JPS62151073A - Data conversion control system - Google Patents

Abstract

PURPOSE:To attain a gradation expression with plural sets of print picture elements by using a conversion table in which a gradation expression matrix consisting of plural printing picture element data is set corresponding to an original picture element data. CONSTITUTION:A conversion table 11 can be accessed by using the original picture element data, the output of a line computer 14, the output of a dot counter 15, or a color selection signal from a color selection circuit 16 as an address signal, and the printing picture element data which represents the presence/absence of a print is read out. The original picture element data in the matrix of an original image are converted to the printing picture element data which are presented as Y, M, C, and K within the matrix, and the original picture element data, such as a character, a graphic, etc., is converted to the printing picture element data in which the print is performed on the original picture in a proportion of 1:1, and the original picture element data of multiple gradation, such an image data, etc., is converted to the printing picture element data using a gradation expression matrix, and the gradation expression can be performed with the set of plural print picture elements.

Description

[Detailed Description of the Invention] [Summary] A gradation expression matrix consisting of a plurality of printing pixel data is created using a conversion table set in correspondence with original pixel data.
Select the gradation expression matrix that corresponds to the original pixel data,
In addition, the value of the position in the gradation expression matrix corresponding to the position in the matrix of the original pixel data is output as printing pixel data that is added to the printer, and images that emphasize gradation and images that emphasize resolution are mixed. This makes it possible to print images of good quality even when

[Industrial application field]

The present invention relates to a data conversion control method for converting original pixel data into pixel data for printing when an image displayed on a display device or the like is printed using a printer with relatively low gradation expressiveness. .

When an image displayed on a cathode ray tube (CRT) display device or the like is printed using a printer such as a thermal printer or an inkjet printer that prints dot by dot, the resolution of the printer is lower than that of the display device. In the case of a color image, the image is separated into a plurality of primary colors and printing for each primary color is repeated. Therefore, when adding an image displayed on a display device to a printer, the pixel data is
It is necessary to convert the image data into pixel data for printing.

[Conventional technology]

BACKGROUND ART In the past, the dither method has been relatively often used when printing images with multi-gradation expression using a printer such as a thermal printer or an inkjet printer that has low gradation expression ability. The dither method is a type of area gradation method, and is Bayer (
Bayer) type, spiral type, halftone type, etc. When printing color images, use Y (yellow) 2M (magenta)
, C (cyan), and further including K (black), and printing is performed repeatedly for each color.

[Problem that the invention seeks to solve]

Recently, it has become common to handle image data that is a mixture of image data and character 1 graphic data, but for image data, gradation expression power is required more than resolution, and on the contrary, for character 1 graphic data, , resolution is required rather than gradation expressiveness. Therefore, a method that expresses gradation by primarily lowering the resolution, such as the conventional dithering method, has the disadvantage that the resolution of one character figure becomes too low.

It is also possible to identify image data and character 1 graphic data and convert them into corresponding printing pixel data, but this method has the disadvantage that the means for identifying image data and character 1 graphic data is complicated and expensive. be.

The present invention uses a conversion table with a relatively simple configuration to
The purpose of this invention is to convert data so that a desired image quality can be obtained even when images that emphasize gradation and images that emphasize resolution coexist.

[Means for solving problems]

The data conversion control system of the present invention converts original pixel data of an image displayed on a display device or the like into printing pixel data to be added to a printer, and will be explained with reference to FIG. A conversion table 1 in which a gradation expression matrix 2 formed by a dithering method etc. consisting of a plurality of printing pixel data is set corresponding to the original pixel data, and a control unit 2 for controlling the conversion table 1 are provided, and a display device etc. The value of the gradation expression matrix 2 corresponding to the original pixel data from the original pixel memory 5 or the like that stores the data of the image to be displayed is outputted as printing pixel data to be added to the printer 4.

[Effect]

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a block diagram of an embodiment of the present invention, showing a case where original color pixel data is converted into printing pixel data to be added to a color printer. In the figure, 11 is a conversion code.

