JP2002002023A - Image processing method and image recorder using that method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prolong the lifetime of a multi-time ink ribbon by suppressing consumption thereof sufficiently even in case of an image recording face for a relatively wide recording sheet of solid print and to ensure clear print recording where characters is sufficiently legible. SOLUTION: The image processing method comprises a step for normalizing image data 10 sectioned into a plurality of pixels to obtain a density correction value where each density value at the halftone density regions, except the maximum and minimum density values and the neighborhood values thereof, is lowered by a set density regulation value L; a step for generating operational data 25 having an emphasized outline by operating the density correction value sequentially through a matrix type outline emphasizing filter 20; and a step for generating binarized print output data 35 from the operational data 25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording apparatus such as a facsimile apparatus, a printer for a personal computer, and a multiprocessor, and an image processing method used in these apparatuses. The present invention relates to an image recording apparatus of a hot-melt transfer system for recording an image on ordinary recording paper by using an image forming apparatus, and an image processing method used for the apparatus.

[0002]

2. Description of the Related Art In general, a facsimile apparatus on a transmitting side in a remote place scans a document by irradiating the document with light, reads image data recorded on the document, converts the image data into an electric signal, and converts the electric signal into a telephone line. To the facsimile machine on the receiving side via. The receiving-side facsimile apparatus reversely converts the received electric signal into image data, and records and reproduces the same image as the image data on ordinary recording paper with ink.

In recent years, there has been proposed a personal use facsimile apparatus in which a printer unit is of a thermal fusion transfer type. The printer unit of the thermal fusion transfer system has a thermal head having a plurality of heating elements regularly arranged in a line, and a ribbon cassette which is arranged opposite to the thermal head at a predetermined interval and stores an ink ribbon. are doing. In the printer unit of the hot-melt transfer method, a head in which a plurality of heated heating elements are arranged in a row is pressed against the ink layer of the ink ribbon, and the ink separated from the ink layer by heating is printed on ordinary recording paper. The image is transferred and recorded.

As shown in FIGS. 16 (a) and 16 (b), a ribbon cassette provided with an ink ribbon R is detachably mounted on a printer unit of a hot-melt transfer system. The ink ribbon R includes a base 141a made of a resin film, and an ink layer 141b applied to the base 141a. The ink layer 141b can be used repeatedly for several tens of times (so-called multi-time), so that all of the ink layer 141b is not transferred in the thickness direction by one peeling.

As shown in FIG. 17A, a multi-time ink ribbon R is mounted on a printer section of an image recording apparatus, and a black (K) The image is recorded by monochrome printing in which the ink of the color (1) is transferred, and a rectangular image recording surface 130 of a rectangular shape is formed on the recording paper 100. In this solid printing, a voltage is applied so that the amount of heat applied to the thermal head 50 (see FIG. 16) is maximized, and the heated thermal head 50 is pressed against the recording paper 100 via the ink ribbon R to form an ink. R1 is transferred to the recording paper 100
The image is recorded in such a manner as to be painted over.

[0006]

By the way, when this solid printing is performed continuously, as shown in FIG. 16B, the ink of the multi-time ink ribbon R is applied to the image recording surface 130.
Is used for image recording after peeling over a wide area corresponding to the above, the consumption of the ink R1 peeled off from the ink layer 141b of the ink ribbon R increases. When the consumption of the multi-time ink ribbon R is increased, the service life is soon reached, and the ribbon cassette accommodating the ink ribbon R has to be frequently replaced.

In particular, the recording paper 10 is repeatedly printed by the solid printing.
When the image is recorded at 0, the ink in the ink layer 141b of the multi-time ink ribbon R runs out immediately,
For example, when about 30 images are recorded on ordinary recording paper 100, there is a problem that the ink ribbon R cannot be used repeatedly and the life is considerably shortened.

Therefore, as shown in FIG. 17 (b), in order to increase the number of times that the ink ribbon R can be used repeatedly even when solid printing is continuously performed, the applicant has called a so-called halftone process. In the solid printing, the image recording surface 13 is coarsely doted so as to form a white (white) portion and densely dotted so as to form a dark (black) portion.
0 formed an image record that appeared faint. As a result,
Until about 100 sheets of ordinary recording paper 100 record images,
The ink ribbon R can be used repeatedly without replacing it.

