JPH0437289A - Signal processor for video printer - Google Patents

Abstract

PURPOSE:To realize freeze processing of a picture, correction processing and print processing mode with one coding processing by adopting the digital picture correction method. CONSTITUTION:An input output of a means 102 storing an output picture of an A/D converter means 1 and having a tri-state output function, and an input of a means 2 correcting the picture are connected to the same data bus, and the output of the means 2 correcting the picture, the input of a D/A converter means 103 decoding the output picture of the means 2 correcting the picture and the input of a means 111 printing out the picture are connected to the same data bus. The picture correction means 2 applies same correction calculation in time division in the picture correction and print modes to obtain a preferred hard copy picture while confirming the correction state on the monitor picture. Thus, the hard copy picture with excellent picture quality is realized by the economical device with only one coding.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a signal processing device for a video printer that outputs full-color hard copy images.

[Prior Art] FIG. 4 is a block diagram showing a conventional video printer signal processing device disclosed in, for example, Japanese Patent Application Laid-open No. 179677/1983.

In the figure, (101) is an A/D circuit I that encodes the input video signal, (102) is an image memory that stores encoded data in a predetermined pixel configuration, and (103) is an A/D circuit I that encodes the input video signal. (104) is an analog demodulation circuit for the restored video signal, (105) is an analog modification circuit for the demodulated signal, (106) is an R (red) circuit from the modified signal. , G (green).

Inverse matrix circuit for restoring the B (blue) signal (107
) is an encoder circuit that generates a video signal from RGB signals. In addition, (108) is an inverse matrix circuit (106
) RGB signals (hereinafter referred to as M
PX) circuit, (109) is an A/D circuit n that re-encodes the MPX signal, (110) is a line memory that temporarily stores encoded data, and (111) is a thermal head (112) that is subject to thermal control. as line memory (110)
This is a printing circuit that generates thermal control data according to encoded data read from the printer. Note that the A/D circuit I (101
), image memory (102) and D/A circuit (103)
executes freezing processing of the desired image, analog demodulation circuit (104), analog correction circuit (105), inverse matrix circuit (106) and encoder circuit (107) executes correction processing of the frozen image, and MPX circuit (108) executes freezing processing of the desired image. )
and A/D circuit U (109) and line memory (110)
and printing circuit (111) and thermal head (112)
and execute the print process.

Next, the operation will be explained.

Input video signals conforming to the NTSC system etc. are A/D
It is encoded in circuit I (101). The encoded data is stored sequentially from a predetermined position in the image memory (102) for the number of screens. This operation completes the image freezing process.

This frozen image data is stored in the image memory (102
) is read out in a predetermined order from a predetermined position, decoded by a D/A circuit (103), and restored to the original video signal.

This video signal is separated into a luminance component Y and color components (RY, B-Y) by a demodulation circuit (104).

The amplitude value and the like of this separated signal are modified by an analog modification circuit (105), and the luminance and hue are adjusted to desired values.

This modified signal is converted into RGB by an inverse matrix circuit (106).
It is converted into three signals. The RGB signal is converted into an NTSC-compliant video signal by an encoder circuit (107) and output as a monitor signal. Corrections can be made while referring to this monitor image.

This is an overview of image retouching processing.

On the other hand, the RGB signals mentioned above are multiplexed in the MPX circuit (108) and encoded again in the A/D circuit II (109). The encoded data is stored in the line memory (110).
The processing operations on the monitor display are converted into print processing operations. In other words, a predetermined number of lines is stored, with one line being the number of pixels in the vertical direction of the image aspect (approximately 480 pixels in the NTSC system). Line memory (110
) The RGB data read from the printing circuit (111
) will be forwarded to. The printing circuit (111) supports Y (yellow), M (magenta), and C (cyan) corresponding to RGB data.
The amount of heat generated by the thermal head (112) is controlled on a pixel-by-pixel basis by executing conversion processing into ink density data and heat control data for the purpose of controlling gradation. This thermal control is performed two-dimensionally to obtain a single ink hardcopy image. This retouching process and printing process are repeated for the number of inks used to obtain a full-color note copy image.

This is an overview of the print process.

In this way, by providing the image freeze processing means, correction processing means, and print processing means, it is possible to obtain a desirable hard copy image of a desired image.

[Problems to be Solved by the Invention] Since the signal processing device of a conventional video printer is configured as described above, encoding and D/A processing (hardware processing) are performed twice within the same device for printing. Copying is also assumed to be a D/A operation in a broad sense), and there are problems such as deterioration of image quality such as a decrease in S/N ratio, decrease in reliability due to circuit redundancy, and high price.

This invention was made to solve the above problems, and by introducing a digital image retouching method, it is possible to perform image freeze processing, retouching processing, and print processing mode with just one encoding process. The object of the present invention is to obtain a signal processing device for a video printer.

