JP3866867B2 - Image processing apparatus and image processing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is applied to a color image forming apparatus such as a digital full-color copier, and takes a color original image as R, G, B image data, and as image data for each plate in the order of Y, M, C, K. The present invention relates to an image processing apparatus and an image processing method for performing processing for removing noise included in image data when forming.
[0002]
[Prior art]
Conventionally, when R, G, B image data read by an image input device such as a color scanner is formed as image data for each plate in the order of Y, M, C, K, the input R, G In general, B image data is temporarily stored in an image memory, and image data for each version is created from the stored image data.
[0003]
[Problems to be solved by the invention]
However, in the conventional techniques as described above, when an input image is captured using the image memory and image processing is performed using the data, data in which noise is included in the image memory due to some reason. May be stored. For this reason, there is a problem that a high-quality image cannot be obtained if the image is created using the data itself including noise.
[0004]
The present invention has been made in view of the above, and an object of the present invention is to obtain a high-quality image by avoiding image formation using image data including noise.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, in the image processing apparatus according to claim 1, R, G, B image data supplied from an image input means for reading a document image is converted into Y, M, C, K. In an image processing apparatus for executing image processing for forming image data for each plate in a frame sequential manner, image data storage means for storing image data read by the image input means, and input from the image input means comprising a calculating means for calculating a difference between the image data read from the image data and the image data storage means, a comparing means for comparing the calculated value with a predetermined reference value by the calculating means When the first version image is created, the image data input from the image input means is stored in the image data storage means, and at the same time, the image input means performs a reading operation again. Reads out the stored image data to generate image data, fetches the image data of the second and subsequent versions from the image input means, calculates the difference between the two image data by the calculation means, If it is larger than the reference value, the image formation that is currently being executed is stopped, and the image data is again taken into the image data storage means from the image input means.
[0006]
In the image processing apparatus according to claim 2, the image data input from the image input means is stored in the image data storage means, and the stored image data is read to obtain the first and second version images. The data is generated, the image input means performs the reading operation again at the time of image formation of the third version, the image data is obtained, the difference between the two image data is calculated by the calculation means, and the difference is the reference value If the value is larger than the image input, the image forming currently being executed is stopped, and the image data is again taken into the image data storage means from the image input means.
[0007]
In the image processing apparatus according to claim 3, the R, G, B image data supplied from the image input means for reading the document image is converted into Y, M, C, and K in the order of the planes. an image processing apparatus for performing image processing for forming the image data, R read by the image input unit, G, and the image data storage means for storing the B image data are input from said image input means R, A calculation means for calculating the difference between the G, B image data and the R, G, B image data read from the image data storage means, a value calculated by the calculation means, and a preset reference value A comparison means for comparing, and R, G, B image data input from the image input means at the time of the first version image formation in which the image data is formed in Y, M, C, K plane sequential order The image data storage means is At the time of image formation for the second and subsequent versions, R, G, B image data stored in the image data storage means are read out to generate image data, and at the same time, R, G, B image data is retaken, and the difference between the R, G, B image data stored in the image data storage means and the R, G, B image data retaken from the image input means is computed by the computing means. If the difference calculated by the calculation means is larger than the reference value, the image forming being executed is stopped and R, G, B image data is again taken into the image data storage means from the image input means. Is.
[0008]
According to another aspect of the image processing method of the present invention , R, G, B image data obtained by reading a document image is formed as image data for each plate in the Y, M, C, K plane order. In the image processing method for image processing, an image data storing step for storing R, G, B image data obtained by reading the original image, and R, G, B image data obtained by reading the original image, A calculation step of calculating a difference from the R, G, B image data stored in the image data storage step;
And a comparison step for comparing a value calculated in the calculation step with a preset reference value, and in the first plate image forming image data in the Y, M, C, and K plane sequential order The image data storing step is executed, and when the second and subsequent versions are formed, the R, G, B image data stored in the image data storing step is read to generate image data, and at the same time, the original document R, G, B image data is re-imported from the image, and the difference between the R, G, B image data stored in the image data storing step and the R, G, B image data re-imported from the original image is determined as the difference. When the difference is calculated in the calculation step and the difference calculated in the calculation step is larger than the reference value, the image formation during execution is stopped and the image data storage step is executed again .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of an image processing apparatus and an image processing method according to the present invention will be described below in detail with reference to the accompanying drawings.
