JPS62189875A - Picture forming device - Google Patents

Abstract

PURPOSE:To form in a printer a binary picture which approximates an original picture by dividing a binary picture in matrix shapes with three reference point on the picture for reference, binarizing resulting picture elements, and newly determining a density value from the density values of respective picture elements by majority. CONSTITUTION:An original G is illuminated by a light source 11, and the picture is photoelectrically converted by a CCD 12 in the unit of picture element. A resulting data is encoded by an A/D converter 13, binarized by a binarization circuit 14. And a resulting binary data is stored in a memory 15. The stored binary picture data is formed by 35X16 pieces of picture elements. Thereafter, using the three reference points determined beforehand as a reference point respectively, three pieces of binary picture are formed by a CPU 6. This binary picture is generated in a manner that the density value over 2.25-pieces of picture elements from the CCD 12 is binarized sequentially and resulting density values are made in form of a 16X16 matrix. The values are newly determined in '0' or '1' from the density values of picture elements corresponding to the same elements of the said matrix by majority, and the results are stored on a RAM 4.

Description

[Detailed Description of the Invention] [Industrial Field of Application] An original image is converted into a binary image by two-stage pixel division and binarization of density values, and this binary image is constructed [Prior Art] FIG. 6 shows an example of a conventional image forming apparatus of this type. In the figure, 1 is a binary image moxibustion means, a light source 11,
c c n (cJ+aryt taLLp class dev
;cb) 12, Al1) Converter 13. Comprised of a binarization circuit 14, a memory 15, and a control circuit 16.i. 2 is Cprt (eaatra-1pvo
ctcs@-) reads out the binary image data stored in the memory 15 via the interface 3, and performs pixel division and binarization of density values. 4 is RAM (n
tntltrwnacacs memory),
Image data obtained by image processing by the CPU 2 is stored. 5 is 7? This is a dot printer (printing means) that performs dot matrix printing based on image data stored in AM'4.

Next, the effect will be shown.

A document (original image) G is fed (sub-scanning) by a document feeding mechanism (not shown) and is irradiated by a light source 11 .

At this time, the light from the light source 11 is reflected by the document G, and the reflected light is incident on the CCD 12. In the CCD 12, photoelectric blood exchange is performed for each pixel, and the original image is converted into a PAN (pμIc
e cL% Pht - ε 1 company omission) is modulated. Next, each pixel is encoded by the A/D converter 16, and then binarized by the binarization circuit 14 and converted into a binary image. The two image data are stored in the memory 15.

Therefore, in the two image data, there is no problem if the resolution of the reading element such as CCD 12 and the resolution of the printing device such as printer are the same, but if they are different, it is necessary to perform linear density conversion using some means. be.

For example, the resolution ratio of the reading element and printing device is 9:4.
shall be. Simply put, the linear density of the read data is 4
It is sufficient to reduce it to /94@-. In such cases, the following methods have been used in the past.

First, to explain FIG. 7, the read pixel data string is divided into nine blocks each, and nine pixel data l in one block are temporarily divided from the beginning to Xl,
X2. Assign Xa...x9. Here, the pixel data X1 (i is an arbitrary integer) is expressed as "0" or "1", and in rOJ, white "1" indicates black.

A logical OR operation is performed on two pieces of the above pixel data from the beginning. That is, a logical sum operation is performed between pixels X1 and X2, and the result of the operation, dl, is sequentially converted to X5, . X4.
The calculation results of Xa, Xa, X7 and x8 are each d2
．． dB, d4.

However, x9, that is, the last pixel, is ignored. Similarly, calculation processing is performed for other blocks not shown.

In this way, the obtained data after linear density conversion is
It is stored in the RAM 4 shown in the figure, read out in response to an external request, outputted via the interface 3, and outputted to a printing device such as a dot printer 5.

[Problem that the invention seeks to solve]

In conventional image forming apparatuses, for pixels obtained by linear density conversion, if at least one of two circles of original pixel data indicates black "1", then the value after conversion also indicates black. It is configured so that Therefore, the number of charred pixels increases, resulting in so-called "whitish" development, and
Since the pixel data of the second pixel is ignored, the binary image formed by the converted pixels has the problem of causing a "shift" or difference in line width from the original image.

