KR100359112B1 - Apparatus for converting field/frame rate and thereof - Google Patents

Abstract

A method and apparatus for field and / or frame rate conversion using motion adaptation and time ratio are disclosed. According to the present invention, when image data of different fields and / or frames is input, the frame rate conversion method includes a method for converting a field and / or frame to be converted each time a sync signal of the field and / or frame to be converted is detected. Determining a temporal weight with respect to the input image field and / or frame; And repeatedly outputting the interpolated field in a predetermined order by applying the same field or time weight and motion value as the input according to the temporal weight determined in the above process.

Description

Field and / or frame rate converting method and apparatus

The present invention relates to field and / or frame rate conversion, and more particularly, to a method and apparatus for field and / or frame rate conversion using motion adaptation and time ratio.

In general, the frame rate is the number of frames transmitted per second. When transmitting a video signal such as a television signal, only a suitable number of screens (frames) are transmitted per second using human visual characteristics. The frame rate in television is 30 frames (60 fields) per second for NTSC systems and 50 frames per second for PAL and SECAM systems. The frame of NTSC also consists of a top field and a bottom field. Therefore, a field / frame converter is required when a video signal having a different field / frame rate is input to a video reproducing apparatus or a video signal is input from a reproducing apparatus having a different field / frame rate.

1 shows a method of frame / field rate conversion from 50 Hz to 60 Hz.

Referring to FIG. 1, the input 50 Hz field is output as it is and the field is doubled and outputted once every fifth. That is, every fifth chapter input field and sixth chapter output field are the same point in time. Therefore, when constructing six output fields, input 5 is used as it is, and the sixth field simply duplicates the last fifth field once more.

2 illustrates a method of frame / field rate conversion from 60 Hz to 50 Hz.

Referring to FIG. 2, the field is discarded once every sixth while the input 60 Hz field is output as it is. That is, every sixth input field and the fifth output field are the same points in time. Therefore, input 5 of the input 6 fields is used as it is, and the 6th field is skipped without being used.

Such a conventional field / frame rate conversion exhibits discontinuity in the field doubled screen. For example, if there is an object flying from the left side of the screen to the right side, the discontinuous portion is displayed, so that the motion screen is inconvenient.

The technical problem to be achieved by the present invention is to move when a video signal having a different field and / or frame rate is input to the video reproducing apparatus or when a video signal is input from a video reproducing device having a different field and / or frame rate. And / or to provide a method and apparatus for field and / or frame conversion by applying temporal gravity.

1 shows a method of frame / field rate conversion from 50 Hz to 60 Hz.

2 illustrates a method of frame / field rate conversion from 60 Hz to 50 Hz.

3 is a block diagram of a field and / or frame rate conversion apparatus according to the present invention.

4 illustrates a field and / or frame rate conversion method according to the present invention.

In order to solve the above technical problem, the present invention provides a frame rate conversion method for inputting image data of different fields and / or frames,

(a) determining a temporal weight with respect to the input image field and / or frame for the image field and / or frame to be converted each time a synchronization signal of the field and / or frame to be converted is detected;

(b) a frame rate conversion method including repeatedly outputting an interpolated field in a predetermined order by applying a field equal to an input, a time weight, and a motion value according to the temporal weight determined in step (b) .

In order to solve the above other technical problem, the present invention provides a frame rate conversion apparatus for converting a frame rate higher than the frame rate of the input signal,

A signal difference detection unit comparing the input current image data with previous image data and detecting a signal difference value;

A motion detector for detecting the presence or absence of a motion by comparing a signal difference value detected from the signal difference detector and a threshold value;

A frame including a frame rate conversion unit for outputting a field as it is or according to a temporal gravity with a current field or generating a field by performing interpolation or intrafield interpolation using a predetermined time weight when a motion is detected by the motion detector. Rate converter.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

3 is a block diagram of a field and / or frame rate conversion apparatus according to the present invention.

Referring to FIG. 3, first, currently input image data is a signal generated by a sub picture reproducing apparatus having a frame standard of 50 Hz.

The first memory 310 stores image data one field earlier, the second memory 320 stores image data two fields (one frame) previous, and the third memory 350 stores the first memory 310. ) Stores the image data which is one line delayed.

The signal difference detector 330 detects a signal difference value by comparing the input current image data with previous image data stored in the second memory 320.

The motion detector 340 detects a motion presence value by comparing a signal difference value detected from the signal difference detector 330 with a threshold.

The controller 370 inputs a 60 Hz synchronization signal from the main picture reproducing apparatus and outputs a field conversion signal to the frame rate converter 360 in accordance with the synchronization signal. In another embodiment, the controller 370 may input a 50 Hz synchronization signal input from the sub-screen reproducing apparatus and output a field conversion signal reproduced with the 60 Hz synchronization signal.

The multiplexer 380 selectively outputs a current field and a field of the second memory 320 whenever the frame conversion signal corresponding to the predetermined synchronization signal is input from the control unit 370.

When the field conversion signal is applied from the controller 370, the frame rate converter 360 generates the motion by the motion detector 340 according to the temporal gravity between the two fields stored in the first memory 310 and the second memory 320. Outputs the input field with reference to the motion presence value or generates a new field by interpolating between frames or fields. At this time, the frame rate converter 360 interpolates and inter-fields using the current field and the previous field stored in the first memory 310 and the second memory 320 and the line data stored in the third memory 330. Perform interpolation. In this case, the first memory 310 and the third memory 350 are used for interpolation in the field, and the second memory 320 is used for interfield interpolation with the current field signal.

