CN100493172C

CN100493172C - Method for scanning TV video frequency signal

Info

Publication number: CN100493172C
Application number: CNB2004100221481A
Authority: CN
Inventors: 李鸿安; 戴青松; 安慎华; 游开忻
Original assignee: Shenzhen Skyworth RGB Electronics Co Ltd
Current assignee: Shenzhen Skyworth RGB Electronics Co Ltd
Priority date: 2004-03-23
Filing date: 2004-03-23
Publication date: 2009-05-27
Anticipated expiration: 2024-03-23
Also published as: CN1674667A

Abstract

The present invention relates to a scanning method of television video signal. It is characterized by that the television video input signal with different standard can be undergone the process of line frequency normalization treatment, and converted into unified line frequency to implement line scanning output. Its convertible frequency is 33.75KHz signal, and can be used for making line scanning output, so that it can raise the reliability of various television video signals.

Description

A kind of scan method of television video frequency signal

[technical field]

The invention relates to TV domain, especially about a kind of scan method of television video frequency signal.

[background technology]

The scan mode of TV domain has mainly been used following several at present:

1. the interlacing scan of traditional 15.625K/15.75K line frequency: advantage is that scan mode realizes easily, and narrow bandwidth, the cost of picture signal is low, good reliability, this scan mode are used till today always.Shortcoming is to exist interline flicker and parity field grating to inlay local parallel phenomenon when undesirable, and when object was enough big along horizontal motion speed, the vertical edges of image produced crenellated phenomena along meeting.Interlace mode row structure line is more coarse, have the large tracts of land field rate flicker, phenomenon such as creep.These phenomenons are especially obvious in large scale display time performance more than 29 inches.

2.100HZ scanning: this be since the mid-90 be with the Philips representative for eliminating a kind of scanning technique that the large tracts of land field rate flicker adopts, this scheme adopts digital technology that image is handled, with SDRAM (buffer storage) image is carried out buffer-stored, speed when reading is to write fashionable 2 times, scan with 2 times of frequencies to the input signal line frequency, guaranteeing under the constant situation of every field signal line number field frequency to be become 100HZ by 50HZ, thereby eliminated the large tracts of land field rate flicker, and can support the VGA input.But be still interlace mode because it adopts, though solved large tracts of land field rate flicker phenomenon, interline flicker still exists, and row structure line problem of rough is not resolved, and overall image quality is undesirable.

3. line by line scan: this technology starts from the end of the nineties, and this technology type is similar to the 100HZ scanning technique, and it is the line number of every frame to be promoted be original 2 times.Line by line scan and eliminated the coarse phenomenon of capable structure line, make image become fine and smooth, also can support the VGA input, but image large tracts of land field rate flicker problem exists still.

4. variable-frequency scanning: this is these 2 years new technologies of just rising.This technology is that the PAL conversion of signals with the 50HZ field frequency is the 60HZ field frequency and handles output simultaneously line by line, and this technology can solve the insurmountable capable rustic of traditional tv scan mode simultaneously, field rate flicker, shortcoming such as creep.

5. HD digital TV class: because the standard of HD digital TV is different from the standard of conventional television signal, the television set of above-mentioned several scan modes all can not be watched digital television signal.The HD digital TV also has several classes: 1080i60HZ, 1080i50HZ, 720P (45K), 480P (31.5K) etc., 1080i60HZ is adopted in Japan, the U.S., Europe, there is the HD digital TV of the 1080i60HZ that pilots in China part city, but China will adopt 1080i50HZ as China's HD digital television standard in the future.At present China is used to watch that the television set of Digital Television adopts multirow mode frequently more, and this multirow frequently mode realize difficulty, the cost height, reliability is relatively poor, thereby the Digital Television of each producer holds at high price, thereby has also influenced the popularization of China's Digital Television.

[summary of the invention]

The object of the present invention is to provide the scan method of television video frequency signal of the vision signal of compatible various conventional video signals of a kind of energy and high-definition format video.

The object of the present invention is achieved like this: the scan method of this a kind of television video frequency signal is that the television video input signal of various criterion to be handled through the line frequency normalizing and be converted to unified line frequency be that the signal of 33.75KHZ scans output.

