JPH0766318B2 - Video signal processor - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for processing a video signal, for example, displaying the video signal on a sheet body such as a blank telephone card or the like, or a screen. The present invention relates to a video signal processing device capable of changing the brightness and contrast of an image when visually displayed.

Conventional technology In order to print an original image on a blank telephone card, the image signal read by an input device such as a scanner is digitized and stored in a frame memory, and the image signal stored in the frame memory is stored. Is temporarily transferred to a random access memory called a lookup table, etc., and in this random access memory, by executing program software, the video signal is calculated and changed, thereby changing the brightness and contrast, The stored content of the random access memory thus obtained is converted into an analog signal, output as a video signal, and visually displayed on a display means such as a monitor TV,
In addition, this image is printed on a blank telephone card.

Problems to be Solved by the Invention In such a prior art, the video signal in the random access memory is rewritten by being operated by executing program software. Therefore, there are a plurality of operations and it takes time, and therefore a control operation is performed. The load on the processing device such as a microcomputer becomes heavy. Such program software needs to be stored and prepared in a read-only memory prepared in advance, which requires a large memory capacity of the read-only memory.

An object of the present invention is to provide a video signal processing device capable of processing and changing the brightness and contrast of an image with a simple operation.

Means for Solving the Problems The present invention is a color video signal generating means for generating each color signal of red, green and blue of a color video signal, and a table provided with a plurality of types for each color signal, which are input. Color signal is x, output color signal is y
Then, when a and b are the first and second constants, y = ax + b is calculated, and in the plurality of types of tables for each color signal,
At least one of the first and second constants a and b is different from each other, and each color signal from the color video signal generating means is stored in the plurality of types of tables corresponding to the color signal. A combination of the tables for each color signal that is selected at the same time is derived by selectively switching and deriving each color signal that has been changed by the selected table. A video signal processing device comprising a switching means and means for displaying a color image by each color signal through the switching means.

Operation According to the present invention, the color image signal generating means outputs red,
Each color signal of a total of three colors of green and blue is generated and given to the table through the switching means, and the color signal changed by the table is printed by a printer through the switching means, or a monitor television or the like. Is provided to the color image display means for visual display. A plurality of (four in the embodiment described later) types of tables are provided for each color signal, and the input color signal x is multiplied by a first constant a,
Further, the second constant b is added, thus changing the input color signal x depending on the first constant a corresponding to the contrast and the second constant b corresponding to the brightness. Therefore, it is possible to change and set the contrast and brightness of each color signal of the color image in a desired manner.

Further, according to the present invention, the switching means has a predetermined combination of tables for each color signal selected simultaneously among a plurality of types of tables provided for each color. For example, in the embodiment described later, Table 14 which is the first combination
R1,14G1,14B1 are defined, and the table is the second combination.
14R2, 14G2, 14B2 are defined, tables 14R3, 14G3, 14B3 are defined as a third combination, and tables 14R4, 14G4, 14B4 are defined as a fourth combination. Therefore, the three color signals are changed in a desired manner by the selection by the switching means, and the color image is displayed by the color image display means. Therefore, the operator does not have to bother with selecting a table for each color. Therefore, since the video signal from the video signal source is not changed by the execution of the program software as described in connection with the above-mentioned prior art, its processing time is short and a simple table selection is required. The video signal can be changed by operation. Therefore, it is possible to reduce the load on the microcomputer or the like that performs arithmetic processing, and further it is possible to reduce the capacity of the read-only memory that stores the program software.