(Means for Solving the Problems) The purpose of the present invention is to use a printer to form a binary image that more closely approximates the original image. The density values of the divided pixels are binarized and converted into a binary image, and the resulting binary image is first converted to a binary image using at least three reference points on the two images as reference points by an image forming means. Then, the pixels obtained by partitioning are divided into a matrix and binarized to form two pixels.Then, by a binarization means, the density values of pixels corresponding to the same element in each matrix are determined by majority vote. A density value is newly determined, and dot matrix printing is performed by a printing means using this binarized 1vM element as one dot.

〔Example〕

, FIG. 1 shows an embodiment of the invention. In the figure,
1.3 to 5.11 to 16, G indicates the same parts as the conventional example in FIG. 6 divides the binary images obtained by the two-image converting means 1 into a matrix based on at least three reference points on the two images, and binarizes the pixels obtained by dividing. The image forming means forms a binary image, and the CPU functions as a binarizing means, which binarizes the density values of pixels corresponding to the same element in each matrix obtained thereby by majority vote.

Next, the operation will be explained based on the flowchart K shown in FIG.

Assume that the original image is converted into a binary image by the binary image converting means 1, and for example, a character pattern shown in FIG. 6 is obtained (STEP-1). This is formed by, for example, 35×16 pixels. This binary image data is stored in the memory 15 in FIG. 1 (57EP-1).

Then, using the three predetermined reference points as reference points, six 2
Form a value image. This binary image is generated by 2.
2 by sequentially targeting the density values of 25 (9/4 times) pixels.
The density values after binarization are converted into a 16×16 matrix (STEP 3 to 7).
'(1) As shown in Figure 4 (-),
When the reference point is placed on the left side of pixel x0, f''0, 1.2... If the calculation result is 0≦Yi <05, Yi = o.

0.5≦Yi (When 1, Y1=1 and binarization is performed. However, i=o, 1.2...

C11) As shown in FIG. 4(h), set the reference point to pixel X. If the calculation result is 174 pixels to the left from the left side of Value conversion is performed. However, as shown in Figure 4 (o), the reference point is pixel X, .
When placed at a position shifted by 174 pixels to the right from the left side of
X9r + 4Xfr+1 + 2X9r+2Y
4r m--1-11----------
--One.

γ If the calculation result is 0≦YL<0.5, Yi-0,
When 0,5≦Yi≦1, Yi”1 is set and binarization is performed. However, i=0.1.2−0.

・Then, the CPU 6 determines by majority vote a new training value of either "0" or "1" from the density values of the pixels that correspond to the same element of the IJ socks (1 to 11). <5rzp-8), and this binary data is stored in the RAM 4 in FIG. The dot printer 5 shown in the figure performs printing to form an image (srnp-10). FIG. 5 shows a printing example of the character pattern shown in FIG. 3. It goes without saying that the present invention can also be applied to a contact type sensor or the like as a reading element.

〔Effect of the invention〕

Since the present invention is configured as described above, it has the advantage that a binary image that is more similar to the original image can be formed by the printer.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is an operation flowchart, Fig. 3 is a diagram showing an example of an original image, Fig. 4 (CG), (h) and (e) are standards, respectively. Explanatory diagram of matrix-like partitioning based on points, fifth
The figure shows an example of printing by a dot printer, FIG. 6 is a block diagram showing a conventional example, and FIG. 7 is an explanatory diagram of the second stage of pixel division in the conventional method. In the figure, 1 is a binary image conversion means, 5 is a dot printer, and 6 is a CPU.

Claims (1)

[Claims] binary image converting means that divides the original image into pixels and binarizes the density values of the divided pixels to convert them into a binary image; An image forming means that partitions into a matrix based on points and binarizes the pixels obtained by partitioning to form a binary image, and density values of pixels corresponding to the same element in each matrix obtained thereby. Binarization means for newly determining a density value by majority vote from
An image forming apparatus comprising a printing unit that performs dot matrix printing using one binarized pixel as one dot.