However, since the image recording surface 130 forms a thin image recording as a whole, the outline is blurred and unclear, and there is a problem that it is difficult to read the image recorded matter, for example, characters. Was.

An object of the present invention is to provide a multi-time ink ribbon that can sufficiently suppress the consumption of the ink ribbon even when the image is to be recorded on a relatively wide recording sheet such as solid printing, thereby achieving a long life. An object of the present invention is to provide a print recording method and a print recording apparatus using the same so that print records are clear and characters and the like can be sufficiently read.

[0011]

At least one of the above objects is attained.
As a first means for solving the problems, a step of normalizing each density value of the image data divided into a plurality of pixels to a density correction value which is lowered by a set density regulation value, A step of sequentially processing the density correction values by a contour-enhancing filter to generate operation data in which the contour is emphasized, and a step of generating the operation data into binarized print output data. .

As a second solving means, a density value of image data divided into a plurality of pixels is compared with a predetermined threshold value, and when the density value is larger than the threshold value, an output value is determined. A step of generating two-level data by a two-level process of generating “1” and generating an output value of “0” when the density value is smaller than the threshold value, and including a plurality of pixels in a matrix. A step of extracting a contour portion from the two-tone data having an output value of "1" based on the contour extraction determining means and generating the contour portion as contour extraction data; and a calculation determining means comprising a plurality of pixels in a matrix. , Output value "1" 2
A step of generating grayscale data into mask calculation data extracted by arithmetic processing, and a step of combining contour extraction data and mask calculation data so that the same pixel overlaps and generating binary output data. It is provided with.

As a third solution, the ink of the ink ribbon for hot-melt transfer, which can be used repeatedly, is transferred to recording paper and printed according to the print output data.

[0014] As a fourth solution, the ratio of the area occupation ratio of the generation and non-generation of the dots of the binarized print output data is changed by displacing the arbitrarily set density control value. And a selection mode for setting the density of the image recorded on the recording paper to at least one of default, dark, and light.

[0015] As a fifth solution means, the value of each dot of the extracted mask operation data is changed by changing the value of each pixel of the operation determination means which can be set arbitrarily, and recording is performed. A selection mode is provided for setting the density of image recording printed on paper to at least one of default, dark, and light.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In an image processing method according to an embodiment of the present invention and an image recording apparatus using the method,
A first image processing method in the ink saving mode for reducing the ink consumption of the ink ribbon R will be described below with reference to FIGS. FIG. 1A shows an example in which the original image data 10 for printing is image-recorded on a recording paper 100 as it is, and FIG. 1B shows the original image data 10 as the first image data.
FIG. 4 is a diagram showing an example in which an image is recorded on recording paper 100 by the image processing method of FIG. FIG. 2 is a diagram showing an example in which the image shown in FIG. FIG. 3 shows an example of the density histogram 12 shown in FIG. 2 and an example of the density histogram 14 obtained by normalizing the density histogram to 50%. FIG. 4 shows the value of the density correction data 15 for each pixel (dot address) after the original image data 10 has been normalized to 50% and the density has been corrected. FIG. 5 shows an example of the contour enhancement filter 20 having a 3 × 3 matrix shape.

FIG. 6 shows an operation data 25 obtained by converting the density correction value at the dot address by the contour emphasis filter 20.
Are shown. FIG. 7 shows, for example, the dot addresses a22, a32, a42, a52, a62, a72, and a82 of the areas (S1, S2) surrounded by the thick frames shown in FIGS. , And each value of the operation data 25 is plotted and graphed. The horizontal axis indicates each dot address, and the vertical axis indicates each density correction value by a solid line, and the data value calculated by the contour emphasis filter 20 by a dotted line. FIG. 8 is a flowchart of the first image processing method. FIG. 9 shows an example in which the value of the operation data 25 is generated as the value of the print output data 35 by the dither method. FIG. 9A shows an 8 × 8 threshold matrix 33, and FIG. 9) shows an example of the print output data 35a when the density regulation value L in the density correction processing is set to “128”, and FIG. 9C shows the print output when the density regulation value L is set to “64”. FIG. 9D shows an example of the data 35b, and FIG. 9D shows an example of the print output data 35c when the density regulation value L is set to "230".

