CN101668113B - Image signal processing method - Google Patents

Abstract

The invention relates to an image signal processing method used for avoiding the erroneous judgment of a signal mode so as to maintain the image play quality. The method comprises the following steps: when an image input signal is detected to belong to a movie mode at a first time, calculating a first critical value according to a plurality of movement amounts generated before the first time; generating a second critical value according to the first critical value and a first offset value; generating a third critical value according to the first critical value and a second offset value; and judging whether an image input signal between the first time and a second time belongs to the movie mode or a video mode or not according to the second critical value and the third critical value.

Description

Video-signal processing method

Technical field

The invention relates to a kind of video-signal processing method, refer to a kind of video-signal processing method especially based on the deviant treatment mechanism.

Background technology

The signal of video signal of TV can be video mode signal or film mode signal.(National Television Standards Committee, the NTSC) normal video of being formulated, signal of video signal broadcast from TV with the speed of 60 frames of per second (Frame) with NTSC.Yet, generally when taking film, most of speed that adopts 24 frames of per second recording of signal of photographing, so when the photography signal will be when TV broadcasts, will utilize 3:2 drop-down (3:2pull-down) technology is the film mode signal of 60 figure of per second (Field) with the photography conversion of signals of 24 frames of per second, in order to be compatible to ntsc video.

Please refer to Fig. 1, Fig. 1 is for being converted to frame based on pull technology under the 3:2 operation chart of figure field.As shown in Figure 1, frame A is figure 0 (a bigraph field AE), figure 1 (a strange figure AO) and figure 2 (a bigraph field AE) by drop-down, frame B is by the drop-down figure of being 3 (very scheming field BO) and figure 4 (a bigraph field BE), and circulation like this just can be 60 film mode signals of scheming the field of per second with the photography conversion of signals of 24 frames of per second.

When TV will be play 60 of per seconds figure video mode signal or film mode signal, need that earlier 60 figure of per second image input signal is carried out release of an interleave and handle to produce the output image signal of 60 frames of per second, again each frame is broadcasted in proper order.Because being different from, the required release of an interleave processing method of displaying video mode signal plays the required release of an interleave processing method of film mode signal, so in playing process, will detect image input signal is video mode signal or film mode signal, in order to suitable release of an interleave processing method to be provided.In other words, if use unsuitable release of an interleave processing method because of the signal mode error detection of image input signal, then the image playback quality will significantly descend.

In order to detect the signal format of image input signal, can calculate a plurality of amount of movements (MotionValue) δ earlier usually _i, thereafter, again with a plurality of amount of movement δ _iMake comparisons with preset critical, form figure variation judgment value sequence (hereinafter to be referred as the JV value sequence) in order to produce a plurality of figure field variation judgment value (Field Variation Judge Value is hereinafter to be referred as the JV value).If amount of movement δ _iGreater than preset critical, then corresponding JV value is 1, if amount of movement δ _iBe not more than preset critical, then corresponding JV value is 0.

Please refer to Fig. 1, when image input signal is the film mode signal, owing to scheming field 0 and scheming the bigraph field AE that field 2 is frame A, so according to an amount of movement δ who schemes field 0 and scheme field 2 calculating generations ₀Be not more than preset critical, promptly its corresponding JV value is 0.In like manner, owing to scheming field 5 and scheming the strange figure field CO that field 7 is frame C, so according to an amount of movement δ who schemes field 5 and scheme field 7 calculating generations ₅Be not more than preset critical, promptly its corresponding JV value also is 0.As for calculate the amount of movement δ that produces according to difference figure field ₁～δ ₄And δ ₆～δ ₈Then can be greater than preset critical, so corresponding JV value is 1.As shown in Figure 1, JV value sequence corresponding to the film mode signal, periodically repeating institute by film mode beat sequence (Film-mode Cadence Sequence) " 01111 " forms, that is, as long as detect periodic film mode beat sequence, represent that then image input signal is the film mode signal.

Please refer to Fig. 2, Fig. 2 is the schematic diagram of existing JV value sequence production method, and wherein transverse axis is a time shaft.In existing figure variation judgment value production method, be to use that fixedly critical value and a plurality of amount of movement are made comparisons with generation JV value sequence.A plurality of amount of movements shown in Figure 2 are all corresponding to the film mode signal, so the JV value sequence is should periodically repeat institute by the film mode beat sequence to form.If the JV value sequence is based on fixedly critical value THf1 and produces, then at the less time section Δ T of amount of movement ₂And Δ T ₃In, can produce wrong JV value sequence because of erroneous judgement, promptly part JV value can be mistaken for 0, in addition at the bigger time section Δ T of amount of movement ₄And Δ T ₅In, also can be because of erroneous judgement produces wrong JV value sequence, promptly part JV value can be mistaken for 1.When wrong JV value produced, image input signal just was mistaken as the video mode signal, thereby used corresponding to the de-interlace method of video mode signal and handle image input signal, so can cause bad image playback quality.

