JP2571045B2 - Image processing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an image processing method.

[Related Art] A conventional video printer obtains a printed image by performing faithful color reproduction based on input image data. For this purpose, for example, a characteristic curve for gradation conversion is selected according to the brightness distribution of the image data.

However, in the above-described conventional example, when character data is combined with image data by an image reproducer or the like, the distribution of brightness of the image data is affected by the character data. Therefore, there is a problem that the brightness changes between the print result of the image data in which the character data is not combined and the print result of the image data in which the character data is combined.

[Object of the Invention] The present invention has been made in order to solve the above-mentioned problem, and when character data is present in given image data, image data is removed from the image data excluding the character data. It is an object of the present invention to provide an image processing method capable of satisfactorily performing a gradation correction process on an image in which the character data exists by detecting the characteristics of the character data and controlling the image processing in accordance with the detected result. is there.

FIG. 1 is a block diagram showing an embodiment of the present invention.

A regenerator 1 as an example of a device on the host side and a printer 2 as a terminal are connected by a plurality of control lines.
These control lines are print request signal, timing pulse, ready / busy signal (busy signal has meaning when negative), FM & error signal (FM & error signal has meaning when negative) Is transmitted.

Further, the printer 2 has an external control terminal for connecting the plurality of control lines, and has a function of switching a data sampling area based on an external control signal received from outside via the external control terminal.

FIG. 2 is a timing chart showing the timing of each signal when a print request signal is output from the reproducing device 1.

The timing pulse is a pulse indicating the timing of the control signal output from the reproducing device 1, and the ready / busy signal is a response signal of the printer 2 to the print request signal output from the reproducing device 1.

At the start of the printing operation, the FM & error signal
Is a signal indicating whether or not the printer 2 has an image memory and indicating whether or not an error has occurred in the printer 2 during printing.

 Next, the operation of the above embodiment will be described.

FIG. 3 (1) is a diagram showing a divided area of image data in the above embodiment, and FIG. 3 (2) is a diagram showing a signal indicating whether or not character data is combined with image data in the above embodiment. It is a figure showing an example.

FIG. 4 is a flowchart showing a processing procedure in the above embodiment.

First, when a print request is output (S1), the printer 2 sets the ready / busy signal to "L" as a response to notify that the printer is busy. At the same time, if an image memory exists in the printer 2, the FM & error signal is set to "L". (S2). The above operation is performed during the period a shown in FIG.

In response to the fact that the ready / busy signal has become “L”, the reproducing device 1 synthesizes information indicating whether or not character data and image data have been synthesized using the print request signal. A start pulse is output (period b shown in FIG. 2) in order to output the data indicating the position on the screen that is present (period c shown in FIG. 2).

After inputting data indicating the position where the character data is input, the player 1 is notified that the position data has been input. In this case, the ready / busy signal is raised once to notify it. At this time, the regenerator 1 checks the level of the FM & error signal,
It is determined whether or not there is an image memory (S3, S4).

Then, the regenerator 1 outputs the image data, and the printer 2
When the image data has been stored in the image memory inside (S
6) The FM & error signal rises to notify the reproducing device 1 that the input of the image data has been completed (S7). At this rise, the regenerator 1 stops sending data.

Thereafter, the CPU (not shown) controlling the system of the printer 2 samples the image data stored in the image memory based on the input position data of the character except for the range indicated by the position data. Then, gradation correction processing by the histogram method is performed (S8).

For example, as shown in FIG. 3 (1), the screen is divided into four parts, and when the display position of the character is substantially determined in each area, a range slightly larger than the range is set. In this case, the position data from the reproducer 1 indicates which of the four divided areas. However, if the most significant bit (first input bit) of the position data is “L”, it indicates that character data is not synthesized. When it is determined that the character data is not synthesized, sampling of the image data is performed over the entire image.

On the other hand, when the character data is synthesized, the image data in the area indicated by the position data is not sampled, but the image data in another area is sampled, and the gradation correction by the histogram method is performed.

That is, when an image reproduced by the reproducing device 1 or the like is to be printed by the printer 2, a signal indicating the position where the character data is synthesized is transmitted from the host side of the reproducing device 1 or the like to the printer 2.
To limit the sampling range of data used for gradation conversion in the printer 2. As a result, it is possible to eliminate the influence of the character data on the gradation conversion and to obtain an image similar to a printer image in the gradation conversion when the character data is not combined.

In the above embodiment, the information on the presence / absence of character data synthesis and the information on the character data display position are transmitted to the printer 2 in a form of being superimposed on the print request signal. A line may be provided, and a signal indicating presence / absence of character data combination and a signal indicating a character data display position may be transmitted via the dedicated signal line.

Further, if the display (combining) position of the character data is determined, only the presence or absence of the combination of the character data may be notified. In the above embodiment, the screen is divided into four parts, but the number of divisions does not need to be limited.

[Effects of the Invention] According to the present invention, even when character data is present in given image data, the image data can be favorably subjected to gradation correction processing.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention. FIG. 2 is a timing chart in the above embodiment. FIG. 3 (1) is a diagram showing a divided area of image data in the above embodiment, and FIG. 3 (2) shows an example of a signal indicating whether or not character data is synthesized in the above embodiment. FIG. FIG. 4 is a flowchart showing a processing procedure in the above embodiment. 1 ... regenerator, 2 ... printer.

Claims (1)

(57) [Claims] An image for forming a visible image according to given image data so that the brightness of the formed image does not change due to character data included in the given image data. A processing method, wherein it is determined whether or not character data exists in the given image data, and if character data exists, based on the image data excluding the character data, An image processing method comprising: detecting a gradation characteristic of an image; and performing a gradation correction process on the given image data according to the detected gradation characteristic.