Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUSRE35910 E
Publication typeGrant
Application numberUS 08/241,810
Publication date29 Sep 1998
Filing date12 May 1994
Priority date11 May 1989
Publication number08241810, 241810, US RE35910 E, US RE35910E, US-E-RE35910, USRE35910 E, USRE35910E
InventorsAtsushi Nagata, Kenichi Takahashi, Nobuyasu Takeguchi
Original AssigneeMatsushita Electric Industrial Co., Ltd.
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Moving image signal encoding apparatus and decoding apparatus
US RE35910 E
Abstract
A moving image signal encoding apparatus includes: a frame decimating circuit for extracting . .encoded.!. frames from an input moving image signal at specified intervals; a frame interpolating circuit for obtaining an interpolated frame between the . .encoded.!. .Iadd.extracted .Iaddend.frames, and a circuit for obtaining an error formed by frame interpolation. A moving image signal decoding apparatus includes: a receiving circuit for extracting a frame code from an inputted signal; a frame decoding circuit for decoding the frame code to obtain a reproduced frame, and a frame interpolating circuit for obtaining an interpolated frame between the reproduced frames. By transmitting an error of the interpolated frame from the encoding apparatus to the decoding apparatus and correcting the error of the interpolated frame with the decoding apparatus, the error of the interpolated frame is eliminated. Alternatively, depending on the value of the error of the interpolated frame obtained with the encoding apparatus, a circuit determines the operation mode as to whether the frame interpolating circuit of the decoder carries out frame interpolation or preceding value holding and sends a flag to show the operation mode to the decoder, so that improvement occurs when the error of the interpolated frame is large.
Images(6)
Previous page
Next page
Claims(9)
What is claimed is:
1. A moving image signal encoding apparatus comprising: a frame decimator for extracting . .the encoded.!. frame from an input moving image signal at specified intervals; a frame encoder for encoding said . .encoded.!. frames .Iadd.extracted by said decimator .Iaddend.to obtain frame codes; a frame interpolator for producing interpolated frames positioned between said . .encoded.!. .Iadd.extracted .Iaddend.frames from said frame codes; an error evaluator for evaluating errors of said interpolated frames, and a transmitter for transmitting said frame codes and output signals of said error evaluator as an output of the moving image signal encoding apparatus.
2. A moving image signal encoding apparatus comprising: a frame decimator for extracting . .encoded.!. frames .Iadd.from an input moving image signal at specified intervals; a frame encoder for encoding said frames extracted by said decimator .Iaddend.to obtain frame codes; a decoder for decoding said frame codes to obtain reproduced frames; a frame interpolator for producing interpolated frames positioned between said reproduced frames; . .and.!. .Iadd.an .Iaddend.interpolated frame encoder for encoding errors of said interpolated frames to obtain interpolated frame codes. .,.!..Iadd.; .Iaddend.and a transmitter for transmitting said frame codes and said interpolated frame codes .Iadd.as an output of the moving image signal encoding apparatus.Iaddend..
3. A moving image signal encoding apparatus according to claim 2, wherein said decoder includes a means for decoding . .the.!. .Iadd.each of said .Iaddend.frame . .code.!. .Iadd.codes .Iaddend.to obtain a reproduced frame, and a means for obtaining a predicted frame .Iadd.from said reproduced frame.Iaddend., and .Iadd.wherein .Iaddend.said encoder comprises a subtractor for obtaining a predicted error signal from said . .encoded.!. .Iadd.extracted .Iaddend.frame and said predicted frame, and a predicted error encoder for encoding said predicted error signal to obtain a frame code.
4. A moving image signal encoding apparatus according to claim 2, wherein said interpolated frame encoder includes a subtractor for obtaining a difference between said interpolated frame and a corresponding frame of said input moving image signal, and an error encoder for encoding said difference to obtain an interpolated frame code.
5. A moving image signal encoding apparatus according to claim 2, wherein said interpolated frame encoder includes: a subtractor for obtaining a difference between said interpolated frame and a corresponding frame of said input moving image signal; an error calculator for obtaining a value of said difference; an encoded area selector for determining an area for encoding said difference by an output of said error calculator, and an encoder for encoding said difference by using an output of said encoded area selector to obtain an interpolated frame code.
6. A moving image signal encoding apparatus according to claim 2, further comprising a motion estimator for detecting a motion vector of the input moving image signal, wherein said decoder includes a means for decoding . .the.!. .Iadd.each of said .Iaddend.frame . .code.!. .Iadd.codes .Iaddend.to obtain a reproduced frame, and a means for motion compensating said reproduced frame by said motion vector to obtain a predicted frame, and .Iadd.wherein .Iaddend.said encoder includes a subtractor for obtaining a predicted error signal from said . .encoded.!. .Iadd.extracted .Iaddend.frame and said predicted frame, and a predicted error encoder for encoding said predicted error to obtain a frame code.