Use less fixedly critical value THf2 to produce the JV value sequence, then at the bigger time section Δ T of amount of movement if yield to less amount of movement ₄And Δ T ₅In, still can produce wrong JV value sequence because of erroneous judgement.Use bigger fixedly critical value THf3 to produce the JV value sequence, then at the less time section Δ T of amount of movement if yield to bigger amount of movement ₂And Δ T ₃In, still can produce wrong JV value sequence because of erroneous judgement.So based on fixing critical value to produce the method for JV value sequence, under the amount of movement variation situation greatly of different time section, be easy to because of erroneous judgement produces wrong JV value, cause using unsuitable de-interlace method processing image input signal and cause bad image playback quality.

Summary of the invention

According to embodiments of the invention, it discloses a kind of video-signal processing method, is used for avoiding the erroneous judgement of signal mode to keep high image playback quality.It is when belonging to film mode that the method is contained in very first time detection image input signal, and the first group of amount of movement corresponding to image input signal according to producing before the very first time calculates first critical value; Produce second critical value according to first critical value and first deviant; Produce the 3rd critical value according to first critical value and second deviant; And judge that according to second critical value and the 3rd critical value the image input signal between the very first time and second time is to belong to film mode or video mode; Wherein second time was after the very first time.

According to embodiments of the invention, it discloses a kind of method that detects film mode in addition, is used for avoiding the erroneous judgement of signal mode to keep high image playback quality.It is when belonging to film mode that the method is contained in very first time detection image input signal, calculates the first group of amount of movement corresponding to image input signal between the very first time and second time; Produce first critical value according to the benchmark critical value and first deviant; Produce second critical value according to the benchmark critical value and second deviant; And judge according to first critical value, second critical value and first group of amount of movement whether the image input signal between the very first time and second time belongs to film mode; Wherein second time was after the very first time.

Description of drawings

For above-mentioned purpose of the present invention, feature and advantage can be become apparent, below in conjunction with accompanying drawing the specific embodiment of the present invention is elaborated, wherein:

Fig. 1 is for being converted to frame based on pull technology under the 3:2 operation chart of figure field.

Fig. 2 is the schematic diagram of existing JV value sequence production method, and wherein transverse axis is a time shaft.

Fig. 3 is the first embodiment schematic diagram of the present invention in order to the JV value sequence production method of detection film mode, and wherein transverse axis is a time shaft.

Fig. 4 is the second embodiment schematic diagram of the present invention in order to the JV value sequence production method of detection film mode, and wherein transverse axis is a time shaft.

Fig. 5 is the flow chart that the present invention is based on the video-signal processing method of deviant treatment mechanism.

Fig. 6 is the three embodiment schematic diagram of the present invention in order to the JV value sequence production method of detection film mode, and wherein transverse axis is a time shaft.

The main element symbol description:

500 video-signal processing methods

JV figure variation judgment value

S505～S565 step

THf1～THf3 is critical value fixedly

The preposition critical value of THx0, THk0

THx1～THx5 dynamic threshold value

THk1 first critical value

THk2 second critical value

THxla～THx5a first dynamic threshold value

THxlb～THx5b second dynamic threshold value

δ _i, δ _-10～δ ₉Amount of movement

Δ T _-1～Δ T ₅The time section

α first deviant

β second deviant

Embodiment

For making the present invention more apparent and understandable, hereinafter according to video-signal processing method of the present invention, cooperate appended graphic elaborating especially exemplified by embodiment, but the scope that the embodiment that is provided is not contained in order to restriction the present invention, carry out precedence and the method flow number of steps is more non-in order to limit it, any execution flow process that is reconfigured by method step is produced the method with impartial effect, is all the scope that the present invention is contained.

