JP2001177723A - Image processor, image processing method and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a print image with a print density ratio according to a gray scale of an original image in the image processing in the manufacturing of a printing master board where a thermoplastic porous material is employed for a material for stamp. SOLUTION: A dot concentration type dither matrix is stored in a dither matrix storage area 175 of a RAM 154 and a binary processing arithmetic section 168 compares the dot concentration type dither matrix with a gradation image stored in a gradation correction image storage area 174 by each block to obtain binary image data. Thus, the linearity between the gray scale of the original image and the print density ratio is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus, an image processing method, and a storage medium, and is particularly suitable for use in image processing when manufacturing a printing plate using a thermoplastic porous material as a stamping material.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. Hei 11-78191 discloses a method in which a stamp material made of a thermoplastic porous resin is made into a plate to form a stamp having an ink exuding portion and an ink non-exuding portion formed on the surface. For example, there is disclosed a stamp creating apparatus for performing the above. The stamping material for plate making with the stamp making apparatus described in the above publication, a lower layer made of a soft porous resin such as urethane in which a light energy absorbing material such as carbon black is dispersed, and ink can be stored. It has a two-layer structure consisting of an upper layer made of a hard porous resin so as to uniformly apply pressure to the lower layer, and is held in a predetermined holder.

In order to make a plate of this stamp material, characters and images are printed by a thermal head on a transparent manuscript film in a stamp making apparatus to create a positive manuscript, and the positive manuscript and the lower layer of the stamp material are combined. The holder is set in the stamp making device so that the stamp material is pressed in the facing state.

In this state, when the xenon tube in the stamp making apparatus emits light, the light is irradiated to the lower layer of the printing material through the positive original. Accordingly, the lower layer portion irradiated with light corresponding to the transparent portion of the document is solidified after being melted by the heat-generating action of the light energy absorbing material, so that it is sealed and does not transmit ink. On the other hand, a portion of the lower layer which is not irradiated with light corresponding to a printed portion of the document remains as it is without being sealed corresponding to characters of the document. By such flash light plate making, a seal is formed in which a seal portion (ink non-bleed portion) and a non-seal portion (ink bleed portion) of a desired pattern are mixed on the lower surface of the printing material. Then, when the holder is pressed toward the printing paper during stamp printing, the ink supplied from above the stamp material oozes out only from the non-seal portion and adheres to the printing paper, and desired characters and the like are printed by stamping.

[0005] The porous resin having the ink bleeding portion and the non-ink bleeding portion formed on the surface by the plate making in this way is not limited to the flash light plate making using the xenon tube as described above, but also generates heat. The element may be subjected to thermal head plate making using a thermal head in which the element is electrically driven, or hot press plate making using a heated hot plate having a surface having irregularities corresponding to a plate making image, and plate making may be performed. .

[0006]

The stamp making apparatus as described above has an advantage that stamp printing can be performed at a relatively high resolution of about 600 dpi, so that not only characters but also each dot is expressed in gradation. It is expected that beautiful figures can be printed on stamps. For this purpose, it is necessary to convert the image data (including both characters and graphics) supplied to the stamp creation device from a gradation image to a binary image.

However, as a result of experiments conducted by the present inventor, as a result of the dither method using a dot-dispersion type dither matrix, which is generally used for original image data,
As a result of creating a stamp of 600 dpi by performing value conversion,
It turned out that only a stamp image as if it were a simple binarization could be obtained. This is considered to have the following causes. First, a small on-dot aggregate portion corresponding to the ink seeping portion (for example, 1 × 1 dot, 1 × 1 dot,
× 2 dots, etc.), compared with a large-scale on-dot aggregate (for example, 4 × 4 dots or more), the printing rate of ink on the original film by the thermal head (= ink length on original film / correspondence) Plate length (the length of the heating element of the thermal head) is poor due to compatibility between the two, and the plate making rate (= length of the ink bleeding part of the printing material / corresponding original film) ), The stamp density ratio of a region where the gray scale value is large and close to white becomes close to 0. In addition, in a large-scale on-dot aggregate portion, the ink bleed rate (= the length of the ink printed on the paper / the length of the corresponding ink bleed portion of the printing material) is large. The stamp density ratio in a region where the scale value is small and close to black is close to 1. For these reasons, the linearity between the gray scale value and the stamp density ratio is broken, and the stamp image cannot be expressed in gradation with the density according to the gray scale value of the original image.

A similar problem arises not only in the case of flash light plate making of a thermoplastic porous resin, but also in the case of laser scan plate making (in this specification, plate making using light including flash light plate making and laser scan plate making is performed by light. Plate making) or thermal plate making such as thermal head plate making or hot press plate making. The reason for this is that, as in the case of the flash light plate making described above, the stencil penetrates into areas where light and heat are not required during plate making, resulting in poor plate making rates in small on-dot gathering parts and large scale It is considered that the reason is that the linearity between the gray scale value and the print density is lost due to the high ink bleeding rate in the appropriate on-dot aggregate portion.

An object of the present invention is to provide an image processing apparatus and an image processing method for manufacturing a printing plate using a thermoplastic porous material as a printing material, and a printing density according to a gray scale value of an original image. An object of the present invention is to provide an image processing apparatus and an image processing method capable of obtaining a print image having a ratio.