As shown in FIGS. 3 and 8, in the first image processing method, first, among the density values “0 to 255” of the original image data 10 shown by the density histogram 12 in FIG.
The density region of the density values “50 to 205” is normalized to a density value “0 to 128” which is half (50%) of the whole by setting the numerical value “128” as the maximum density limiter (density regulation value) L (FIG. 8). Procedure S1). The density histogram 12 shown in FIG.
Is a count of the number of pixels having a density value of each brightness color in a predetermined area, and the scale value of the density value (for example, 0 to 255) of the image data 10 input on the horizontal axis is indicated by a scale. The vertical axis indicates the frequency at that density value. The density value “0” at which the image recording is the brightest (white) is taken at the right end of the horizontal axis, and the density value “255” at which the image recording is the darkest (black) is taken at the left end. It is changing. In addition, when all the frequencies of the respective density values are added, the total number matches the number of pixels in the entire area.

As described above, the input image data 10
By compressing the entire density value to "128" at the maximum and to 50% of the whole, it becomes gray even at the highest density, and the degree of change for each adjacent pixel is reduced, so that it is apparently thin. I try to make it feel (blur). Note that the maximum density value “255” and its neighboring value Δmax
(205 <Δmax <255) is the density regulation value L.
It is assumed that density correction is performed with 128 "as the maximum density value,
The minimum density value “0” and its neighboring value Δmin (0 <Δmin <5
0) performs density correction as the minimum density value “0”.

Next, as shown in FIG. 4, FIG. 5, and FIG.
The density value normalized to 0% (the value of the density correction data 15) is subjected to contour enhancement processing for each pixel in a matrix (step S2 in FIG. 8). Assuming that the density correction value of the dot address (pixel) a22 shown in FIG.
With this dot address a22 as a pixel of interest, the weighting factor “10” of the contour emphasis filter 20 shown in FIG. 5 is multiplied, and eight adjacent dot addresses (pixels) a11,
For each of the density correction values of a21, a31, a12, a32, a23, and a33, the weight coefficient “−
Then, as shown in FIG. 6, the density correction value “120” at the dot address a22 becomes a large positive value with the value “1130” of the calculation data 25, as shown in FIG.
This calculation process is performed by shifting the dot address a32 adjacent to the right side shown in FIG. 4 which is the scanning direction (X direction) of the thermal head 50 (see FIG. 13).

Similarly, the dot address a32 which is the pixel of interest and the dot addresses a in the eight directions adjacent to the dot address a32
The density correction values of 21, a31, a41, a22, a42, a23, a33, and a43 are multiplied by weight coefficients "10" and "-1" of the contour emphasis filter 20, respectively, and added. Then, as shown in FIG. 6, for example, the dot address a32
Is the value "-136" of the calculation data 25.
These operations are sequentially repeated for all dot addresses to perform arithmetic processing to generate arithmetic data 25 in which a contour (edge) is emphasized as shown in FIG.

As shown in FIG. 7, the portion where the density correction value of the adjacent dot address greatly changes, for example, the dot addresses a22, a32, and a42, are further greatly changed by the value of the operation data 25 and emphasized. Above, the image becomes sharp. Also, a portion where the density correction value changes only slightly, for example, dot addresses a62, a72,
The value a82 is further reduced in the calculated data value, and the change is suppressed, so that the image is apparently blurred.

As described above, the outline enhancement has been described using the 3 × 3 matrix outline enhancement filter 20, but is not necessarily limited to this size.
A × 5 matrix-like contour enhancement filter may be used. In this case, for example, the value “25”,
A contour emphasis filter is applied to the peripheral pixels by applying a numerical value “−1”. Increasing the size of the matrix enables complex and highly accurate arithmetic processing, but on the contrary increases the amount of calculation, so a 5 × 5 matrix size is preferably optimal.

Next, as shown in FIG. 8, the value of the operation data 25 for each dot address (pixel) is generated as a value of the binarized print output data 35 (step S3 in FIG. 8). FIG.
For example, an 8 × 8 dither matrix 3 shown in FIG.
3, each value of the operation data 25 is compared with each threshold value (th) using an 8 × 8 dot address as one unit. In FIG. 9A, for example, 1 of the operation data 25
If the two values are “50”, the threshold (th) of the dither matrix 33, “28”, “20”, “4” for one line
4 ", 3 lines" 40 ", 4 lines" 8 "," 1 "
Since "32", "24", "48" on line 6, "36" on line 7, "36" on line 7, and "4", "12" on line 8 are smaller than the value "50", a dot is generated ( (Dots are turned on) and painted black (dots are drawn).
As described above, the binarized print output data 35 is generated for each value of the operation data 25 by the dither method using the dither matrix 33.