Embodiment FIG. 1 is a block diagram of an embodiment of the present invention. A video signal of a still image or a moving image from the input means 1 is stored in the frame memory 2. The input means 1 may be, for example, a so-called NTSC video signal such as a television receiver, or may also be a charge storage element (abbreviation).
It may be a video signal obtained by scanning the surface of an object to be read with a CCD) line sensor. Red R, green G and blue B total 3 for color display from frame memory 2
The three color signals are the changeover switches 3 and 4 that constitute the changeover means.
Is applied to the random access memory 5 to change its video signal, and the video signal thus obtained is applied to the digital / analog conversion circuit 6 to be an analog signal, which is applied to the NTSC encoder 7. ,
It is given to the printer 8. The printer 8 can print on the surface of a blank telephone card or the like. Further, it can be visually displayed by the screen display means 9 such as a monitor television. The printer 8 is a so-called sublimation type thermal transfer recording system containing a sublimable dye, and has a configuration capable of selectively changing the temperature for each pixel by a thermal head and thereby performing color printing.

The processing circuit 10 is realized by a microcomputer or the like, and stores the video signal from the input means 1 in the frame memory 2 in accordance with the address designation of the address generation circuit 11 provided in the processing circuit 10, and also the frame memory 2 The stored contents of are read out in accordance with the address of the address generation circuit 11, and such an operation is performed in timing with the horizontal and vertical synchronizing signals. Processing circuit 10
Is performed by executing the program stored in the read-only memory 12. The image printed by the printer 8 can be visually displayed using the screen display means 9 such as a monitor television by the operation of the processing circuit 10 as described above.

The video signal for each color from the frame memory 2 is
It is given to the common contact of the changeover switch 3 via R, 13G, 13B. The random access memory 5 has a plurality (for example, 4 in this embodiment) of tables 14R1 to 14R4,1 for each color.
4G1 to 14G4 and 14B1 to 14B4 are provided, and a video signal is selectively applied from each common contact of the changeover switch 3 via the individual contact. For example, table 14R1 performs an operation for converting a video signal to bright, table 14R2 performs an operation for making a video signal dark, table 14R3 performs an operation for weakening the contrast of a video signal, and table 14R4 does an operation for a video signal. Performs calculations to increase contrast. Such tables 14R1 to 14R4 correspond to red R video signals, tables 14G1 to 14G4 correspond to green G video signals, and tables 14B1 to 14B4 correspond to blue B video signals. .

The arithmetic operation of the tables 14R1 to 14R4 will be described with reference to FIG. A video signal is input from line 13R, and the input video signal is represented by x, and tables 14R1 to 14R14
One of R4 is selected by the changeover switch 3,
Assuming that the changed video signal output by this is y, y = ax + b (1) where the gradient a represents the strength of contrast, and the y contact is
Represents the brightness of light and dark. In each of the tables 14R1 to 14R4, such numerical values a and b are predetermined, and the inputted video signal x is calculated and output as the changed video signal y. Such a configuration is used for the remaining tables 14G1-14G4 and 14B1-14B4.
Is also the same.

The changed video signals of the tables 14R1 to 14R4 are given to the individual contacts of the changeover switch 4, led out from the common contact to the line 15R, and converted into analog video signals in the digital / analog conversion circuit 6. Residual line 15G, 15
The same applies to B.

A key 16 is provided to change the brightness and contrast, the output of which is the processing circuit 10 and up / down.
It is given to the down counter 17. Every time the key 16 is operated, the up / down counter 17 is incremented by 1 to perform a counting operation, and the changeover switches 3 and 4 are interlocked to be switched. For example, in order to change the video signal brightly, the table 14R1, 14G1 The switching state is changed so that 14B1 is selected. After the count value reaches 4, the up / down counter 17 returns to 1 again, and thus, each time the key 16 is operated, four tables for each color R, G, B are sequentially switched and circulated. Up / down counter 17
The operation may decrement the count value by one.

The operation will be described with reference to FIG. From step s1 to step s2, it is determined whether the key 16 has been operated. When the operation of the key 16 is detected in step s2, the process proceeds to step s3, and it is determined whether or not the first key operation is performed. If the key 16 is operated for the first time, the changeover switches 3 and 4 select the tables 14R1, 14G1 and 14B1 for changing the image signal brightly and change the video signal.

