JPH0746464A - Picture signal; processing unit - Google Patents

Abstract

PURPOSE:To properly decide weighting coefficients used to mix an output of in-field processing and an output of inter-field processing in the motion adaptive scanning line interpolation. CONSTITUTION:An interlace signal received from an input terminal 31 is respectively fed to processing circuits 13, 14 and an ADRC circuit 15. The processing circuit 13 applied in-field processing to an input signal to supply output data x1 to a multiplier 32. The processing circuit 14 applies inter-field processing to the input signal to give output data x2 to a multiplier 33. The ADRC circuit 15 compresses the input signal by the ADRC and a class code generating circuit 17 gives a class code (c) corresponding to the compressed input signal to a weighting coefficient memory 18 to give weighting coefficients w1(c), w2(c) decided by the learning in advance and corresponding to the class code to the multipliers 32, 33 from the coefficient memory 18 respectively. Output data of non-interlace subjected to weighting and mixing are generated by the multipliers 32, 33 and an adder 34.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image signal processing device,
In particular, it relates to an apparatus for performing adaptive mixing processing used in scanning line interpolation or the like.

[0002]

2. Description of the Related Art A conventional image signal processing apparatus shown in FIG.
A plurality of different processing means, processing circuits 52 and 53, and a feature amount detection circuit 5 for the input signal input from the input terminal 51.
Supply to 4 respectively. The processing circuit 52 forms an interpolated pixel by intra-field processing. On the other hand, the processing circuit 53
Forms interpolated pixels by inter-field processing.

The characteristic amount detection circuit 54 calculates the weighting factors k and (1-k) from the characteristic amounts such as the correlation value and the movement amount of the image by the calculation formula based on the theoretically assumed model of the image signal. To the multipliers 55 and 56, respectively.
The multiplier 55 multiplies the output data of the processing circuit 52 and the weighting coefficient k from the feature amount detection circuit 54. Multiplier 56
Multiplies the output data of the processing circuit 53 by the weighting coefficient (1-k) from the feature amount detection circuit 54. Adder 57
Respectively mixes the outputs of the multipliers 55 and 56 and outputs the mixed output to the output terminal 58. This output signal is obtained by doubling the scanning line of the input image signal.

[0004]

In the above-described motion-adaptive signal mixing method, when the assumed model and the actual image signal have different properties, appropriate mixing cannot be performed,
The output signal may be deteriorated, and the effect of signal processing such as scanning line interpolation may be reduced.

Therefore, an object of the present invention is not to simply mix signals, but to obtain a weighting coefficient by learning from a known image signal, and to use the weighting coefficient to mix the signals. To provide.

[0006]

Class detection means for detecting a level distribution pattern of an input image signal, determining a class to which the image signal belongs based on the detected pattern, and outputting class information, A plurality of processing means for processing the input image signal by different methods and a weighting coefficient preliminarily obtained by learning for mixing the output signals of the plurality of processing means so as to obtain a desired final output signal are stored for each class. The weighting coefficient storage means for outputting the weighting coefficient according to the class information from the class detection means, and the coefficient supplied from the weighting coefficient storage means are used to perform weighted addition of the output signals of the plurality of processing means. An image signal processing device having a means for outputting.

[0007]

Since the weighting coefficient at the time of mixing is determined in advance by learning, signal mixing can be performed based on the characteristics of the actual image.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to scanning line interpolation will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration at the time of learning according to an embodiment of the present invention. 11
Is an input terminal to which a large number of non-interlaced standard still image signals are input and supplied to the vertical thinning filter 12 and the least squares arithmetic circuit 16. The vertical thinning filter 12 to which the still image signal is supplied from the input terminal 11 vertically thins the non-interlaced still image signal into 1/2, and processes a still image equivalent to a normal interlaced image in the processing circuit 13. , 14 and ADRC circuit 15 respectively.

