JP2707917B2 - Automatic black expansion controller for luminance signal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to automatic control of a black extension control circuit for a luminance signal, and more particularly to an improved distribution state of a luminance signal of 0IRE to 30IRE of a video signal and a luminance of 30IRE to 60IRE of a video signal. A black extension control circuit according to the distribution state of the signal, the distribution state of the luminance signal of 60 IRE to 90 IRE of the video signal, the distribution state of the luminance signal of 90 IRE or more of the video signal, the average luminance level of the video signal, and the minimum value of the luminance signal. It relates to a device for automatic control.

[0002]

2. Description of the Related Art In recent years, there has been a remarkable increase in the size of a television screen, and as a result, demands for image quality have been increasing. In particular, the gradation of the luminance signal greatly affects the contrast of the image quality.

FIG. 3 shows a conventional black expansion control device. Reference numeral 1 denotes a black expansion control circuit for performing black expansion control of a luminance signal. Reference numeral 2 denotes a control unit for controlling the control level of the black expansion control circuit. A circuit that controls the amount of black expansion correction.
Reference numeral 3 denotes a video chroma jungle IC.

In the conventional black expansion control circuit configured as described above, the volume in the black expansion control circuit adjustment circuit is adjusted from the outside, so that the black expansion correction amount of the one black expansion control circuit is adjusted. adjust.

[0005]

However, in the above configuration, if the black expansion control amount is uniquely determined at the time of adjustment at the factory, the control amount of the black expansion control circuit is fixed at the set value. This makes it impossible for the viewer to watch the television with an optimal black expansion correction amount according to the state of the video that changes every moment.

In view of the foregoing, it is an object of the invention of an automatic black extension control apparatus for the present luminance signal to enable a viewer to view television with an optimal black extension correction amount according to a video.

[0007]

In order to solve the above-mentioned problems, an automatic control device for a black extension control circuit of a luminance signal according to the present invention comprises: a black extension control circuit capable of black extension control of a luminance signal of a video signal; A circuit S1 detection circuit for detecting a luminance signal of 0IRE to 30IRE of a signal;
A circuit S2 detecting circuit for detecting a luminance signal of 60 IRE to 60 IRE, a circuit S3 detecting circuit for detecting a luminance signal of 60 IRE to 90 IRE of the video signal, a circuit S4 detecting circuit for detecting a luminance signal of 90 IRE or more of the video signal, An APL detection circuit for detecting an average luminance level of the signal, a black level detection circuit for detecting a minimum value of the luminance signal, and a preprocessing means for creating a control index for evaluating an output of the S1 detection circuit as a fuzzy set. Preprocessing means for creating a control index for evaluating the output of the S2 detection circuit as a fuzzy set; preprocessing means for creating a control index for evaluating the output of the S3 detection circuit as a fuzzy set; Preprocessing means for creating a control index for evaluating the output of the S4 detection circuit as a fuzzy set;
Preprocessing means for creating a control index for evaluating the output of the L detection circuit as a fuzzy set; preprocessing means for creating a control index for evaluating the output of the black level detection circuit as a fuzzy set; An output from the preprocessing means for creating a control index for evaluating the output of the detection circuit as a fuzzy set, and an output from the preprocessing means for creating a control index for evaluating the output of the S2 detection circuit as a fuzzy set; The output from the preprocessing means for creating a control index for evaluating the output of the S3 detection circuit as a fuzzy set and the output from the preprocessing means for creating a control index for evaluating the output of the S4 detection circuit as a fuzzy set are provided. The output from the preprocessing means for creating a control index for evaluating the output and the output of the APL detection circuit as a fuzzy set. Fuzzy inference means for performing each fuzzy inference with an output from a preprocessing means for creating a control index for evaluating a force and an output of the black level detection circuit as a fuzzy set; and an output of the fuzzy inference means Fuzzy black expansion control output determining means for determining a fuzzy black expansion control output, and a black expansion control amount correction circuit for controlling the control amount of the black expansion control circuit in accordance with the control output of the fuzzy black expansion control output determining means And an automatic control device for a black extension control circuit for a luminance signal.

