment, the unit of a combination pattern functioning as an element is the region (range) in the main scanning direction of a combination pattern such as shown in
The combination pattern optimum coverage calculating portion 120 previously knows the relationships between the density optimum number and the coverage (Cin). The density optimum numbers 1, 2, 3, 4, and 5 correspond to the coverages (Cin) of 40%, 35%, 30%, 25%, and 20%, respectively.
(1) The inclination of the left side is obtained based on “Nleft=5” and “Ncent=3”, and the coverages (Cin) of element combination patterns which are to be laid in the left side are obtained.
(2) The inclination of the right side is obtained based on “Nright=5” and “Ncent=3”, and the coverages (Cin) of element combination patterns which are to be laid in the right side are obtained.
The calculation process of (1) above will be described in more detail. From the density optimum numbers, the combination pattern optimum coverage calculating portion 120 may know the coverages (Cin) of the background combination patterns corresponding to the numbers, and hence determines which one of the coverages (Cin) is optimum at the points of the left portion L, the center portion C, and the right portion R.
Next, from the determined coverages (Cin) of the three points, the combination pattern optimum coverage calculating portion 120 obtains the values of steps the coverages (Cin) by which the element combination patterns are to be laid in the gaps.
For example, a case will be considered where the coverage of the patch (Left patch) of a background combination pattern which is placed in the left portion L is indicated as Cleft, that of the patch (Center patch) of a background combination pattern which is placed in the center portion C is indicated as Ccent, the number of element combination pattern units that are laid between Left patch and Center patch is indicated as L, and the coverage of a reference background combination pattern is indicated as Co. In this case, the coverage Cn of an n-th element combination pattern is expressed by following Exp. (1):
C
n={(Ccent−Cleft/L}×n+C0 (Exp. 1)
Then, the calculation process of (2) above will be described in more detail. Similarly with the case of the above-described calculation process of (1) above, a case will be considered where the coverage of the patch (Right patch) of a background combination pattern which is placed in the right portion R is indicated as Cright, that of the patch (Center patch) of a background combination pattern which is placed in the center portion C is indicated as Ccent, the number of element combination pattern units that are laid between Right patch and Center patch is indicated as L, and the coverage of a reference background combination pattern is indicated as C0. In this case, the coverage Cn of an n-th element combination pattern is expressed by following Exp. (2):
C
n={(Ccent−Cright/L}×n+C0 (Exp. 2)
Then, the combination pattern optimum coverage calculating portion 120 calculates the inclinations of the right and left sides with respect to Center patch, to obtain coverages of the element combination patterns. As a result, different coverages (Cin) in the main scanning direction are determined in all the regions (see P13 of
In the whole region (whole surface) of the background combination pattern (combination pattern for “background dot pattern”), therefore, there are a plurality of element combination patterns in which the coverages (Cin) are different in the main scanning direction. Namely, there are a plurality of regions (element combination patterns) in which the coverages (Cin) are different in the main scanning direction.
A specific example of the coverages (Cin) which are different in the main scanning direction will be described. It is assumed that, in P13 of
Under the preconditions, the coverage Cin of the element combination patterns which are laid between Left patch and Center patch, and that of the element combination patterns which are laid between Right patch and Center patch are, for example, larger than 20% and less than 30%.
The coverage Cin of the element combination patterns which are laid on the left side of Left patch, and that of the element combination patterns which are laid on the right side of Right patch are, for example, less than 20%.
On the other hand, the combination pattern optimum coverage calculating portion 120 determines the coverage Cin of the whole region of the hidden character combination pattern (combination pattern for “hidden character dot pattern”) based on one of the density optimum numbers of “Nleft=5”, “Ncent=3”, and “Nright=5” (see P14 of
Namely, with respect to the hidden character combination pattern (combination pattern for “hidden character dot pattern”), the combination pattern optimum coverage calculating portion 120 does not change the coverage (Cin) of (each element combination pattern of) the hidden character combination pattern in the plane, employs the hidden character combination patterns of one of three points or the left portion L, the center portion C, and the right portion R, for example, the hidden character combination pattern of the center portion C, and determines it as the coverage (Ccent) of the hidden character combination pattern which is identical in the whole region (see P15 of
Therefore, the whole region (whole surface) of the hidden character combination pattern (combination pattern for “hidden character dot pattern”) is configured by (element combination patterns of) the hidden character combination pattern having the same coverage (Ccent).