Now, the respective processes of the processing circuits 13 and 14 will be described. The processing circuit 13 extracts the average value of the pixel data of the upper scanning line and the pixel data of the lower scanning line of the interpolation scanning line as the interpolation pixel of the interpolation scanning line. The processing of the processing circuit 14 outputs the pixel data of the previous field at the same position as the interpolation pixel of the interpolation scanning line of the current field as the interpolation pixel of the interpolation scanning line of the current field.

As described above, the processing circuit 13 processes the interlaced signal in the field to output the interpolated data x ₁ . The output data x ₁ is supplied to the least square method arithmetic circuit 16. The processing circuit 14 performs inter-field processing on the interlaced signal to obtain the interpolated data x.
Output ₂ After the inter-field processing, the output data x ₂ is supplied to the arithmetic circuit 16 of the least square method.

In the least square method arithmetic circuit 16, the still image signal supplied from the input terminal 11 and the respective output data x ₁ and x ₂ supplied from the processing circuits 13 and 14, that is, the input non-interlaced signal. And the error of the image obtained by weighting the interlaced signal is calculated by the method of least squares, and the weighting factors w ₁ and w are calculated from the calculation result.
Identify ₂ . That is, y ′ = w ₁ x ₁ + w ₂ x ₂ (1) is obtained as a weighted mixed output value y ′, and the weighting coefficient that minimizes the square of the error between this value y ′ and the actual value y. w ₁ and w ₂ are calculated by the least-squares arithmetic circuit 16.

The ADRC circuit 15 compresses the interlaced signal supplied from the vertical thinning filter 2 by adaptive dynamic range coding (hereinafter referred to as ADRC), which will be described later. The output of the ADRC circuit 15 is supplied to the class code generating circuit 17 to generate the class code c. The weighting coefficient memory 18 holds the weighting coefficients w ₁ and w ₂ supplied from the least square method arithmetic circuit 16 using the supplied class code c as an address.

Here, taking 1-bit ADRC as an example, A
The DRC will be described. Further, the 1-bit ADRC will be described by taking the pixel data of the (3 × 3) block as an example centering on the pixel of interest on the interlaced image. An example of a block of the ADRC circuit 15 is shown in FIG. In FIG. 2, the detection circuit 22 detects the maximum value MAX and the minimum value MIN for each block with respect to the data converted into the order of blocks from the input terminal 21. MAX and MIN are supplied to the subtraction circuit 23, and the dynamic range DR is generated at the output thereof. Input data and MIN are subtraction circuit 2
4 and the minimum value is removed from the subtraction circuit 24 to generate normalized pixel data.

The dynamic range DR is supplied to the division circuit 25, the normalized pixel data is divided by the dynamic range DR, and the output data of the division circuit 25 is supplied to the comparison circuit 26. In the comparison circuit 26, it is determined whether the ratio calculation power of the eight pixels other than the target pixel is larger or smaller than 0.5. Depending on this result,
Data DT of "0" or "1" is generated. This comparison output DT is taken out to the output terminal 27. This 1-bit AD
If class division is performed using RC, the class code of the (3 × 3) block is represented by 9 bits. The pixels used for the class division are not limited to the pixels of the (3 × 3) block, but may be the blocks including the pixels of the previous field.
Various ones can be used.

As described above, the learning unit can acquire the weighting factor w _i using the image signal which is the actual data, and stores it in the memory. Next, when performing adaptive mixing, it is possible to generate an output image in which scan line interpolation is performed on an arbitrary input image. The configuration for this is shown in the block diagram of FIG.

An input terminal 31 receives a standard interlaced image signal. The signals input from the input terminal 31 are supplied to the processing circuits 13 and 14 and the ADRC circuit 15, respectively. The processing circuit 13 performs in-field processing on the input image signal and supplies the output data x ₁ to the multiplier 32. The processing circuit 14 performs inter-field processing on the input image signal and supplies the output data x ₂ to the multiplier 33.

The input image signal supplied to the ADRC circuit 15 is compressed by ADRC, and its output is supplied to the class code generation circuit 17. The class code generation circuit 17 generates a class code c corresponding to the compressed input image signal. The generated class code c is supplied to the weight coefficient memory 18, and the weight coefficients w ₁ (c) and w ₂ (c) corresponding to the class code are read out.