[0008]

According to the present invention, according to the above-described configuration, the video signal 0I
A circuit S1 detection circuit for detecting a luminance signal of 30 IRE from RE, a circuit S2 detection circuit for detecting a luminance signal of 30 IRE to 60 IRE of a video signal, and a 60IR of a video signal
A circuit S3 detection circuit for detecting a luminance signal of 90 IRE from E, a circuit S4 detection circuit for detecting a luminance signal of 90 IRE or more of the video signal, an APL detection circuit for detecting an average luminance level of the video signal, Evaluate the output from the black level detection circuit that detects the value as a fuzzy set, calculate the fuzzy black expansion control output by fuzzy inference, and use this fuzzy black expansion control output to automatically control the black expansion control circuit for the optimal luminance signal. Do.

[0009]

FIG. 1 is a block diagram showing the configuration of an automatic control device of a luminance signal black expansion control circuit according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a black extension control circuit for a luminance signal, and reference numeral 2 denotes a circuit for controlling a correction level of black extension by controlling a control level of the black extension control circuit 1. FIG. 10 is a graph showing characteristics when the black extension correction is applied to the luminance signal. The black extension correction amount 1 can be changed to positions 2 and 3 by controlling the correction amount. 3 is a video chroma jungle IC, and 4 is a video signal from 0IRE to 30IR.
E is a circuit for detecting the luminance signal, and 5 is 3 of the video signal.
A circuit for detecting a luminance signal of 60 IRE from 0IRE, a circuit for detecting a luminance signal of 60 IRE to 60 IRE of the video signal, a circuit for detecting a luminance signal of 90 IRE or more of the video signal, and a circuit 8 for detecting a luminance signal of 90 IRE or more of the video signal. An APL detection circuit 9 detects an average luminance level of the video signal. A black level detection circuit 9 detects a minimum value of the luminance signal.
Reference numeral 0 denotes a fuzzy black expansion control device which receives outputs from the detection circuit 4 to the detection circuit 9 as inputs and fuzzy infers an optimal black expansion control amount.

FIG. 2 is a detailed block diagram of the fuzzy black expansion control device 10 in FIG. The fuzzy black expansion controller obtains the detection values from the detection circuit 4 to the detection circuit 9 and creates control index values for evaluating the fuzzy sets in the preprocessors 11 to 16. The fuzzy inference devices 17 to 22 perform fuzzy inference using the control index values of the preprocessing devices 11 to 16 as inputs. This fuzzy inference device 1
The outputs 7 to 22 are supplied to a fuzzy black expansion control output determining device 23, where the fuzzy black expansion control output as the output of the fuzzy black expansion control device 10 is determined. The output from the fuzzy black expansion control device 10 is input to a black expansion control amount correction circuit for correcting the black expansion correction amount of the black expansion control circuit 2. Then, the black expansion control amount correction circuit 2 controls the black expansion correction amount applied to the luminance signal of the black expansion control circuit 1 and always maintains the optimum black expansion control.

The operation of the automatic control of the luminance signal black extension control circuit configured as described above will be described below. First, the detection circuit 4 in FIG. 1 detects what percentage of one screen is from 0 IRE to 30 IRE, and the detected result is converted into a voltage. Next, the detection circuit 5 detects what percentage of one screen is from 30 IRE to 60 IRE in the same manner as the detection circuit 4, and the result is converted into a voltage. Next, as in the detection circuit 4, in the detection circuit 6, what percentage of one screen is 60I
The RE detects whether it is 90IRE or not and converts the result to a voltage. Next, similarly to the detection circuit 4, the detection circuit 7 detects what percentage of one screen is 90 IRE or more, and the result is converted into a voltage. Note that it is preferable that the detection circuit 4, the detection circuit 5, the detection circuit 6, and the detection circuit 7 are set to an appropriate slice level according to the performance of the black extension control circuit 1. Next, the detection circuit 8 detects the average luminance level, and the result is converted into a voltage. Next, the detection circuit 9 detects the minimum value of the luminance signal, and the result is converted into a voltage. It goes without saying that the output of the detection circuit may be not only a voltage but also a current.