7. A moving image signal decoding apparatus for decoding a signal . .produced by a moving image signal encoding apparatus comprising: a frame decimator for extracting encoded frames from an input moving image signal at specified intervals; a frame encoder for encoding said encoded frames to obtain frame codes; a decoder for decoding said frame codes to obtain reproduced frames, a frame interpolator for producing interpolated frames positioned between said reproduced frames; an interpolated frame encoder for encoding errors of said interpolated frames to obtain interpolated frame codes, and a transmitter for transmitting said frame codes and said interpolated frame codes;.!. .Iadd.containing frame codes which have been produced by encoding frames extracted from a moving image signal at specified intervals and interpolated frame codes which have been produced by encoding errors of interpolated frames positioned between the extract frames; .Iaddend.said decoding apparatus comprising: a receiver for extracting said frame . .code.!. .Iadd.codes .Iaddend.and said interpolated frame . .code.!. .Iadd.codes .Iaddend.from an input signal; a decoder for decoding said frame . .code.!. .Iadd.codes .Iaddend.to obtain . .the.!. reproduced . .frame.!. .Iadd.frames.Iaddend.; a frame interpolator for producing the interpolated . .frame.!. .Iadd.frames .Iaddend.positioned between said reproduced frames; an error corrector for correcting an error of .Iadd.each of .Iaddend.said interpolated . .frame.!. .Iadd.frames.Iaddend., and a means for producing a moving image signal from said reproduced . .frame.!. .Iadd.frames .Iaddend.and an output of said error corrector.
8. A moving image signal encoding apparatus comprising: a frame decimator for extracting . .encoded.!. frames from an input moving signal at specified intervals; a motion estimator for obtaining motion vectors between said . .encoded.!. .Iadd.extracted .Iaddend.frames; a frame encoder for encoding said . .encoded.!. .Iadd.extracted .Iaddend.frames to obtain frame codes; a frame interpolator for producing interpolated frames positioned between said . .encoded.!. .Iadd.extracted .Iaddend.frames from said frame codes; . .a.!..Iadd.an .Iaddend.error calculator for obtaining errors of said interpolated frames; a selector for selecting whether to output said . .motor.!. .Iadd.motion .Iaddend.vectors or to output a flag to indicate not to output said motion vectors by using the errors obtained by said error calculator, and a means for outputting said frame codes and an output of said selector.
9. A moving image signal decoding apparatus for decoding . .the.!. .Iadd.a .Iaddend.signal . .produced by a moving image signal encoding apparatus comprising: a frame decimator for extracting encoded frames from an input moving image signal at specified intervals; a motion estimator for obtaining motion vectors between said encoded frames; a frame encoder for encoding said encoded frames to obtain frame codes; a frame interpolator for producing interpolated frames positioned between said encoded frames from said frame codes; an error calculator for obtaining errors of said interpolated frames; a selector for selecting whether to output said motion vectors or the output a flag to indicate not to output said motion vectors by using the errors obtained by said error calculator, a means for outputting said frame codes and an output of said selector.!. .Iadd.containing frame codes which have been produced by encoding frames extracted from a moving image signal at specified intervals and interpolated frame codes which have been produced by encoding errors of interpolated frames positioned between the extracted frames and one of either a motion vector between said extracted frames and a flag indicating the absence of a motion vector between said extracted frames.Iaddend.; said decoding apparatus comprising: a receiver for extracting the frame codes and said interpolated frame codes from an inputted signal; a frame decoder for decoding said frame codes to obtain reproduced frames, and a frame interpolator for producing .Iadd.an .Iaddend.interpolated . .frames.!. .Iadd.frame .Iaddend.positioned between said reproduced frames or holding a preceding reproduced frame, wherein, when said receiver outputs . .a.!. .Iadd.said .Iaddend.motion vector, said frame interpolator produces . .an.!. .Iadd.said .Iaddend.interpolated frame, and when said receiver receives . .a.!. .Iadd.said .Iaddend.flag, said frame interpolator holds the preceding reproduced frame.
Description
BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a moving image signal encoding apparatus for performing compression encoding of a moving image signal for transmission of the moving image signal or recording of the same on a recording medium and a decoding apparatus for decoding the codes which have been transmitted or reproduced from a recording medium to obtain a reproduced image.

