JPH0736611B2 - Video image processor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a video image processing apparatus for obtaining a high-quality color-separated plate for printing a video image arbitrarily selected from a video signal.

[Prior art and its problems]

In recent years, due to the rise of television broadcasting in the mass media and the development and spread of video technology, there is an increasing demand for recording desired images from printed images on a printed matter or the like for mass duplication.

Conventionally, when making a video image into a printed matter, a method of making a color film obtained by photographing the cathode ray tube surface of a color monitor with a still camera with a plate making scanner, and making R, G, B video images projected on a black and white monitor respectively R, G, A method of plate making a color film obtained by multiple exposure through a B color filter with a plate making scanner, and further a method of directly inputting R, G, B video signals as electric signals to the plate making scanner in JP-A-55-74545 was there.

However, in the method of shooting a color monitor,
The color tone and gradation of the video image cannot be reproduced satisfactorily due to the spectral emission characteristics of the R, G, B phosphors and the spectral sensitivity of the color film and the mismatch of the density regions, and the R, G, B phosphors are not reproduced well. There is a defect that dots and printed dots of the printed matter interfere with each other to cause moire. Even in the method of multiple exposure with a black and white monitor, the scanning lines of the video image interfere with the dots of the printed matter to cause moire, and the resolution of the video image deteriorates due to the addition of the step of making a color film and then plate-making. There was a flaw. With the method of directly inputting the R, G, B video signals in JP-A-55-74545 to the plate-making scanner, the color tone, gradation, and resolution represented by the video signal are reproduced almost as they are, but the original image quality of the video image is It is often not enough as a manuscript.

The reason for this is that the video signal complies with the standard system of color television broadcasting, and NTSC is adopted in Japan among several kinds of standard systems, but the video signal of NTSC is different from that of black and white television broadcasting before that. This is because the information amount of the image is compressed in consideration of compatibility and the like. The compression method of the image information utilizes the property of the human eye for the moving image, and even if the image quality looks sufficient as the moving image of the monitor TV, the printed matter from the TV image (that is,
Still images) do not provide satisfactory image quality. Further, processing applied to a video signal by various devices so that the video image can be better seen by human eyes as a moving image, noise added in recording and transmission system of the video signal, and the like are factors that deteriorate the image quality of a still image. Ghost failure is one of the causes of deterioration.

As shown in FIG. 4, a ghost failure means that when transmitting and receiving a television signal, a transmitter (101) receives a reception antenna (102).
In addition to the direct wave (103) that arrives at obstacles, the reflected waves (104) and (105) reflected from nearby buildings and mountains also arrive at two locations where the propagation distances of the two waves are If it is large, the time behind the direct wave of the reflected wave cannot be ignored, and as shown in FIG. 5, the image of the direct wave and the image of the reflected wave appear in double or triple on the screen. Makes the screen very unsightly. That is, the ghost obstacle is a phenomenon caused by multiple waves generated by the reflected waves and the like. This is the waveform distortion of a television signal caused by multiple propagation paths with complex diffraction and reflection.

Considering here from the transmitter input to the receiver detection output as a television signal transmission line, when synchronous detection is performed, the ghost transfer function is the transfer function Hi () of the in-phase component based on the vestigial sideband modulation method. ω) and the transfer function Hp (ω) for the orthogonal component are expressed by a linear combination.

As shown in FIG. 6, when a video signal g (t) is supplied and a carrier having an angular frequency ω _c is modulated with a modulation factor m, f (t) = {1 + mg (t)} cos ω _ct − (1) Is a linear filter whose impulse response is h (t) and is considered to be the output of the modulator. If there is no unnecessary signal source, in the demodulator, the television signal b _β (t) has a local signal co that differs in phase from the carrier by θ.
When synchronous detection is performed with s (ω _ct −θ), detection output V _θ (t)
Is Becomes When the phase is adjusted so that θ = 0 and the DC component is removed, the detection output becomes _o (t) = m / 2g (t)-(4), and the video signal is restored without distortion.