[0010]

According to a first aspect of the present invention, there is provided an image processing apparatus, comprising: an image processing apparatus for performing image processing when manufacturing a printing plate using a thermoplastic porous material as a printing material; In the processing device, a storage unit for storing a gradation image as an original image, a binarization unit for performing a binarization process on the gradation image and outputting a binary image, The gradient of the characteristic curve showing the change in the print density ratio by the printing original plate made at a predetermined resolution based on the binary image obtained by the binarizing means with respect to the gray scale value of the original image is represented by the gray scale value And control means for controlling the binarization means so that the value becomes 1/256 or more in a continuous range of 64 or more.

Further, the image processing apparatus according to claim 2 further comprises a resolution changing means capable of changing the resolution of the gradation image or the binary image. For the grayscale value of the original image of
Based on the binary image obtained by the binarizing unit, the slope of the characteristic curve indicating the change in the print density ratio by the printing original plate made with the resolution changed by the resolution changing unit is 64 in gray scale value. 1/256 within the above continuous range
As described above, the binarizing means and the resolution changing means are controlled.

The image processing apparatus according to a third aspect of the present invention further comprises a gradation correcting means capable of correcting a gradation of a gradation image, and the binarizing means comprises a gradation correcting means. The binarization process is performed on the tone image that has been subjected to the tone correction, and a binary image is output. The control unit determines the grayscale value of the original image when the number of tones is 256 by the binarization unit. The slope of the characteristic curve indicating the change in the print density ratio by the printing original plate made at a predetermined resolution based on the obtained binary image is 1 / gray scale in a continuous range of 64 or more.
The binarizing means and the gradation correcting means are controlled so as to be 256 or more.

According to a ninth aspect of the present invention, there is provided an image processing method for manufacturing a printing original plate using a thermoplastic porous material as a printing material, wherein the gray scale of the original image when the number of gradations is 256 is obtained. The slope of the characteristic curve indicating the change in the print density ratio of the printing original plate made with the changed resolution based on the obtained binary image with respect to the value is 1 / g in a continuous range of 64 or more in grayscale value. At least two of the binarization processing for the gradation image, the resolution change of the gradation image or the binary image, and the gradation correction of the original image are performed so as to be 256 or more.

[0013] Further, a storage means for storing a gradation image as an original image, a binarization means for performing a binarization process on the gradation image and outputting a binary image, Tone 25
6 with respect to the gray scale value of the original image at 6
The slope of a characteristic curve indicating a change in the print density ratio by a printing original plate made at a predetermined resolution based on the binary image obtained by the binarization means is 1 / g in a continuous range of 64 or more in gray scale value. A computer as an image processing device for performing image processing when manufacturing a printing original plate using a thermoplastic porous material as a stamping material, comprising: a control unit for controlling the binarization unit so that the number becomes 256 or more. Is a computer-readable recording medium on which a program for causing a computer to function is recorded.

According to the first to third, ninth and thirteenth aspects of the present invention, the ratio of the printing density of the printing original plate made at a predetermined (or changed) resolution to the gray scale value of the original image when the number of gradations is 256 is 256. A binarization process (in addition to an appropriate resolution change and / or an appropriate resolution if necessary) such that the slope of the characteristic curve indicating the change becomes 1/256 or more in a continuous range of 64 or more gray scale values. ), It is possible to use a wider range of gray scale values for gradation expression as compared with the conventional method, and to obtain a print image with more excellent gradation reproducibility. Become.

In the present invention, the continuous range of the gray scale value at which the gradient of the print density ratio to the gray scale value becomes 1/256 or more may be 64 or more, but is preferably 96 or more, and 128 or more. More preferably, it is the above. Such conditions are experimentally determined as preferable values so as to obtain a printed image having excellent gradation reproducibility.

Further, in claims 1 to 3, 9 and 13,
The binarization processing is preferably performed by dither processing using a dot concentration type dither matrix. However, if there is no problem even if the resolution of a print image is reduced, dither processing using a dot diffusion type dither matrix or error may be performed. The binarization may be performed by a diffusion process or the like. In these cases, the binarizing means according to the first to third, ninth and thirteenth aspects includes a storage means for storing a dither matrix and a comparing means for comparing the gradation image with the dither matrix to output a binary image. May be.

An image processing apparatus according to a fourth aspect of the present invention is an image processing apparatus for performing image processing when manufacturing a printing plate using a thermoplastic porous material as a printing material, and stores a gradation image as an original image. A first storage unit, a second storage unit for storing a dot concentration type dither matrix, and a gray scale image stored in the first storage unit, the dot concentration type dither matrix stored in the second storage unit. A comparing means for comparing the dither matrix with each block and outputting a binary image;

According to a tenth aspect of the present invention, there is provided an image processing method for manufacturing a printing plate using a thermoplastic porous material as a printing material. This is to perform dither processing using a matrix.

Further, the first storage means for storing a gradation image as an original image, the second storage means for storing a dot concentration type dither matrix, and the first storage means. Comparing the obtained gradation image with the dot concentration type dither matrix stored in the second storage unit for each block and outputting a binary image. A computer-readable recording medium in which a program for causing a computer to function as an image processing device for performing image processing when manufacturing a printing original plate is recorded.

According to the fourth, tenth and fourteenth aspects, the dither processing using the dot concentration type dither matrix is performed on the gradation image as the original image, so that
The printed image is expressed in gradation with the density according to the gray scale value of the original image. As described above, a favorable result can be obtained by using the dot concentration type dither matrix because a small number of small on-dot aggregate portions can be relatively reduced, and a portion having a large gray scale value can be expressed in gradation better than before. It is thought that it becomes.