The above-described density correction due to a combination pattern is performed only on the background pattern, because it is easy to handle correction of only the background portion (high-density pattern) which is weak in the density stability (density variation) and in-plane evenness (in-plane density unevenness).
Referring again to
Next, the combination pattern producing portion 130 reads out the combination pattern optimum coverages which correspond respectively to the background combination pattern and the hidden character combination pattern, from the combination pattern optimum coverage storage portion 101, and produces combination patterns for the background combination pattern and the hidden character combination pattern based on the coverages (step S105).
Specifically, the combination pattern producing portion 130 produces the background combination pattern which is to be combined with the background pattern, based on the combination pattern optimum coverage corresponding to the background combination pattern, and produces the hidden character combination pattern which is to be combined with the hidden character pattern, based on the combination pattern optimum coverage corresponding to the hidden character combination pattern.
The background combination pattern (combination pattern for “background dot pattern”) shown in
In the example shown in
The coverage Cin of the element combination patterns which are on the left side of Left patch, and that of the element combination patterns which are on the right side of Right patch are, for example, less than 20%.
Referring again to
Moreover, the ground tint pattern image producing portion 140 combines the background tint pattern with the hidden character tint pattern to produce the ground tint pattern image (step S107).
As shown in
As shown in
Then, the ground tint pattern image producing portion 140 combines the background tint pattern shown in
The ground tint pattern image which is produced as described above is combined with the print data of the print object by the combining portion 150. Thereafter, the combined data (image data) are output to the image forming apparatus which is not shown.
As described above, in the case where a ground tint pattern image is print-output as a result of an imaging process (ground tint pattern image production process) by an image processing apparatus which does not have the configuration of the first exemplary embodiment, an output result (same as that of the example of
Next, an application example of the first exemplary embodiment will be described.
In the above-described ground tint pattern image production process shown in
Namely, the processes may be split into a preprocessing in which the processes ranging from the acquiring of the density optimum number to the calculation of the combination pattern optimum coverage are performed, and a ground tint pattern image production process in which the productions of combination patterns (the background combination pattern and the hidden character combination pattern) and the production of the ground tint pattern image are performed.
First, the preprocessing will be described with reference to
As shown in
If it is determined in step S112 that the currently acquired density optimum numbers are not thoroughly identical with the previously acquired density optimum numbers (at least one of the density optimum numbers is different), the currently acquired density optimum numbers (Nleft, Ncent, Nright) are output to the combination pattern optimum coverage calculating portion 120. By contrast, if it is determined that the density optimum numbers are thoroughly identical, the preprocessing is ended.
The combination pattern optimum coverage calculating portion 120 which receives the density optimum numbers from the density optimum number acquiring portion 110 performs processes which are identical with above described steps S102 to S104 (steps S113 to S115), and then terminates the processes.
Next, the ground tint pattern image production process which is performed after the preprocessing will be described with reference to
As shown in
With respect to instructions for producing the ground tint pattern image, for example, there are cases where the user issues the instructions for each of the print data of the print object which is received by the combining portion 150, and where the administrator previously instructs (sets) so that the instructions are applied to print data of all print objects.
In the former case, the image processing portion 100 determines whether instructions for producing a ground tint pattern image are input through the user interface (not shown) or not, thereby performing determination whether instructions for producing a ground tint pattern image are issued or not.
In the latter case, the image processing portion 100 determines whether or not information of instructions for producing a ground tint pattern image is stored in a storage portion (or a storage area) which is to hold information of instructions for producing a ground tint pattern image that is input through the user interface which is not shown, thereby performing determination whether instructions for producing a ground tint pattern image are issued or not.
The combination pattern producing portion 130 which is instructed so as to produce a combination pattern performs a process which is similar to that of above-described step S105, to produce combination patterns (step S122), and outputs a result (a background combination pattern and a hidden character combination pattern) of the process to the ground tint pattern image producing portion 140.