The density regulation value L shown in FIG.
8 ", and when the normal ink saving mode is set (default), as can be seen by comparing with the dither matrix 33, each value of the operation data 25 is any one of the range of 0 to 128, and the color density is Becomes an intermediate color (gray) between white and black, for example, and the image recording pattern 35a has the maximum density.

The density regulation value L shown in FIG.
64 ", each value of the operation data 25 is 0-6, as can be seen by comparing with the dither matrix 33.
4, the density of the image recording pattern 35b is, for example, slightly higher than that of the above-described default, and the density color is, for example, an intermediate density value between the intermediate color (gray) and white. Has the maximum density.

The density regulation value L shown in FIG.
230 ”, the dither matrix 33
As can be seen from the comparison, each value of the operation data 25 is 0 to
230, the density color is, for example, slightly dark gray, which is a color intermediate between the intermediate color (gray) and black, compared to the default setting, and the image recording pattern 35c is the largest. It will be thick.

In the ink saving mode, the default is usually set to "thin" by the operator according to the preference.
Each mode (selection mode) of “dark” can be switched by an operation switch (not shown). In the first image processing method, of the image data divided into a plurality of pixels, the density correction is performed for the halftone except for the maximum density value and its neighboring values, and the minimum density value and its neighboring values. Although the processing speed is increased as the density area, the present invention is not limited to this.
0 to 255 "may be set as a target of density correction. In the above example, monochrome printing of black and white has been described. However, the same applies to color printing, and color materials C (cyan) and M (magenta) are used. ) And Y (yellow) are subjected to image processing by the first image processing method, and by combining them, an image can be recorded on the recording paper 100 in a predetermined color.

In this way, by setting the density regulation value L in the density correction processing to a predetermined value so that each density value of the dot address (pixel) decreases, the image recording surface 3
Since the dots are generated such that the density of 0 becomes lighter as a whole, the consumption of ink can be saved, and
Since the outline of the image recording is emphasized, characters and the like can be sufficiently read. In particular, even on an image recording surface on a relatively wide recording paper 100 such as solid printing, the consumption of the multi-time ink ribbon R is sufficiently suppressed, and a long life is achieved. In addition, instead of the above dither method,
Similar results can be obtained by the error diffusion method.

Next, a second image processing method will be described below with reference to FIGS. FIG. 10 is a flowchart of the second image processing method. FIG. 11 is an explanatory diagram illustrating an example of a contour extraction method in the second image processing method. FIG. 12 is a diagram illustrating an example of an image recording pattern in the second image processing method.

First, as shown in FIG. 10, the density values "0 to 25" of the original image data 10 divided into a plurality of pixels.
A process of reducing the number of gradations from “5” to two gradations “0” and “1” of the two gradation data 40 is performed (step S1 ′).
Is set to, for example, 128, and when each density value is compared with the threshold value (z), when each density value is equal to or larger than the threshold value (z = 128), an output value “1” is generated and dots are formed. When the density value is smaller than the threshold value (z = 128), an output value "0" is generated to prevent dots from being formed.
Therefore, the values “0” and “1” of the two gradation data 40
Thus, for example, image recording is performed in two colors of white and black.

Next, as shown in FIG. 10, a contour portion is extracted from the value of the two-tone data 40 output by performing the two-tone process (step S2a '). An example of a contour extraction method will be described based on a contour extraction determination table (means) 55 composed of a plurality of pixels in a 3 × 3 matrix shown in FIG. As shown in FIGS. 11A, 11B, and 11C, 3 × 3 contour extraction determination tables 55a, 55b,
In 5c, the display ○ indicates dot-off (no dot) as white, and the display ド ッ ト indicates dot-on (dot generation) as black. A pixel position surrounded by a thick bold frame at the center corresponds to the position of the target pixel P.