[0010]
[Embodiment 1]
(System configuration)
FIG. 1 is a block diagram showing a main configuration of a system suitable for application of an image processing apparatus according to Embodiment 1 of the present invention. In the figure, 101 is a scanner as an image input means for optically scanning a color original and inputting it as R, G, B digital data, and 102 is an image data storage means for writing the digital data inputted from the scanner 101. An image memory 103, a subtractor as a calculation means for calculating the difference between the data input from the scanner 101 and the data read from the image memory 102, 104 sets a reference value for comparison in advance The threshold value register 105 is a comparator as a comparison means for comparing the threshold value set in the threshold value register 104 with the output value of the subtractor 103.
[0011]
(System operation)
Next, an operation that characterizes the present invention in the system configured as described above will be described. First, input image data read by the scanner 101 is written into the image memory 102. For example, when creating a color image with four plates, the first image is written into the image memory 102 at the same time as the first plate. After the second version is created, reading from the image memory 102 eliminates the need for a normal scan operation.
[0012]
However, when creating a color image for the second and subsequent versions, image data is captured from the scanner 101 and compared with the image data written in the image memory 102. That is, the second version uses the image data stored in the image memory 102 to generate an image, and simultaneously inputs the image data from the scanner 101 again, and inputs the two image data to the subtractor 103.
[0013]
The subtractor 103 calculates the difference between the two image data and inputs it to the comparator 105. The comparator 105 compares the threshold value preset in the threshold register 104 with the value input from the subtractor 103. If the difference is larger than the threshold value as a result of the comparison, the image formation is stopped. Then, the image data is input again from the scanner 101 and written into the image memory 102.
[0014]
Therefore, by performing such an operation, it is possible to reduce the influence of noise on the output when outputting image data from the image memory 102.
[0015]
When the image data output operation is speeded up, the reading speed of the scanner 101 may be a problem. Therefore, in the above-described configuration, the second version does not request comparison data from the scanner 101, and the third version requests comparison data, thereby reducing the speed of the scanner 101. In other words, a low-speed scanner can be used.
[0016]
That is, the input image data read by the scanner 101 is written into the image memory 102. The second version uses the image data stored in the image memory 101 to generate an image. At this time, no image is requested from the scanner 101. Then, the image data is read again from the scanner 101 when the third plate is formed. Then, the two image data are input to the subtractor 103 and the difference between them is calculated. Then, the result is compared with a threshold value preset in the threshold value register 104, and if the difference is larger than the threshold position, the image formation is stopped. The image data is again written into the image memory 102 from the scanner 101.
[0017]
Therefore, by performing such an operation, it is possible to detect noise included in the image data even when the scanning speed of the scanner 101 is low.
[0018]
[Embodiment 2]
By the way, when comparing the image data fetched into the image memory 102 with the image data from the scanner 101, errors occur frequently if the reading accuracy of the scanner 101 is poor. Therefore, in this embodiment, an example in which only fatal noise is detected by using the comparison data as an average value of a plurality of pixels will be described.
[0019]
(System configuration)
FIG. 2 is a block diagram showing a main configuration of a system suitable for application of the image processing apparatus according to Embodiment 2 of the present invention. The present configuration is the second average value generating means for averaging the image data read from the image memory 102 between the image memory 102 and the subtractor 103, compared to the configuration of FIG. 1 described in the first embodiment. As an average value generation circuit 201, an average value generation circuit 202 is provided between the scanner 101 and the subtractor 103 as first average value generation means for averaging the image data read by the scanner 101. Since other components and their functions are the same as those of the first embodiment, the same reference numerals as those in FIG.
[0020]
(System operation)
Next, an operation that characterizes the present invention in the system configured as described above will be described. First, input image data read by the scanner 101 is input to the average value generation circuit 202, and the generated average value is input to the subtractor 103. At the same time, input image data read by the scanner 101 is input to the image memory 102, the image data is input to the average value generation circuit 201, and the generated average value is input to the subtractor 103. The subtractor 103 calculates the difference from the two average values. Then, the result is compared with a threshold value preset in the threshold register 104, and if the difference is larger than the threshold position, the image formation is stopped as an error. Thereafter, the image data is again written into the image memory 102 from the scanner 101.