For traditional television video frequency signal, it is to be converted to digital YUV signal earlier, go interlacing to handle this digital signal, with line frequency is that the conversion of signals of 15.625KHZ is that line frequency is the progressive signal of 31.5KHZ, then every frame signal being carried out interpolate value benefit row in the ranks, is that frequency is the signal scanning output of 33.75KHZ with conversion of signals.

For the DVD signal, be converted into digital YUV signal, this signal is carried out interpolation in the ranks, be that the conversion of signals of 31.5KHZ is that line frequency is that the signal of 33.75KHZ scans output with line frequency.

For the VGA signal, this signal is inserted row get row and handle, unified is that line frequency is that the signal of 33.75KHZ scans output with conversion of signals.

For the 720P signal, it is that the conversion of signals with 720P is that the signal of 33.75KHZ scans output.

Compared with prior art, the present invention has following advantage: the signal that is converted to single line frequency by the television video input signal with various criterion scans output, thereby the problem that has solved television line rustic, field rate flicker and creeped, and support the various traditional television video frequency signals and the HD digital TV signal of various reference formats, improved reliability.

[description of drawings]

Fig. 1 is the schematic diagram of signal processing flow of the present invention.

Fig. 2 is the circuit theory diagrams of the present invention when conversion of signals is 33.75KHZ line frequency signal.

[embodiment]

See also 1 to Fig. 2, the scan method of this a kind of television video frequency signal is the input signal process line frequency normalizing processing of various criterion to be converted to unified line frequency scan output.This method can be converted to the input signal of various various criterion forms the line frequency of single 33.75KHZ.

When being converted to single line frequency and being the signal of 33.75KHZ for input signal with various criterion:

A) for traditional television video frequency signal after the digital YUV signal that Video Decoder (model is VPC3230) decodes is delivered to Digital Video Processing chip (model is PW1235), chip goes earlier interlacing to handle (Deinterlace) for sort signal, with line frequency is that the signal of 15.625KHZ transfers the progressive signal that line frequency is 31.5KHZ to, then every frame signal is carried out interpolate value benefit row in the ranks, transfer signal to signal that frequency is 33.75KHZ.

B) the DVD signal is after the digital YUV signal that Video Decoder (model is VPC3230) decodes is delivered to Digital Video Processing chip (model is PW1235), chip only carries out interpolation in the ranks for sort signal, interpolation row technology in adopting is the signal that the conversion of signals of 31.5KHZ becomes line frequency 33.75KHZ with original line frequency.

C) for high definition 1080i 50HZ signal, because field frequency is 50HZ, have large tracts of land field rate flicker phenomenon when showing at large-screen, high brightness, therefore Digital Video Processing chip (model is PW 1235) is converted to 1080i 60HZ with signal by 1080i 50HZ when sort signal is handled, and this moment, the line frequency of signal also just was 33.75KHZ.

D) signal for 1080i 60HZ then only carries out image quality lifting processing.

E) for 720P signal (the signal line frequency is 45KHZ), this is a kind of signal format that is of little use, demonstration for large-screen, the reproduction of carrying out picture by the 1080i display mode is the display mode of image quality optimum, so Digital Video Processing chip (PW1235) is that conversion of signals with 720P is that the signal of 33.75KHZ carries out scan process when handling.

F) all need insert row for the VGA signal (VGA:640 X 480 SVGA:800 X 600XGA:1024 X 768) of various forms and get the row processing, unified is that 33.75KHZ exports demonstration with conversion of signals.

The method that above-mentioned field frequency with 50HZ is converted to the field frequency of 60HZ is by digital circuit input signal to be stored calculation process, compresses on time shaft; Signal for input 50HZ/20ms writes about 20ms of time of one, and by software, and signal is read time of one under the control of clock pulse be about 16.7ms, and every read-around ratio writes with regard to fast 3.3ms like this.Per 5 will have more 3.3 X 5=16.5ms, and the time of 16.5ms just can be inserted a field signal, and just input is 5 field signals, and be output as 6 field signals, insert one for per 5,50 just can be inserted 10 field signals, so just guarantee 50HZ is converted to 60HZ.

Above-mentioned in the Digital Video Processing chip, different input signals is handled respectively accordingly, and be converted to unified line frequency (33.75KHZ) signal, data image signal promotes through colored and brightness and handles, and after the black level extension processing, after high accuracy digital-to-analogue conversion (D/A), with row, field sync signal, give that handle in the pillow school and previewing is put process chip (model of this chip is TDA9332), put by previewing and deliver to video amplifier circuit after process chip is handled various small-signals such as row, field scans and amplify output.Simultaneously, in the digital signal processing module of Digital Video Processing, also adopted advanced graph processing technique such as motion compensation technique, low-angle image edge treatment technology, film mode processing, made image more clear, more smooth.

