JPH02253767A - Gradation picture dot output device - Google Patents

Abstract

PURPOSE:To form the gradation picture of a comparatively coarse picture element to be dots with suppressing degradation and maintaining high quality without preparing a device, which is equipped with large storing capacity, by generating a lot of binary dots from one picture element of the gradation picture, executing prescribed arrangement and forming the dots. CONSTITUTION:In a half-tone dot meshing processor 3, mask arithmetic is executed to a digital signal B, which is stored in a gradation picture storage device 2, and a digital binary signal C, which is formed to be a bit map, is outputted. The picture elements of the digital signal B are superimposed and added with the value of the bit map mask. According to whether this value exceeds 255 or not, the bit is set to '1' or '0' and finally, one picture element of the gradation picture 0 is converted into the digital binary signal C of the '1' or '0' having the 16X16 picture elements. The digital binary signal C obtained in the half-tone dot meshing processor 3 is inputted to a binary picture storage device 4, rearranged in the prescribed arrangement, stored, outputted and displayed on the screen of an output device 5. Thus, the gradation picture 0 is outputted and displayed by the dots.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a device that outputs a gradation image using halftone dots.
In particular, the present invention relates to a gradation image halftone output device that can halftone a gradation image of relatively coarse pixels with little deterioration and with high quality.

(Prior Art) Conventionally, in printing and the like, gradation images have been output using halftone dots. In other words, shading is achieved by changing the area ratio of halftone dots.

By the way, if it is possible to output and display each pixel with a gradation, as is the case with a TV monitor, for example, even if the minimum pixel unit is coarsely displayed, the roughness will not be noticeable, but the pixel unit as it is. “ON” “O” for each pixel with
If FF" is assigned, it is inevitable that the roughness will become noticeable.

That is, unless there is a pixel smaller than the minimum unit of gradation pixels, ie, the first pixel, it is impossible to output a gradation image using halftone dots.

(Problem to be solved by the invention) However, in this case, if we want to have a gradation image with the minimum number of pixels for gradation output using halftone dots, it is necessary to prepare a device with a large storage capacity for this purpose. The problem is the reality.

The present invention was made in order to solve the above-mentioned problems, and allows halftone images of relatively coarse pixel gradation images to be printed with little deterioration and high quality without the need for a device with a large storage capacity. It is an object of the present invention to provide a gradation image halftone dot output device that can be used to create halftone images.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a gradation image halftone output device that outputs a gradation image using halftone dots. An image input means for converting into a signal and outputting it; a gradation image storage means for inputting and storing the digital signal from the image input means; and a mask operation for performing a mask operation on the digital signal stored in the gradation image storage means. , a shading processing means for outputting a digital binary signal converted into a bitmap; a binary image storage means for inputting and storing the digital binary signal from the shading processing means; and output means for outputting a digital binary signal.

(Function) In the gradation image halftone output device of the present invention, the gradation image 1
By generating a large number of binary dots from pixels and arranging them in a predetermined manner, it is possible to form halftone dots for representing a gradation image as a whole. Therefore, it is no longer necessary to have a gradation image using the minimum number of pixels for gradation output using halftone dots as in the past, and there is no need to prepare a device with a large storage capacity.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing an example of the configuration of a gradation image halftone dot output device according to the present invention. In FIG. 1, the gradation image halftone dot output device of this embodiment includes an image input device 1, a gradation image storage device 2, a halftone processing device 3, and a binary image storage device 4.
and an output device 5.

Here, the image input device 1 consists of a color camera, for example,
A gradation image 0 as shown in the figure is input, and this is converted into a digital signal A at a predetermined resolution and output. The gradation image storage device 2 is made of a storage medium such as a magnetic disk, an optical disk, or an IC memory, which is large enough to store the image size of the digital signal A, and receives the digital signal A from the image input device 1. This data is rearranged into a predetermined arrangement, that is, the pixel arrangement of pixel data due to different image input devices is rearranged into a predetermined arrangement and stored. On the other hand, the shading processing device 3 is composed of, for example, a computer,
A mask operation is performed on the digital signal B stored in the gradation image storage device 12, and the result is output as a digital binary signal C converted into a bitmap. The binary image storage device 4 receives the digital binary signal C from the halftone processing device 3, rearranges it into a predetermined array, and stores it. Furthermore, the output device 5 is composed of, for example, a CRT device, and the digital image data stored in the binary image storage device 4 is
The value signal is output and displayed on both sides.

Next, the operation of the gradation image halftone dot output device configured as described above will be explained using FIGS. 2 and 3.

In FIG. 1, a gradation image 0 is captured by an image input device 1, converted into a digital signal A at a predetermined resolution, and output. The digital signal A from the image input device 1 is input to the gradation image storage device 2, rearranged into a predetermined array, and stored. Then, in the halftone processing device 3, a mask operation is performed on the digital signal B stored in the gradation image storage device 2, and a digital binary signal C converted into a bitmap is output. In this case, the mask calculation for the digital signal B is performed using a bitmap mask as shown in FIG. 2, for example, and four parts of the bitmap mask in FIG. This is done by alternately applying a pit mask, which looks like the left and right sides are reversed, to the pixel. Each bitmap mask is a square of 16×16 pixels, and each pixel is given a value from 0 to 255 as shown.

That is, the values within the bitmap mask of FIG. They are arranged according to different rules as shown in the figure. Further, the numbers are arranged so that halftone dots can be easily formed from the arrangement of numbers on the mask.

