JPS6314375B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an image display device that processes an image signal inputted by a manual image input device or the like and displays the processed image signal on a CRT.

Conventional technology and its problems A figure is drawn on the board of an image input device such as a digitizer, the output X-Y position information is stored in memory, and the read output of this memory is converted into a video signal and displayed on a CRT. Image display devices that allow the user to display images are conventionally known. With this device, X-Y position information is stored in each cell in the memory as "1" or "0" information (1 bit), so The disadvantage is that the contour line becomes "jagged".

OBJECTS OF THE INVENTION It is an object of the present invention to eliminate the above-mentioned drawbacks and to obtain an image having smooth contour lines without "jaggies".

Embodiment FIG. 1 is a plan view of a known digitizer, which is an example of an image input device used in an embodiment of the present invention. This digitizer includes sliding bodies 1a and 1b that can slide in the X direction, and a sliding body 2 that is held by these sliding bodies and can slide in the Y direction.
Then, draw an arbitrary figure on the board 4 with the cursor 3 attached to the sliding body 2, and drive the rotary encoders 7, 8 with the wire 5 connected to the sliding body 1a and the wire 6 connected to the sliding body 2. The encoders 7 and 8 are configured to obtain image input signals indicating the X-Y coordinates of points on the figure. In addition to the digitizer shown in Figure 1,
Rand using Y matrix-shaped capacitance electrodes
A tablet, a photoelectric conversion type tablet using a hologram code plate for coordinate conversion, a Grafpen tablet using a spark pen and X, Y microphones, etc. can be used.

FIG. 2 is a block diagram showing an embodiment of an image display device according to the present invention. The output of the digitizer 10 shown in FIG. 1 is first written into the XY memory 11. If the size of the minimum unit (picture element) of a figure displayed on a monitor TV screen is the length L of the horizontal scanning line as shown in Figure 3, and the width approximately equal to the above L, then the size of the figure on the screen is The number of picture elements is 493 (effective number of scanning lines) x 657 (493 x 4/3). It is assumed that the digitizer 10 has, for example, 4×4=16 times the resolution in the vertical and horizontal directions for one picture element S on the TV screen, as shown in FIG. Therefore, X-Y
The memory 11 has (493×4)×(657×4) memory cells, and an image input signal (X-Y position information) is written as “1” or “0” in each cell (1 bit). .

The output of the XY memory 11 is applied to a converter 12, where it is converted into information for one pixel for each 4×4 memory cell. This converter 12 is composed of a microcomputer, counts the number N of "1"s in one pixel area made up of each 4x4 segment, and calculates the ratio N/16 of each pixel on the monitor screen. Convert to brightness level information. For example, as shown in Figure 4, in a certain 4x4 area Sij, the ratio is 13/16, so
The information representing the brightness level of the picture element corresponding to the area Sij is set to 13/16. This is 4-bit binary information and corresponds to "1101" (=13).

The output of the converter 12 is a 493 x 657 x 4 bit video memory 1 with a capacity of 4 bits per pixel.
3 is written. The output of the video memory 13 is D/
After being converted into an analog signal by the A converter 14, it is sent to a monitor TV, where the input graphic is displayed.

According to this display method, the brightness level of the picture element located at the outline of the figure on the monitor screen changes suddenly from "0" (black) to "1" (white), creating a step-like pattern. There are no contour lines, and a smooth luminance change from the figure part to the ground color part is obtained, and in combination with the integral action of the eye, a display figure with smooth contour lines can be obtained.

In the above explanation, it is assumed that the resolution of the digitizer 10 is 16 times (4 x 4) per pixel, but in reality, the accuracy is 36 (6 x 6) to 64 (8 x 8) times. Therefore, the converter 12 converts each picture element into, for example, 64 levels (8 bits) of information, and the 8-bit level information is displayed graphically on the screen. The converter 12 may also have a function of changing the line thickness of the line drawing drawn by the digitizer 10 or a function of filling in the loop drawn by the line drawing.

Effects of the Invention As described above, the present invention calculates the area ratio occupied by characters and figures in m segments from the output of an image input device having a resolution in which one pixel on a monitor screen is subdivided into 1/m. , the level information of the gradation proportional to this ratio is converted and displayed. Therefore, step-like jaggedness does not occur in the outline of the displayed figure, and it is possible to obtain an easy-to-read display figure with a smooth outline.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a conventionally known digitizer showing an example of an image input device used in an embodiment of the present invention, FIG. 2 is a block diagram showing an embodiment of an image display device according to the present invention, and FIG. 4 is a plan view showing the relationship between the picture elements on the monitor screen and the graphic input segment of the digitizer, and FIG. 4 is a partial plan view of the graphic drawn by the digitizer. In addition, in the symbols used in the drawings, 1a, 1b...
...Sliding body, 2...Sliding body, 3...Cursor, 4...
...Board, 5,6...Wire, 7,8...Encoder, 10...Digitizer, 11...X-Y
Memory, 12...Converter, 13...Video memory, 14...D/A converter, S...Picture element.

Claims (1)

[Claims] 1. An image input device capable of forming image input information having a resolution of 1/m for one pixel, which is the smallest unit of characters and figures displayed on a monitor screen; a converter for determining the area ratio occupied by characters and graphic parts in the corresponding m segments from the image input information and converting it into gradation level information proportional to this ratio for each picture element; character based on the output of the converter,
An image display device characterized by displaying figures.