The detected values thus detected are shown in FIG.
Is input to each of the pre-processing devices 11 to 16, and a control index for evaluation as a fuzzy set is created in each of the pre-processing devices 11 to 16.

FIG. 4 shows a membership function used in the preprocessor 11 shown in FIG. 2 for inputting an output from the circuit 4 for detecting the distribution state of the video luminance signal from 0IRE to 30IRE in FIG.

FIG. 5 shows a membership function used in the preprocessor 12 shown in FIG. 2 for inputting an output from the circuit 5 for detecting the distribution state of the image luminance signal from 30 IRE to 60 IRE shown in FIG.

FIG. 6 shows a membership function used in the preprocessor 13 shown in FIG. 2 for inputting the output from the circuit 6 for detecting the distribution state of the image luminance signal from 30 IRE to 60 IRE shown in FIG.

FIG. 7 shows a membership function used in the preprocessor 14 shown in FIG. 2 for inputting an output from the circuit 7 for detecting the distribution state of the video luminance signal from 30 IRE to 60 IRE in FIG.

FIG. 8 shows a membership function used in the preprocessor 15 shown in FIG. 2 for inputting an output from the APL detection circuit 8 for detecting the average luminance level of the video luminance signal shown in FIG.

FIG. 9 shows a membership function used in the preprocessor 16 shown in FIG. 2 for inputting an output from the black level detection circuit 9 for detecting the minimum value of the luminance signal shown in FIG. (Table 1) is a control rule showing the relationship between the luminance signal distribution state from 0IRE to 30IRE and the black extension correction amount.

[0019]

[Table 1]

Table 2 shows control rules representing the relationship between the luminance signal distribution state of 30 IRE to 60 IRE and the black extension correction amount.

[0021]

[Table 2]

Table 3 shows control rules representing the relationship between the luminance signal distribution state of 60 IRE to 90 IRE and the black extension correction amount.

[0023]

[Table 3]

Table 4 shows a control rule representing a relationship between a luminance signal distribution state of 90 IRE or more and a black extension correction amount.

[0025]

[Table 4]

(Table 5) This is a control rule representing the relationship between the average luminance level and the black extension correction amount.

[0027]

[Table 5]

Table 6 shows a control rule representing the relationship between the minimum value of the luminance signal and the black extension correction amount.

[0029]

[Table 6]

The fuzzy inference method by the fuzzy inference devices 17 to 22 shown in FIG. 2 is based on a general rule of controlling a rule using a membership function of an antecedent part, a membership function of a consequent part, and an input value. A fuzzy operation is performed along the line, a combined fuzzy set is calculated, the maximum value of the combined fuzzy set is used as an output combining function, and the center of gravity of the output combining function is used as an output of fuzzy inference. It goes without saying that not only the centroid method but also a height method or another output value calculation method may be used.

The fuzzy black expansion control output determination device 2 shown in FIG.
3, a final black expansion control correction amount is calculated by arithmetic averaging using the outputs of the fuzzy inference devices 17 to 22 of FIG. 2 obtained according to the above inference method as an input, and the black expansion control amount correction circuit of FIG. 2, the control of the black extension control circuit 1 is performed. It goes without saying that not only the arithmetic mean but also the center of gravity method, the height method, and other calculation methods may be used.

As described above, according to the present embodiment, by detecting the distribution state of the luminance signal, the average luminance level, or the minimum value of the luminance signal, the optimum black extension correction control according to the image state at that time can be performed. It becomes possible.