Please refer to Fig. 3, Fig. 3 is the first embodiment schematic diagram of the present invention in order to the JV value sequence production method of detection film mode, and wherein transverse axis is a time shaft.Amount of movement shown in Figure 3 is to calculate according to following formula (1) to produce:

${\mathrm{\δ}}_i=\underset{j=1}{\overset{N}{\mathrm{\Σ}}}\left(\right|R_i^j-R_{i+2}^j|+|G_i^j-G_{i+2}^j|+|B_i^j-B_{i+2}^j\left|\right)$ Formula (1)

δ wherein _iBe i amount of movement, j is a figure number of pixels for figure pixel sequence number, N, therefore for example

With

Be red pixel value, green pixel values and the blue pixel value of i figure j pixel.

A plurality of amount of movements shown in Figure 3 are formed so the JV value sequence should periodically repeat institute by the film mode beat sequence all corresponding to the film mode signal.Before time T a, promptly image input signal is identified as before the film mode signal, for example at time section Δ T ₀And Δ T _-1In, all use preposition critical value THx0 to produce the JV value sequence.After time T a, after promptly image input signal has been identified as the film mode signal, the employed dynamic threshold value of each time section be a plurality of amount of movements according to last time section calculate produce.For example, in time section Δ T _NInterior employed dynamic threshold value THxN can calculate and produce via following formula (2):

$\mathrm{THxN}=\frac{{\mathrm{\δ}}_{5N-10}}{2}+\frac{1}{8}({\mathrm{\δ}}_{5N-9}+{\mathrm{\δ}}_{5N-8}+{\mathrm{\δ}}_{5N-7}+{\mathrm{\δ}}_{5N-6})$ Formula (2)

Wherein N is a positive integer, δ _5N-10～δ _5N-6Be last time section Δ T _N-1A plurality of amount of movements.Therefore, as shown in Figure 3, in time section Δ T ₁In be to use dynamic threshold value THx1, in time section Δ T2, be to use dynamic threshold value THx2, and in time section Δ T ₃In be to use dynamic threshold value THx3, the rest may be inferred by analogy for it.

In another embodiment, after image input signal has been identified as the film mode signal, the employed dynamic threshold value of each time section be a plurality of amount of movements according to the first two time section calculate produce.For example, in time section Δ T _NInterior employed dynamic threshold value THxN can calculate and produce via following formula (3):

$\mathrm{THxN}=\frac{{\mathrm{\δ}}_{5N-15}}{4}+\frac{1}{16}({\mathrm{\δ}}_{5N-14}+{\mathrm{\δ}}_{5N-13}+{\mathrm{\δ}}_{5N-12}+{\mathrm{\δ}}_{5N-11})$

$+\frac{{\mathrm{\δ}}_{5N-10}}{4}+\frac{1}{16}({\mathrm{\δ}}_{5N-9}+{\mathrm{\δ}}_{5N-8}+{\mathrm{\δ}}_{5N-7}+{\mathrm{\δ}}_{5N-6})$ Formula (3)

δ wherein _5N-15～δ _5N-6Be the first two time section Δ T _N-2And Δ T _N-1A plurality of amount of movements.In an equivalent embodiment, after image input signal has been identified as the film mode signal, employed dynamic threshold value is that a plurality of amount of movements according to preceding at least one time section calculate institute and produce in each time section, and is can reach (3) according to above-mentioned formula (2) analogize in order to the correlation formula of generation dynamic threshold value.

Please continue with reference to figure 3, because above-mentioned dynamic threshold value treatment mechanism can significantly reduce the False Rate of JV value, therefore, the JV value sequence that is produced almost periodically repeats institute by the film mode beat sequence and forms.Yet, when the amount of movement difference of adjacent time section is too big, still may cause the erroneous judgement of JV value.As shown in Figure 3, because adjacent time section Δ T ₃And Δ T ₄Amount of movement difference too big, so according to time section Δ T ₃The dynamic threshold value THx4 that a plurality of amount of movement produced, in time section Δ T ₄In the JV value sequence that still can lead to errors because of erroneous judgement.

Please refer to Fig. 4, Fig. 4 is the second embodiment schematic diagram of the present invention in order to the JV value sequence production method of detection film mode, and wherein transverse axis is a time shaft.A plurality of amount of movements shown in Figure 4 are to be same as a plurality of amount of movements shown in Figure 3.After time T a, after promptly image input signal has been identified as the film mode signal, in time section Δ T _NThe interior employed first dynamic threshold value THxNa and the second dynamic threshold value THxNb produce according to following formula (4) and formula (5) calculating:

TH χ Na=TH χ N+ α formula (4)

TH χ Nb=TH χ N+ β formula (5)

Wherein THxN calculates the dynamic threshold value that is produced for analogizing correlation formula according to formula (2), formula (3) or its, and α is first deviant, and β is second deviant.