The weighting factors read out w ₁ (c) and w
₂ (c) is supplied to the multipliers 32 and 33, respectively. In the multiplier 32, the output data x ₁ of the processing circuit 13 is multiplied by the weighting coefficient w ₁ (c), and in the multiplier 33, the output data x ₂ of the processing circuit 14 is multiplied by the weighting coefficient w ₂ (c). . The multipliers 32 and 33 are respectively supplied to the adder 34 and added. The addition result is output from the output terminal 35. Here, the weighted and mixed output data y
′ Is shown by a calculation formula. This y'constitutes scanning line interpolation, and a non-interlaced image signal is obtained at the output terminal 35. y '= w ₁ (c) x ₁ + w ₂ (c) x ₂ (2)

FIG. 4 is a flowchart of the above-described scanning line interpolation processing. The control of the scanning line interpolation is started from step 41, and in the data block formation of step 42, a process of extracting the input image in processing block units is performed. At the end of the data in step 43, if the processing of all the input data has been completed, the control proceeds to the end of step 47, and if the processing is not complete, the control proceeds to the class determination of step 44.

In step 44, the class is determined from the signal pattern of the input image. With this control,
As in learning, for example, 1-bit AD to reduce the number of bits
RC is used. In the weighting factor restoration of step 45, the weighting factor corresponding to the class code is restored from the memory. In the weight calculation in step 46, the interpolated value obtained by the intra-field processing and the interpolated value obtained by the inter-field processing are weighted and added, and the interpolated data is output.
This series of control is repeated for all the data, and when the processing of all the data is completed, the control moves from the data end of step 43 to the end of step 47, and the scanning line interpolation processing is completed.

Although the ADRC circuit 15 is provided as the information compression means, this is merely an example.
Instead of the RC circuit 15, for example, DCT (Discrete Cos)
ineTransform) circuit, VQ (vector quantization) circuit,
DPCM (Predictive Coding) circuit or BTC (Block
It is possible to appropriately select what is provided as long as it is a means capable of performing data compression, such as providing a Trancation encoding circuit.

[0022]

According to the present invention, the class and the weighting coefficient corresponding to the class are learned on the basis of the property of the actual image, so that the results of different signal processing can be well weighted and mixed without deterioration of the output signal. it can.

[Brief description of drawings]

FIG. 1 is a block diagram of an example of a configuration for acquiring a weighting coefficient in an image signal conversion device according to the present invention.

FIG. 2 is a block diagram used to describe an ADRC circuit.

FIG. 3 is a block diagram of an embodiment of scanning line interpolation according to the present invention.

FIG. 4 is a flowchart of an example of scanning line interpolation according to the present invention.

FIG. 5 is a block diagram used for explaining a conventional signal mixing method.

[Explanation of symbols]

 13, 14 Processing circuit 15 ADRC circuit 17 Class code generation circuit 18 Weight coefficient memory 32, 33 Multiplier 34 Adder

Claims (2)

[Claims] 1. A class detecting means for detecting a level distribution pattern of an input image signal, determining a class to which the image signal belongs based on the detected pattern, and outputting class information, said input image signal. And a plurality of processing means for processing the output signals of the plurality of processing means in such a manner that the output signals of the plurality of processing means are mixed so as to become a desired final output signal. Therefore, the output signals of the plurality of processing means are weighted and added by using the weight coefficient storage means for outputting the weight coefficient according to the class information from the class detection means and the coefficient supplied from the weight coefficient storage means. An image signal processing apparatus having means for outputting the same. 2. The image signal processing apparatus according to claim 1, wherein the information indicating the level distribution pattern of the image information of the block detected by the class detecting means is compressed to output pattern compression information. An image signal processing apparatus, characterized in that, in addition to providing information compression means, the class detection means outputs the class detection information according to the pattern compression information supplied from the information compression means.