[0033]

As described above, according to the present invention, a black extension control circuit capable of controlling black extension of a luminance signal of a video signal and a circuit S1 for detecting a luminance signal of 0IRE to 30IRE of the video signal.
A detection circuit; a circuit S2 for detecting a luminance signal of 30 IRE to 60 IRE of the video signal;
A circuit S3 detecting circuit for detecting a luminance signal of 90 IRE from the IRE; a circuit S4 detecting circuit for detecting a luminance signal of 90 IRE or more of the video signal; an APL detecting circuit for detecting an average luminance level of the video signal; A black level detection circuit for detecting a value, preprocessing means for creating a control index for evaluating the output of the S1 detection circuit as a fuzzy set, and a control index for evaluating the output of the S2 detection circuit as a fuzzy set And a control index for evaluating the output of the S3 detection circuit as a fuzzy set, and a control index for evaluating the output of the S4 detection circuit as a fuzzy set. Preprocessing means for creating a control index for evaluating the output of the APL detection circuit as a fuzzy set; Preprocessing means for creating a control index for evaluating the output of the black level detection circuit as a fuzzy set; output from the preprocessing means for creating a control index for evaluating the output of the S1 detection circuit as a fuzzy set; The output from the preprocessing means for creating a control index for evaluating the output of the S2 detection circuit as a fuzzy set and the output from the preprocessing means for creating a control index for evaluating the output of the S3 detection circuit as a fuzzy set. Preprocessing means for generating a control index for evaluating the output and the output of the S4 detection circuit as a fuzzy set and for generating a control index for evaluating the output of the APL detection circuit as a fuzzy set and an output from the preprocessing means A control index for evaluating the output from the CPU and the output of the black level detection circuit as a fuzzy set Fuzzy inference means for performing respective fuzzy inferences by using an output from the preprocessing means as input, fuzzy black expansion control output determining means for determining a fuzzy black expansion control output by using the output of the fuzzy inference means, and the fuzzy black By providing a black extension control amount correction circuit that controls the control amount of the black extension control circuit according to the control output of the extension control output determination unit,
It is possible for the viewer to view with optimal black extension correction according to the video state, and the practical effect is great.

[Brief description of the drawings]

FIG. 1 is a block diagram of an automatic black extension control device for a luminance signal according to an embodiment of the present invention.

FIG. 2 is a detailed block diagram of the arithmetic and control unit according to the embodiment of FIG. 1;

FIG. 3 is a block diagram of a conventional black extension control device.

FIG. 4 is a membership function showing a relationship between a distribution state of 0IRE to 30IRE of a video signal and a black extension correction amount.

FIG. 5 is a membership function showing a relationship between a distribution state of 30 IRE to 60 IRE of a video signal and a black extension correction amount.

FIG. 6 is a membership function showing a relationship between a distribution state of a video signal from 60 IRE to 90 IRE and a black extension correction amount.

FIG. 7 is a membership function showing a relationship between a distribution state of a video signal of 90 IRE or more and a black extension correction amount.

FIG. 8 is a membership function showing a relationship between an average luminance level and a black extension correction amount.

FIG. 9 is a membership function showing a relationship between a minimum value of a luminance signal and a black extension correction amount.

FIG. 10 is a graph illustrating characteristics when a black signal is corrected for a luminance signal.

[Explanation of symbols]

1 luminance signal black expansion control circuit 2 circuit for controlling the amount of black expansion correction by controlling the control level of black expansion control circuit 1 3 video chroma jungle IC 4 detecting luminance signal from 0IRE to 30IRE of video signal 5 A circuit for detecting a luminance signal from 30 IRE to 60 IRE of a video signal 6 A circuit for detecting a luminance signal from 60 IRE to 90 IRE of a video signal 7 A circuit for detecting a luminance signal of 90 IRE or more of a video signal 8 An average of video signals APL detection circuit for detecting a luminance level 9 Black level detection circuit for detecting a minimum value of a luminance signal 10 Fuzzy black expansion control device for fuzzy inference of an optimal black expansion control amount using outputs from the detection circuit 4 to the detection circuit 9 as inputs. 11 Obtain detection values from the detection circuit 4 and create control index values for fuzzy set evaluation Pre-processing device 12 Pre-processing device for obtaining control values for fuzzy set evaluation by obtaining detection values from detection circuit 5 13 Control for obtaining fuzzy set evaluation by obtaining detection values from detection circuit 6 Preprocessing device for creating index values 14 Preprocessing device for obtaining control values for evaluation of fuzzy sets by obtaining detection values from detection circuit 7 15 Evaluating fuzzy sets by obtaining detection values from detection circuits 8 Pre-processing device for creating control index values for 16 16 Pre-processing device for obtaining control values for fuzzy set evaluation by obtaining detection values from detection circuit 9 17 Control index values from pre-processing device 11 Fuzzy inference device that performs fuzzy inference as an input 18 Fuzzy inference device that performs fuzzy inference using a control index value from the preprocessing device 12 as an input 19 A control index value from the preprocessing device 13 is input Fuzzy inference device 20 that performs fuzzy inference by using a control index value from the preprocessing device 14 as input fuzzy inference device 21 that performs fuzzy inference by using a control index value from the preprocessing device 15 as input 22 A fuzzy inference device 23 that performs fuzzy inference using the control index value from the processing device 16 as an input. A fuzzy black expansion control output determination device that determines the final black expansion control amount by using the output of the fuzzy inference devices 17 to 22 as input.