First, as shown in a contour extraction determination table 55a shown in FIG.
If the target pixel P is dot-off and the neighboring eight pixels (range of 3 × 3) in the surrounding direction are also dot-off, it is determined that a white background is continued, and dot-off (dot Do not hit).

Second, as shown in the contour extraction determination table 55b shown in FIG. 11 (b), the pixel of the center thick frame is set as the pixel of interest P, the pixel of interest P is dot-on, and the neighboring pixels around the pixel are set to 8 pixels. In the case where there is no dot-off in the pixel in the direction (range of 3 × 3), that is, in the case of dot-on, it is determined that the target pixel P itself is not an outline, and the pixel is turned off (does not dot).

Third, as shown in the contour extraction determination table 55c shown in FIG. 11C, the pixel of the center thick frame is set as the pixel of interest P, the pixel of interest P is dot-on, and the neighboring pixels of the peripheral pixel 8 are adjacent. If there is at least one dot-off in a pixel in the direction (range of 3 × 3), the target pixel P itself is determined to be a contour, and is turned on. The contour extraction data 54 from which the contour is extracted is generated by the contour extraction determination tables 55a, 55b, and 55c that perform three kinds of determinations as described above (procedure S3 'in FIG. 10).

Next, as shown in FIG. 10, a mask process is performed for each pixel from the value of the two-gradation data 40 output by performing the two-gradation process by using the calculation determination table 60 (procedure S2b 'in FIG. 10). ). FIG. 12 shows three types of operation determination tables 60a, 60b, and 60c. FIG.
(A) is an operation determination table 60a used in the normal setting (default) of the ink saving mode. This operation determination table 60a has a matrix form of 8
It consists of a plurality of × 8 pixels, and this pixel area is equally divided into four wide-area pixels D1, D2, D3 and D4.
All coefficients of each pixel of the wide area pixels D1 and D4 are set to “1”,
All the coefficients of each pixel of the wide area pixels D2 and D3 are set to "0", and the image recording pattern is such that when the pixel value of the fill such as solid printing is input, the dot of which the entire area occupancy is 50% at the maximum. Will be generated. According to such a calculation determination table 60a, the calculation processing is sequentially performed in the scanning direction of the thermal head 50, a pattern such as the above-described image recording pattern is repeated, and the value of the mask calculation data 70 is extracted in a substantially staggered manner. Apparently, the image recorded on the recording paper 100 is, for example, printed in an intermediate color (gray) between black and white. The image recording pattern is not limited to the illustrated staggered pattern, but may be any thinned pattern.
It may be a line (horizontal line, vertical line, diagonal line) or an irregular pattern.

Next, FIG. 12B shows an operation determination table 60b that can be arbitrarily set by the operator and is in the "dark" mode. This operation determination table 60b is
This is almost the same as the default operation determination table 60a described above, and is different from the default operation determination table 60a in that the area occupancy of the dot generation of the wide area pixels D2 and D3 is increased from 0 to 50%. different. Therefore, the pixel recording pattern (mask operation data 70)
When a pixel value of a fill such as solid printing is input, dot generation is performed with a total area occupancy of 75% at the maximum. And, apparently, the image recording on the recording paper 100 is
For example, the image is printed darker than the above-described default setting of the intermediate color (gray) between black and white.

Next, FIG. 12C shows an operation determination table 60c in the case of the "thin" mode, which can be arbitrarily set by the operator. This operation determination table 60
c is also the default operation determination table 60 described above.
a, which is different from the default operation determination table 60a in that the area occupancy of the dot generation of the wide area pixels D1 and D4 is reduced from 100% to 50%. Therefore, in the pixel recording pattern (mask calculation data 70), when a pixel value of a fill such as solid printing is input, dot generation is performed with a maximum area occupancy of 25% as a whole. Then, apparently, image recording on the recording paper 100 is, for example, the default setting described above.
The print becomes lighter than the intermediate color (gray) between black and white.

Next, as shown in FIG. 10, the outline extraction data 54 and the mask calculation data 70 are combined so that the dot addresses (pixels) of the same portion overlap each other to generate print output data 35 '(FIG. 10). Procedure S3 '). The print output data 35 'is already 2
Since the binarization process is performed, predetermined data is obtained for each pixel simply by combining. Then, as shown in an example of FIG. 10, the outline portion is emphasized, and the other portions are generated in a substantially staggered dot manner. In this manner, the dots are generated in a substantially staggered manner, thereby saving ink consumption, and extracting and emphasizing the outline of the image recording so that the image recording material such as characters can be sufficiently read. It becomes possible.