Based on the result (the background combination pattern and the hidden character combination pattern) of the process from the combination pattern producing portion 130, then, the ground tint pattern image producing portion 140 performs a process which is similar to that of above-described step S106, to produce a background tint pattern and a hidden character tint pattern (step S123), and performs a process which is similar to that of above-described step S107, to produce a ground tint pattern image (step S124).
In the above-described application example of the first exemplary embodiment, each time when density optimum numbers are acquired, combination pattern optimum coverages corresponding to a background combination pattern and a hidden character combination pattern are calculated based on the density optimum numbers, and the background combination pattern and the hidden character combination pattern are produced based on the calculated combination pattern optimum coverages. However, the example is not limited to this, and may be configured in the following manner.
In the case where the image forming unit (print engine) of the image forming apparatus has no difference depending on unit, and the changing manner of the density output characteristics related to the image forming unit is in a predetermined range, a background combination pattern and hidden character combination pattern which are obtained by first and second methods described below may be employed.
In the first method, during production or shipment of the image forming apparatus, the combination pattern optimum coverage calculating portion 120 of the image processing apparatus disposed in the image forming apparatus calculates combination pattern optimum coverages respectively corresponding to a background combination pattern and a hidden character combination pattern, in a manner similar to the above-described process of calculating combination pattern optimum coverages respectively corresponding to a background combination pattern and a hidden character combination pattern. The calculated combination pattern optimum coverages are previously stored as default information in the combination pattern optimum coverage storage portion 101.
In this case, the coverage in the main scanning direction of the background combination pattern must be stepwisely changed in accordance with the changed density output characteristics. Therefore, a plurality of combination pattern optimum coverages corresponding to a plurality of background combination patterns that are different in coverages of a plurality of regions (element combination patterns) in the main scanning direction are previously stored in the combination pattern optimum coverage storage portion 101.
With respect to the combination pattern optimum coverage corresponding to the background combination pattern, a specific one of the plurality of background combination patterns is selected in accordance with the operation state (for example, the total of the number of recording media which are subjected to a print process, and that of recording media which are subjected to a copy process) of the image forming apparatus.
Then, without performing the preprocessing (from the acquiring of density optimum numbers and the calculation of combination pattern optimum coverages) shown in
Next, in the second method, during production or shipment of the image forming apparatus, the combination pattern optimum coverage calculating portion 120 of the image processing apparatus disposed in the image forming apparatus calculates combination pattern optimum coverages respectively corresponding to a background combination pattern and a hidden character combination pattern, and the combination pattern producing portion 130 produces a background combination pattern and a hidden character combination pattern based on the combination pattern optimum coverages. The background combination pattern and hidden character combination pattern themselves which are thus produced are previously stored as default information in a storage portion (not shown) of the image processing apparatus 10.
In this case, for a reason similar to that in the above-described first method, a plurality of background combination patterns that are different in coverages of a plurality of regions (element combination patterns) in the main scanning direction are previously stored in the storage portion (not shown).
With respect to the background combination patterns, a specific one of the plurality of background combination patterns is selected in accordance with the operation state (for example, the total of the number of recording media which are subjected to a print process, and that of recording media which are subjected to a copy process) of the image forming apparatus.
Then, without performing the preprocessing (from the acquiring of density optimum numbers and the calculation of combination pattern optimum coverages) shown in
In both the above-described first and second methods, with respect to the background combination pattern which, among the combination patterns to be combined respectively with the background pattern (background portion) and hidden character pattern (latent image portion) related to a ground tint pattern image, is to be combined with the background pattern (background portion), the combination pattern optimum coverage calculating portion 120 and the combination pattern producing portion 130 cooperate to produce a pattern having a plurality of regions in which the coverages are different in the main scanning direction.
In the above-described first method, it is configured so that the combination pattern optimum coverages calculated by the combination pattern optimum coverage calculating portion 120 of the image processing apparatus disposed in the image forming apparatus are previously stored. However, the method is not limited to this. Alternatively, combination pattern optimum coverages calculated by a processing apparatus which is different from the image processing apparatus may be stored as default information.