[Means for Solving the Problems] A signal processing device for a video printer according to the present invention is a signal processing device for a video printer that outputs a full-color hard copy image, and includes (a) analog demodulation of an input video signal. (b) A/D converting the two signals to generate luminance data Y and color data C; (c) memory means for storing the encoded data; (c) memory means for storing the encoded data; (v) Means for generating a monitor video signal; (f) Means for printing an image by controlling the heat of the thermal head; It is equipped with means for reproducing a reference clock signal, etc., and (h) means for generating or controlling modification coefficients by inputting the overall sequence operation, amount of modification, etc.

To put it simply, ■ the output of the A/D means with a 3-state output function, the input and output of the means for storing 0 images, and ■ the input of the means for modifying the image are connected to the same data bus, and ■ the input of the means for modifying the image. The output of the means for restoring the 0 image is input to the D/A means for printing the 0 image, and the inputs of the means for printing the 0 image are connected to the same data bus.

[Operation] The image retouching means according to the present invention performs the same retouching operation in a time-sharing manner in the image retouching mode and the print mode.
It works to check the retouched state on the monitor image and obtain a desirable hard copy image.

[Example] Hereinafter, this invention will be explained based on the drawings.

FIG. 1 is a block diagram showing a signal processing device for a video printer according to an embodiment of the present invention.

In the figure, (1) is an A/
D circuit, (2) is a digital correction circuit, (3) is a clock regeneration circuit for synchronizing signals, etc., and (4) is a control circuit that controls the overall operation.Other components have the same functions as conventional ones. Or take action.

Next, this operation will be explained in detail.

The input video signal Y/C is sent to an analog demodulation circuit (104)
The luminance signal Y and color signal C (demodulated R-Y signal and B-Y
time-division multiplexed signals). These signals are encoded by an A/D circuit (1). The conditions for this encoding are: number of quantization bits == 8 bits, sampling frequency = 4
*fsc (fsc: subcarrier frequency 3.58MHz
), pixel configuration 768 (H) * 480 (V)
Adopt. At this time, the A/D circuit (1) is used in a mode that outputs normal binary data. Encoded data Y
(a) and C(b) are transferred to the image memory (102) which is set in advance to input mode, and data for one screen is stored in a predetermined order from a predetermined position.

With the above operations, the freeze processing of the desired image is completed.

In order to proceed to the next step, the output terminal of the A/D circuit (1) is set to the OFF state, and the input/output terminal of the image memory (102) is set to the output mode.

The freeze data in the image memory (102) is read out from a predetermined position in a predetermined order and input to the digital correction circuit (2) as data of Y(d) and C(e).

The data is modified to become Y(f) and C(g) data and transferred to the D/A circuit (103).

At this time, the printing circuit (Ill) is controlled not to input the data.

This data is restored into a luminance signal Y and a color signal C, or a luminance signal Y, a RY signal, and a BY signal, respectively. The encoder circuit (107) converts the restored signal into a video signal Y.
/C is generated and output as a monitor signal. At this time, a synchronization signal (m) reproduced by a clock reproduction circuit (3) is added to produce a video signal compliant with the NTSC system. Referring to this monitor image, the digital correction circuit (
2) executes the calculation (supplementary explanation) to be described later to correct the image to a preferable image.

This processing is carried out in the video section of the synchronizing signal section, and is the same as the monitor display processing operation described in the conventional section, that is, the operation of normal video signals. This is an outline of the operation of the retouching process.

Next, print processing will be explained.

The image memory (102) contains (Y, RY) or (
Y, BY) data pairs are stored.

However, one pixel of color information is (Y, RY.

B-Y). Therefore, in print processing, it is assumed that data always operates in (Y, RY, BY). In other words, the missing pixels of R-Y or B-Y are
Use data from adjacent pixels.

Image memory (
The Y and C data from 102) are subjected to the same correction calculation as the correction process, and are read out and transferred in the vertical (vertical) direction of the image, which is different from the monitor display, which transfers data in the horizontal (horizontal) direction of the image. Ru.

The data is transferred to the printing circuit (111) via routes d-4f and 6+g for each synchronization signal determined in units of a predetermined number. At this time, the D/A circuit (103) is placed in a non-operating state.

The printing circuit (111) operates as described below (supplementary explanation 2),
Thermal control is performed on each pixel of the thermal head (112) according to input data. Thermal head (112
) is 480 dots (referred to as one line of printing), printing is repeated for the number of pixels in the horizontal direction (768) to complete printing with Y ink, and the same operation is performed with M ink and C ink.
Also run on ink to get a full color hardcopy image.

Next, supplementary explanation 1 and supplementary explanation 2 will be described.