According to a fifth aspect of the present invention, the image processing apparatus further includes a gradation correcting means for correcting a gradation of the original image stored in the first storage means, and the comparing means includes a gradation correcting means. The corrected gradation image is compared with the dot concentration type dither matrix stored in the second storage unit for each block, and a binary image is output.

The image processing method according to the present invention is characterized in that the original image is subjected to gradation correction and then subjected to dither processing.

According to the fifth and eleventh aspects, since the dither processing is performed after the tone correction is performed on the original image, the printed image can be more accurately expressed in the tone.

An image processing apparatus according to a sixth aspect of the present invention is an image processing apparatus for performing image processing when manufacturing a printing original plate using a thermoplastic porous material as a stamp material, wherein a gradation image as an original image is stored. Storage means; gradation correction means for correcting the gradation of the original image stored in the storage means; and binarization means for binarizing the gradation image gradation-corrected by the gradation correction means. ing.

According to a twelfth aspect of the present invention, there is provided an image processing method for manufacturing a printing plate using a thermoplastic porous material as a printing material, wherein the tone correction is performed on a tone image as an original image. After the application, it is binarized.

Further, a storage means for storing a gradation image as an original image, a gradation correction means for correcting the gradation of the original image stored in the storage means, and a gradation correction means. A computer as an image processing apparatus for performing image processing when manufacturing a printing plate using a thermoplastic porous material as a stamping material, the computer including a binarizing unit for binarizing a gradation image with gradation corrected Is a computer-readable recording medium on which a program for causing a computer to function is recorded.

According to the sixth, twelfth and fifteenth aspects, the gradation correction is performed on the gradation image which is the original image, especially when the resolution is small, regardless of the type of the binarization processing.
The printed image is expressed in gradation with the density according to the gray scale value of the original image.

The image processing apparatus according to claim 7 is characterized in that an optical plate is applied to a stamp material to form a stamp surface, and the image processing apparatus according to claim 8 is characterized in that a thermal plate is applied to the stamp material. Is applied to form a stamped surface.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

In the first embodiment of the present invention, binarization using a dot concentration type dither matrix is performed as image processing when a stamp using a thermoplastic porous material as described above is manufactured. Things. FIG. 1 is a schematic block diagram of a personal computer (hereinafter, abbreviated as “PC”), which is an image processing apparatus according to a first embodiment of the present invention, and a stamp creating apparatus connected thereto. FIG. 2 is an overall perspective view of the stamp making apparatus shown in FIG. 1, and FIG. 3 is an overall sectional view thereof.

First, the structure of the stamp making apparatus will be described with reference to FIGS. Stamp making device 1
A film magazine 2 detachable from the apparatus main body 12 and capable of storing a plurality of transparent original films 8;
Based on the supply port 3 of the cut sheet CS for the printing plate identification (ID) label provided in the apparatus main body 12 near the film magazine 2, the printing unit 4 provided with the thermal head 5, and the printed original film 8 Stamp section 6 for forming a stamp on a stamp material (not shown) disposed on the lower surface of the stamp body 7, a stamp storage section 70 for accommodating the stamp body 7 when the stamp face is formed, and a device near the stamp section 6. Body 12
And a discharge port 108 for the original film 8.

The head holder unit 102 provided on the upper surface of the printing unit 4 has the thermal head 5 below the head unit 102 and is rotatable upward about a shaft 110. Can be maintained. Further, the leading end of the original film 8 at the top of the film magazine 2 comes into pressure contact with the feeding roller 23, and in this state, the feeding roller 23 is driven and rotated so that the original film 8 is favorably conveyed toward the printing unit 4. be able to. Further, the cut sheet CS includes a pair of feed rollers 19 and 20 provided immediately after the supply port 3.
The guide rail 15 and the sheet guide 21 provided immediately after the feed rollers 19 and 20 and curved in the direction of the thermal head 5 convey the print head to a position where printing by the thermal head 5 is possible.

The printing section 4 is provided with a main roll 13a and a take-up roll 13b of the thermal transfer ribbon 9 coated with wax-based ink. Head holder unit 10
A platen 14 is provided below the thermal head 5 arranged below the thermal head 2. Also, the original roll 13a
A guide rail 15 for guiding the original film 8 and the cut sheet CS between the thermal head 5 and the platen 14, a pressing guide 16 for preventing the original film 8 and the cut sheet CS from being lifted during conveyance, Are arranged. A transfer guide 17 and a pair of supply rollers 18 are provided downstream of the thermal head 5.

Below the stamp section 6, a light emitting unit (HU) 10 having a xenon tube 11 surrounded by a reflector box 34 is detachably provided. The light emitting unit 10 having the stage 33 on which the stamp body 7 is mounted can be removed from the stamp making apparatus 1 by sliding the slide lever 101 upward. Further, the stamp section 6 is provided with an upper lid 36 and an upper front lid 106 which are opened and closed when the stamp body 7 is taken in and out.

The stamp making apparatus 1 is connected to a personal computer 150 shown in FIG. 1 by a cable (not shown) or the like to print a positive original on the original film 8 and to form a cut sheet CS under the control of the personal computer 150. Various operations such as printing of an ID label and plate making of a stamp based on the original film 8 on which a positive original is printed are executed.

That is, from the film magazine 2 to the printing unit 4
The thermal head 5 prints a positive image composed of predetermined characters and the like on the original film 8 conveyed to the original film 8, and the printed original film 8 is sent to the stamp unit 6. The light emitting unit 10 irradiates the stamp material arranged on the lower surface of the stamp body 7 with light via the original film 8 to make the stamp material, and a series of stamp making operations by the stamp making apparatus 1 is completed.

