JP4614301B2 - Print output method and printed matter inspection apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention belongs to the technical field of printing. In particular, the present invention belongs to a technical field in which, when a defect is detected in a printed matter inspection apparatus, the defect information is printed out.
[0002]
[Prior art]
In roll-to-roll printing, where a printed roll is obtained from a roll to be printed, even if a defect occurs in the printed material, that part must be removed in-situ. I can't. If the printing machine is stopped, it can theoretically be removed manually or the like, but it cannot be stopped because it becomes a significant hindrance to productivity. Therefore, it is possible to print out an image of a printed matter from which defects have been extracted by the printed matter inspection apparatus, and to remove the defective portion from the printed winding body including the defect while referring to the printed output in a later process. Done. Conventionally, as shown in an example in FIG. 7, an image obtained by combining data indicating a defect position on a winding body with a normal print image together with an image of a defective portion is printed out.
[0003]
[Problems to be solved by the invention]
However, the conventional printed output as shown in FIG. 7 as an example has a problem in that the efficiency of the work of finding and removing the defect cannot be improved because the defect portion has poor visibility. There is also a problem that the cost of print output is high.
[0004]
SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to provide a print output method capable of reducing the cost of print output and the visibility of defective portions in a printed output product, and its An object of the present invention is to provide a printed matter inspection apparatus to which the method is applied.
[0005]
[Means for Solving the Problems]
The above problems are solved by the present invention described below. That is, the print output method according to claim 1 of the present invention is a print output method for obtaining a print output that supports the removal work of a defective portion in a printed matter, wherein a defect or a defect is detected from a printed matter image obtained by imaging with a printed matter inspection apparatus. A defect image is generated by cutting out a defect and a region in the vicinity thereof, and a converted printed image is generated by converting the pixel value in a normal printed image to be larger in the positive image, and the defective image is converted into the converted image. A print output image is generated by being pasted on a printed product image, thereby reducing the ink density in a region other than the defective image in the print output image and performing print output. ADVANTAGE OF THE INVENTION According to this invention, the visibility of the defective part in a printed output thing is good, and the printing output method which can reduce the cost of printing output is provided.
[0006]
According to a second aspect of the present invention, there is provided a printed matter inspection apparatus that includes a printout unit that extracts and inspects defects in a printed matter image obtained by imaging and obtains a printout that supports a removal operation of defective portions in the printed matter. An inspection apparatus, which generates a defect image by cutting out a defect or a defect and a region in the vicinity thereof from the printed image, and converts the pixel value in a normal printed image to be large in the positive image, thereby converting the printed image And generating the print output image by pasting the defect image onto the converted printed image, thereby reducing the ink density in the area other than the defect image in the print output image , and outputting the print output. Print output means is provided. ADVANTAGE OF THE INVENTION According to this invention, the visibility of the defective part in a printed output thing is good, and the printed matter inspection apparatus which can reduce the cost of printed output is provided.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described. First, the print output method of the present invention will be described, and the printed matter inspection apparatus of the present invention will be described later. The process of data processing in the print output method of the present invention will be described with reference to the flowchart shown in FIG. First, in step S1 of FIG. 1, a lookup table (LUT) for pixel value conversion is prepared. The look-up table is a table that is referred to when converting pixel values, and the conversion characteristics are determined by the prepared look-up table.
[0008]
As the look-up table in the present invention, a table having conversion characteristics such that the density of the printed output is low and the ink consumption is reduced is prepared. That is, in the case of a positive image, generally, the smaller the pixel value, the higher the density and the greater the ink consumption. In the case of a negative image (original), it is reversed because the image is reversed and printed out, but the following description will be made assuming that the image is a positive image. Therefore, a pixel having a conversion characteristic such that the relationship between the pixel value in the image before conversion and the pixel value of the corresponding pixel in the image after conversion becomes large (at least the same) after conversion is prepared.