When it is determined in step s4 that the operation of the key 16 is the second time, the tables 14R2, 14G2, 14B2 for changing the video signal to dark are selected by the changeover switches 3 and 4, and the video signal is changed. It

If the key 16 is the third operation in step s5,
The change-over switches 3 and 4 are switched so as to select the tables 14R3, 14G3, and 14B3 whose contrast of the video signal is weakly changed, whereby the contrast of the video signal is changed to be weak.

When it is determined in step s6 that the key 16 is the fourth operation, the changeover switches 3 and 4 use the tables 14R4, 14G4 and 14B4 for increasing the contrast of the video signal.
Is changed to a switching state for selecting, so that the contrast of the video signal is increased. The image of the changed image signal can be visually displayed and confirmed on the screen display means 9, and the printer 8 can print in the same state as the screen. More tables may be provided and switched. Thus, the image changed by the operation of the key 16 can be instantly viewed on the screen display means 9.

In this way, even if the image input from the input means 1 such as a scanner is too dark, or conversely too bright, by operating the key 16 without re-inputting by the scanner 1,
The operability is improved by easily changing and correcting the video signal. Also, depending on the taste of the person, I like dark images,
Differences in sensitivity, such as preferring a high-contrast image, can be handled by operating the key 16.

The power supply 19 energizes each component of the video signal processing device of the present invention.

In the above-described embodiment, the still image stored in the frame memory 2 is displayed, but the moving image of the television receiver or the like is directly used in the plurality of tables by using the changeover switches 3 and 4. The video signal may be changed by changing the video signal.

As described above, according to the present invention, the video signal from the video signal generation source is given to one of the plurality of tables switched by the switching means, and the video signal is changed. Since the brightness and contrast of the screen are changed, the calculation process is simplified, the video signal can be changed at high speed, and the operability is good because the table can be switched by a simple operation. In addition, it is not necessary to prepare the program software described in connection with the above-mentioned prior art, and the capacity of the read-only memory for storing the program software can be reduced.

In particular, according to the present invention, a total of three color signals of red, green and blue of the color video signal are given to the table. In this table, the input color signal x is multiplied by the first constant a to change the contrast. Also, the second constant b can be added to set the brightness, and thus the contrast and brightness can be set for each color signal in a desired manner, thereby improving the operability. Therefore, the operator does not have to make individual adjustments for contrast and brightness, and only needs to select the desired table.

Further, according to the present invention, the combination of the tables for each color signal simultaneously selected by the switching means is predetermined, and therefore, by selecting these combinations,
A color image in a desired manner in which the respective color signals are combined is displayed by the color image display means, which also improves the operability.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a graph for explaining the operation of a table provided in the random access memory 5, and FIG. 3 is for explaining the operation of the processing circuit 10. It is a flowchart of. 1 ... Input means, 2 ... Frame memory, 3, 4 ... Changeover switch, 5 ... Random access memory, 6 ... Digital / analog conversion circuit, 7 ... NTSC encoder, 8 ... Printer, 9 ...... Screen display means, 10 ... Processing circuit, 11 ... Address generation circuit, 12 ... Read only memory, 14R1-14R4,14G1-14G4,14B1-14B4 ... Table

Claims (1)

[Claims] 1. A color video signal generating means for generating each color signal of red, green and blue of a color video signal, and a table provided for a plurality of types for each color signal, wherein an input color signal is x. The output color signal is y
Then, when a and b are the first and second constants, y = ax + b is calculated, and in the plurality of types of tables for each color signal,
At least one of the first and second constants a and b is different from each other, and each color signal from the color video signal generating means is stored in the plurality of types of tables corresponding to the color signal. A combination of the tables for each color signal that is selected at the same time is derived by selectively switching and deriving each color signal that has been changed by the selected table. A video signal processing device comprising: switching means and means for displaying a color image by each color signal through the switching means.