Next, a modified example of the second image processing method is shown in FIG.
This will be described below with reference to FIGS. FIG. 13 (a)
FIGS. 13A to 13E show an example of an image recording pattern and an outline extraction determination table, respectively, in which outlines are sequentially formed from 1 dot to 5 dots. FIG.
(F), (g), and (h) correspond to FIGS.
This is the same as (e), in which the contour is formed sequentially from 6 dots to 8 dots. FIG. 15 shows that the area occupancy is
5 shows an operation determination table for mask processing of 5%.

In the modification of the second image processing method, the basic processing is the same as that of the above-mentioned second image processing method, and the contour extraction judgment table (means) 55 has a 3 × 3 matrix shape. While it consists of multiple pixels,
Outline extraction determination table (means) 7 shown in this modified example
5 is n × n (where n = 2m + 1 (m = 1, 2, 3,
..)) Are characterized by comprising a plurality of pixels in a matrix. That is, the formation of the contour by the contour extraction processing is not limited to one dot (based on the above-mentioned 3 × 3 matrix-shaped pixels), but is formed by n dots. Then, the contour extraction determination table (means)
75 indicates that the pixel of interest (）) P itself is dot-on (●) and that the pixel of interest (、 (x, y)) P
When there is a dot off (o) in the range of (x-n, yn) to (x + n, y + n), the target pixel P itself is turned on (-). Even if the pixel of interest (◎) P itself is dot-on (●), in other cases such as when there is no dot-off (な ど) in the above range, the pixel of interest (◎) P itself is all dot-off. (○).

As shown in FIG. 13A, the contour extraction judgment table 75 is composed of a plurality of pixels in a 3 × 3 matrix, and in this case, the second image processing method itself. In this 3 × 3 range, the outline is formed by one dot, and the thickness of the outline is thin. As shown in FIG. 13B, the contour extraction determination table 75 includes a plurality of pixels in a 5 × 5 matrix and has a predetermined range (5 × 5).
Since there is a dot-off (）) inside the pixel of interest ◎) P
Dot on (●). In this 5 × 5 range, the outline is formed by two dots. Similarly, FIG.
As shown in (d) and (e), 7 × 7 and 9 ×
A 9 × 11 × 11 matrix is obtained, and by expanding the pixel range in order, the outline becomes 3 dots, 4 dots, 5 dots,
Each of the dots is formed by a dot, and the thickness of the contour is sequentially increased. Similarly, FIGS. 14 (f), (g) and (h) also show 13 × 13, 15 × 15 and 17 × 17, respectively.
By expanding the pixel range, contours are sequentially formed with 6 dots, 7 dots, and 8 dots, and the thickness of the contour is sequentially increased. In this way, by arbitrarily setting the thickness of a desired contour in an nxn matrix, contour extraction data for desired contour enhancement described later is formed.

As shown in FIG. 15, the operation determination table 8
0 is composed of a plurality of pixels arranged in a matrix of 14 × 8, and furthermore, this pixel area is defined as wide area pixels E1, E2,
It is equally divided into four E3 and E4. Wide area pixel E2,
At E3, the coefficients of all pixels are set to “0”,
In the wide area pixels E1 and E4, the coefficient of the pixel in the central part is set to “1”, the coefficient of the pixel in the other area is set to “0”, and the area of the coefficient “1” is １ ／ of the whole (for the dot generation). The area occupancy is 25%). According to such an operation determination table 80, when the arithmetic operation processing is sequentially performed in the operation direction of the thermal head to print and record on the recording paper, it is apparently printed in an intermediate color (gray) between black and white. Become.

The desired print output data is obtained by synthesizing the contour extraction data based on the contour extraction determination table 75 and the mask calculation data based on the calculation determination table 80. On the recording paper, the outline is emphasized, the thickness of the outline is set to a desired thickness, and the other parts are thinned out and recorded on the recording paper by the print output data.