Claims (7)

(57) [Claims] 1. A black extension control circuit capable of controlling black extension of a luminance signal of a video signal, and a video signal from 0IRE to 30IRE.
S1 detection circuit for detecting a luminance signal, preprocessing means for creating a control index for evaluating the output of the S1 detection circuit as a fuzzy set, and fuzzy inference for performing fuzzy inference using the output of the preprocessing means as an input Means, fuzzy black expansion control output determination means for determining a fuzzy black expansion control output using the output of the fuzzy inference means as input, and control of the black expansion control circuit in accordance with the control output of the fuzzy black expansion control output determination means. A black extension control amount correction circuit for controlling the amount is provided.
A fuzzy control of a black expansion control circuit in accordance with the distribution state of the luminance signal. 2. A black extension control circuit capable of controlling black extension of a luminance signal of a video signal, and a video signal from 30IRE to 60IR.
An S2 detection circuit for detecting a luminance signal of E; preprocessing means for creating a control index for evaluating an output of the S2 detection circuit as a fuzzy set; and fuzzy inference using the output of the preprocessing means as an input. Inference means, and fuzzy black expansion control output determination means for determining a fuzzy black expansion control output using the output of the fuzzy inference means as input,
A black extension control amount correction circuit for controlling the control amount of the black extension control circuit in accordance with the control output of the fuzzy black extension control output determining means, and
An automatic black stretch control device for a brightness signal, wherein fuzzy control is performed on a black stretch control circuit according to a distribution state of a brightness signal of RE. 3. A black extension control circuit capable of controlling black extension of a luminance signal of a video signal, and a video signal from 60IRE to 90IR.
An S3 detection circuit for detecting a luminance signal of E; a preprocessing means for creating a control index for evaluating an output of the S3 detection circuit as a fuzzy set; and a fuzzy inference using the output of the preprocessing means as an input. Inference means, and fuzzy black expansion control output determination means for determining a fuzzy black expansion control output using the output of the fuzzy inference means as input,
A black extension control amount correction circuit for controlling the control amount of the black extension control circuit in accordance with the control output of the fuzzy black extension control output determining means, and
An automatic black stretch control device for a brightness signal, wherein fuzzy control is performed on a black stretch control circuit according to a distribution state of a brightness signal of RE. 4. A black extension control circuit capable of controlling black extension of a luminance signal of a video signal, an S4 detection circuit detecting a luminance signal of 90 IRE or more of the video signal, and evaluating an output of the S4 detection circuit as a fuzzy set. Pre-processing means for creating the control index of the above, fuzzy inference means for performing fuzzy inference using the output of the pre-processing means as input, and fuzzy black expansion control for determining fuzzy black expansion control output using the output of the fuzzy inference means as input Output control means for controlling the control amount of the black expansion control circuit in accordance with the control output of the fuzzy black expansion control output determination means; and a luminance signal of 90 IRE or more of the video signal. An automatic black stretch control device for a luminance signal, wherein fuzzy control is performed on a black stretch control circuit according to a distribution state. 5. A black extension control circuit capable of controlling black extension of a luminance signal of a video signal, an APL detection circuit for detecting an average luminance level of the video signal, and control for evaluating an output of the APL detection circuit as a fuzzy set. Preprocessing means for creating an index; fuzzy inference means for performing fuzzy inference using the output of the preprocessing means as input; and fuzzy black expansion control output determination for determining fuzzy black expansion control output using the output of the fuzzy inference means as input. Means for controlling the amount of control of the black expansion control circuit in accordance with the control output of the fuzzy black expansion control output determining means, wherein the black expansion control amount correction circuit performs black expansion in accordance with the average luminance level of the video signal. An automatic black extension control device for a luminance signal, wherein a control circuit performs fuzzy control. 