JPH0822032B2 - A device that automatically detects cut changes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a device for automatically detecting cut transitions,
In particular, the present invention relates to an apparatus capable of automatically detecting a cut transition recorded on a film and automatically positioning a frame of the cut transition recorded in a film imaging apparatus.

(Prior Art) Conventionally, a film imaging device which reproduces a video signal by scanning each frame of a traveling film with a flying spot scanner is known, and is widely used for broadcasting, for example. A video signal reproduced by such a film image pickup device is once recorded in a VTR and is reproduced to obtain a broadcast signal. However, a video signal obtained by picking up the image recorded on the film as it is. Cannot be directly used as a broadcasting signal, and it is necessary to correct black balance, white balance, γ balance and the like, and in particular in the case of a color film, it is necessary to further perform various color corrections. In performing such various corrections, the same applies to the successive frames that make up one cut of the film, so it is necessary to perform the correction for each cut of the film. In making such a correction, it is necessary to detect the transition of the film cut and stop the film so that the first frame of each cut is reproduced. For this reason, conventionally, film is taken while watching the reproduced image on the monitor, the cut transition is visually determined, and when the cut transition is found, the stop button is pressed to stop the film and the necessary correction amount is set. It is carried out.

(Problems to be Solved by the Invention) As described above, conventionally, the cut transition is detected while monitoring the reproduced image, and the film is stopped by pressing the stop button. The delay time until the stop button is pressed and the delay time from when the stop button is pressed until the film actually stops cannot be ignored, and the film stops at a frame position considerably ahead of the frame where the cut changes. become. Therefore, after the film is stopped, the film is reproduced while running in the reverse direction, and when the cut transition is detected again, the stop button is pressed again to stop the film. However, even in this case, the film is stopped at a position beyond a predetermined frame, the film is again run in the forward direction, and the same operation is repeated. As described above, conventionally, it is necessary to repeatedly run the film in the forward and reverse directions at the turning point of the cut. For this reason, there is a drawback that it takes a lot of labor for the operator and it takes time. Further, there is a drawback that the valuable film is damaged when the film is repeatedly moved back and forth.

The above-mentioned problem is not limited to the case of reproducing the film, but also occurs, for example, in the case of detecting the cut transition of the image recorded on the magnetic tape.

An object of the present invention is to provide an apparatus capable of significantly reducing the labor of an operator and shortening the working time by automatically detecting the change of cut, and further suppressing the possibility of damaging a recording medium as much as possible. It is the one we are trying to provide.

(Means and Actions for Solving Problems) FIG. 1 is a conceptual diagram showing a basic configuration of an apparatus for automatically detecting cut transitions according to the present invention. For example, the output image signal of the reproducing means 2 for reproducing the recording medium 1 such as a film while traveling in the direction indicated by the arrow is supplied to the image information extracting means 3. In this image information extraction means 3,
As shown in FIG. 2, one frame F is divided into a plurality of sections S11, S12, ..., S33, and an image signal is processed for each section to obtain image information. Various image information extraction methods can be considered. For example, the average brightness level of each section can be detected and the image information can be obtained as a binary signal of black or white. Alternatively, various control signals originally created as control signals for the film image pickup device, such as an automatic white level control signal (AWL),
Automatic black level control signal (ABL), automatic white balance control signal (AWB), automatic black balance control signal (ABB), automatic gamma balance control signal (AGB), automatic light control signal (AL
Image information can also be obtained by obtaining C) for each section. Regardless of which signal is used, the image information extraction means 3 extracts a signal representing the image feature for each section. In the present invention, this image information is a binary signal representing each section by "0" or "1". That is, the average value of any one of the above-mentioned signals is obtained for each of the plurality of scanning lines, and the average value obtained for each scanning line is compared with the reference value to obtain "0" or "1". Is determined, and the value "0" is determined in this way.
Alternatively, the image extracting means 3 is configured to compare the number of "1" with the reference value for each section to determine "0" or "1".

