JPH0581437A - Picture processing device - Google Patents

Abstract

PURPOSE:To improve the printing quality by performing the painting-out processing in the subpixel level obtained by fractionizing the resolution of a printer as the output medium and determining an output picture in accordance with the number of continuous painted-out picture elements to minimize the inversion of relations of painting-out width. CONSTITUTION:A printer controller 2 interprets PDL from a host computer 1 and converts it to image data so that it can be outputted to a printer 3. When a character drawing instruction exists in the PDL, vector data in a font ROM 10 is used and a resolution converter is used to generate font bit map data and draws it in a page memory 8. The painting-out processing is performed in the subpixel level obtained by fractionizing the resolution of the output medium, and the output picture is determined in accordance with the number of continuous painted-out picture elements, in the level.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vector / font expansion technique for a printer, and more particularly to vector / raster conversion for performing a filling process in a closed area of a vector image and outputting this as an output image to a printing device or a display device. The present invention relates to an image processing device using the.

[0002]

2. Description of the Related Art In the field of desktop publishing, when a character or the like is output to a printing device or a display device, a contour image of the character or the like to be output, that is, a vector image is generally created, and then the contour image is created. The filling process is performed in the closed area of the image.

Conventionally, the filling processing of the closed area of the contour image is completely performed by software, or the boundary line forming the closed area is once drawn on the memory so that the boundary line is not crossed thereafter. The drawing point is moved up and down, left and right to fill the inside, or a simple figure such as a rectangle is filled with hardware as a paper, and any figure is first made into a simple figure with software. After conversion, the converted simple figure was filled with hardware.

However, in the method of completely using software, although it is possible to flexibly fill an arbitrary area, there is a drawback that the filling processing takes a very long time.

In addition, even in the method in which the boundary line of the closed area is once drawn in the memory, it is necessary to read the data in the memory and determine the drawing point, so that the filling process takes time and an unpainted area is generated. There was a flaw.

Further, in the method of performing the filling process of only the simple figure by hardware, although the process of converting an arbitrary figure into the simple figure and the filling process of the simple figure can be performed in parallel, There is a drawback that the overhead is large and the filling process also takes time.

In order to solve such problems, a straight line drawing means for drawing a boundary line of a closed region so that a filled portion of each line is sandwiched by even number of boundary lines, and the straight line drawing means An image processing apparatus has been proposed which is provided with a filling unit that sequentially scans each line drawing performed for each line, and fills the pixels from the boundary line that intersects an odd number in the line scan to the boundary line that intersects next. There is.

According to this apparatus, the boundary line of the closed area is drawn linearly so that the filled portion of each line is sandwiched by even numbered boundary lines, and this line drawing is scanned sequentially for each line. Pixels from an odd-numbered intersecting boundary line to the next intersecting boundary line in the line scan are filled, and thereby the entire closed region is filled to generate an image, which enables high-speed font expansion.

However, in the above technique, since the resolution of the printer which is the output medium has a finite value, the point of the quantization error is not taken into consideration, and the size relationship of the width of the filled area in the calculation is not shown in the printer output image. There was a problem of flipping over.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and it is a sub-pixel that is divided more finely than the resolution of the printer.
Filling at the pixel level,
By determining the output pixels that are output by the printer based on the number of consecutive pixels that are filled at the pixel level, it is possible to obtain an output image with high print quality by minimizing the reversal of the size relationship of the fill width. It is in.

According to the second aspect of the present invention, by using a printer having different resolutions in the main scanning direction and the sub-scanning direction, the main scanning direction and the sub-scanning direction can be realized without expanding the processing of the first aspect to two dimensions. Both aim at obtaining an output image having high print quality and being close to a true image.

[0012]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention performs a filling process at a sub-pixel level that is subdivided more than the resolution of a printer which is an output medium, and determines the pixel to be filled at this sub-pixel level. It is characterized in that the output image is determined by the continuous number.

As a result, it is possible to minimize the reversal of the size relationship of the fill width caused by the quantization error due to the finite resolution of the printer, and an output image of high print quality can be obtained. ..

Further, by using a printer having different resolutions in the main scanning direction and the sub-scanning direction, the filling process can be performed in the main scanning direction without expanding the filling process in two dimensions.
An output image with high print quality can be obtained because it is close to a true image in both sub-scanning directions.

Further, when the number of consecutive fills at the sub-pixel level is 1 or more and 4 or less, one pixel is provided at the resolution level of the printer, and when the number of consecutive fills is 5 or more, the consecutive number is 4
It is possible to obtain an output image with high print quality by performing the filling process so that black is painted by the number of pixels which is divided by and the remainder is cut off.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in detail with reference to the preferred embodiments shown in the accompanying drawings.

FIG. 1 shows an example of a circuit diagram for implementing the present invention. In FIG. 1, reference numeral 1 is a host computer, which sends out data to be output to a printer 3. In this embodiment, the output image is described in the form of language. That is, P
It is sent in DL (page description language).

Reference numeral 2 is a printer controller,
The PDL from the host computer 1 is interpreted and converted into image data so that the printer 3 can output it. It also controls the printer 3. In the printer controller 2, the CPU 4 has a program ROM 5
PDL input through the host interface 7 while using the RAM 6 according to the contents described in
While drawing the image output by the printer 3 in the page memory 8 while interpreting the Output.

When there is a character drawing command in the PDL, the bit map data of the font is created by using the resolution converter 11 using the belt data in the font ROM 10, Drawing in the memory 8. FIG. 3 shows the flow of creating the bitmap data of the font. In this embodiment, the main scanning direction has double the resolution in the sub scanning direction, and 1/4 of one dot in the sub scanning direction is set as one unit of sub pixel. The main scanning direction will be referred to as the Y-axis direction, and the sub-scanning direction will be referred to as the X-axis direction.