[0021]
Therefore, by performing such an operation, even when the reading accuracy of the scanner 101 is poor, the detection accuracy of noise included in the image data can be increased.
[0022]
[Embodiment 3]
As described above, there is a great penalty for stopping image formation when noise occurs. Therefore, in the third embodiment, an example will be described in which, when an error occurs, an image having a smaller difference from surrounding pixels is output as a correct image.
[0023]
(System configuration)
FIG. 3 is a block diagram showing the main configuration of a system suitable for application of the image processing apparatus according to Embodiment 3 of the present invention. In the figure, 301 is an image memory as image data storage means for storing R, G, B image data input from the outside such as a scanner, 302 reads out the image data stored in the image memory 301, An average value generation circuit as an average value generation means for averaging the pixels, and 303 a subtractor as an operation means for calculating the difference between the image data read from the image memory 301 and the value from the average value generation circuit 302, 304 Is a scanner side difference circuit as difference detection means for obtaining a reading difference of the scanner (image input device), and 305 is a comparator as comparison means for comparing the value of the scanner side difference circuit 304 with the output value of the subtractor 303. .
[0024]
(System operation)
Next, an operation that characterizes the present invention in the system configured as described above will be described. The image data stored in the image memory 3301 is read out, and the image data and the average value of the image data are input to the subtracter 303. Then, the value is supplied to the comparator 305. The comparator 305 compares the output of the scanner side difference circuit 305 with the value from the subtractor 303.
[0025]
In this case, when it is determined that the difference is large and an error, the difference from the surrounding pixels of each image data is obtained in another pass. The one with the larger difference is defined as error data. If the difference is larger in the scanner (image input device), it is assumed that the data from the image memory 301 is correct, the image data is output from the image memory 301, and the contents of the memory remain unchanged. On the other hand, if the difference is larger in the image memory 301, it is assumed that the image data from the scanner (image input device) is correct, the output of the scanner (image input device) is used, and the image data in the image memory 301 is simultaneously converted to the scanner data. Replace with
[0026]
Therefore, by performing such an operation, it is possible to reduce the number of times of performing the scanning operation again when noise included in the image data is detected.
[0027]
【The invention's effect】
As described above, according to the image processing apparatus (claim 1) of the present invention, the image data input from the image input means is stored in the image data storage means at the time of the first version image formation, and at the same time The image input means performs the reading operation again, the second and subsequent versions read the stored image data to generate image data, and the second and subsequent versions of the image data are taken in from the image input means. When the difference is calculated by the calculation means, if the difference is larger than the reference value, the image formation currently being executed is stopped, and the image data is stored again by taking the image data from the image input means into the image data storage means. When image data is output from the means, it is possible to reduce the influence of noise on the output, so that a high-quality image can be obtained.
[0028]
According to the image processing apparatus of the present invention (Claim 2), the image data input from the image input means is stored in the image data storage means, the stored image data is read out, and the first and second versions Generate image data, read the image data again with the image input means at the time of image formation of the third version, acquire the image data, calculate the difference between the two image data with the calculation means, and the difference is compared to the reference value If the image input unit is low, the image forming process currently being executed is stopped and the image input unit is read again into the image data storage unit, so that the image data is included in the image data even when the reading speed is low. Since noise can be detected, a high-quality image can be obtained.
[0029]
Further, according to the image processing apparatus of the present invention (Claim 3), it is inputted from the image input means at the time of the first plate image forming the image data in the Y, M, C, K plane sequential order. R, G, B image data is stored in the image data storage means, and when the second and subsequent versions are created, the R, G, B image data stored in the image data storage means is read to generate image data. At the same time, the R, G, B image data is again taken from the image input means, the R, G, B image data stored in the image data storage means, and the R, G, B image data taken again from the image input means, When the difference calculated by the calculation means is larger than the reference value, the image formation being executed is stopped, and R, G, In order to capture B image data, images are stored from the image data storage means. When outputting image data, it is possible to reduce the influence of noise on the output, so that a high-quality image can be obtained.