- pull, 12 is a gradation expression matrix, 13 is a synchronous circuit, 14 is a line counter, 15 is a dot counter, 1
6 is a color selection circuit. Synchronous circuit 13° line counter 14. The dot counter 15, color selection circuit 16, etc. constitute the control section 3 in FIG.

The conversion table 11 is a random access memory (RAM).
), the values of the gradation expression matrix 12 can be written using table data. In this case, it is also possible to set the gradation expression matrix 12 corresponding to the properties of the image. Also, read-only memory (
Of course, it is also possible to use a ROM. This conversion table 11 contains original pixel data, line counter 1
4 output, dot counter 15 output and color selection circuit 1
The color selection signal from 6 is accessed as an address signal, and printing pixel data indicating whether printing is to be performed or not is read out.

The gradation expression matrix 12 of the conversion table 11 includes, for example, 17 gradations representing θ to 16 gradations for each printing color Y, C, and M.
It consists of 4×4 matrices, and a color selection circuit 16 selects a gradation expression matrix for each color.
When there are four printing colors, they are selected by a 2-bit color selection signal. Further, a row address in the gradation expression matrix 12 is specified by a line counter 14 indicating a line of original pixel data, and a column address of the gradation expression matrix is specified by a dot counter 15 indicating a dot position of the original pixel data.

As described above, when the gradation expression matrix 12 is 4×4, the line counter 14 and dot counter 15 each designate the row and column addresses of the gradation expression matrix 12 by outputting 2 bits.

The synchronization circuit 13 supplies a synchronization signal to the original pixel memory (not shown), a line counter 14 and a dot counter 1.
5, a signal to sequentially output color selection signals in the color selection circuit 16, and a synchronization signal to be applied to a printer (not shown) are output, and the original pixel data is converted into pixel data for printing. Synchronous operations of each part are performed to convert the data into a file and print it using a printer.

For example, the original pixel data represents the color information and gradation information of the original pixel using 8 bits, and when it includes components of each color, it is necessary to print the color components according to the printing order of the printer. Data conversion is performed for each color according to the order.

For example, in color thermal printers, Y, M,
Since a color image with good printing order in C, can be obtained,
The color selection circuit 16 also selects colors in this printing order. It is also possible to select a color each time one original pixel data is converted. It is also possible to convert one screen's worth of original pixel data into printing pixel data of a certain color and then converting it into printing pixel data of another color. In this case, it is necessary to repeatedly input the original pixel data a number of times corresponding to the number of printing colors.

FIG. 3 is an explanatory diagram of the gradation expression matrix, which consists of a 4×4 matrix of each color Y, M, C, and the matrix of each color is provided corresponding to the number of gradations, and the color selection circuit 16 When the Y, M, C, and K matrices are selected and the color matrix that matches the color information of the original pixel data is selected, the gradation expression matrix corresponding to the gradation information of the original pixel data is selected and its The row address of the gradation expression matrix is determined by the line counter 14, which indicates the line of original pixel data in 4 notation, and the column address of the gradation expression matrix is determined by the dot counter 15, which indicates the line direction position of the original pixel data in 4 notation. It is determined.

For example, °, the original pixel data contains a black component,
It has a gradation of (2+4i) lines (i=0
．． 1.2.3. ...) eyes (3+43) dots (j=0.1, 2, 3. ...) eyes, when black K is selected by the color selection circuit 16, the gradation information of the original pixel data is The corresponding gradation expression matrix is selected, and the line counter 14 reads out the second line, and the dot counter 15 reads out the third dot 7 as printing pixel data.

In the case of gradations from 0 to 16, if the gradation is O, all 4x4 are white, so "0" with no printing is set.
If the number is 16, all 4×4 pixels are of each color, so "1" indicating printing is set is set. For the other gradations 1 to 15, 0'' and '1'' are set as the values of the 4×4 matrix in accordance with the dither method and the like.