2. Description of Prior Art

Recently, in the moving image signal encoding apparatus and decoding apparatus, in consequence of the developments of television telephones and television conference systems, various compression encoding systems have been in practical use. As a procedure for curtailing the information amount to be used in these encoding systems there is a frame decimation. This is to curtail the information amount by decimating selected frames of the moving image signal in encoding. Since the movements of the reproduced images become unnatural by decimating the frames, frame interpolation is carried out in the decoding apparatus to obtain the reproduced images having smooth movements.

As one of the precedents to carry out frame interpolation with a moving image signal decoding apparatus there is a construction shown in U.S. Pat. No. 4,727,422. Hereinafter, the construction of the conventional moving image signal encoding apparatus and decoding apparatus is described.

The input of the moving image signal encoding apparatus is a moving image signal of 30 frames/sec. The inputted moving image signal, after decimation of the number of frames to 1/2, becomes a moving image signal of 15 frames/sec. These remaining frames of the moving image signal will be encoded. In the description hereinafter, these frames are called "encoded frames". Interframe motion vectors are obtained from the encoded frames. The motion vectors are obtained on a block by block basis. The motion vectors are used for frame interpolation in the decoding apparatus. The encoded frames and the motion vectors are respectively encoded, after which additional information is incorporated to obtain an output signal of the moving image signal encoding apparatus. The output signal is sent out to a transmission channel or recorded on a recording medium.

The moving image signal decoding apparatus is to decode the signal encoded by the moving image signal encoding apparatus and reproduce the moving image signal. By a signal receiving circuit, each code is received from the transmission channel or read out from the recording medium. The codes are decoded by respective decoding circuits to become the reproduced frames and the motion vectors. The frequency of the reproduced frames is 15 frames/sec. A frame interpolation circuit obtains interpolated frames each positioned between two reproduced frames. The frame interpolation is a motion compensating frame interpolation using a motion vector between the frames. By alternately outputting the interpolated frames and the reproduced frames, an output image signal of 30 frames/sec is obtained.

However, the above construction involves the problem to cause errors to the interpolated frames because there are no correct motion vectors in such cases that: (1) there are objects which move in different directions from each other in a block; (2) the background appears from the shade of a moving object or the background is hidden by a moving object; (3) the moving object changes in shape; and (4) there is a movement accompanied with rotation.

SUMMARY OF THE INVENTION

An object of the present invention is to realize reduction in interpolation errors of frames in a moving image signal encoding apparatus which decimates frames in encoding and a moving image signal decoding apparatus which interpolates frames in decoding.