6. A black extension control circuit capable of controlling black extension of a luminance signal of a video signal, a black level detection circuit for detecting a minimum value of the luminance signal, and an output for evaluating the output of the black level detection circuit as a fuzzy set. Preprocessing means for creating a control index; fuzzy inference means for performing fuzzy inference using the output of the preprocessing means as input; and fuzzy black expansion control output for determining fuzzy black expansion control output using the output of the fuzzy inference means as input. Determining means, and a black expansion control amount correction circuit for controlling a control amount of the black expansion control circuit according to a control output of the fuzzy black expansion control output determining means,
An automatic black expansion control device for a luminance signal, wherein fuzzy control is performed on a black expansion control circuit according to a minimum value of the luminance signal. 7. A black extension control circuit capable of controlling black extension of a luminance signal of a video signal, and the video signal 0I according to claim 1,
3. A circuit S1 detection circuit for detecting a luminance signal of 30 IRE from RE, a circuit S2 detection circuit for detecting a luminance signal of 30 IRE to 60 IRE of the video signal according to claim 2,
4. The video signal according to claim 3, wherein the video signal is from 60 IRE to 90 IR.
6. A circuit S3 detecting circuit for detecting a luminance signal of E, a circuit S4 detecting circuit for detecting a luminance signal of 90 IRE or more of the video signal according to claim 4, and detecting an average luminance level of the video signal according to claim 5. An APL detection circuit for detecting a minimum value of a luminance signal according to claim 6, a preprocessing means for generating a control index for evaluating an output of the S1 detection circuit as a fuzzy set, A preprocessing means for creating a control index for evaluating the output of the S2 detection circuit as a fuzzy set; a preprocessing means for creating a control index for evaluating the output of the S3 detection circuit as a fuzzy set; Preprocessing means for creating a control index for evaluating the output of the detection circuit as a fuzzy set; and evaluating the output of the APL detection circuit as a fuzzy set. Preprocessing means for generating a control index,
Preprocessing means for creating a control index for evaluating the output of the black level detection circuit as a fuzzy set;
The output from the preprocessing means for creating a control index for evaluating the output of the detection circuit as a fuzzy set and the S2
The output from the preprocessing means for creating a control index for evaluating the output of the detection circuit as a fuzzy set and the S3
The output from the preprocessing means for creating a control index for evaluating the output of the detection circuit as a fuzzy set;
An output from the preprocessing means for creating a control index for evaluating an output of the detection circuit as a fuzzy set and the AP
The output from the preprocessing means for creating a control index for evaluating the output of the L detection circuit as a fuzzy set and the output from the preprocessing means for creating a control index for evaluating the output of the black level detection circuit as a fuzzy set. Fuzzy inference means for performing each fuzzy inference with an output as input, fuzzy black expansion control output determination means for determining fuzzy black expansion control output with the output of the fuzzy inference means as input, and fuzzy black expansion control output determination means. A black extension control amount correction circuit for controlling the control amount of the black extension control circuit in accordance with the control output, the distribution state of the luminance signal of 0IRE to 30IRE of the video signal and the 30% of the video signal;
According to the distribution state of the luminance signal of IRE to 60 IRE, the distribution state of the luminance signal of 60 IRE to 90 IRE of the video signal, the distribution state of the luminance signal of 90 IRE or more of the video signal, the average luminance level of the video signal, and the minimum value of the luminance signal. An automatic black stretch control device for a luminance signal, wherein the black stretch control circuit is fuzzy controlled.