In the above-described second method, it is configured so that the background combination pattern and hidden character combination pattern which are produced by the combination pattern producing portion 130 of the image processing apparatus disposed in the image forming apparatus are previously stored. However, the method is not limited to this. Alternatively, combination pattern optimum coverages may be calculated by a processing apparatus which is different from the image processing apparatus, and a background combination pattern and a hidden character combination pattern may be produced based on the calculated combination pattern optimum coverages. Then, the background combination pattern and hidden character combination pattern which are produced by the processing apparatus may be stored as default information.
In the first exemplary embodiment, as described above, the image processing apparatus sets the background combination pattern which, among the combination patterns to be combined respectively with the background pattern (background portion) and hidden character pattern (latent image portion) related to a ground tint pattern image, is to be combined with the background pattern (background portion), as a pattern having a plurality of regions in which the coverages are different in the main scanning direction, and executes a process of combining the background combination pattern with the background pattern.
In the first exemplary embodiment, as described above, deterioration of the image quality (print image quality and copy image quality) is suppressed in both cases of printing and copying of a ground tint pattern.
Even when the output characteristics related to the density of the image forming unit (print engine) of the image forming apparatus are varied (the in-plane evenness or the density stability is varied), it is possible to suppress deterioration of the image quality (print image quality and copy image quality), in both cases of printing and copying of a ground tint pattern.
Moreover, the in-plane evenness is corrected in the image process performed by the image processing apparatus, without adjusting the image forming unit (print engine) in which the in-plane evenness is low. Therefore, deterioration of the image quality is suppressed in both cases of printing and copying of a ground tint pattern.
The functional configuration of an image forming apparatus having an image processing apparatus of a second exemplary embodiment will be described with reference to FIG. 20.
As shown in
The image processing apparatus 10A has an image processing portion 100A, a print data receiving portion 201, a user interface portion 202, a density check chart data storage portion 203, and the combination pattern optimum coverage storage portion 101 and background/hidden character pattern storage portion 102 in the first exemplary embodiment shown in
The print data receiving portion 201 receives print data which are transmitted from an external apparatus such as a computer.
The user interface portion 202 is configured by interfaces such as an operation panel for inputting instruction information such as instructions for outputting a ground tint pattern image density check chart image, and inputting input information such as an input of a density optimum number, and inputting/outputting apparatuses (an inputting apparatus, a displaying apparatus, and the like).
The density check chart data storage portion 203 stores density check chart data indicating a chart for checking the output characteristics related to the density of the image outputting apparatus 20 (hereinafter, the chart is referred to as “ground tint pattern image density check chart”).
The image processing portion 100A has a functional configuration in which a density check chart producing portion 210 is added to the image processing portion 100 of the first exemplary embodiment shown in
In the second exemplary embodiment, the combination pattern optimum coverage calculating portion 120 causes the above-described density optimum numbers, and the combination pattern optimum coverages which are calculated based on the density optimum numbers, to be stored in the combination pattern optimum coverage storage portion 101.
The density check chart producing portion 210 reads out ground tint pattern image density check chart data from the density check chart data storage portion 203, and, in the case where the density optimum numbers are stored in the combination pattern optimum coverage storage portion 101, reads out the density optimum numbers therefrom, and produces ground tint pattern image density check chart image data based on the read out information.
The image outputting apparatus 20 includes an image forming unit (print engine) which performs a print process based on the ground tint pattern image density check chart image data output from the density check chart producing portion 210, and which performs a print (ground tint pattern print) process based on image data (image data in which a ground tint pattern image is incorporated into the image of the print object) output from the combining portion 150.
In
Next, a process of inputting a density optimum number by the user will be described with reference to
The user operates the user interface portion 202 to instruct the output of the ground tint pattern image density check chart image (step S201).
The density check chart producing portion 210 which receives the output instructions produces the ground tint pattern image density check chart image data, and outputs the data to the image outputting apparatus 20. The image outputting apparatus 20 print-outputs the ground tint pattern image density check chart image based on the received ground tint pattern image density check chart image data.