[0009]
An example of the lookup table is shown in FIG. In FIG. 2, the horizontal axis represents the original pixel value (pixel value in the image before conversion). The vertical axis represents the converted pixel value (pixel value in the converted image). The pixel value has a value ranging from 0 to 255, i.e. 8 bits. As shown in FIG. 2, when the original pixel value is “0”, the converted pixel value is “120”. When the original pixel value increases from “0”, the post-conversion pixel value increases from “120” in proportion. In the original pixel value “160”, the converted pixel value is “255”. Furthermore, even if the original pixel value increases from “160”, the converted pixel value remains “255”. In the original pixel value “255”, the post-conversion pixel value is “255”, and both match only at this coordinate. Other than that, the converted pixel value is larger than the original pixel value.
[0010]
When the LUT as described above is prepared, in step S2, the pixel value of the image before conversion is converted with reference to the prepared lookup table. The image before the conversion is not an image of only the defect and the area in the vicinity thereof, but an entire image including these areas. Or it is the normal whole image which does not contain a defect. If the image is an image captured by the printed matter inspection apparatus, it is an image of the printed matter corresponding to one rotation of the plate cylinder. Usually, as an image before conversion, a reference image obtained by imaging a printed matter serving as an inspection reference is used. By this conversion, the pixel value in the image after conversion is larger (at least the same) as the pixel value of the corresponding pixel in the image before conversion.
[0011]
Next, in step S3, a process of attaching a defect image to the converted image is performed. A defect image is an image of a defect or a defect and a region in the vicinity thereof, and is an image corresponding to a partial image in the entire image described above. The pasting of the defect image is to place the defect image at a corresponding portion of the converted image, that is, to replace the image (pixel value). This defect image is not converted by the lookup table referred to in step S2. Therefore, the pasted defect image is printed with a higher density than the peripheral portion in the print output.
[0012]
Next, in step S4, processing for writing frame and character information is performed on the converted image. This frame is a frame for clearly indicating the range of the defect image. The character information is information indicating the attribute of the defect image. For example, the position information indicating the position (distance from the head) of the defect image on the web, the serial number of the defect image, and the like.
[0013]
Next, in step S5, it is determined whether there is a remaining defective image to be pasted. When it exists, it returns to step S3 and the process of the subsequent steps is repeated. If not, exit.
When the data processing process is completed as described above, an image for print output according to the present invention is generated.
[0014]
An example of the printed output in the present invention is shown as a pictorial diagram in FIG. FIG. 3 shows the difference from the conventional printed output shown as an example in FIG. That is, the overall image density in the printed output is higher in FIG. 7 than in FIG. Further, the density of the defect image in the printed output is not different between FIG. 3 and FIG. Therefore, in the present invention, the visibility of the defective portion is good, and the cost of print output can be reduced.
[0015]
Next, the printed matter inspection apparatus of the present invention to which the above-described print output method is applied will be described. By implementing the above-described print output method in an inspection apparatus such as a printed matter inspection apparatus that performs inspection based on a captured image, a significant advantage can be given to the apparatus. An explanatory diagram of data stored in the printed matter inspection apparatus of the present invention is shown in FIG. FIG. 4A shows a reference image as one of data to be stored. This reference image may be the same as an image serving as an inspection reference in the printed material inspection apparatus. Further, the reference image may be stored only for one rotation of the plate cylinder in printing performed using the same printing plate.
[0016]
FIG. 4B shows a defect image (cutout image 1) as one of data to be stored. An image that is an inspection target (inspection target image) in the printed matter inspection apparatus and that is determined to include a defect by comparison inspection with a reference image is referred to as a defective inspection image here. The defect image is an image obtained by cutting out a region including the defect and the periphery of the defect in the defective inspection image.
[0017]
As shown in FIG. 4B, in this example, the defect image is cut out into a rectangle. The cut-out area is defined by the coordinates (x1, y1) of a predetermined corner (upper left corner) of the rectangle and the dimensions (sx1, sy1) of the rectangle. The coordinates in this case are coordinates in the defective inspection image because the defect image is cut out from the defective inspection image.
[0018]
When the defective image is pasted on the reference image to generate the defective inspection image, it is necessary to convert the coordinates of the defective image from the coordinates in the defective inspection image to the coordinates in the reference image. The positional deviation amounts (cx1, cy1) shown in FIG. 4B are data for the coordinate conversion. Therefore, as shown in FIG. 1B, the defect image (dimensions are (sx1, sy1)), the coordinates (x1, y1) of the defect image, and the displacement amount (cx1, cy1) of the defective inspection image are also stored. One of the data to be processed.