Next, the image information thus obtained is supplied to the correlation means 4. This correlating means counts the number of “0” or “1” obtained for each section as described above,
The difference between this count value and the corresponding count value of the previous frame is obtained, and this is obtained as a correlation output. In the embodiment described later, the number of sections representing "1" is calculated for each frame, the difference between this number and the corresponding number in the previous frame is calculated, and this difference is output as a correlation output.

Next, the correlation output of the correlation means 4 is supplied to the determination means 5. The determination means 5 compares the difference obtained as described above with a reference value, and when the difference is less than or equal to the reference value, the frame is correlated with the previous frame and is determined to be a continuous frame within one cut. On the other hand, if it exceeds the reference value, it is determined that the frame has no correlation with the previous frame, and it is determined that the frame is a frame where the cut changes, and a detection signal is output. In this way, the cut transition can be automatically detected.

(Embodiment) FIG. 3 is a block diagram showing the configuration of an embodiment of an apparatus for automatically detecting a change in cut according to the present invention.
In this example, an example applied to a telecine system in which a video signal obtained by imaging a color film is corrected and recorded in a VTR is shown. The color film 12 is loaded into the telecine device 11 which is wholly represented by a block, and the color image of each frame is imaged by the three image pickup tubes 13R, 13G and 13B while intermittently feeding at a rate of 24 frames / sec, and red, green The blue image signals R, G, B are reproduced. These color image signals are supplied to the matrix circuit 14, and these are combined at a predetermined ratio to create a signal representing a luminance signal. In this example, an NTSC color television signal is processed, and a luminance signal Y is created by synthesizing R, G, B signals at a ratio of 0.30R + 0.59G + 0.11B. In this example, the luminance signal Y is created from the RGB signals in this way, but the present invention is not limited to such an example. For example, R, G, B signals may be combined at other ratios or only the green signal may be generated. You can also take out.

The luminance signal Y obtained as described above is then passed through the low pass filter 15 and averaged over the period of 1 / 32H. Next, the luminance signal passed through the low pass filter 15 in this manner is supplied to the first comparison circuit 16. This first
In the comparison circuit 16, for example, a level of 50% of the luminance signal is set as a reference signal, and this is compared with the input luminance signal. If the input luminance signal is less than or equal to the reference value, “0”, exceeding the reference value. In this case, "1" is output. As described above, since the input luminance signal has an average value in the period of 1 / 32H, "0" or "1" is output for each section obtained by dividing the period of 1H into 32 equal parts. The binarized signal is then supplied to the shift register circuit 17.

In this example, as shown in FIG. 4, one frame is vertically and horizontally divided into 32 equal parts and divided into 1024 sections in total. Therefore, one section is composed of eight lines (1 / 32V) each having a period of 1 / 32H in the horizontal direction. The output of the first comparison circuit 16 in units of sections is composed of eight "0" s and "1" s, as shown in FIG. In this example, for each section, if the number of “1” is 5 or more, the section is set to “1”,
When the number of "1" is 4 or less, it is set to "0". That is, in the first section shown in FIG. 4, since there are five "1" s, the entire section is set to "1". In this way, in order to obtain "0" or "1" for each of 1024 sections obtained by dividing one frame into 32 equal parts vertically and horizontally, the shift register circuit 17 can delay the accumulation of image signals for 7 lines as described later. A shift register group is provided, and a total of eight lines of signals of delayed seven lines and undelayed one line signals are simultaneously output.