Here, applying a bitmap mask to the pixels of digital signal B means, in other words, to superimpose the pixels of digital signal B and add it to the value of the bitmap mask5, and then determine whether this value exceeds 255 or not. By setting the bit to 1" or 0", one pixel of the gradation image 0 is finally converted to 16
], to convert into a digital binary signal C of "1" and "Oo" of 66 pixels.In other words, if the above added value exceeds 255, that bit of IJ is set to "1", and if the added value is 255
If the value does not exceed 255, the bit is set to "0". Accordingly, in this embodiment, if the value of digital signal B is "0", all the added values do not exceed 255, so all bits Digital binary signal C1 of which is "0": Converted. Also, if the value of digital signal B is -128", the addition value of half of the mask side 128 or more exceeds 255, and 128
Since the added value of the less than I6 number does not exceed 255, it is converted into a digital binary signal C in which half of the bits are "1" and the remaining half of the bits are "0". Further, when the value of the digital signal B is "255°," the bits where the mask side is 0 are "0" and all remaining bits are converted into the digital binary signal C of "1° □."

Therefore, in the case of a bitmap mask as shown in Figure 2, when the gradation image 0 changes from 0 to 255, it changes to "1" in order from the top left and bottom right, and finally the top right and bottom left]
,”.In this way, the digital signal B is 0 to 255.
When the screen changes to , the area of the halftone dots changes in order, and the size of the mesh changes in order. In other words, a digital binary signal C having a resolution 16 times higher than that of the digital signal B is obtained.

Next, the digital binary signal C obtained by the halftone processing device 3 as described above is input to the binary image storage device 4, where it is rearranged into a predetermined array and stored.

The digital binary signals stored in the binary image storage device 4 are rearranged into a predetermined array and output and displayed on the screen of the output device 5, so that a gradation image 0 is output as halftone dots. It will be displayed.

As mentioned above, the gradation image halftone dot output device of this embodiment has the following features:
An image input device that inputs a gradation image 0, converts it into a digital signal A at a predetermined resolution, and outputs it; and an image input device.
A gradation image storage device 2 receives the digital signal A from the gradation image storage device 2, rearranges it in a predetermined arrangement, and stores it, and stores the digital signal B stored in the gradation image storage device 2 in two different arrangements. A shading processing device 3 performs a mask operation using a bitmap mask and outputs a bitmapped digital binary signal C, and a shading processing device 3 inputs the digital binary signal C from the shading processing device 3 and arranges it in a predetermined array. It is composed of a binary image storage device 4 for rearranging and storing digital binary signals, and an output device 5 for displaying the digital binary signals stored in the binary image storage device 4 on an output screen.

Therefore, it is possible to halftone and output display a gradation image of relatively coarse pixels with little deterioration and high quality.

Furthermore, in this case, it is possible to generate a large number of binary dots from one pixel of the gradation image 0 and arrange them in a predetermined manner to form halftone dots for expressing the gradation image as a whole.
There is no need to have a gradation image using very small pixels for gradation output using halftone dots as in the past, and there is no need to prepare a device with a large storage capacity.

In the above embodiment, a case was described in which a bitmap mask as shown in FIG. 2 was used, but the invention is not limited to this. For example, a value of θ to 255 may be given to each pixel as shown in FIG. 4. A bitmap mask may also be used. That is, the values in the bitmap mask of FIG. 4 are arranged according to a certain rule as shown in FIG. 5, which is different from the one described above. In the case of a bitmap mask as shown in FIG. 4, when the gradation image 0 changes from 0 to 255, the center and four corners become "1" at the end. By adopting such an arrangement, it becomes possible to form halftone dots that can be used as halftone dots for printing. Further, by arbitrarily determining the above-mentioned arrangement, the size of the halftone dots can be changed, so that it can be used as a pseudo-dot for purposes other than printing.

On the other hand, in the above embodiment, the case where the digital signal is 8 bits has been described, but the present invention is not limited to this, and the present invention can be similarly applied to cases where the digital signal is 7 bits or any other number of bits.

Furthermore, in the above embodiment, the digital signal A is
It may be obtained using a color scanner or the like, or it may be one in which the artificial side of CG or the like has already been expressed as a digital gradation signal.

Furthermore, in the above embodiment, a case has been described in which the digital binary signal stored in the binary image storage device 4 is output and displayed on a CRT device. It is also possible to output it to, etc.

(Effects of the Invention) As explained above, according to the present invention, a large number of binary dots are generated from one pixel of a gradation image, arranged in a predetermined manner,
Since halftone dots are formed to express the gradation image as a whole, gradation images with relatively coarse pixels can be processed without deterioration and at high quality without requiring a device with large storage capacity. A gradation image halftone output device capable of halftone dot formation can be provided.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a gradation image halftone output device according to the present invention, FIG. 2 is a diagram showing an example of a bitmap mask in the 511 embodiment, and FIG. 3 is a block diagram showing an example of a bitmap mask in the 511 embodiment. A diagram for explaining the mask creation method, FIG. 4 is a diagram showing another example of a bitmap mask,
FIG. 5 is a diagram for explaining a method of creating the bitmap mask shown in FIG. 4. 0... Gradation image, 1... Image input device, 2... Gradation image storage device, 3... Shading processing device, 4... Binary image storage device, 5... Output Device. Applicant's representative Patent attorney Takehiko Suzue Figure 2 Figure 3 Figure 4

Claims (1)

[Scope of Claims] A gradation image halftone output device that outputs a gradation image using halftone dots, comprising image input means for inputting the gradation image, converting it into a digital signal at a predetermined resolution, and outputting the digital signal; gradation image storage means for inputting and storing the digital signal from the image inputting means; and performing a mask operation on the digital signal stored in the gradation image storage means to generate a bitmapped digital binary signal. a binary image storage means for inputting and storing the digital binary signal from the hatching processing means; and a binary image storage means for outputting the digital binary signal stored in the binary image storage means. A gradation image halftone dot output device comprising: an output means;