As shown in Figure 4, at time section Δ T _NIn, the amount of movement of first ordering is to make comparisons to produce corresponding JV value with the first dynamic threshold value THxNa, the amount of movement of all the other orderings is to make comparisons to produce corresponding JV value with the second dynamic threshold value THxNb.For example, at time section Δ T ₂In, the amount of movement δ of first ordering ₅Be to make comparisons to produce corresponding JV value, the amount of movement δ of all the other orderings with the first dynamic threshold value THx2a ₆～δ ₉Be to make comparisons to produce corresponding JV value with the second dynamic threshold value THx2b.

The first deviant α and the second deviant β are for adjusting.If the first deviant α is a positive number and the second deviant β is a negative, then can improve the judgement tolerance, in order to avoid that the erroneous judgement of film mode signal is the video mode signal.So, as shown in Figure 4, even adjacent time section Δ T ₃And Δ T ₄Amount of movement widely different, but because of utilizing the first deviant α and the second deviant β improve to judge tolerance, in time section Δ T ₄In still can produce correct JV value sequence, that is, can avoid using unsuitable de-interlace method to handle image input signal, in order to keep high image playback quality.Yet the first deviant α and the second deviant β are not defined as positive number or negative, and for example both can be all zero, as described in the first embodiment of the present invention.

In another embodiment, if be different from aforesaid film mode beat sequence, for example be " 01011 " in order to the periodicity beat sequence of judging signal mode, then can utilize other formula to calculate for time section Δ T _NInterior dynamic threshold value THxN, substitution formula (4) and formula (5) are to produce the first dynamic threshold value THxNa and the second dynamic threshold value THxNb again.Then, in time section Δ T _NIn, the amount of movement of first ordering and the 3rd ordering is to make comparisons to produce corresponding JV value with the first dynamic threshold value THxNa, the amount of movement of all the other orderings is to make comparisons to produce corresponding JV value, with generation time section Δ T with the second dynamic threshold value THxNb _NThe JV value sequence, this JV value sequence is made comparisons to judge signal mode with beat sequence " 01011 " again.Therefore, in signal mode determination methods, all can release corresponding dynamic threshold value treatment mechanism to produce the JV value sequence according to above-mentioned and class based on any periodicity beat sequence.

Please refer to Fig. 5, Fig. 5 is the flow chart that the present invention is based on the video-signal processing method of deviant treatment mechanism.As shown in Figure 5, video-signal processing method 500 comprises the following step:

Step S505: received RF signal;

Step S510: the low noise processing and amplifying of carrying out radiofrequency signal;

Step S515: the tuning processing of carrying out radiofrequency signal is to produce the frequency-selecting signal;

Step S520: the demodulation process of carrying out the frequency-selecting signal is to produce image input signal;

Step S525: when very first time detection image input signal belongs to film mode, calculate first dynamic threshold value according to the first group of amount of movement that produced before the very first time corresponding to image input signal;

Step S530: produce second dynamic threshold value according to first dynamic threshold value and first deviant;

Step S535: produce the 3rd dynamic threshold value according to first dynamic threshold value and second deviant;

Step S540: calculate the second group of amount of movement between the very first time and second time corresponding to image input signal;

Step S545: produce the JV value sequence according to second dynamic threshold value, the 3rd dynamic threshold value and second group of amount of movement;

Step S550: relatively JV value sequence and film mode beat sequence are to judge that the image input signal between the very first time and second time is to belong to film mode or video mode, if the image input signal between the very first time and second time is to belong to film mode, execution in step S555 then, otherwise execution in step S560;

Step S555: the image input signal between the very first time and second time is carried out the film mode release of an interleave handle to produce output image signal;

Step S560: the image input signal between the very first time and second time is carried out the video mode release of an interleave handle to produce output image signal; And

Step S565: output image signal is converted to figure pattern output image signal or simulation model output image signal.

In above-mentioned video-signal processing method 500, the described radiofrequency signal of step S505 can be corresponding to the radiofrequency signal of Digital Television or corresponding to the radiofrequency signal of simulated television.The program of step S520 comprises the demodulation process of carrying out the frequency-selecting signal and simulates to digital translation and handle to produce image input signal.The described first group of amount of movement of step S525 is that calculating produces according to formula (1).The program of step S525 comprises according to formula (2) or formula (3) calculates first dynamic threshold value.The program of step S530 comprises first dynamic threshold value is produced second dynamic threshold value mutually with first deviant.The program of step S535 comprises first dynamic threshold value is produced the 3rd dynamic threshold value mutually with second deviant.First deviant and second deviant are for adjusting.