In the example shown in
In the example shown in
The symbol “*” indicates the currently set density optimum numbers, i.e., the density optimum numbers of the left portion L, the center portion C, and the right portion R which are stored in the combination pattern optimum coverage storage portion 101.
Here, it is assumed that the image outputting apparatus 20 outputs the ground tint pattern image density check chart image shown in
The user views the thus output ground tint pattern image density check chart image (for example, see
If it is determined that the currently selected density optimum numbers are not thoroughly identical with the currently set density optimum numbers (the numbers affixed with “*”) (at least one of the density optimum numbers is different), the user operates the user interface portion 202 to input the currently selected density optimum numbers (Nleft, Ncent, Nright) (step S204).
In this example, Nleft=5, Ncent=3, and Nright=5 are input as the density optimum numbers, respectively.
If step S204 is ended, or if the user determines that the density optimum numbers which are selected in step S203 are thoroughly identical with the currently set density optimum numbers, the input process is ended.
Next, a ground tint pattern image production process performed by the image processing apparatus will be described with reference to
In the ground tint pattern image production process, a procedure in which steps S211 and S212 are added to that of the ground tint pattern image production process in the first exemplary embodiment shown in
In the ground tint pattern image production process, the preconditions are as follows. It is assumed that a ground tint pattern image density check chart image which is a print object, and which is printed by the image outputting apparatus 20 of the image forming apparatus has the contents shown in
In the image processing apparatus 10A, when the user interface portion 202 receives information of instructions for producing a ground tint pattern image density check chart image, the density check chart producing portion 210 of the image processing portion 100A reads out ground tint pattern image density check chart data from the density check chart data storage portion 203, and, in the case where the density optimum numbers are stored in the combination pattern optimum coverage storage portion 101, reads out the density optimum numbers therefrom, and produces ground tint pattern image density check chart image data based on the read out information (step S211). Thereafter, the image data are output to the image outputting apparatus 20.
Next, the image processing portion 100A determines whether the density optimum numbers (Nleft, Ncent, Nright) are received through the user interface portion 202 or not (step S212). If it is determined that the density optimum numbers are received, processes which are similar to those of above-described steps S101 to S107 are performed. By contrast, if it is determined that the density optimum numbers are not received, the process is ended.
Incidentally, if the image processing portion 100A receives the density optimum numbers through the user interface portion 202, the density optimum number acquiring portion 110 acquires the above-described density optimum numbers (Nleft, Ncent, Nright) such as Nleft=5, Ncent=3, and Nright=5. Detailed description of the processes of step S102 to S107 is omitted.
In step S104, the combination pattern optimum coverage calculating portion 120 stores the above-described density optimum numbers, and combination pattern optimum coverages which are calculated based on the density optimum numbers, in the combination pattern optimum coverage storage portion 101.
In the second exemplary embodiment, as described above, even when the output characteristics related to the density of the image forming unit (print engine) of the image outputting apparatus constituting the image forming apparatus are varied (the in-plane evenness or the density stability is varied), it is possible to suppress deterioration of the image quality (print image quality and copy image quality), in both cases of printing and copying of a ground tint pattern.
The functional configuration of an image forming apparatus having an image processing apparatus of a third exemplary embodiment will be described with reference to
The image forming apparatus 1 shown in
For example, the image reading apparatus 30 is a scanner which is an example of an imaging unit, optically reads a recording medium (printed matter) which is output from the image outputting apparatus 20, and on which a ground tint pattern image density check chart image is printed, and outputs image data (scan data) corresponding to a result of the reading, i.e., the ground tint pattern image density check chart image to the image processing apparatus 10B.
The image processing apparatus 10B has the functional configuration in which a density optimum number detecting portion 310 is added to the image processing apparatus 10A shown in
The density optimum number detecting portion 310 selects, among, for example, fifteen ground tint pattern image patches in 3 columns by 5 rows, the ground tint pattern image patch in which the difference between the density of the background tint pattern and that of the hidden character tint pattern is minimum, in each column, based on the ground tint pattern image density check chart image (scan data) received from the image reading apparatus 30. Moreover, the portion detects the number allocated to the ground tint pattern image patch which is selected in each column, as the density optimum number.