4 is a diagram illustrating a field and / or frame rate conversion method according to the present invention, and converts and outputs image data input in a 50 Hz format into a 60 Hz format.

In FIG. 4, a dotted line indicates an image data field (①--) input at a rate of 50 Hz, and a solid line indicates an image data field (-1--⑫) converted at a frame rate of 60 Hz. Also, the "O" superimposed on the dotted line and the solid line represents a line in the field.

Referring to FIG. 4, methods for setting a new image data field according to a synchronization signal of 60 Hz to be converted at 50 Hz within a predetermined period according to temporal gravity are as follows. S and T) are repeated every 12 fields in a certain order. In other words,

1) How to replace the same or near field in time (F)

2) A method of generating a new field by applying a motion presence value (S).

3) Method of interpolating the field by applying time ratio (T).

A frame and / or field conversion method to which the conversion method set as described above is applied will be described with reference to FIG. 4.

First, the first, second, and third fields to be output are 100%, 83%, and 67 in time compared to the input first, second, and third fields (①, ②, ③). There is a percentage of weight, but the input field is used as it is (F method).

The fourth field ④ to be output has a specific gravity of 50% and 50% in the middle of the input third and fourth fields ③ and ④. In this case, interpolation is performed by applying a motion value. generated by interpolation (T method).

Where 3D is an interfield interpolation value, 2D is an intrafield interpolation value, and m is a motion value.

Referring again to Equation 1, if the stationary part without the motion value m, the line of the field to be generated is simply interpolated between the fields (3D), and if the motion part with the motion value m, the line of the field to be generated. Is multiplied by a weight of 0.5 to interfield interpolation and multiplied by a weight of 0.5 by intrafield interpolation (2D) and added to each other.

The fifth and sixth fields (⑤, ⑥) have 33% and 17% specific gravity in the input fourth and fifth fields (④, ⑤). In this case, the motion values are applied and interpolated as shown in Equation 2 below. generated by interpolation (S method).

Where 3D is an interfield interpolation value, 2D is an intrafield interpolation value, and m is a motion value.

Referring back to Equation 2, if the stationary part without the motion value m does not exist, the line of the field to be generated is simply inter-field interpolation (3D). )do.

After the seventh field (⑦), the time ratio is symmetrical, but since the top / bottom fields are changed, the seventh, eighth, and ninth fields (⑦, ⑧, ⑨) apply Equation 2 ( S method), the tenth field (i) applies Equation 1 (T method), and the eleventh and twelfth fields (i, i) are output as they are (F method).

The present invention is not limited to the above-described embodiment, and of course, modifications may be made by those skilled in the art within the spirit of the present invention.

As described above, according to the present invention, the unnaturalness of the screen can be eliminated by generating a new field according to the temporal weight of the field and / or the field input during the frame conversion in the image reproducing apparatus.

Claims (7)

In the frame rate conversion method when image data of different fields and / or frames is input, (a) determining a temporal weight with respect to the input image field and / or frame for the image field and / or frame to be converted each time a synchronization signal of the field and / or frame to be converted is detected; (b) mixing the inter-field interpolation and the intra-field interpolation according to the temporal weight determined in the step (a), and generating a field in which the inter-field interpolation value and the temporal weight are mixed according to the presence or absence of movement. Frame / field rate conversion method comprising the process. delete The method of claim 1, wherein the step (b) is a field in the form of 3D * (1-m) + m * {3D * T + 2D * (1-T)} when the time weight is intermediate to the input fields. Where 3D is an interfield interpolation value, 2D is an intrafield interpolation value, T is a specific gravity value of time, and m represents a motion value. The frame / field rate conversion method of claim 3, wherein the specific gravity value T of time is 0.5 when converting 50 Hz to 60 Hz. The method of claim 1, wherein in the step (b), when the time weights of the input fields are different from each other, fields are formed in a form of {3D * (8-m) + m * 2D} / 8, wherein 3D is a field. The interpolation value, 2D is an intra-field interpolation value, and m is a motion value. A field and / or frame conversion method for converting a 50 Hz vertical frequency into a 60 Hz vertical frequency, Repeatedly generating the 60 Hz vertical synchronization signal; According to the sequence of the vertical synchronization signal generated in the above process, the first, second and third fields are output as input fields, and the fourth field is applied between fields and / or frames according to the presence or absence of motion by applying a predetermined time ratio. The interpolated field is output, and the fifth to ninth fields apply the motion value between adjacent fields to output the interpolated field between the field and / or the frame, and the tenth field applies the predetermined time ratio. And outputting a field interpolated between the field and / or the frame, and outputting the eleventh and twelfth fields as an input field as it is. 7. The method of claim 6, wherein when the motion value is detected, the fourth and tenth fields add a time weight of 0.5 to the inter-field interpolation value and a time weight of 0.5 to the intra-field interpolation value, respectively. The ninth field is to add a time weight of 0.5 to the inter-field interpolation value, respectively, and to add a time weight of 0.5 to the intra-field interpolation value, respectively.