In the case of cut sheet CS printing,
The cut sheet CS is supplied from the supply port 3, and positive images such as characters and graphics are printed on the cut sheet CS instead of the original film 8 by the thermal head 5, and are discharged from the discharge port 108. The printed cut sheet CS may be attached to the stamp body 7 as an ID label.

Here, the structure of the stamp material arranged on the lower surface of the stamp body 7 will be described. The printing material used here is a soft porous resin (for example, a urethane-based resin) in which a light energy absorbing material such as carbon black is dispersed as disclosed in Japanese Patent Application Laid-Open No. 11-78191 by the present applicant. ) And a hard porous resin (e.g., polyvinyl formal) that stores ink and ensures that pressure is uniformly applied to the lower layer.
And a two-layer structure including an upper layer made of

When light is selectively irradiated through a transparent original film (positive original) on which a positive image is printed in a state where the printing material is compressed, the lower side irradiated with light corresponding to the transparent portion of the original is obtained. The portion of the layer is solidified after being melted by the heat-generating action of the light energy absorbing substance, so that it is sealed and does not transmit ink. On the other hand, the lower layer portion corresponding to the printed portion of the document is not not only irradiated with light but also is not melted and solidified by conduction heat from the printed portion of the document,
The original remains without being sealed in accordance with the characters of the original. As a result, a stamp is formed in which the seal portion (non-print portion) and the non-seal portion (print portion) of the desired pattern are mixed on the lower surface of the printing material.

Next, a control system of a personal computer which is an image processing apparatus according to the present embodiment and a stamp forming apparatus connected to the personal computer will be described with reference to FIG. The personal computer 150 includes a CPU (binarizing unit, resolution changing unit, gradation correcting unit, control unit, comparing unit) 152 and a RAM (2
154, a hard disk 156
And an input / output interface 162, which are interconnected by a bus 164. The input / output interface 162 includes a monitor 158.
And the input device 160 are connected.

On the monitor 158, a stamp data creation screen including a stamp image to be made by the stamp creating apparatus 1 is displayed. The input device 160 includes a character input device such as a keyboard and an input pad, a pointing device such as a mouse, and a graphic data capturing device such as a scanner.

The hard disk 156 is a storage medium according to the present embodiment which magnetically stores an image processing program (editor), dictionary data for kana / kanji conversion, and various types of character fonts. . RAM1
Reference numeral 54 temporarily stores a program read from the hard disk 156, data provided from the input device 160, and the like. The RAM 154 has an input buffer 17
1, a resolution changed image storage area 172, a gradation correction table storage area 173, a gradation corrected image storage area 174,
A dither matrix storage area 175, a binary image storage area 176, and a display image buffer 177 are provided.

The input buffer 171 stores graphic data generated using a keyboard or a mouse or graphic data input from a scanner as grayscale gradation image data having 256 gradations. The resolution-changed image storage area 172 stores resolution-changed image data obtained by changing the resolution of the image data in the input buffer 171. The gradation correction table storage area 173 stores a gradation correction table for performing gradation correction on the gradation image data stored in the resolution change image storage area 172.
The gradation-corrected image storage area 174 stores image data obtained by performing gradation correction on the gradation image data stored in the resolution-changed image storage area 172. The dither matrix storage area 175 stores a dither matrix used when binarizing the gradation image data stored in the gradation correction image storage area 174. Binary image storage area 1
At 76, binary image data obtained by binarizing the gradation image data stored in the gradation correction image storage area 174 by the CPU 152 is stored. The display image buffer 177 stores data relating to an image displayed on the monitor 158.

The CPU 152 operates in accordance with the program stored in the hard disk 156 to control the resolution changing unit 166, the gradation correcting unit 167, the binarizing operation unit (including the comparing unit) 168, and the respective units. It is possible to function as the unit 169. CP
U152, as described in detail below,
Based on the program stored in 56, the image data stored in input buffer 171 is subjected to gradation correction and binarization processing (and resolution change processing if necessary), and the resulting binary image The data is stored in the binary image storage area 176 of the RAM 154. And the CPU 15
2 sends the created binary image data to the stamp creation device 1 when an image is printed on the original film 8 or the cut sheet CS.

The recording medium on which the image processing program according to the present embodiment is recorded may be, for example, a floppy disk or a CD-ROM other than the hard disk 156, and although not shown in FIG. Is a floppy disk drive and / or CD-R
OM drive is equipped.

The stamp creating device 1 includes a CPU 1
80, a ROM 182, a RAM 184, and an input / output interface 188.
They are interconnected by 90. The input / output interface 188 of the personal computer 150 is connected to the input / output interface 188 via a cable or the like. In this way, the stamp creating apparatus 1 transmits the stamp face data image-processed according to the present embodiment to the personal computer 15.
It is possible to take in from zero. Further, a head drive circuit 192 and a motor drive circuit 194 are connected to the input / output interface 188, respectively. The thermal head 5 is connected to the head drive circuit 192, and the motors 178 which are disposed at various points of the stamp forming apparatus 1 and drive the thermal head 5 and various rollers are connected to the motor drive circuit 194, respectively. .

The ROM 182 stores a control program for controlling the entire operation of the stamp making device 1. The RAM 184 is provided with an image buffer 197 for storing stamp face data given from the personal computer 150.