In such an image processing method, the thickness of the contour can be arbitrarily set according to the condition of the font (the size and shape of the character), so that the visibility is good and the running cost is reduced. can do. For example, FIG.
When the outline is formed by 2 dots to 6 dots as in the example of the image recording pattern in FIG. Further, when the outline is formed by one dot (a range of 3 × 3), the consumption of ink can be greatly reduced in a font that can ensure visibility even if the outline is thin.
Further, the outline is formed by 7 dots (range of 15 × 15) and 8 dots (range of 17 × 17), and even if the character is large, the outline is thickened, so that the outline is sufficiently emphasized.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment.
Changes can be made without departing from the spirit of the invention. For example, a printing device such as an ink jet printer or a laser printer may be used. In particular, the present invention is effective for a method based on a printing principle such as a hot-melt transfer method, in which the ink consumption affects the life of the ink in printing. Further, the operation switch for switching the mode between “light” and “dark” may be switched by a switch whose density continuously changes.

[0047]

According to the image processing method of the present invention described above, each density value of image data divided into a plurality of pixels is converted into a density correction value which is reduced by a set density regulation value. A step of normalizing, a step of sequentially processing density correction values by a matrix-shaped contour enhancement filter to generate calculation data in which contours are emphasized, and a step of generating calculation data as binarized print output data With the provision of (1) and (2), since the image recording is formed at a low density by being halftoned, the ink consumption can be reduced and the life of the ink ribbon R can be extended, and the outline of the image recording is emphasized. Can be read well.

Further, the density value of the image data divided into a plurality of pixels is compared with a predetermined threshold value, and when the density value is equal to or larger than the threshold value, an output value "1" is generated. Generating two-level data by two-level processing for generating an output value “0” when the density value is smaller than the threshold value;
A step of extracting a contour portion from two-tone data having an output value of “1” based on a contour extraction determining means composed of a plurality of pixels in a matrix to generate contour extraction data; A step of calculating the two-tone data having an output value of “1” to generate extracted mask calculation data based on the calculation determination means, and the same pixel overlapping the contour extraction data and the mask calculation data. And generating the binarized print output data, thereby forming the mask operation data thinned out in a substantially staggered manner from the operation determination means, so that the print output data is output. At this time, the life of the ink ribbon R can be extended by reducing the ink consumption, and the outline of the image recording is extracted and emphasized, so that it is possible to sufficiently read the outline.

Further, since the ink of the ink ribbon for hot-melt transfer, which can be used repeatedly, is transferred to recording paper and printed according to the print output data, the frequency of ink ribbon replacement can be reduced. ,It does not take time and effort.

Further, by changing the density control value that can be set arbitrarily, the ratio of the area occupation ratio of dot generation and non-generation of the binarized print output data is changed to print on the recording paper. At least default image recording density,
By providing a selection mode for setting one of dark and light, the light can be freely selected according to the preference of the operator.
Settings such as darkness can be made.

Further, by changing the value of each pixel of the calculation determining means which can be set arbitrarily, the ratio of dot generation and non-generation of the extracted mask calculation data is changed, and the image recorded on the recording paper is changed. By providing a selection mode for setting the density of at least one of the default, dark, and light, it is possible to freely set the light, dark, and the like according to the operator's preference.

[Brief description of the drawings]

1A and 1B show a first image processing method according to an embodiment of the present invention. FIG. 1A shows an example of image recording using original image data for printing, and FIG. 3) is a diagram showing an example of image recording after the original image data has been processed by the image processing method.

FIG. 2 is a diagram illustrating a density histogram of original image data in a first image processing method according to an embodiment of the present invention.

FIG. 3 is a diagram illustrating a density histogram of original image data and a density histogram of image data after density correction in a first image processing method according to an embodiment of the present invention.

FIG. 4 is a diagram illustrating an example of original image data values in a first image processing method according to an embodiment of the present invention.

FIG. 5 is a diagram illustrating an example of an outline emphasis filter in the first image processing method in the first image processing method according to an embodiment of the present invention.

FIG. 6 is a diagram illustrating an example of a calculation data value after a calculation process by a contour enhancement filter in the first image processing method in the first image processing method according to an embodiment of the present invention;

FIG. 7 is a diagram illustrating an example of a density correction value obtained by performing density correction on an original image data value in a first image processing method according to an embodiment of the present invention, and after the density correction value has been subjected to arithmetic processing by a contour enhancement filter; FIG. 9 is a diagram showing operation data values.