[0019]
FIG. 4C is a defect image (cutout image 2) different from the above-described FIG. 1B as one of data to be stored. In this case as well, the defect image (dimensions (sx2, sy2)), the coordinates (x2, y2) of the defect image, and the displacement amount (cx2, cy2) of the defective inspection image are stored.
[0020]
In this way, one reference image, a set including a defect image, its coordinates, and a positional deviation amount of the inspection defect image are stored. When a plurality of defects exist in one inspection defect image, a plurality of defect images are cut out from the one inspection defect image. Therefore, the number of sets composed of the defect image, its coordinates, and the amount of misalignment of the defective inspection image is the number of defective images cut out and does not necessarily match the number of defective inspection images.
[0021]
Next, the process of data processing in the printed matter inspection apparatus of the present invention is shown in FIG. 5 as a flowchart. In the example shown in FIG. 5, a process for storing a defect image is incorporated in the flow.
First, in step S201 in FIG. 5, the printed matter inspection apparatus captures, as a reference image, an image (image data) obtained by imaging a printed matter serving as an inspection reference.
Next, in step S202, the read reference image is stored in a storage device such as a hard disk device.
[0022]
Next, in step S203, the printed matter inspection apparatus captures an image (image data) obtained by imaging the printed matter to be inspected as an inspection target image.
Next, in step S204, the printed matter inspection apparatus corrects the positional deviation between the reference image and the inspection target image. This misalignment is caused by meandering of the printed material transferred by a printing machine or the like, expansion / contraction of the web due to tension fluctuation, deviation of the imaging timing in the imaging means, and the like. As a method for correcting this misalignment, a known method can be applied, and the present invention is not limited thereby, and detailed description thereof is omitted. When the printed matter inspection apparatus performs this displacement correction, the printed matter inspection device inevitably calculates the displacement amount. This misalignment amount matches the misalignment amounts (cx, cy) stored in the subsequent step (step S210).
[0023]
Next, in step S205, a process for comparing and inspecting the reference image and the image to be inspected whose position deviation has been corrected is performed. As this inspection method, a well-known method can be applied, and the present invention is not limited thereby.
[0024]
Next, when it is determined that the process is good in step S205, the process proceeds from step S206 to step S211. Further, if the entire inspection is not completed, the process returns from step S211 to step S203, and the above-described subsequent processes are repeated. If the entire inspection has been completed, the inspection ends.
[0025]
On the other hand, if it is determined as defective in the process in step S205, the process proceeds to step S207. In step S207, a process of cutting out a defective portion is performed. The process of cutting out the defective portion is performed as a process of cutting out a rectangular area surrounding the defect in the inspection target image as described above (see the description of FIG. 4). An image obtained by cutting out this defect together with its periphery is a defect image.
[0026]
Next, in step S208, the defect image (an image obtained by cutting out the defect together with its periphery) is stored in a storage device such as a hard disk. At this time, a frame for clearly indicating the range of the defect image, position information indicating the position of the defect image on the web (distance from the head), a serial number of the defect image, and the like are simultaneously stored.
Next, in step S209, the coordinates of the defect image in the inspection target image are stored in a storage device such as a hard disk. For example, as already described (see the description of FIG. 1), the coordinates (x, y) of a predetermined corner (upper left corner) of the rectangle and the dimensions (sx, sy) of the rectangle are stored.
[0027]
Next, in step S210, the amount of positional deviation of the inspection target image with respect to the reference image is stored in a storage device such as a hard disk. This misregistration amount coincides with the misregistration amount calculated in the process in which the printed matter inspection apparatus performs a process of correcting misregistration between the reference image and the inspection target image in step S204.
Next, when the entire inspection is not completed, the process returns from step S211 to step S203, and the above-described subsequent processes are repeated. If the entire inspection has been completed, the inspection ends.
[0028]
In the process of the above data processing, the reference image, and the set including the defect image, its coordinates, and the positional deviation amount of the inspection defect image are stored. Although one reference image is stored, a set of defect images and the like is a number determined from 0 to a plurality of inspection situations.