FIG. 2 is a diagram showing an embodiment of the digital correction circuit (2). In the figure, (10), (11), and (12) are a Y arithmetic unit, an RY arithmetic unit, and a BY arithmetic unit, respectively.
(13) is a separator for R-Y and BY data, and (14) is a multiplex combiner for the calculated R-Y and BY data. The Y arithmetic unit (lO) calculates α*Y, the R-Y arithmetic unit (11) calculates β* (R-Y), and the B-Y arithmetic unit (12) calculates γ* (B-Y ) are executed respectively. Here, the calculation coefficients α, β, and γ are given from the modification instruction signal (n).

Note that the C data (e) is separated from R-Y and B by the separator (13).
-Y data, R-Y operation unit (11) and B-Y
Modification calculations are performed in a calculation unit (12). The result of the calculation is again sent to the synthesizer (14) and becomes multiplexed composite data g.

Y data (d) is directly given to the Y arithmetic unit (10) and output as operand data (f).

The above calculation coefficients α, β, and γ are calculated by the control circuit (4) from R-Y
It is generated by taking into account the relationship between B and B, the relationship between gain increase/decrease, and image quality. The above operation corresponds to supplementary explanation 1.

FIG. 3 is a diagram showing an embodiment of the printing circuit (111). In the figure, (20) is an RGB restorer, (21) is a pixel decomposer, (22) is a multiplex (MPX) circuit, (23) is an address generator, and (24) is an SRAM and R
Memory consisting of OM, (25) is a head driver, (26
) is a clock generator, and (27) is an arithmetic unit.

It works as follows.

The luminance data Y (f) and color data C (g) of the input signal are restored to RGB data by an RGB restorer (20).

The RGB data is decomposed into achromatic data and chromatic data by a pixel decomposer (21). These two data are M
PX circuit (22), memory (24), and arithmetic unit (2)
7), the data is converted into YMC ink density data. The ink density data is temporarily stored in the memory (24) for the purpose of time axis adjustment. The ink density data read from the memory (24) at a predetermined timing is sent to the head driver (24).
5) and converted into thermal control data (head data) for the thermal head (112). Note that the address generator (23) appropriately generates an address signal for the memory (24).

The entire sequence of these is performed by the clock generator (26)
is controlled by The details of the printing circuit are disclosed by the present inventors in Japanese Patent Laid-Open No. 64-216696. The above corresponds to supplementary explanation 2.

In the above embodiment, the NTSC system was used, but the P
The same can be applied to the AL system.

Also, the pixel configuration of the image is 480 (V) * 768 (H)
Although it has been explained as 400 (V) * 640 (H), it can be arbitrarily set.

Furthermore, the embodiment of the digital correction circuit shown in FIG. 2 and the embodiment of the printing circuit shown in FIG. Can be adopted.

[Effects of the Invention] As described above, according to the present invention, not only can images be retouched to a preferable value through digital calculation, but also functions equivalent to conventional ones can be realized with only -degree encoding, and hard copy images with good image quality can be produced. The effects can be obtained with an economical device.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a signal processing device for a video printer according to an embodiment of the present invention, FIG. 2 is a diagram showing an embodiment of a digital correction circuit, and FIG. 3 is a diagram showing an embodiment of a printing circuit. 2 and 4 are professional diagrams showing a signal processing device of a conventional video printer. In the figure, (1) is an A/D circuit, (2) is a digital correction circuit, (3) is a clock regeneration circuit, (4) is a control circuit, and (1) is a clock regeneration circuit.
0) is a Y operator, (11) is an RY operator, (12) is a BY operator, (13) is a separator, (14) is a combiner,
(20) is an RGB restorer, (21) is a pixel decomposer, (2
2) is the MPX circuit, (23) is the address generator, (24
) is the memory, (25) is the head driver, (26) is the clock generator, (27) is the arithmetic unit, and (101) is the A
/D circuit I, (102) is image memory, (103)
is a D/A circuit, (104) is an analog demodulation circuit, (10
5) is an analog correction circuit, (10&) is an inverse matrix circuit, (107) is an encoder circuit, (108) is MPX
The circuit, (10,9) is an A/D circuit, (]10) is a line memory, (111) is a printing circuit, and (112) is a thermal head. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] A signal processing device for a video printer that outputs a full-color hard copy image, comprising: (a) analog demodulation of an input video signal to generate luminance signals Y, RY signals, and B-Y signals; Time division multiplexed color signal C
(b) Encoding means for A/D converting the two signals to generate luminance data Y and color data C, and controlling the output of the data in a three-state mode; (c) (d) means for correcting the Y and C data read from the memory means into preferred image data; (e) means for generating a monitor video signal; (f) means for generating a monitor video signal; ) Means for printing images by executing thermal control of the thermal head; (G) Means for reproducing synchronization signals, reference clock signals, etc. from input video signals; (H) Overall sequence operation and amount of correction, etc. A signal processing device for a video printer, comprising means for generating or controlling a modification coefficient by inputting the following.