The output signals of these shift register circuits 17 are then supplied to the synthesizing circuit 18, and the added signals are obtained. Therefore, the output signal of this synthesis circuit 18 is "1" in each section.
Represents the number of This is the second comparison circuit
19 and compare with reference signal. This reference signal is larger than the output signal level of the combining circuit 18 when there are four "1" s in one section, but smaller than the output signal level of the combining circuit when there are five "1" s. Set to level. Therefore, the second comparison circuit 19 outputs a signal representing "1" or "0" for each section. The output signal of the second comparison circuit 19 is supplied to the counter 20, the number of "1" sections per frame is counted, and this is supplied to the central processing unit (CPU) 21. In the CPU 21, the difference between the count value of the section of "1" and the count value of the section of the previous frame "1" is calculated for each frame, and if the difference exceeds the preset reference value, the cut is performed. Is detected, the frame is detected as the first frame of the next cut, and when the difference is less than or equal to the reference value, it is determined that there is no significant difference with the previous frame, It is determined that the frame is not the cut transition point. The reference value can be determined by trial and error by processing an actual image signal,
For example, it can be set to ± 20% of the total number of all sections in one frame, and in the embodiment described later, the number of "1" sections in the frame is compared with the number of "1" sections in the previous frame. If there is a difference of ± 200 sections or more, it is considered that there is a significant difference between these frames, and the frame is judged to be the turning point of the cut. CPU2
Since 1 receives the signal representing the frame recorded on the film 12 from the telecine device 11 and creates the serial number of each frame, it is possible to record the frame number of the cut change. When the frame where the cut changes is detected in this way, the CPU 21 sends a stop signal to the telecine device 11 to automatically stop the film. in this case,
When the film cannot be stopped instantaneously in the telecine device 11, the reverse is operated after the stop so that the frame where the cut changes is located. In this way, when the frame of the cut transition is cued, black balance, white balance, γ-balance,
Decide various correction amounts such as color balance and hue correction,
These are stored in correspondence with the frame numbers. In this way, the correction amount is set for each cut of the film 12 and stored, and the number of the first frame of each cut is stored correspondingly. Next, the film 12 is reproduced again, and while performing correction based on a predetermined correction amount based on the number of the first frame of each cut obtained as described above, the VT
Supply to R23 and record.

FIG. 5 is a circuit diagram showing in detail mainly the configuration of the shift register circuit and the combining circuit of the above-mentioned device, and the same parts as those shown in FIG. 3 are designated by the same reference numerals.

The shift register circuit 17 is provided in parallel with seven shift registers 31-1 to 31-7 each having a bit position of one line, that is, 32 bit positions. In order to sequentially supply the binary signal of "1" or "0" output from the first comparison circuit 16 to the shift register, the crystal oscillator 32 oscillating at 8.055936MHz is provided, and the crystal oscillator 32 is composed of a binary counter. Divide by frequency divider 33 to 0.503496MHz (15.73425kHz ×
32) The section synchronization pulse of 32) is created and is supplied to each shift register 31-1 to 31-7 in parallel. Also, the first
The frequency divider 33 also produces a 15.73425 kHz horizontal sync pulse and supplies it to a second divider 34 comprising a binary counter to create a 59.94 Hz vertical sync pulse. This divider 3
The output of 4 is also supplied to the decoder 35, the signals of 1H to 8H are created, and the signals of 1H to 7H are respectively shifted registers 31-1 to 31.
Supply to -7. In this way, the signal of the first line is supplied to the first shift register 31-1, the signal of the second line is supplied to the second shift register 31-2, and so on.
The signal on the line is supplied to the seventh shift register 31-7. The signal on the eighth line is supplied to line 36. The output terminals of each shift register have equal resistances 41-1 to 41-1.
Connect to summing point 42 via 41-7 and line 36 with equal resistance
Connect to addition point 42 via 41-8. In this way, at the addition point 42, a voltage proportional to the number of "1" s of the eight lines included in one section appears in sequence, and this is amplified by the amplifier 43. In the feedback path of the amplifier 43, a resistor 4 having a value equal to 1/8 of the resistors 41-1 to 41-8 is used.
Connect 4. In this way, the output of the synthesis circuit 18 is 8
A signal proportional to the number of "1" lines appears in one section made up of lines.
Next, this is compared with the reference value by the second comparison circuit 19, and it is detected whether the number of lines of "1" is 5 or more or 4 or less, and 5
The section above is “1”. This "1" is counted by the counter 20.
The AND gate 45 takes the logical product of the 0.503496 MHz section clock output from the frequency divider 33 and the 8H signal output from the decoder 35, and the output is passed through the clock phase adjustment circuit 46 to obtain the clock pulse. To supply. Further, the counter 20 is supplied with the 512H signal from the second frequency divider 34 as a strobe pulse signal, and "1" is supplied for one frame.
Then, the number of sections is calculated.