Furthermore, the density optimum number detecting portion 310 outputs the thus detected density optimum numbers to the image processing portion 100A.
Next, a ground tint pattern image production process performed by the image processing apparatus will be described with reference to
The ground tint pattern image production process performs a procedure in which steps S301 to S303 are added to that of the ground tint pattern image production process in the first exemplary embodiment shown in
Initially, the user operates the user interface portion 202 to instruct the output of the ground tint pattern image density check chart image.
When the density check chart producing portion 210 which receives the output instructions produces the ground tint pattern image density check chart image data, and outputs the data to the image outputting apparatus 20, the image outputting apparatus 20 print-outputs the ground tint pattern image density check chart image based on the received ground tint pattern image density check chart image data.
Here, it is assumed that the recording medium (printed matter) which is output from the image outputting apparatus 20, and on which the ground tint pattern image density check chart image is printed has the contents shown in
In the third exemplary embodiment, without performing the viewing of the output recording medium (on which the ground tint pattern image density check chart image is printed), the user sets the recording medium in the image reading apparatus 30, and operates an operating portion (not shown) of the image reading apparatus 30 to issue instructions for reading.
The image reading apparatus 30 which receives the read instructions optically reads the set recording medium (printed matter), i.e., the recording medium (printed matter) on which the ground tint pattern image density check chart image (see
In the image processing apparatus 10B, when the user interface portion 202 receives information of instructions for producing a ground tint pattern image density check chart image, the density check chart producing portion 210 of the image processing portion 100A reads out ground tint pattern image density check chart data from the density check chart data storage portion 203, and, in the case where the density optimum numbers are stored in the combination pattern optimum coverage storage portion 101, reads out the density optimum numbers therefrom, and produces ground tint pattern image density check chart image data based on the read out information (step S301). Thereafter, the image data are output to the image outputting apparatus 20.
In the image processing portion 100A, next, the density optimum number detecting portion 310 determines whether the scan data are received from the image reading apparatus 30 or not (step S302), and, if it is determined that the scan data are not received, waits until the scan data are received.
By contrast, if it is determined that the scan data are received, the density optimum number detecting portion 310 selects, among, for example, fifteen ground tint pattern image patches in 3 columns by 5 rows, the ground tint pattern image patch in which the difference between the density of the background tint pattern and that of the hidden character tint pattern is minimum, in each column, based on the scan date, i.e., the ground tint pattern image density check chart image (see
Here, it is assumed that the density optimum number detecting portion 310 selects the ground tint pattern image patches L5, C3, R5 as a ground tint pattern image patch in which the density difference between the background tint pattern and the hidden character tint pattern is minimum.
Namely, it is assumed that Nleft=5, Ncent=3, and Nright=5 are selected as the density optimum numbers.
The thus detected density optimum numbers (Nleft=5. Ncent=3, and Nright=5) are given to the density optimum number acquiring portion 110 of the image processing portion 100A.
Thereafter, processes which are similar to those of above-described steps S101 to S107 are performed.
In step S104, the combination pattern optimum coverage calculating portion 120 stores the above-described density optimum numbers, and combination pattern optimum coverages which are calculated based on the density optimum numbers, in the combination pattern optimum coverage storage portion 101.
In the third exemplary embodiment, as described above, the user is not required to perform the work of viewing a printing medium (printed matter) on which the ground tint pattern image density check chart image is printed, and selecting the density optimum numbers, as compared with the case of the second exemplary embodiment.
The functional configuration of a computer which is an example of an information processing apparatus having an image processing apparatus of a fourth exemplary embodiment will be described with reference to
As shown in
The image processing apparatus 10 has the same function as the case of the first exemplary embodiment, and hence its description is omitted.