FIG. 2 shows the internal structure of the resolution converter 11. The input data to this device is the 4-bit portion of the working memory in which the boundary line portion of the closed region is inverted and drawn, and the previous status is fed back and input thereto.

5 (a) to 5 (c) show the input / output relationship of this device. 4 bits of data in the working memory are simultaneously input. They are input as A0, A1, A2, A3 from the left. Here, white is 0 and black is 1.

Further, A4, A5, and A6 are feedbacks of the previous status, and all are cleared to 0 at the first time. As the output for this input, D0 is the monochrome of the pixel at the resolution of the printer, 0 for white, 1 for black
Is. D1 indicates the continuity of the filled area, which is 1 if the area is continuous. Two bits D2 and D3 indicate the position of the sub-pixel on the boundary line of the filled area, and D1, D2 and D3 are used for the next output pixel determination.

In the present embodiment, if the number of consecutive filled areas at the sub-pixel level is 1 or more and 4 or less,
When the resolution level of the printer is one pixel, and when the number of consecutive pixels is 5 or more, the number of consecutive pixels is divided by four, and the remainder is cut off, so that black is painted.

In this way, as shown in FIG. 5, output data at the resolution level of the printer can be obtained.

The operation of the present invention will be described below with reference to the flow charts of FIGS.

That is, first, in step 301, the initial state is set, and the work memory is cleared. Then, from the font ROM 10, the first vector (X
S, YS)-(XE, YE) is read (step 30)
2).

Then, the read vector is multiplied by 4 in the X-axis direction and doubled in the Y-axis direction, and the fractional part is discarded to obtain new vectors XS, YS, XE and YE (step 3).
03).

In step 304, the vector ΔX / ΔY
= 2 (XE-XS) / (YE-YS), H = 2YE-2
YS and S = 2 (YE-YS) .vertline.YE-YS.vertline. Are obtained respectively. Next, it is determined whether or not H = 0 (step 30
5) If YES, the next vector (XS, YS)-(XE, YE) is read from the font ROM 10 (step 308).

On the other hand, if H = 0 is not satisfied, the bit corresponding to (XS, YS) in the working memory is inverted (step 306), and the vector H = H-1, YS = YS + S,
XS = XS + ΔX / ΔY is calculated respectively (step 30).
7). Then, it returns to step 305 again.

In step 309 following step 308, it is determined whether or not all the vectors of the corresponding font have been read. If NO, the process returns to step 303, and if YES, the process moves to step 310. X =
Set 0 and Y = 0.

Then, the working memories (X, Y), (X
The data corresponding to the coordinates (+1, Y), (X + 2, Y), (X + 3, Y) is substituted into the resolution converter 11 to obtain an output pixel for one dot having the pixel density of the printer (step 3).
11).

Then, X = X + 4 is set (step 31
2) In step 313, it is determined whether or not X> XMAX. If NO, the process returns to step 311 and YES.
If so, in step 314, X = 0 and Y = Y + 1 are set.

In step 315, it is determined whether or not Y> YMAX, and if NO, step 311
If YES is returned to, the work ends (step 31).
6).

Even in the main scanning direction in which this processing is not performed, the resolution is double that in the sub scanning direction, so that an image close to a true image can be obtained in both the main scanning direction and the sub scanning direction.

[0035]

As described above, according to the present invention, the filling process is performed at the sub-pixel level obtained by further dividing the resolution of the printer which is the output medium, and the output is performed by the continuous number of pixels to be filled at the sub-pixel level. Since the image is determined, it is possible to minimize the reversal of the size relationship of the fill width caused by the quantization error due to the finite value of the resolution of the printer, and an output image with high print quality can be obtained.

Further, by using a printer having different resolutions in the main scanning direction and the sub-scanning direction, dividing the low resolution direction into sub-pixel levels, and performing the above processing, this processing is not expanded in two dimensions. An image close to a true image can be obtained in both the main scanning direction and the sub-scanning direction, and high print quality can be secured.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a configuration of an image processing apparatus according to the present invention.

2 is an explanatory diagram of a configuration of a resolution converter in FIG.

FIG. 3 is a flowchart showing a procedure for creating font bitmap data according to the present invention.

FIG. 4 is a flowchart showing a procedure for creating font bitmap data according to the present invention, which is a continuation of FIG. 3;

FIG. 5 is a diagram showing a relationship of input / output data of the image processing apparatus according to the present invention.

[Explanation of symbols]

1 host computer, 2 printer controller, 3 printer, 4 CPU, 5 program RO
M, 6 RAM, 7 host interface, 8 page memory, 9 printer interface, 10
Font ROM, 11 resolution converter,

Claims (3)

[Claims] 1. A method of performing a filling process at a sub-pixel level that is subdivided further than the resolution of a printer that is an output medium, and determining an output image by the number of consecutive pixels filled at the sub-pixel level. Characteristic image processing device. 2. The image processing according to claim 1, wherein the low resolution direction is divided into sub pixel levels by using a printer having different resolutions in the main scanning direction and the sub scanning direction. apparatus. 3. The resolution level of the printer is 1 pixel when the number of consecutive fills at the sub-pixel level is 1 or more and 4 or less, and the consecutive number is divided by 4 when the number of consecutive fills is 5 or more. An image processing apparatus, wherein the processing according to claim 1 is performed so that black is painted by the number of pixels of which the remainder is cut off.