[0030]
According to the image processing method of the present invention (Claim 4) , the image data storing step is executed at the time of the first version image formation in which the image data is formed in the Y, M, C, K plane sequential order. At the time of image formation for the second and subsequent versions, the R, G, B image data stored in the image data storage step is read to generate image data, and at the same time, the R, G, B image data is again generated from the original image. The difference between the R, G, B image data stored in the capture and image data storage process and the R, G, B image data captured again from the original image is calculated in the calculation process, and the difference calculated in the calculation process is the reference. If the value is larger than the value, the current image formation is stopped and the image data storage process is executed again. Therefore, when image data is output from the image data storage means, the influence of noise on the output is reduced. To get a good image be able to.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a main configuration of a system suitable for application of an image processing apparatus according to Embodiment 1 of the present invention.
FIG. 2 is a block diagram showing a main configuration of a system suitable for application of an image processing apparatus according to Embodiment 2 of the present invention.
FIG. 3 is a block diagram showing a main configuration of a system suitable for application of an image processing apparatus according to Embodiment 3 of the present invention.
[Explanation of symbols]
101 Scanner 102, 301 Image memory 103, 303 Subtractor 104 Threshold register 105, 305 Comparator 201, 202, 302 Average value generation circuit 304 Scanner side difference circuit

Claims (4)

Image processing apparatus for executing image processing for forming R, G, B image data supplied from image input means for reading a document image as image data for each plate in the order of Y, M, C, K In
Image data storage means for storing image data read by the image input means;
Computing means for computing a difference between the image data input from the image input means and the image data read from the image data storage means;
Comparing means for comparing the value calculated by the calculating means with a preset reference value;
With
At the time of image formation of the first version, the image data input from the image input means is stored in the image data storage means, and at the same time, the image input means performs a reading operation again. Data is read out to generate image data, and the second and subsequent image data is fetched from the image input means, the difference between the two image data is calculated by the calculation means, and the difference is compared with the reference value. An image processing apparatus that stops image formation that is currently being executed and captures image data from the image input means to the image data storage means again.   The image data input from the image input means is stored in the image data storage means, and the stored image data is read to generate first and second version image data. The image data is acquired by performing the reading operation again, and the difference between the two image data is calculated by the calculation means, and if the difference is larger than the reference value, the image formation currently being executed is stopped. 2. The image processing apparatus according to claim 1, wherein image data is fetched again from the image input means into the image data storage means. Image processing apparatus for executing image processing for forming R, G, B image data supplied from image input means for reading a document image as image data for each plate in the order of Y, M, C, K In
Image data storage means for storing R, G, B image data read by the image input means ;
Computing means for computing the difference between the R, G, B image data input from the image input means and the R, G, B image data read from the image data storage means;
Comparing means for comparing the value calculated by the calculating means with a preset reference value;
With
R, G, B image data input from the image input means is stored in the image data storage means at the time of the first version image formation in which the image data is formed in the order of Y, M, C, K, At the time of image formation for the second and subsequent versions, R, G, B image data stored in the image data storage means is read out to generate image data, and at the same time, R, G, B image data is read from the image input means. And the difference between the R, G, B image data stored in the image data storage means and the R, G, B image data re-imported from the image input means is calculated by the calculation means. If the difference calculated by the means is larger than the reference value, the image forming under execution is stopped, and R, G, B image data is again taken into the image data storage means from the image input means. An image processing apparatus. In an image processing method for forming R, G, and B image data obtained by reading a document image as image data for each plate in the order of Y, M, C, and K,
An image data storing step for storing R, G, B image data obtained by reading the original image;
A calculation step of calculating a difference between the R, G, B image data obtained by reading the original image and the R, G, B image data stored in the image data storage step;
A comparison step of comparing the value calculated by the calculation step with a preset reference value;
Including
The image data storage step is executed in the first version image formation in which the image data is formed in the sequential order of Y, M, C, and K, and the image data storage is performed in the second and subsequent version image formation. The R, G, B image data stored in the process is read out to generate image data. At the same time, the R, G, B image data is re-imported from the original image, and stored in the image data storage process. The difference between the image data and the R, G, B image data re-captured from the original image is calculated in the calculation step, and if the difference calculated in the calculation step is larger than the reference value, execute An image processing method characterized in that the image formation is stopped and the image data storing step is executed again .

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