An image forming apparatus 60 has a density check chart data storage portion 61 and density check chart producing portion 62 which have functions similar to the density check chart data storage portion 203 and density check chart producing portion 210 in the second exemplary embodiment shown in
Also in the fourth exemplary embodiment, the user selects density optimum numbers while viewing a recording medium (printed matter) which is output from the print engine 63 of the image forming apparatus 60, and on which a ground tint pattern image density check chart image (for example, see
Then, the user operates an inputting apparatus (not shown) to input corresponding density optimum numbers into setting columns of “Nleft=”, “Ncent=”, and “Nright=” of an input screen which is displayed on a displaying portion of the displaying apparatus (not shown), and which is used for inputting density optimum numbers. The density optimum numbers are given to the image processing apparatus 10 of the computer 50.
The image processing apparatus 10 to which the density optimum numbers are given as described above performs processes (see
In an application example of the fourth exemplary embodiment, the image forming apparatus 60 may have the image processing apparatus in any one of the first to third exemplary embodiments.
In this case, in image processing apparatus, instructions for producing a ground tint pattern image which is to be applied to print data of all print objects is issued by, for example, the administrator, and information of the instructions for producing is stored in the storage portion (or the storage area) which is to hold information of instructions for producing a ground tint pattern image.
According to the configuration, even in the case where print data (print data having no ground tint pattern image) into which a ground tint pattern image is not incorporated is transmitted from the computer to the image forming apparatus, the image forming apparatus performs the process of producing a ground tint pattern image, then combines the received print data with the ground tint pattern image, and thereafter performs an image formation process (printing of a ground tint pattern). This means that the printing of a ground tint pattern is forcibly performed.
In the case where print data (print data having a ground tint pattern image) into which a ground tint pattern image is incorporated is transmitted from the computer to the image forming apparatus, the image forming apparatus gives preference to the received print data (print data having a ground tint pattern image), and performs an image formation process (printing of a ground tint pattern) without performing the process of producing a ground tint pattern image by the image forming apparatus.
In the fourth exemplary embodiment, as described above, similarly with the first exemplary embodiment, deterioration of the image quality (print image quality and copy image quality) is suppressed in both cases of printing and copying of a ground tint pattern.
Next, the hardware configuration of the image processing apparatus in the first to fourth exemplary embodiments will be described with reference to
As shown in
The image processing apparatus 70 corresponds to the image processing apparatus 10 (the first and fourth exemplary embodiments), the image processing apparatus 10A (the second exemplary embodiment), and the image processing apparatus 10B (the third exemplary embodiment).
The storage apparatus 72 is, for example, a hard disk drive, and stores various kinds of installed programs such as software (programs) and process program 72A for realizing the function of the image processing portion 100 or 100A.
The function of the image processing portion 100 includes software (programs) for realizing the functions of the components (components 110 to 150) which are applied in the case of realizing the first or fourth exemplary embodiment, and which are shown in
The process program 72A includes software (programs) corresponding to the procedure (shown in
For example, the process program 72A includes at least: an execution process of executing a process of combining a pattern (background combination pattern) that is to be applied as a pattern (background combination pattern) which, among patterns (the background combination pattern and the hidden character combination pattern) to be combined respectively with the background portion (background pattern) and latent image portion (hidden character pattern) related to a ground tint pattern image, is to be combined with the background portion (background combination pattern), and that has a plurality of regions in which the coverages are different in the main scanning direction, with the background portion (background pattern); or a production process of, with respect to the pattern (background pattern) to be combined with the background portion (background pattern), producing a pattern having a plurality of regions in which the coverages are different in the main scanning direction.
The execution process is performed by the ground tint pattern image producing portion 140, and the production process is performed by the cooperation of the combination pattern optimum coverage calculating portion 120 and the combination pattern producing portion 130.
The storage apparatus 72 has the function of the combination pattern optimum coverage storage portion 101.
The ROM 73 is a read-only memory, and stores information which is necessary for the image processing portion 100, 100A to perform the image process, communication protocol information for performing communication with an external apparatus, and the like.
Furthermore, the ROM 73 has the function of the background/hidden character pattern storage portion 102. Alternatively, the storage apparatus 72 may have the function of the background/hidden character pattern storage portion 102.