The CPU 180 controls the control program stored in the ROM 182 and the image buffer 1 of the RAM 184.
The head drive circuit 192 and the motor drive circuit 194 are controlled based on the stamp image data stored in the memory 97. Thereby, the original film 8 or the cut sheet C
On S, a desired imprint image is printed by the thermal head 5,
The original film 8 is thereafter provided for plate making of a stamp material.

Next, the procedure for creating a stamp and an ID label in this embodiment will be described with reference to FIG.
This will be described with reference to FIGS. FIG. 4 is a flowchart showing a procedure for creating a stamp in the present embodiment. First, in step S1, data of a stamp surface to be used as a stamp is created. In order to do so, a figure created by a user using paint software or the like and stored in the input buffer 171 or a figure input to the personal computer 150 using a scanner or the like and stored in the input buffer 171 of the RAM 154 is fetched by a predetermined procedure. Is displayed on the editing screen of the editor on the monitor 158.

At this time, the resolution of the image data taken into the editor is changed by the resolution changing unit 167 of the CPU 152 in accordance with the plate making resolution of the stamp making apparatus 1 (that is, the resolution of the thermal head 5), and the resolution is changed. The image data is stored in the resolution change image storage area 172 of the RAM 154. The operation of the resolution changing unit 167 is controlled by the control unit 169. If both resolutions are the same, there is no need to change the resolution.
Then, if necessary, characters are input from a keyboard or desired image processing is performed on the input figures to create imprint image data of a desired layout.

Next, in step S2, the stamp creator 1 designates whether stamp making or ID label printing is to be performed by the user via the editor. A flag is set in a predetermined area of the RAM 154 according to the specified contents. This flag specifies whether stamp making or ID label printing is performed by the stamp creating device 1.

Next, in step S3, it is determined based on the flag whether to perform stamp making or ID label printing next time. As a result, if it is determined that ID label printing is specified (S3: YES), the process proceeds to step S4, and if it is determined that stamp plate making is specified (S3: NO), the process proceeds to step S6.

In step S4, the gradation correction section 167 of the CPU 152 uses the gradation correction table for ID label printing stored in the gradation correction table storage area 173 of the RAM 154 to change the resolution change image storage area 172.
Is subjected to gradation correction.
The operation of the tone correction unit 167 is controlled by the control unit 169. The gradation-corrected image data is stored in the gradation correction image storage area 174 of the RAM 154. The gradation correction table for ID label printing has almost no cause for deteriorating the linearity between the gray scale value and the print density unlike plate making, so that the input value and the output value as indicated by the straight line 201 in FIG. They may be approximately equal.

In step S5, the image data stored in the gradation corrected image storage area 174 is subjected to a binarization process using, for example, a 4 × 4 dot dispersed dither matrix as shown in FIG. Is performed by the binarization operation unit 168. In FIG. 8, a numerical value in each matrix element represents a threshold value for performing binarization. In the binarization processing, the binarization operation unit 168 of the CPU 152 converts the gradation image stored in the gradation correction image storage area 174 into the dot dispersion type dither matrix stored in the dither matrix storage area 175 for each block. The comparison is performed by outputting the magnitude of the value obtained by dividing the gray scale value of each pixel of the gradation image into 16 levels and the corresponding element of the dither matrix. The operation of the binarization operation unit 168 is controlled by the control unit 169. Binarization operation unit 1
The binary image obtained by the calculation at 68 is stored in the RAM 15
4 is stored in the binary image storage area 176. here,
In the case of ID label printing, the binarization process is performed using the dot dispersion type dither matrix, because a fine print image is obtained because the spatial frequency of the dots is high.

On the other hand, in step S6, the tone correction unit 167 of the CPU 152 stores the image in the resolution change image storage area 172 by using the tone correction table for plate making stored in the tone correction table storage area 173 of the RAM 154. Tone correction is performed on the image data. The gradation-corrected image data is stored in the gradation correction image storage area 174 of the RAM 154. The tone correction table for plate making uses the input gray scale as shown by the curve 202 in FIG. 6 in response to the deterioration of the linearity between the gray scale value of the original image and the print density as described above. It is preferable that the output grayscale value be smaller in an area where the value is large and the output grayscale value be larger in an area where the input grayscale value is small.

The curve 202 can be obtained by the following procedure. First, "0" (black) to "255"
256 with each grayscale value up to (white)
Sample data is created, and the stamp density obtained by binarizing the sample data by a dither method using a dot concentration type dither matrix without gradation correction is made to correspond to the original gray scale value. This allows
A characteristic curve like curve 204 in FIG. 5 is obtained. Curve 2
In 04, when the gray scale value is less than 180, the density ratio is too large compared to the gray scale value, and when the gray scale value is 180 or more, the density ratio is too small. Therefore, for example, a gray scale value of 128 is changed to a density ratio of 0.5 at that time.
Is corrected to the gray scale value 170 so as to decrease to. By creating a gradation correction table by repeating the same operation, both can be made to have a substantially linear relationship.

In step S7, the image data stored in the gradation corrected image storage area 174 is subjected to a binarization process using a dot concentration type dither matrix as shown in FIG. This is performed by the arithmetic unit 168. In FIG. 7, the numerical value in each matrix element is 2
This represents a threshold value for performing value conversion. In the binarization processing, the binarization operation unit 168 of the CPU 152 converts the gradation image stored in the gradation correction image storage area 174 into the dot concentration type dither matrix stored in the dither matrix storage area 175 for each block. The comparison is performed by outputting the magnitude of the value obtained by dividing the gray scale value of each pixel of the gradation image into 16 levels and the corresponding element of the dither matrix. The binary image obtained by the calculation in the binarization calculation unit 168 is stored in the binary image storage area 176 of the RAM 154.

