JP2844766B2 - Recording gradation processing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an improvement in a gradation processing method when a brightness-modulated waveform is represented by a hard copy on a screen such as an oscilloscope.

<Prior Art> Conventionally, there is an oscilloscope having a function of hard-copying an image (display waveform or the like) displayed on a screen of a CRT display or the like to a printer. As a printer, there is a printer using a thermal type thermal printer.

The thermal printer records (prints) image data stored in an image memory corresponding to a display screen.

<Problems to be solved by the invention> By the way, when the display waveform is subjected to luminance modulation,
Even when a hard copy of the screen is taken by the printer, there is a problem that the luminance modulation on the screen is not expressed as it is. The following describes various conventional methods and their problems.

For example, there is a method of controlling the temperature of the printer head and printing with shading, but the printing density is low overall,
When the printed matter is further copied by a copying machine, there is a disadvantage that the shading becomes more difficult to understand.

On the other hand, the dither method is widely used as a method of expressing light and shade regardless of the temperature change of the head. This method is the third
As shown in the figure, dots are thinned out at a ratio corresponding to the density, but there is a drawback that it is effective for shading of a surface but is not suitable for shading of a line such as a waveform.

There is also a method of changing the thickness of a line as shown in FIG. However, this method has the following problems. The display screen of the oscilloscope employs a raster scan screen, and the original data of the hard copy is also in a bitmap format suitable for raster scan. In the bitmap format, since the screen is represented as a set of points, there is a problem that it is difficult to directly check the inclination of the line.

SUMMARY OF THE INVENTION An object of the present invention has been made in view of the above points, and a gradation processing method capable of obtaining gradation recording corresponding to a screen display by changing the thickness of a recording line according to luminance modulation of a screen. Is to provide.

<Means for Solving the Problems> FIG. 1 shows a principle flow of a recording gradation processing method according to the present invention. The present invention shows a flow of processing (gradation processing) for changing the print density in relation to luminance on a dot-by-dot basis for waveform data stored in a bitmap format in a memory. That is, it is determined whether the dot directly above or below the dot is a recording dot.

If it is a recording dot in the above determination, at least a dot on the left or right of the dot is set as a recording dot.

If it is not a recording dot in the above determination, at least a dot directly above or below the recording dot is changed to a recording dot.

<Function> The present invention relates to a device capable of hard-copying a waveform of a waveform displayed on a display screen with a brightness modulation to a printer, and converting the dot data of the brightness modulation display into dot data of gradation suitable for printer output. When you do
Change the dot on the left or right of the vertical dot to a recording dot, and change the dot directly above or below the horizontal dot to a recording dot, so that Convert to dots of related gradation.

<Example> Hereinafter, the present invention will be described in detail with reference to examples. Here, one dot is represented by 2-bit information (b ₁ , b ₀ ). The dot of (0,0) is a dot not to be recorded, and (0,0)
1), (1, 0), and (1, 1) are associated in such a way as to have high luminance, and the gradation process for hard copy is performed by focusing on the (1, 1) dot.

The gradation processing is performed by the processing shown in FIG. 1, but is actually realized by the following simple logical operation. Here, in order to simplify the description, a case where the upper and left sides of the dot are changed to recording dots is taken as an example.

OR of the bit b ₁ and b ₀ (logical OR: OR) taking make the data of the presence or absence of dot recording.

And bits b ₁ and b ₀ (logical product: the AND) making data of the highest luminance record taking.

The data of the highest luminance record created above is shifted up by one dot.

Dot overlapping part (AND of data created above and data shifted above is created.

The portion where the dots overlap is lowered by one dot, and it is further shifted one dot to the left. The portion shifted to the left is overlapped, and the original data (the data on the left) and the shifted data are ORed.

Such a logical operation is performed for all dots from the upper left dot to the lower right dot. Note that the uppermost dot row and the leftmost dot row of the screen cannot be shifted further up or to the left, and logical operations cannot be performed. The above logical operation is performed for the subsequent dots.

FIG. 2 is a configuration diagram of a main part of an oscilloscope for implementing the method of the present invention. In the figure, 1 is the main CPU (C
PU is a central processing unit), 2 is a sub CPU that is in charge of display, 3
Is a control circuit for performing necessary control for displaying image data on the CRT 4, 5 is a video RAM for storing image data, 6
Is a shared RAM for storing programs and waveform data, and 7 is a work RA for storing the contents of the hard copy by the printer 9.
M and 8 transfer the data in the work RAM 7 to the printer 9 by DMA (Direct M
omory Access) DMA controller for transfer.

In such a configuration, waveform display is performed by the control circuit 3 sequentially reading out image data (dot data) from the video RAM 5 and displaying the image data on the CRT 4 by a raster scan method. The data stored in the video RAM 5 is data having information of 2 bits per dot as described above.

On the other hand, a hard copy of the display waveform is performed in the following procedure.

The main CPU 1 performs the above gradation processing for each dot.

The dot data obtained by the gradation processing is stored in the work RAM 7.

After the gradation processing is completed, the DMA controller 8 is activated, and the contents created in the work RAM 7 are transferred to the printer 9. The printer 9 sequentially prints the transferred data.

In this way, a waveform whose luminance has been modulated on the screen of the oscilloscope can be represented by a hard copy on a printer.

In the embodiment, the description has been made using the oscilloscope.
The present invention is not limited to this, and can be applied to any device requiring a luminance gradation. In the embodiment, the case of two gradations has been described, but the present invention can be applied to three or more gradations by extending to the right side and the lower side.

Furthermore, in the gradation processing, the gradation is changed only for one dot adjacent to the dot, but two or more dots may be changed simultaneously.

<Effects of the Invention> As described in detail above, according to the present invention, a gradation waveform corresponding to a screen display can be obtained on a printer by changing the thickness of a recording line according to the luminance modulation of the screen. Can be.

[Brief description of the drawings]

FIG. 1 is a flow chart of the principle of a gradation processing method for thermal recording according to the present invention, FIG. 2 is a diagram showing a main part of an oscilloscope for carrying out the method of the present invention, and FIGS. It is a figure for explaining an expression system. 1 ... Main CP
U, 2 ... Sub CPU, 3 ... Control circuit, 4 ... CRT, 5 ...
... Video RAM, 6 ... Shared RAM, 7 ... Work RAM, 8 ... D
MA controller, 9 printer.

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Claims (1)

(57) [Claims] 1. An apparatus capable of hard-copying a waveform displayed on a display screen after being subjected to luminance modulation to a printer. The apparatus converts luminance-modulated dot data for display into dot data of gradation suitable for printer output. A tone processing method for recording, wherein the processing means performs tone processing for recording according to the following procedure. It is determined whether the dot immediately above or below the dot is a recording dot. If it is a recording dot in the above determination, at least a dot on the left or right of the dot is set as a recording dot. If it is not a recording dot in the above determination, at least a dot directly above or below the recording dot is changed to a recording dot.