Next, when there is a ghost signal, first, the amplitude ratio of the radio wave arriving through the i-th propagation path to the desired wave is R _i ,
If the delay time is τ _i (sec), Microscopically, the radio wave reflection coefficient of the reflector varies depending on the frequency, and the refractive index of the space in which the radio wave propagates also varies depending on the frequency. However, considering that the ratio band of each channel of the television signal is narrow, R _i And τ _i are considered constant. The ghost wave that has arrived through the i-th propagation path, that is, the unnecessary signal is However, ω _c τ _i = 2κπ + ψ _i κ is an arbitrary integer, and ψ _i is a carrier phase angle depending on a propagation path satisfying 0 ≦ ψ _i ≦ 2π.

Generally, if there are n delayed ghosts and m preceding ghosts, the received signal containing the ghosts is This is a local signal cos (ω
_Detecting the detection output P _θ (t) when synchronous detection is performed with ( _ct − θ), Then, if the phase is adjusted so that θ = 0 and the DC component is removed, the detection output is _o (t) = m / 2 {g (t) + U _o (t)}-(8) Therefore, the detection output becomes distorted. At this time, the ghost transfer function is It is represented by.

Conventionally, in the case of removing a ghost, a Fourier transform of the received signal of the formula (8) is performed. A transmission system including a ghost in D _o (ω) = D _β (ω) {1 + Hg (ω)}-(10) Inverse filter H _R (ω) The ghost is removed by applying.

So far, I have described ghost failures and ghost removal.
This is a quotation from the Television Society, Television System, Circuit Study Group, and material TBS36-1 in 1977, and the details are omitted here.

As a practical problem, the above processing must be performed on sequentially received signals, and accurate ghost removal is currently impossible.

Further, in the video plate making apparatus which is the object of the present invention, when there is a ghost failure in the video signal, the ghost phenomenon is clearly reproduced on the printed matter as an image, which causes a great deterioration in quality.

<Objects of the Invention> The present invention has been invented to solve the above-mentioned problems, and in a printed matter created from a video image, video image processing provided with means for removing several stages of ghosts caused by a ghost failure. A device is provided.

<Outline of the Invention> The present invention, for a video image arbitrarily selected from the video signal, in a video plate making apparatus for obtaining a color separation plate of high image quality for printing, A / D conversion of the video signal As a digital signal, this is stored in a frame memory or the like, and in order to remove the ghost phenomenon due to the ghost disturbance of the stored image data, the image data is Fourier transformed, and the image data after the Fourier transform is used for ghost removal. The image data obtained as a result of the filter processing is subjected to an inverse Fourier transform, the image data after the calculation is color-converted into the print separation version creation data, and the color conversion data is output. In particular, the video image processing apparatus is capable of interactively setting the parameters of the ghost transfer function obtained at the stage of the ghost elimination calculation processing.

<Embodiment of the Invention> An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a block diagram showing the system of the present invention. As a video signal source showing a video image, a TV tuner (1) and a VT are provided.
When there is R (2) etc. and you want to edit the image for video plate making, once the image is recorded in 1 inch VTR (3) etc., the video signal of the video image for plate making is input to the frame buffer section (4). To be done. The video signal is A / D converted by the frame buffer (4) and the information of the video image becomes digital data and is stored in the frame buffer. The computer unit (5) performs digital image processing on the video image stored in the frame buffer unit (4) to improve the image quality of the video image for printing, and outputs the processed video image information to the plate making scanner (6). Output and get a color separated version of the video image.

FIG. 1 is a block diagram of a portion for performing image processing in the video image processing apparatus of the present invention. The video signal generated from the video signal generation source is converted into an RGB video signal and a sync signal by a decoder (not shown) or the like, and then input to the frame buffer unit (4). In the frame buffer section (4), the RGB video signal is converted into digital data by the A / D converter (10) and stored in the frame memory (12). The video image data stored in the frame memory (12) is transferred to the RAM (21) of the computer unit (5) via the interfaces (14) (23) of the frame buffer unit (4) and the computer unit (5). CPU
Image processing according to (20) is performed. The processed video image data is transferred from the RAM (21) to the interface (23) again.
The state of the video image stored in the frame memory (12) via (14) and processed is shown by a D / A converter (not shown) connected to the frame memory (12) as an RGB video signal on a color monitor (not shown). You can confirm with (). Also, while looking at the color monitor, digitizer (1
6) can be used for interactive processing.

Next, the means for eliminating the ghost phenomenon according to the present invention will be described in more detail.

FIG. 3 is a flowchart showing the process for removing the ghost phenomenon.

First, for the image to be processed, the parameters of R _i , ψ _i and τ _i shown in equation (9) are selected in step S ₁ .