FIG. 4 is an explanatory diagram of conversion operation, and Y+z of original pixel data.
, Me , Ca , K16 is the keyword 12 of yellow Y
, the gradation 1i18 of magenta M, the gradation 4 of cyan C, and the gradation 16 of black. Although it has a gradation expression matrix, only the gradation expression matrix of gradation 4°8.12 in the case of the Bayer type dither method is shown, and the shaded position indicates the presence of printing (“1”). Stores pixel data for printing.

Also, set the pixel position of the original image to (1, yj) (i=1, 2.3.
..., j=1.2.3. ...) and 4
×4 pixels in matrix MXI.

MX2. ...Find this matrix MXI, MX
2. The original pixel data is converted into printing pixel data by making the position of the original pixel data in .

For example, original pixel data K16 of (x+ + y+)
is added to the conversion table 11, and when blank K is selected by the color selection circuit 16, a gradation expression matrix of gradation 16 of K is selected, and (x+
, 3'+) is output as printing pixel data. This gradation expression matrix of gradation 16 is 4×4
Since all values of are set to “1” (printing value), (x+, yt), (xI+ yz), (XI
, yi), (Xl,)'4) are converted into printing pixel data for printing black K. Therefore, when printing black K on a printer, (x
+, yl).

(Xl, Yt), (Xl, Y3)+ (X
Black K is printed at the position 1, 'la).

For the next (xz, yl) original pixel data C4, the gradation expression matrix of gradation 4 is selected when the cyan C color is selected, and the (xz, yl) value of this gradation expression matrix is is "O" (no printing), so it is converted into printing pixel data indicating no printing. Furthermore, the following (xs, yl
), when cyan C was selected, the gradation expression matrix of gradation 4 was selected, and the value of (X3.yl) in this gradation expression matrix was 1'' (with printing). ), it is converted into printing pixel data for printing cyan C.The next original pixel data M8 of (XJ, )'+) is, when magenta M is selected,
The gradation expression matrix of gradation 8 is selected, and the value "O" (no printing) of (Xa+'Jl) of this gradation expression matrix is read out.

Also, for the original pixel data M8 of (xs, yl) in the matrix MX2 of the original image, when the color selection of magenta M is performed, the gradation expression matrix of gradation 8 is selected, and the (x+ , )'+ ) is "1" (printing), so it is converted to printing image data indicating printing.

Therefore, the original pixel data of matrix MXI of the original image is
It is converted into printing pixel data indicated by Y, M, and C in the matrix mxl.

Then, the original pixel data of gradation 16 or close to it, such as characters and figures, is converted to printing pixel data that is printed one-to-one on the original pixel, resulting in a printed image with sufficient resolution.
Further, multi-gradation original pixel data such as image data is converted into printing pixel data using a gradation expression matrix, and the gradation is expressed by a set of a plurality of printing pixels.

For example, a set of 5 original pixels of cyan C at gradation 4 will be represented by a set of 2 printing pixels among the 5, and a set of 5 original pixels of gradation 12 of yellow Y. A set of pixels will be represented by a set of four of the five printed pixels. Note that in the case of mixed colors, printing is performed by, for example, overprinting, depending on the characteristics of the printer.

FIG. 5 is a block diagram of another embodiment of the present invention, 21
22 is a conversion table, 22 is a gradation expression matrix, 23 is a synchronization circuit, 24.26 is a line counter, and 25.27 is a dot counter.
3. The line counter 24 and dot counter 25 have substantially the same configuration as in the previous embodiment. Also, this embodiment shows a case where original pixel data is converted into printing pixel data to be added to a monochrome printer.

When converting 1 original pixel data into 4 dots of printing pixel data, the gradation expression matrix 22 is a 4 x 4 matrix corresponding to the original pixel data, and each is a 2 x 2 matrix.
The matrix of The synchronization circuit 23, line counter 24, and dot counter 25 operate in the same manner as in the previous embodiment, and select a gradation expression matrix corresponding to the gradation information of the original pixel data. A line of data is specified, a dot position is specified by the dot counter 25, a 2×2 line position is specified by the line counter 26, and a 2×2 dot position is specified by the dot counter 27.