Described second time of step S540 is after the very first time.The program of step S540 comprises according to formula (1) calculates second group of amount of movement.The program of step S545 comprises makes comparisons at least one amount of movement of second group of amount of movement and second dynamic threshold value, and all the other amount of movements and the 3rd dynamic threshold value of second group of amount of movement are made comparisons, in order to produce the JV value sequence.

Please refer to Fig. 6, Fig. 6 is the three embodiment schematic diagram of the present invention in order to the JV value sequence production method of detection film mode, and wherein transverse axis is a time shaft.A plurality of amount of movements shown in Figure 6 are to be same as a plurality of amount of movements shown in Figure 3.After time T a, after promptly image input signal has been identified as the film mode signal, in each time section Δ T _NThe interior employed first critical value THk1 and the second critical value THk2 produce according to following formula (6) and formula (7) calculating:

THk1=THkb+ α formula (6)

THk2=THkb+ β formula (7)

Wherein THkb is the benchmark critical value, and α is first deviant, and β is second deviant.In one embodiment, benchmark critical value THkb is employed preposition critical value THk0 before time T a, that is, in JV value sequence production method shown in Figure 6, the first critical value THk1 and the second critical value THk2 directly cooperate the first deviant α and second deviant β calculating to produce according to preposition critical value THk0, so the first critical value THk1 and the second critical value THk2 can result from before the time T a, and each the time section Δ T behind time T a _NAll directly compare to produce corresponding JV value sequence according to the first critical value THk1 and the second critical value THk2.As shown in Figure 6,, just can improve the judgement tolerance, therefore each the time section Δ T behind time T a as long as the first deviant α is that the positive number and the second deviant β are negative _NAll can produce correct JV value sequence, can avoid the erroneous judgement of film mode signal is the video mode signal.In another embodiment, benchmark critical value THkb is in time section Δ T ₁In, the dynamic threshold value THx1 that is produced according to formula (2) or formula (3), and produce the first critical value THk1 and the second critical value THk2 according to this, and each the time section Δ T behind time T a _NAll be pursuant to time section Δ T ₁The first critical value THk1 that is produced and the second critical value THk2 are to produce corresponding JV value sequence.

From the above, video-signal processing method of the present invention can be applicable to the detection of film mode, even under the very big situation of the amount of movement change of adjacent time section, still can produce correct JV value sequence, therefore can avoid using unsuitable de-interlace method to handle image input signal, in order to keep high image playback quality.In addition, signal mode determination methods based on many deviants provided by the present invention, can be applicable to judge the signal of video signal or the circuit signal of tool cyclical signal value changing pattern, as long as utilize positive offset amount to improve the critical value of judging the low level signal, and utilize negative deviant to reduce the critical value of judging the high levle signal, can improve the judgement tolerance, can cooperate dynamic threshold value with further lifting accuracy of judgement degree in addition.

Though the present invention discloses as above with preferred embodiment; right its is not in order to qualification the present invention, any those skilled in the art, without departing from the spirit and scope of the present invention; when can doing a little modification and perfect, so protection scope of the present invention is when with being as the criterion that claims were defined.

Claims (13)

1. the method handled of a signal of video signal, it comprises:

A plurality of pixel values corresponding to an image input signal produce one first group of amount of movement;

Detecting an image input signal in a very first time is when belonging to a film mode, and this first group of amount of movement according to producing before this very first time calculates one first critical value;

Produce one second critical value according to this first critical value and one first deviant;

Produce one the 3rd critical value according to this first critical value and one second deviant; And

Judge that according to this second critical value and the 3rd critical value this image input signal between this very first time and one second time is to belong to this film mode or a video mode;

Wherein this second time is after this very first time.

2. the method for claim 1 is characterized in that, this first deviant and this second deviant are for adjusting, and this first group of amount of movement comprises a plurality of continuous mutually amount of movements.

3. the method for claim 1 is characterized in that, calculates this first critical value according to this first group of amount of movement, is to calculate this first critical value according to following formula:

$\mathrm{THx}1=\frac{{\mathrm{\δ}}_1}{2}+\frac{1}{8}({\mathrm{\δ}}_2+{\mathrm{\δ}}_3+{\mathrm{\δ}}_4+{\mathrm{\δ}}_5)$

Wherein THx1 is this first critical value, δ ₁Be first amount of movement of this first group of amount of movement, δ ₂Be one second amount of movement of this first group of amount of movement, δ ₃Be one the 3rd amount of movement of this first group of amount of movement, δ ₄Be one the 4th amount of movement of this first group of amount of movement, δ ₅One the 5th amount of movement for this first group of amount of movement.