It is as follows that described brightness promotes the meaning of handling: in the luminance channel of digital signal processing module, provide a DC reference voltage by blanking signal, brightness is postponed, and luminance delay line is made up of the filter of can delay time 45ns, 90ns, 100ns, 180ns and a 450ns.I is passed through in the delay of luminance signal ²The C bus is with the control of cycle between 20～1100ns of 45ns, with the maximum delay of guaranteeing luminance signal and color difference signal within+22ns, based on the variation (with line frequency as a reference) of offset component by auto brightness time of delay of inner loop control.In field blackout period, control voltage is handled by the peaking of chip internal circuit, and it mainly acts on is to improve the definition of the high fdrequency component of vision signal with the raising image,

The meaning that described colored lifting is handled is as follows: it mainly is the instantaneous variation that is used for improving color difference signal that colored lifting is handled, and improves the edge characteristic of colour transition.Carry out clamp by a reference voltage during processing, each color difference signal all be sent to one moment a detector and analog signal switch that has associated voltage, memory circuit.The analog signal switch was opened a way in certain moment, and keeping voltage then outwards provides, and when this moment arrived, switch closure received these live signal level rapidly, made these live signal level have consistent gain.

The meaning that described black level extends processing is as follows: in luminance signal, detect the somber level of luminance signal, and this level compared with blanking level, if do not reach the expansion of blanking level (black level) direction, it is pitch black that original somber part is become through expansion, but can not surpass blanking level, so just improved the contrast of image, make the level that demonstrates super scenery on the screen when the details in a play not acted out on stage, but told through dialogues background, eliminated glimmer.

The meaning of described motion compensation technique is as follows: when interlace signal was converted to progressive signal, the picture for motion can not simply get a frame with on-the-spot addition, can cause image sawtoothization and obfuscation like this.For the picture of motion, the heart needs the motion feature according to image, and the two field picture content is done different compensation, constructs the new picture of a frame then.The quality of motion compensation directly affects the quality of the motion picture behind the interlace signal commentaries on classics progressive signal.

Described low-angle image edge treatment technology is as follows: because motion compensation is compensation to a certain extent, for the image edge is low-angle and when being moving image, crenellated phenomena appears easily, therefore, when detection recognizes this situation, medium filtering is made with two field signals in low-angle image edge to motion, makes image edge part become level and smooth.

Described film mode is handled as follows: the program source of TV may be the interlace signal by the TV picked-up, also might be to handle through interlacing by the movie program of per second 24 frames, can identify for the signal that transfers by movie program, and the interlacing of movie program changes different with the method for being changeed line by line by the program interlacing of general television camera picked-up line by line, need not carry out processing such as motion compensation, but directly signal is reduced into the image state of original film, show through scanning output then.

Claims

1, a kind of scan method of television video frequency signal is characterized in that: the television video input signal of various criterion being handled through the line frequency normalizing and be converted to line frequency is that the signal of 33.75KHZ scans output, comprises the steps:

When importing traditional television video input signal, it is converted to digital YUV signal earlier, go interlacing to handle this digital signal, with line frequency is the progressive signal that the signal of 15.625KHZ is converted into 31.5KHZ, then every frame signal is carried out in the ranks interpolate value and mend row, it is that the signal of 33.75KHZ scans output that signal frequency is converted to line frequency;

When input DVD signal, when being converted into digital YUV signal, this signal is carried out interpolation in the ranks, be that the conversion of signals of 31.5KHZ is that line frequency is that the signal of 33.75KHZ scans output with line frequency;

When input VGA signal, when this signal was taken out row and got row and handle, unified was that line frequency is that the signal of 33.75KHZ scans output with conversion of signals;

When input 720P signal, it is that the conversion of signals with 720P is that line frequency is that the signal of 33.75KHZ scans output.

2, the scan method of television video frequency signal according to claim 1, it is characterized in that: the television video input signal of various criterion being handled through the line frequency normalizing and be converted to line frequency is after the signal of 33.75KHZ scans output, the signal that also will be 33.75KHZ to the line frequency of this output carries out colour and brightness lifting processing, and black level extends processing.