FIG. 6 is an explanatory diagram of a gradation expression matrix, which is a 4 x 4 matrix further divided into 2 x 2, with a number of gradations by dithering etc. corresponding to the number of gradations of original pixel data. A representation matrix is provided. The row address of the gradation expression matrix selected corresponding to the gradation of the original pixel data is added from the line counter 24, the column address is added from the dot column 25, a 4×4 position is designated, and the position is The dot addresses in the 2.times.2 matrix are added from line counter 26 and dot counter 27.

For example, when the row address is 2 and the column address is 3, printing pixel data 7-1 to 7-4 corresponding to the original pixel data is specified, and the dot address by the line counter 26 and dot counter 27 is 1. At the same time, the printing pixel data of 7-1 is read out. Next, the line counter 26 and dot counter 27 calculate ? -2.7-3.7-4
, printing pixel data are read out sequentially, and 4 printing pixel data are read out for each original pixel data, so when one pixel has a resolution of 8 lines/mm, one print dot has 16 lines/mm. It has a resolution of mm, making high-resolution printing possible.

The character 2 graphic data becomes original pixel data of either gradation 0 or gradation 16, and as the gradation expression matrix 22,
Since it becomes an all-white or all-black matrix, when it is converted to printing pixel data and printed by a printer, an image that faithfully follows the original pixel data will be printed. In addition, the image data will be converted to printing pixel data using a gradation representation matrix of gradations O to 16, and in this case, 1 original pixel data will be converted to 4 printing pixel data, so The gradation level can be improved.

In the above embodiment, the original image is a 4×4 matrix,
Although this is a case where gradation expression matrices are made to correspond, it is also possible to use gradation expression matrices with other configurations. When applied to a color printer, if the color printer is capable of printing in two types of shading and light, a gradation expression matrix is set correspondingly, and a shading selection circuit is provided outside the color selection circuit 16. A gradation expression matrix corresponding to gradation is selected, and gradation information is added to the printer.

〔Effect of the invention〕

As explained above, the present invention provides a conversion table 1.11.21 in which a gradation expression matrix 2, 12.22 consisting of a plurality of printing pixel data is set corresponding to original pixel data.
This is a device that outputs the value of the gradation expression matrix corresponding to information such as one gradation color of the original pixel data as pixel data for printing, and prints the original pixel data in a 1:1 or 1:n relationship. Because it can be converted to pixel data for use in printing, and gradation can be expressed by a collection of multiple printing pixels, the desired resolution can be maintained even if images that emphasize gradation and images that emphasize resolution coexist. It becomes possible to print an image with gradation expression using a printer with low gradation expression ability.

[Brief explanation of drawings]

Fig. 1 is a block diagram of the principle of the present invention, Fig. 2 is a block diagram of an embodiment of the present invention, Fig. 3 is an explanatory diagram of a gradation expression matrix, Fig. 4 is an explanatory diagram of conversion operation, and Fig. 5 is a block diagram of an embodiment of the present invention. FIG. 6, a block diagram of another embodiment of the present invention, is an explanatory diagram of a gradation expression matrix. 1.11.12 is a conversion table, 2.12゜22 is a gradation expression matrix, 3 is a control section, 4 is an original pixel memory, 5
is the printer, 13.23 is the synchronous circuit, 14, 24.26
is a line counter, and 15°25.27 is a dot counter. Fig. 1 is a block diagram of an embodiment of the present invention; Fig. 5 is a block diagram of another embodiment of the invention; OM is an explanatory diagram of a signal gradation expression matrix; and table data is a block diagram of another embodiment of the invention.

Claims (1)

[Claims] In a data conversion control method that converts original pixel data into printing pixel data and adds it to a printer, a gradation expression matrix (2) consisting of a plurality of printing pixel data corresponds to the original pixel data. a conversion table (1) that is set as follows; and a control unit (2) that controls the conversion table (1), the conversion table (1) corresponding to one original pixel data.
A data conversion control method characterized in that the values of the gradation expression matrix (2) are output as printing pixel data to be added to the printer.