FIG. 8 is an explanatory diagram showing a flowchart of a first image processing method and an example (sample) of image recording corresponding to the flowchart.

FIG. 9 is a diagram illustrating an example of an image recording pattern in which an image is recorded using print output data that has been binarized by a first image processing method.

FIG. 10 is an explanatory diagram showing a flowchart of a second image processing method according to an embodiment of the present invention and an example (sample) of image recording corresponding to the flowchart.

FIG. 11 is a diagram for explaining a contour extraction method in a second image processing method.

FIG. 12 is a diagram illustrating an example of an image recording pattern in which an image is recorded using print output data that has been binarized by a second image processing method.

FIG. 13 is a diagram illustrating a contour extraction method in a modification of the second image processing method.

FIG. 14 is a diagram for describing an outline extraction method in a modification of the second image processing method.

FIG. 15 is a diagram for explaining a mask processing method in a modification of the second image processing method.

FIG. 16A is a schematic cross-sectional view of a multi-time ink ribbon generally used in an image recording apparatus of a hot-melt transfer system, and FIG. 16B shows a transfer state of the multi-time ink ribbon. It is an outline sectional view.

17A is an explanatory diagram showing a state of solid printing (image recording) of the multi-time ink ribbon shown in FIG. 16, and FIG. 17B is a diagram showing image recording after halftone processing. FIG.

[Explanation of symbols]

Reference Signs List 10 image data 15 density correction data 20 contour emphasis filter 25 operation data 35, 35 'print output data 40 two-tone data 54 contour extraction data 55, 55a, 55b, 55c, 75 contour extraction judgment table (contour extraction judgment means) 60 , 60a, 60b, 60c, 80 Calculation determination table (calculation determination means) 70 Mask calculation data 100 Recording paper R Ink ribbon th threshold L Density regulation value

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 1/409 H04N 1/40 101D F-term (Reference) 2C062 AA24 2C066 AA03 AA14 AD03 CD02 CD03 CD04 CD05 CD08 CD12 CZ11 2C262 AA03 AA24 AA27 AB13 BB01 BB06 BB15 BB22 BC07 DA03 DA18 EA04 EA18 FA18 GA19 5C074 AA15 AA20 BB13 CC26 DD06 FF11 HH02 HH04 5C077 MP06 NN04 PP65 TT01

Claims (5)

[Claims] A step of normalizing each density value of the image data divided into a plurality of pixels to a density correction value which is reduced by a set density regulation value; and An image processing method comprising: a step of sequentially processing density correction values to generate calculation data in which contours are emphasized; and a step of generating the calculation data to binarized print output data. 2. A density value of image data divided into a plurality of pixels is compared with a predetermined threshold value, and an output value “1” is generated when the density value is equal to or greater than the threshold value. Generating an output value “0” when the density value is smaller than the threshold value 2
A step of generating two gradation data by gradation processing, and extracting a contour portion from the two gradation data having the output value “1” based on a contour extraction determining means including a plurality of pixels in a matrix. Mask extraction data extracted by performing arithmetic processing on the two-tone data having the output value “1” based on arithmetic determination means including a plurality of pixels in a matrix. Image processing comprising: synthesizing the contour extraction data and the mask calculation data so that the same pixels overlap each other; and generating binarized print output data. Method. 3. An image processing method according to claim 1, wherein the print output data is used to transfer the ink of the ink ribbon for hot-melt transfer, which can be used repeatedly, onto a recording paper for printing. An image recording apparatus of a hot-melt transfer system, characterized in that: 4. A method for generating and not generating dots of binarized print output data by displacing the arbitrarily set density control value using the image processing method according to claim 1. By changing the ratio of the area occupancy, the density of the image recorded on the recording paper is set to at least the default, dark,
An image recording apparatus, comprising: a selection mode for setting any one of thin modes. 5. The method according to claim 2, wherein the value of each pixel of the calculation determining means, which can be set arbitrarily, is displaced to generate or not generate dots of the extracted mask calculation data. An image recording apparatus, comprising: a selection mode for changing the generation ratio and setting the density of an image recorded on a recording sheet to at least one of a default, a dark, and a light.