[0029]
Next, the process of data processing for reproducing an image to be printed out based on the data stored as described above will be described. FIG. 6 is a flowchart showing the data processing process.
First, in step S301 in FIG. 6, the printed matter inspection apparatus reads a reference image stored in a storage device such as a hard disk.
Next, in step S302, a lookup table (LUT) for pixel value conversion is prepared. This step S302 is the same as the above-mentioned step S1 (see FIG. 1).
Next, in step S303, the pixel value of the reference image is converted with reference to the prepared lookup table. This step S303 is the same as the above-mentioned step S2 (see FIG. 1).
[0030]
Next, in step S304, the printed matter inspection apparatus reads a defect image (an image obtained by cutting out a defect together with its periphery) stored in a storage device such as a hard disk.
In step S305, the printed matter inspection apparatus reads the coordinates of the defect image stored in a storage device such as a hard disk. In the above example, the coordinates (x, y) of the predetermined corner (upper left corner) of the rectangle and the dimensions (sx, sy) of the rectangle are read.
Next, in step S306, the printed matter inspection apparatus reads the misregistration amount (cx, cy) stored in a storage device such as a hard disk.
[0031]
Next, in step S307, the printed matter inspection apparatus calculates the coordinates when the defect image is pasted on the reference image whose pixel value has been converted in step S303. In the above example, the coordinates (x-cx, y-cy) in the reference image of a predetermined corner (upper left corner) in the rectangle are calculated. The dimensions (sx, sy) of the rectangle do not change.
[0032]
Next, in step S308, the printed matter inspection apparatus pastes the defect image (cutout image) on the reference image based on the calculated coordinates. This step S309 is the same as the above-mentioned step S3 (see FIG. 1).
Next, in step S309, processing for writing frame and character information is performed on the reference image. This step S309 is the same as the above-mentioned step S4 (see FIG. 1).
Next, in step S310, it is determined whether there is a defect image remaining to be pasted. When it exists, it returns to step S304 and repeats the process of the subsequent steps. If not, exit.
The reference image to which the defect image is pasted in this way is an image for print output in the present invention.
[0033]
【The invention's effect】
As described above, according to the print output method of the first aspect of the present invention, there is provided a print output method capable of improving the visibility of defective portions in the printed output and reducing the cost of the print output. The
[0034]
Further, according to the printed matter inspection apparatus of the second aspect of the present invention, there is provided a printed matter inspection apparatus that has good visibility of a defective portion in the printed output matter and can reduce the cost of the printed output.
[Brief description of the drawings]
FIG. 1 is a flowchart showing a process of data processing in a print output method of the present invention.
FIG. 2 is a diagram showing an example of a lookup table used in the present invention.
FIG. 3 is a pictorial diagram showing an example of a printed output in the present invention.
FIG. 4 is an explanatory diagram showing data stored in the printed matter inspection apparatus of the present invention.
FIG. 5 is a flowchart showing a data processing process in the printed matter inspection apparatus of the present invention.
FIG. 6 is a flowchart showing a data processing process for reproducing an image to be printed out.
FIG. 7 is a pictorial diagram showing an example of a conventional printed output.

Claims (2)

A print output method for obtaining a print output that supports the removal work of defective portions in a printed matter,
A defect image is generated by cutting out a defect or a defect and a region in the vicinity thereof from a printed image obtained by imaging with a printed material inspection apparatus,
A converted printed image is generated by converting the pixel value in the normal printed image to be larger in the positive image,
By pasting the defect image on the converted printed image to generate an image for print output,
A print output method, wherein a print output is performed by lowering an ink density in a region other than the defective image in the print output image . A printed matter inspection apparatus having print output means for extracting and inspecting defects in a printed matter image obtained by imaging and obtaining a print output for supporting a removal operation of defective portions in the printed matter,
Generate a defect image by cutting out a defect or a defect and its neighboring area from the printed image,
A converted printed image is generated by converting the pixel value in the normal printed image to be larger in the positive image,
By pasting the defect image on the converted printed image to generate an image for print output,
An apparatus for inspecting printed matter, comprising: a print output unit that outputs a print by reducing an ink density in a region other than the defective image in the print output image .

Images