The RAM 74 is a random access memory, and stores: programs including the process program 72A read from the storage apparatus 72, and data; information read from the ROM 73; information acquired by the density optimum number acquiring portion 110; a result (the combination pattern optimum coverages and the like) of the calculation process performed by the combination pattern optimum coverage calculating portion 120; a result (the background combination pattern, the hidden character combination pattern, and the like) of the production process performed by the combination pattern producing portion 130; a result (the ground tint pattern image) of the production process performed by the ground tint pattern image producing portion 140; data which are transmitted and received by the communication I/F 77; and the like.
The operation panel 75 has the function of the user interface, and includes, for example, an inputting portion for inputting information such as a density optimum number, and a displaying portion on which display information is displayed. In the case where the hardware configuration in the fourth exemplary embodiment is to be realized, the operation panel 75 is not necessary.
The I/F 76 is configured by one or a plurality of interfaces which govern communication with peripheral apparatuses. For example, the I/F governs communication with the image outputting apparatus in first and second exemplary embodiments, that with the image outputting apparatus and the image reading apparatus in the third exemplary embodiment, and that with peripheral apparatuses such as inputting/outputting apparatuses (the inputting apparatus, the displaying apparatus) in the fourth exemplary embodiment. In the case where the hardware configuration in the fourth exemplary embodiment is to be realized, the inputting/outputting apparatuses (the inputting apparatus, the displaying apparatus) connected to the I/F 76 exert the function of the user interface.
The communication I/F 77 is used for communicating with an external apparatuses through a communication line (the Internet or the like), and, for example, governs communication with a computer which transmits print data, in the first to third exemplary embodiments, and that with the image forming apparatus which prints print data, in the fourth exemplary embodiment.
The CPU 71 is a central processing unit, reads programs including the process program 72A from the storage apparatus into the RAM 74, and executes the programs, thereby realizing the function of the above-described image processing portion 100 or 100A, and a processing function corresponding to the process program 72A. Moreover, the CPU 71 controls the whole of the image processing apparatus 70.
Although the invention conducted by the inventors has been specifically described on the basis of the exemplary embodiments, the exemplary embodiments disclosed in the specification are exemplarily shown in all aspects, and it is to be understood that the invention is not restricted to the disclosed techniques. Namely, the technical scope of the invention should not be restrictively interpreted on the basis of the description of the exemplary embodiments, and should be interpreted in accordance with the description of the appended claims. The invention includes techniques equivalent to those set forth in the claims, and all changes within the scopes of the claims.
In the case where a program is used, the program may be provided through a network, or being stored in a recording medium such as a CD-ROM.
Namely, the invention is not limited to the case where programs including the process program are recorded in a storage apparatus such as a hard disk, and the programs may be provided in the following manners.
For example, the programs may be stored in a ROM, and a CPU may load the programs from the ROM to a main storage apparatus, and then execute the programs.
Alternatively, the programs may be stored in a computer readable storage medium such as a DVD-ROM, a CD-ROM, a MO (magnetooptical disk), or a flexible disk, and then distributed.
Alternatively, the image processing apparatus and the like may be connected to a server apparatus or a host computer through a communication line (for example, the Internet), and the programs may be downloaded from the server apparatus or the host computer, and then executed. In this case, the download destination of the programs may be a memory such as a RAM, or a storage apparatus (storage medium) such as a hard disk.
The foregoing description of the exemplary embodiment of the present invention has been provided for the purpose of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and various will be apparent to practitioners skilled in the art. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, thereby enabling other skilled in the art to understand the invention for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents.
The image processing apparatus of the invention may be applied to a dedicated image processing apparatus, an image forming processing which is incorporated in a printer that is an example of an image forming apparatus, or an image processing apparatus which is incorporated in an image forming apparatus (so-called multifunction machine) having a plurality of image forming functions such as a print function and a copy function.
The image forming apparatus of the invention may be applied to an image forming apparatus which forms a color image or a monochrome image.
Although the case where the image forming apparatus of the invention is applied to an image forming apparatus which performs the toner recording process has been described, the invention may be applied to, for example, an ink-jet image forming apparatus in which the recording process is performed by means of ejected ink.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2010-157076 | Jul 2010 | JP | national |