Next, in step S ₂ , several lines of the portion to be processed are designated and the arithmetic processing is carried out. The details of the processing will be described later.

Then image which has been stored in the frame memory before the process in real time on the monitor at step S _3, by'll be output alternately with the processed image, the determination of whether set parameters suitable after the image on the monitor performed in step S ₄ is determined to be appropriate, the processing of the ghost removal step S _5, or all of the multiple stages is the ghost is removed, subjected to judgment, all the ghost is removed If so, the entire surface is processed in step S _{6 and} if it is inappropriate, step S ₆
Return to ₁ and select the parameter again. Here, more accurate ghost removal can be performed by setting the parameters interactively with the monitor.

The ghost elimination processing means has a ghost in the detection output video signal of the receiver when it is regarded as a system in which the video signal is linearly transmitted from the input terminal of the transmitter video modulator to the video detection output terminal of the receiver. Since it suffices to apply an inverse filter to the system, as described above, one line of the video signal _o (t) (Equation (8)) obtained by the detection output of the receiver is Fourier-transformed to obtain The inverse filter H _R (ω) of the system including the ghost shown in the equation (11) is applied to _o (f). In the conventional ghost canceller, the parameters τ _i , R _i , and ψ _i in the transfer function Hg _od (ω) (equation (9)) of the system including the ghost are generally calculated from the synchronization signal, and the inverse filter is performed in real time. However, in the present invention, the parameters τ _i , R _i , and ψ _i are interactively set, and after confirming that the ghost has been removed, the process can be performed to perform accurate ghost removal. Further, even if it is impossible to calculate the parameter from the synchronization signal of the symmetrical image data, the ghost can be surely removed by using the present invention.
After that, a desired signal can be obtained by performing an inverse Fourier transform. By performing this a plurality of times, it is possible to perform the ghost removal processing on a desired plurality of lines.

As a result of the completion of the above processing, the ghost phenomenon is removed from the image data.

Further, in this embodiment, the plate making scanner was used as the output means, but it may be another plate making device such as a cylinder engraving machine. Although the video signal is input to the frame buffer via the 1-inch VTR, another device may be used as long as it can output the video signal.

<Effects of the Invention> As described above, according to the present invention, the data representing the video image is directly converted into the separation version creation data for printing without using a hard copy as an intermediate medium such as a color film or a color print. By the conversion, not only the deterioration of the image can be prevented, but also by removing the ghost noise due to the ghost interference, it is possible to obtain a higher quality printed matter.

[Brief description of drawings]

The drawings show an embodiment of the present invention, FIG. 2 is an explanatory diagram showing a system configuration of an embodiment of a video plate making apparatus of the present invention, and FIG. 1 is an image processing block diagram in the present system. Yes, FIG. 3 is a flowchart of a process for removing a ghost phenomenon in a video image, FIGS. 4 and 5 are waveform diagrams showing the principle of ghost failure occurrence, and FIG. 6 is an explanation of a television signal transmission line. It is a figure. (4) …… frame buffer, (5) …… minicomputer (10) …… A / D converter, (12) …… frame memory (14), (23) …… interface (16) …… digitizer, ( 20) …… CPU (24) …… Terminal

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kotoshi Naito 1-5-1 Taito, Taito-ku, Tokyo Toppan Printing Co., Ltd. Inspector Tomoko Miyamoto (56) Reference JP-A-55-74545 (JP, A) ) J.K. 46-12341 (JP, Y1) Yoshitaka Hashimoto "Ghost elimination by video signal processing", Television Society of Television System and Circuits Research Group sample TBS36-1 (February 24, 1977)

Claims (1)

[Claims] 1. A video image processing apparatus for producing a disassembled version for printing from a video image without using an intermediate medium such as film, and A / D conversion means for converting the video image into a digital signal, A storage unit that stores the converted signal, performs a Fourier transform on the stored image data, and filters the image data after the Fourier transform,
After that, the ghost disturbance removing means by inverse Fourier transform, means for setting the parameters of the transfer function of the ghost obtained in the process of the arithmetic processing in the ghost disturbance removing means, and printing the image data from the ghost disturbance removing means A video image processing apparatus, comprising: a color conversion unit for converting into the separation version creation data for use, and an output unit for outputting the image data from the color conversion unit.