Next, in step S8, step S
5 or the binary image data created in S7 is transmitted from the binary image storage area 176 to the stamp creating device 1,
It is stored in the image buffer 197 of the RAM 184. Further, in step S9, the thermal head 5 is driven according to the binary image data stored in the image buffer 197, so that a positive original is thermally printed on the original film 8 or an ID label is printed on the cut sheet CS. Is performed. The original film 8 on which the positive original has been printed is thereafter subjected to flash plate making in the stamp unit 6.

The relationship between the imprint density ratio as a result of stamp printing on paper using the stamp created by the above-described process and the gray scale value of the original image is shown by curve 2 in FIG.
06. As is apparent from the curve 206, as a result of performing the image processing according to the present embodiment, the gray scale value of the original image and the density ratio have a substantially linear relationship. Therefore, according to the present embodiment, the entire range of the gray scale values of the original image can be used for gradation expression, and a stamp image with excellent gradation reproducibility can be obtained. That is, according to the present embodiment, the gray scale value is “
In a comparatively long range close to 0 "or" 255 ", the density ratio of the printing result does not substantially take a value close to" 1 "or" 0 ". This makes it possible to reflect the stamp density, so that the printing result can be expressed with the density according to the gray scale value of the original data.

Next, a second embodiment of the present invention will be described. The second embodiment of the present invention is the same as the first embodiment.
In this embodiment, the gradation correction is not performed. The device configuration and the stamp creation procedure according to the present embodiment are almost the same as those in the first embodiment except for the presence or absence of gradation correction, and therefore description thereof is omitted.

The relationship between the density ratio of the result of stamp printing on paper using the stamp created according to the present embodiment and the gray scale value of the original image is shown by a curve 204 in FIG. The curve 204 is a curve in which the linearity between the gray scale value and the density ratio of the original image is deteriorated as compared with the curve 206 in FIG. 9. However, according to the present embodiment, it is possible to express a certain gradation in the stamped image. It is possible.

The present inventor examined the characteristics of the characteristic curve showing the relationship between the gray scale value of the original image and the stamp density ratio and the gradation expression of the stamp image. It was found that if the slope of the characteristic curve was 1/256 or more in a continuous range of 64 or more in value, a stamp image with good gradation expression could be obtained.
Even if the slope of the characteristic curve locally becomes less than 1/256 within a narrow range of about 10 to 20 in gray scale value, when a wide range of 30 to 40 or more in gray scale value is viewed in total, There is no problem if the inclination is 1/256. In the case of the curve 204, the slope is 1/25.
Six or more ranges are continuous in about 96 from about 112 to about 208 in gray scale value, which satisfies this condition.

In order to obtain more excellent gradation reproducibility, the continuous range of the gray scale value at which the slope of the characteristic curve becomes 1/256 or more is preferably 96 or more, and 128 or more. It has also been found that some are more preferred. The slope of the curve 206 shown in FIG. 9 is 1/256 or more substantially in the entire range from the gray scale value 0 to 255, which satisfies the most preferable condition.

As a modification of the present embodiment, a dot loss area of a gray scale value (an area in which the density ratio with respect to the gray scale value is relatively small, and an area where plate making is unstable: curve 204) Stamp making may be performed without using data of about 186 to 225). Also in this case, the gradient becomes 1/256 in a range of about 74 from about 112 to about 186 in gray scale value, so that a certain degree of gradation reproducibility can be obtained.

Next, a third embodiment of the present invention will be described. The third embodiment of the present invention is the same as the first embodiment described above.
In this embodiment, the binarization processing for stamp plate making is performed using a dot dispersion type dither matrix as shown in FIG. 8 and the resolution of image data is controlled. is there.

A procedure for creating a stamp according to the present embodiment will be described focusing on differences from the first embodiment. In the first embodiment, when the stamp data is created in step S1, the resolution of the image data taken into the editor is changed so as to be the same as the plate making resolution of the stamp creating apparatus 1. In the embodiment, the resolution of the image data is reduced so that the condition that the slope of the characteristic curve is 1/256 or more is satisfied in the above-described continuous range of 64 or more gray scale values. Along with this, the plate making resolution on the side of the stamp making device 1 is controlled so as to be reduced in a pseudo manner. For example, when the resolution of the image data is reduced from 600 dpi to 300 dpi, two adjacent heating elements of the thermal head 5 generate 1
In such a way that the dots are represented, the plate making at 300 dpi is performed in a pseudo manner also on the stamp creating apparatus 1 side.

A curve 208 shown in FIG. 10 represents image data (floor data) obtained by performing a binarization process using a dot dispersion type dither matrix as shown in FIG. 8 with the resolution changed by the resolution changing unit 166 set to 600 dpi. 3 shows the relationship between the gray scale value of the original image and the print density ratio of the stamp made based on the tone adjustment (without tone correction). This curve 2
In the case of 08, there are only about 48 continuous ranges of the gray scale values in which the inclination is 1/256 or more from about 128 to about 176. For this reason, the tone reproducibility of the stamped image is not satisfactory.

Therefore, in the present embodiment, the resolution of the gradation image is reduced to 600 dpi or less by the resolution changing unit 166, and this image data is stored in the resolution changed image storage area 172. At this time, the extent to which the resolution of the image data should be reduced can be changed according to the binarization means (in the case of the present embodiment, the specific type of the dot dispersed dither matrix). Preferably, the control unit 169 controls the resolution change unit 166 to adjust the resolution after the reduction.

