JPS63223687A - Image processor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Summary] An image processing device that can stably display photo me data expressed using a dither method even when the screen is moved.

[Industrial application field]

The present invention relates to an image processing device, and attempts to suppress screen changes such as brightness and darkness caused by screen scrolling when high-resolution image data expressed using a dither method is thinned out and displayed on a low-resolution display. It is something.

An image processing device equipped with a display, a printer, a keyboard, a memory, a processor, etc. is also used to edit each page of a document or book, and in this case, not only text but also photographs may be included. Characters are essentially binary data, so you can treat them as they are and run a dot printer, which is also essentially binary, but photographs have shading, so you can't treat them as they are ( Simple binarization results in an unsightly image).

Dithering is used to binarize objects with shading (gradation), such as photographs. This dithering method and improved methods thereof are available in various documents, and the applicant of the present invention also describes a method for thinning out image data using the dithering method in Japanese Patent Application Laid-Open No. 39170/1983. Referring to this, the outline of the systematic dither method is explained in Fig. 6.
This causes the darkness value of each pixel to differ as shown in (b) during binarization. In this example, the unit is a 4×4 matrix, and (a) shows the gray level (0) of each pixel in the matrix.
-15). As shown in the figure, when the darkness values for each gray pixel are binarized are set as 0 to 15 and distributed in the matrix, and the corresponding pixels are binarized using this (C
). In this example, the level of each pixel is all 8, so there are every other white and black (1,0) data, and there are eight black (1) data.Darkness in (b) As is clear from the value array, if each pixel in (a) is all 0 (pure black), (C) is all black (1), and if each pixel in (a) is all 15 (pure white), (C) is 1 in the lower left Only one is black (1) and the rest is white (0), and in this way, the shading of pixels is expressed in a pseudo manner in matrix units.

If expressed using this dithering method, pseudo gradation can be expressed using binary values, which is suitable for digital processing of photographic data. Image data expressed using the dither method can be converted to other types of image data (
Increasingly, a single printed product is created by combining images (characters, graphics), and image data can be displayed in the same way as viewing a printed material.

[Conventional technology]

The edited image data, including text, graphics, and sometimes photographs, is displayed on a display and printed by a printing device (printer), which is high-resolution because it creates the final product. On the other hand, since the display is only needed for editing work, it can be of low resolution.

Therefore, a method is used in which high-resolution image data is prepared for the printer, this is thinned out to create low-resolution data, and the data is supplied to the display.

FIG. 4 shows the structure of a conventional device for displaying high-resolution image data in full size on a low-resolution display.

10 is high resolution memory, 16 is low resolution memory, 20 is CR
It is a T display. The low resolution memory 16 is supplied with data from a part of the high resolution memory 10 (a rectangular area with Xs and Ys as the upper left coordinates and a rectangular area of Lx horizontally and Ly vertically) after being thinned out by the thinning display device 12, and this data is displayed on the display. 20 is displayed. For example, as shown in Figure 3, for thinning, only one out of every four dots is taken out in the horizontal direction (the black circles indicate the dots that are taken out), and the same is done in the vertical direction (now, one out of every 16 dots is taken out, The thinning rate is 1/16). In addition, the above-mentioned upper left end (starting end) coordinate (Xs.

Ys) is the up/down of the operator operation panel 18,
By operating the left/right shift keys (respectively indicated by arrows), the shift changes by 1 in the up, down, left, and right directions (14 is ys-it Y3+1°Xs-1, or Xs+ each time the key is pressed.
1), thereby scrolling the display screen.

[Problem that the invention seeks to solve]

In conventional devices, when scrolling the screen, the display coordinates are changed in the smallest unit (such as Y s -1), and the data read out from the high-resolution memory is thinned out, stored in the low-resolution memory, and displayed on the display, so dithering is possible. There is a problem that image data based on legal expression changes unnaturally.

That is, the image data obtained by the dithering method is as shown in FIG. 5, for example, and when this is read out with the Δ mark point as the upper left corner and displayed after being thinned out to 1/4, it becomes 22 (or Ys+
If the X mark point is read out as the upper left corner and displayed after being thinned out to 1/4, the result will be 24, which is different from normal scrolling. This is because the data obtained by the dither method is not random as usual, but is biased.
When s is changed by 1, which pixel becomes the display target changes every moment.

The present invention aims to improve this point and make it possible to perform normal scrolling even if there is image data obtained by dithering.

[Means for solving problems]

FIG. 1 shows the principle of the present invention. The same parts as in FIG. 4 are given the same reference numerals. The thinning display device 12 shows the starting end (upper left end) coordinates XS of the high resolution memory 10.

Y S % Data in a rectangular area with vertical and horizontal lengths LX and Ly is thinned out at a thinning rate of 1/H and transferred to the low resolution memory 16. The display coordinate control section 14 is an operator operation panel 18.
Every time the up/down/left/right shift keys are pressed, the above-mentioned upper left corner coordinates are changed and the display screen is scrolled.
In the present invention, Xs and Ys, which are changed with one key press, are ±
Let it be N.

[Effect]

In this way, if the display coordinates are changed by N when the thinning rate is 1/N, the data that has been 1/H-transferred from the high-resolution memory to the low-resolution memory will be scrolled in the low-resolution memory. (Of course, new data appears at the leading edge in the scroll direction, and data disappears at the trailing edge.)
, the screen of the display 20 becomes a normal scroll screen (however, the pitch of movement is N), and there is no unnatural change that occurs when the display coordinates are changed one by one.

[Example] Fig. 2 shows an example of the present invention. Reference numeral 30 denotes an image processing device that scans a photographic image or the like to obtain image data, processes this using a dither method, converts it into a binary data, and inputs it into the high-resolution memory 10. Reference numeral 34 denotes a character/figure input device which processes characters and figures input by operating the operation panel 36, inputs the data into the memory 10, and adds it to the image data from the image input device 30. These data combination states in the high-resolution memory can be visually displayed on the display 2o through the thinning display device 12 and the low-resolution memory 16, and when the desired state is obtained, a printing device 32 such as a high-resolution laser printer This enables high-quality printing on paper.

〔Effect of the invention〕

As described above, according to the present invention, a stable scrolling screen can be displayed on the display even when the photo data has a skewed pattern when the screen is scrolled.

[Brief explanation of drawings]

FIG. 1 is a diagram explaining the principle of the present invention, FIG. 2 is a detailed explanatory diagram of the present invention, Figure 3 is an explanatory diagram of thinning, Figure 4 is an explanatory diagram of the conventional device; Figure 5 is an explanatory diagram of the problems of the conventional device. FIG. 6 is an explanatory diagram of the dither method.

Claims (1)

[Claims] A high-resolution memory (10) into which binary data representing a grayscale image using a dithering method is input, and data in a predetermined area starting at the starting point coordinates (Xs, Ys) of the high-resolution memory. is thinned out to 1/N and low-resolution memory (16
); a display (20) for inputting and displaying data in the low-resolution memory; and a display coordinate system for scrolling the screen by increasing or decreasing the start coordinate by N each time a key is pressed. An image processing device comprising: a control section (14).