The present invention is not limited to the above-mentioned embodiments, but various modifications can be applied. For example, in the above-described embodiment, the color signals obtained by imaging the color film are combined at a predetermined ratio to create the luminance signal, and the luminance signal is processed to obtain the correlation of the successive frames. It can also be processed to determine the correlation. Further, various automatic correction signals created in the telecine system can be used instead of the luminance signal and the green signal. Further, in the above-described example, the comparison circuit 16 compares the level of the luminance signal with the reference value fixedly set to the level of 50%, but this reference value depends on the level of the average luminance signal of the entire one screen. It can also be variable. In this case, for example, when the entire screen is dark, the reference value also becomes low, so
Correlation can be detected with higher accuracy than in the case where the reference value is fixedly set.

Further, in the above-described embodiment, after detecting the frame of the cut change, various correction amounts are manually set,
When this correction amount can be automatically obtained, the film correction work can be performed completely automatically, which significantly reduces the labor of the operator and shortens the working time.

Further, although the color film is used in the above-mentioned embodiment, the present invention can be applied to the case of correcting the video signal recorded on the magnetic tape such as VTR.

(Effects of the Invention) According to the present invention described above, since the frame at the cut transition can be automatically detected, it becomes extremely easy to perform various corrections on the image signal picked up from the film, and it is possible to shorten the time. Becomes Further, since the film is not repeatedly moved back and forth, damage to the film can be suppressed as much as possible. Furthermore, in order to detect cut transitions, each frame is divided into multiple sections, and processing is performed for each section to obtain the correlation with the previous frame. Therefore, cut transitions can be detected reliably. Signal processing is also simplified.

Also, for each section, automatic white level control signal, automatic gamma balance signal, automatic black level control signal,
An average value of any one of the automatic light control signal and the luminance signal is obtained for each of the plurality of scanning lines, and the average value obtained for each scanning line is compared with the first reference value to obtain "0". Or “1” is determined, and the number of “0” or “1” thus determined is compared with a second reference value for each section to determine “0” or “1”. The image information is extracted, the number of “0” or “1” in the frame is counted, and the difference between this count value and the corresponding count value in the previous frame is obtained as a correlation output. The configurations of the information extraction means and the correlation means can be simplified.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of an apparatus for automatically detecting a change in cut according to the present invention, FIG. 2 is a diagram for explaining the operation thereof, and FIG. 3 is an apparatus for the apparatus of the present invention. FIG. 4 is a block diagram showing the configuration of one embodiment, FIG. 4 is a diagram for similarly explaining the operation thereof, and FIG. 5 is a circuit diagram showing a detailed configuration of a part thereof. 1 ... Recording medium, 2 ... Reproducing means, 3 ... Image information extracting means, 4 ... Correlating means, 5 ... Judging means, F ... Frames S11 to S33 ... Section 11 ... Telecine device, 12 ... Film 13R, 13G, 13B …… Image pickup tube 14 …… Matrix circuit, 15 …… Low-pass filter 16 …… First comparison circuit, 17 …… Shift register circuit 18 …… Combining circuit, 19 …… Second comparison circuit 20 …… Counter, 21 …… Central processing unit 22 …… Correction circuit, 23 …… VTR

Claims (1)

[Claims] 1. A reproducing unit for reproducing an image signal by reproducing a recording medium on which frames constituting successive cuts are continuously recorded, and an image signal reproduced by the reproducing unit for receiving each frame. The average value of any one of the automatic white level control signal, the automatic gamma balance signal, the automatic black level control signal, the automatic light control signal, and the luminance signal is calculated for each of a plurality of sections obtained by dividing one frame into The average value obtained for each of the plurality of scanning lines is compared with the first reference value to determine "0" or "1". Or "1"
Image information extraction means for comparing the number of each of the sections with the second reference value to determine “0” or “1”, and counting the number of “0” or “1” in the frame,
Correlation means for obtaining the difference between this count value and the corresponding count value of the previous frame as a correlation output, and the difference output as a correlation output from this correlation means is compared with a third reference value to obtain a third reference value. An apparatus for automatically detecting a change in cut, comprising: a determining unit that determines that there is a correlation when the value is less than or equal to a value, and determines that there is no correlation otherwise.