When the resolution is reduced, the slope near the median gray scale value is gentler than that of the curve 208 as a characteristic curve because ink bleeding in a portion where the gray scale value is small is reduced. A curve 210 is obtained. In the case of the curve 210, the continuous range of the gray scale value in which the gradient is 1/256 or more is about 100 from about 90 to about 190, and the tone reproducibility to some extent is more satisfactory with the stamp image stamped. It is possible to obtain The change of resolution is 2
The processing may be performed on the binary image obtained by the quantifying operation unit 168, and the same effect as in the present embodiment can be obtained. Thus, the present embodiment is
This method is effective as a means for obtaining a stamp having excellent tone reproducibility when there is little problem even if the plate making resolution is lowered.

In the present embodiment, binarization is performed using a dot-dispersion type dither matrix. However, binarization may be performed according to an error diffusion method or other known techniques. For example, when binarization is performed by using an error diffusion method, the error due to binarization is weighted and assigned to peripheral dots, so that a reduction in resolution can be minimized.

As a modification of the present embodiment, before performing the binarization process using the dot dispersion type dither matrix, the gradation correction unit 1 of the CPU 152 in step S6.
The gradation correction by 67 may be performed. By performing the gradation correction, the curve near the median of the gray scale values has a gentler slope than the curve 210 as a characteristic curve.
Is obtained. In the case of this curve 212, the slope is 1/25.
The continuous range of grayscale values of 6 or more is about 160 from about 64 to about 224,
With the stamp image stamped, relatively good tone reproducibility can be obtained. An appropriate gradation correction table may be selected from several predetermined types according to the judgment of the control unit 169 and used by the control unit 169 according to the dither matrix to be used and the resolution to be changed. A gradation correction table may be generated.

Further, as still another modification of the present embodiment, gradation correction is performed in step S6 so as to satisfy the above-mentioned condition regarding the gradient of the gray scale value without lowering the resolution in step S1. Is also good. At this time, as the tone correction table, an appropriate one may be selected from a plurality of predetermined types according to the judgment of the control unit 169 and may be used in accordance with the dither matrix to be used or the resolution to be changed. The unit 169 may generate an appropriate gradation correction table. Further, as another modified example, when the gradation correction table to be used and / or the resolution after being changed by the resolution changing unit 166 is predetermined, the above-described gray scale value is determined by the control unit 169. The binarization may be performed by the binarization calculation unit 168 using a dither matrix that satisfies the condition for the gradient of.

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to this, and various design changes can be made within the scope of the appended claims. For example, the stamp making device may be a device that makes a thermoplastic porous material by thermal plate making using a thermal head or the like in addition to optical plate making such as the flash light plate making described above. Further, the function as the image processing apparatus may be incorporated not in a personal computer but in a device such as a stamp creating device that performs plate making based on created stamp face data.

[0075]

As described above, claims 1 to 3,
According to Nos. 9 and 13, a wider range of gray scale values can be used for gradation expression as compared with the related art, and a printed image with more excellent gradation reproducibility can be obtained.

According to the fourth, tenth, and fourteenth aspects, the dither processing using the dot concentration type dither matrix is performed on the gradation image as the original image.
The printed image is expressed in gradation with the density according to the gray scale value of the original image.

According to the fifth and eleventh aspects, since the dither processing is performed after the tone correction is performed on the original image, the printed image can be more accurately expressed in the tone.

According to the sixth, twelfth and fifteenth aspects, the gradation correction is performed on the gradation image which is the original image, so that the resolution is particularly small, regardless of the type of the binarization processing.
The printed image is expressed in gradation with the density according to the gray scale value of the original image.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of a personal computer, which is an image processing apparatus according to a first embodiment of the present invention, and a stamp creating apparatus connected thereto.

FIG. 2 is an overall perspective view of the stamp making apparatus shown in FIG.

FIG. 3 is an overall sectional view of the stamp making apparatus shown in FIG.

FIG. 4 is a flowchart showing a procedure for creating a stamp in the first embodiment of the present invention.

FIG. 5 is a graph showing a relationship between a grayscale value of an original image and a print density ratio when tone correction is not performed in the first embodiment of the present invention.

FIG. 6 is a graph showing a gradation correction table.

FIG. 7 is a diagram illustrating an example of a dot concentration type dither matrix.

FIG. 8 is a diagram illustrating an example of a dot dispersion type dither matrix.

FIG. 9 is a graph showing a relationship between a gray scale value of an original image and a print density ratio when gradation correction is performed in the first embodiment of the present invention.

FIG. 10 is a graph showing a relationship between a grayscale value of an original image and a print density ratio in the third embodiment of the present invention.

[Explanation of symbols]

 1 Stamp Creation Device 150 Personal Computer 152 CPU 154 RAM 156 Hard Disk 158 Monitor 166 Resolution Change Unit 167 Gradation Correction Unit 168 Binarization Operation Unit 169 Control Unit 171 Input Buffer 172 Resolution Changed Image Storage Area 173 Gradation Correction Table Storage Area 174 Floor Tone correction image storage area 175 Dither matrix storage area 176 Binary image storage area 177 Display image buffer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G06F 3/12 B41J 3/00 A 5C077 G06T 5/00 G06F 15/68 320A H04N 1/407 H04N 1/40 101E F-term (reference) 2C262 AA03 AA24 AA29 AB07 BA09 BA20 BB06 BB23 DA16 2H084 AA17 AE06 AE10 BB04 BB13 CC01 CC20 2H095 AA10 AB15 5B021 AA01 AA30 DD00 LG08 5B057 CA08 CA12 CA16 CB07 CB07 CB07 CC02 NN19 NP01 PP15 PP20 PP47 PQ08 PQ12 PQ20 PQ22 PQ23 RR02 TT08