4. the method for claim 1 is characterized in that, an i amount of movement of this first group of amount of movement is to calculate according to following formula:

${\mathrm{\δ}}_i=\underset{j=1}{\overset{N}{\mathrm{\Σ}}}\left(\right|R_i^j-R_{i+2}^j|+|G_i^j-G_{i+2}^j|+|B_i^j-B_{i+2}^j\left|\right)$

δ wherein _iBe this i amount of movement, j is a figure field pixel sequence number, and N is a figure field number of pixels,

Be a red pixel value of a j pixel of an i figure,

Be a red pixel value of a j pixel of one (i+2) individual figure field,

Be a green pixel values of this j pixel of this i figure,

Be a green pixel values of this j pixel of this (i+2) individual figure field, Be a blue pixel value of this j pixel of this i figure,

Blue pixel value for this j pixel of this (i+2) individual figure field.

5. the method for claim 1 is characterized in that:

This second critical value is by with this first critical value and this first deviant addition and produce; And

The 3rd critical value is by with this first critical value and this second deviant addition and produce;

Wherein this first deviant is a positive number, and this second deviant is a negative.

6. the method for claim 1 is characterized in that, judges that this image input signal between this very first time and this second time is that the step that belongs to this film mode or this video mode comprises:

The one second group amount of movement corresponding to this image input signal of calculating between this very first time and this second time;

Produce figure field variation judgment value sequence according to this second critical value, the 3rd critical value and this second group of amount of movement; And

Relatively this a figure field variation judgment value sequence and a film mode beat sequence are to judge that this image input signal between this very first time and this second time is to belong to this film mode or this video mode.

7. method as claimed in claim 6, it is characterized in that relatively this figure variation judgment value sequence and this film mode beat sequence are to judge that this image input signal between this very first time and this second time is that the step that belongs to this film mode or this video mode comprises:

When this figure field variation judgment value sequence is identical with this film mode beat sequence, judge that this image input signal between this very first time and this second time belongs to this film mode.

8. method as claimed in claim 6 is characterized in that, the step that produces this figure field variation judgment value sequence according to this second critical value, the 3rd critical value and this second group of amount of movement comprises:

At least one amount of movement and this second critical value of this second group of amount of movement are made comparisons, and all the other amount of movements and the 3rd critical value of this second group of amount of movement are made comparisons, in order to produce this figure field variation judgment value sequence.

9. method that detects film mode, it comprises:

Detecting an image input signal in a very first time is when belonging to a film mode, calculates the one first group of amount of movement corresponding to a plurality of pixel values of this image input signal between this very first time and one second time;

Produce one first critical value according to a benchmark critical value and one first deviant;

Produce one second critical value according to this benchmark critical value and one second deviant; And

Judge according to this first critical value, this second critical value and this first group of amount of movement whether this image input signal between this very first time and this second time belongs to this film mode;

Wherein this second time is after this very first time.

10. method as claimed in claim 9 is characterized in that:

This first deviant and this second deviant are for adjusting; And

This benchmark critical value is a preposition critical value or a dynamic threshold value, and this dynamic threshold value is produced by calculating according to the one second group of amount of movement corresponding to this image input signal before this very first time.

11. method as claimed in claim 9 is characterized in that:

This first critical value is by with this benchmark critical value and this first deviant addition and produce; And

This second critical value is by this benchmark critical value is produced this second critical value mutually with this second deviant;

Wherein this first deviant is a positive number, and this second deviant is a negative.

12. method as claimed in claim 9 is characterized in that, the step whether judgement this image input signal between this very first time and this second time belongs to this film mode comprises:

Produce figure field variation judgment value sequence according to this first critical value, this second critical value and this first group of amount of movement; And

When this figure field variation judgment value sequence is identical with a film mode beat sequence, judge that this image input signal between this very first time and this second time belongs to this film mode.

13. method as claimed in claim 12 is characterized in that, the step that produces this figure field variation judgment value sequence according to this first critical value, this second critical value and this first group of amount of movement comprises:

At least one amount of movement and this first critical value of this first group of amount of movement are made comparisons, and all the other amount of movements and this second critical value of this first group of amount of movement are made comparisons, in order to produce this figure field variation judgment value sequence.

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