Claims (15)

[Claims] 1. An image processing apparatus for performing image processing when manufacturing a printing plate using a thermoplastic porous material as a printing material, comprising: a storage unit for storing a gradation image as an original image; And a binarization unit that performs a binarization process on the binary image and outputs a binary image. The binary image obtained by the binarization unit with respect to the gray scale value of the original image when the number of gradations is 256 The binarization is performed so that a slope of a characteristic curve indicating a change in a print density ratio by a printing original plate made based on a predetermined resolution is 1/256 or more in a continuous range of 64 or more gray scale values. An image processing apparatus comprising: control means for controlling means. 2. The image processing apparatus according to claim 1, further comprising: a resolution changing unit configured to change a resolution of the gradation image or the binary image. Based on the binary image obtained by the binarizing unit, the slope of the characteristic curve indicating the change in the print density ratio by the printing original plate made with the resolution changed by the resolution changing unit is 64 in gray scale value. 2. The image processing apparatus according to claim 1, wherein the binarizing unit and the resolution changing unit are controlled so that the ratio becomes 1/256 or more in the continuous range. 3. The image processing apparatus according to claim 1, further comprising: a gradation correction unit configured to perform a gradation correction on the gradation image, wherein the binarizing unit performs a gradation correction on the gradation image corrected by the gradation correction unit. The control means outputs a binary image by performing binarization processing on the basis of the binary image obtained by the binarization means with respect to the gray scale value of the original image when the number of gradations is 256. The binarizing unit and the binarizing unit, wherein a slope of a characteristic curve indicating a change in a print density ratio by a printing original plate made at a predetermined resolution is 1/256 or more in a continuous range of 64 or more in gray scale value. 2. The image processing apparatus according to claim 1, wherein said tone correction unit is controlled. 4. An image processing apparatus for performing image processing when manufacturing a printing plate using a thermoplastic porous material as a stamping material, wherein: a first storage means for storing a gradation image as an original image; A second storage unit that stores a dot concentration type dither matrix; and a second storage unit that stores the gradation image stored in the first storage unit in the second storage unit.
An image processing apparatus comprising: a dot concentration type dither matrix stored in a storage unit of the present invention; 5. The image processing apparatus according to claim 1, further comprising: a gradation correction unit configured to correct a gradation of the original image stored in the first storage unit; 5. The image processing apparatus according to claim 4, wherein a binary image is output by comparing each block with the dot concentration type dither matrix stored in the second storage unit. 6. An image processing apparatus for performing image processing when manufacturing a printing plate using a thermoplastic porous material as a printing material, wherein: a storage unit for storing a gradation image as an original image; And a binarizing unit for binarizing the gradation image whose gradation has been corrected by the gradation correcting unit. Image processing device. 7. The image processing apparatus according to claim 1, wherein an optical plate is applied to the stamp material to form a stamp surface. 8. The image processing apparatus according to claim 1, wherein the printing material is subjected to thermal plate making to form a printing surface. 9. An image processing method performed when manufacturing a printing plate using a thermoplastic porous material as a stamping material, wherein the obtained binary image is obtained with respect to the gray scale value of the original image when the number of gradations is 256. The gradient of the characteristic curve indicating the change in the print density ratio by the printing original plate made at the resolution after the change based on the gray scale value is 1/256 or more in a continuous range of 64 or more in gray scale value. 2 for the image
An image processing method comprising performing at least a binarization process among a binarization process, a resolution change of a gradation image or a binary image, and a gradation correction of an original image. 10. An image processing method for producing a printing plate using a thermoplastic porous material as a printing material, wherein a dithering process using a dot concentration type dither matrix is performed on a gradation image as an original image. An image processing method characterized by the following. 11. The image processing method according to claim 10, wherein a dither process is performed after performing tone correction on the original image. 12. An image processing method performed when manufacturing a printing plate using a thermoplastic porous material as a printing material, wherein the binarization is performed after performing gradation correction on a gradation image as an original image. Characteristic image processing method. 13. A storage means for storing a gradation image as an original image, a binarization means for performing a binarization process on the gradation image and outputting a binary image, The characteristic curve showing the change in the print density ratio of the printing original plate made at a predetermined resolution based on the binary image obtained by the binarizing means with respect to the gray scale value of the original image of Control means for controlling the binarization means so that the value becomes 1/256 or more in a continuous range of 64 or more when producing a printing original plate using a thermoplastic porous material as a stamping material. A computer-readable recording medium in which a program for causing a computer to function as an image processing device for performing image processing is recorded. 14. A first memory for storing a gradation image as an original image.
Storage means for storing a dot concentration type dither matrix; and a gradation image stored in the first storage means,
A dot-concentration-type dither matrix stored in the storage means and a comparison means for comparing each block to output a binary image. A computer-readable recording medium in which a program for causing a computer to function as an image processing device for performing processing is recorded. 15. A storage unit for storing a gradation image as an original image, a gradation correction unit for correcting the gradation of the original image stored in the storage unit, and a gradation corrected by the gradation correction unit. A binarizing means for binarizing a gradation image, wherein the computer functions as an image processing apparatus for performing image processing when manufacturing a printing plate using a thermoplastic porous material as a stamping material. A computer-readable recording medium on which a program is recorded.