To achieve this object, a moving image signal encoding apparatus of the present invention comprises a frame decimator for extracting . .encoded.!. frames from an input moving image signal at specified intervals, a frame encoder for encoding said . .encoded.!. frames .Iadd.extracted by the decimator .Iaddend.to obtain frame codes; a frame interpolator for producing interpolated frames positioned between said . .encoded.!. .Iadd.extracted .Iaddend.frames from said frame codes; a motion estimator for evaluating errors of said interpolated frames, and a transmitter for transmitting said frame codes and output signals of said error evaluator as an output signal of the moving image signal encoding apparatus.

A moving image signal decoding apparatus of the present invention is to decode the signals transmitted from the aforementioned moving image signal encoding apparatus, and comprises: a receiver for extracting said frame codes and said error evaluator output signals from the input signal; a frame decoder for decoding said frame codes to obtain the reproduced frames, and a frame interpolator for producing interpolated frames positioned between said reproduced frames.

Preferably, said error evaluator includes a means for encoding the errors of said interpolated frames to error codes, and said moving image signal decoding apparatus includes a means for correcting the errors of said interpolated frames according to the error codes to obtain said reproduced frames and error-corrected interpolated frames in a specified sequence.

Alternatively, said error evaluator includes a means for obtaining the errors of said interpolated frames to obtain error codes and a means for producing a mode selection signal from the error codes for changing over an operation mode of the frame interpolator of the moving image signal decoding apparatus, and, in the moving image signal decoding apparatus, the frame interpolator includes a means for selecting whether to perform frame interpolation or to hold a preceding reproduced frame (to repeat the preceding reproduced frame) according to the mode selection signal, and outputting said reproduced frames and said interpolated frames in a specified sequence.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a moving image signal encoding apparatus and a moving image signal decoding apparatus in accordance with a first embodiment of the present invention;

FIGS. 2(a)-2(b) are illustrative . .view to explain.!. .Iadd.views for explaining .Iaddend.a . .relation,.!. .Iadd.relationship .Iaddend.between frames;

FIG. 3 is a block diagram of a moving image signal encoding apparatus in accordance with a second embodiment of the present invention;

FIG. 4 is a block diagram of a moving image signal decoding apparatus in accordance with the second embodiment of the present invention;

FIG. 5 is a block diagram of an error evaluator and coder of a moving image signal decoding apparatus in accordance with a third embodiment of the present invention;

FIG. 6 is a view showing an interpolated frame divided into a plurality of blocks;

FIG. 7 is a block diagram of a moving image signal encoding apparatus in accordance with a fourth embodiment of the present invention;

FIG. 8 is a block diagram of a moving image signal decoding apparatus in accordance with the fourth embodiment of the present invention;

FIGS. 9(a)-9(b) are views showing a relationship between frames in accordance with the fourth embodiment of the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

Hereinafter, the moving image signal encoding apparatus and decoding apparatus according to the embodiments of the present invention are explained with reference to the drawings.

FIG. 1 shows a block diagram of a moving image signal encoding apparatus and a decoding apparatus in accordance with a first embodiment of the present invention. In FIG. 1, the numeral 1 denotes the moving image signal encoding apparatus for encoding and transmitting a moving image signal, in which element 101 is an input moving image signal; element 102 is a frame decimator; 103 is a frame encoder; 104 is a local frame decoder; 105 is a frame interpolator; 106 is an error calculator and coder; 107 is a multiplexer and transmitter, and element 108 is an output signal of the moving image signal encoding apparatus. The numeral 2 denotes the moving image signal decoding apparatus for reproducing the moving image signal, in which element 201 is an input signal of the moving image signal decoding apparatus; element 202 is a receiver and demultiplexer; 203 is a frame decoder; 204 is a frame interpolator; 205 is an error corrector; 206 is a selector, and 207 is an output signal of the moving image signal decoding apparatus.

The operations of the moving image signal encoding apparatus and decoding apparatus constituted as above are explained by way of FIG. 1.

To an input of the moving image signal encoding apparatus, a moving image signal 101 to be encoded is inputted. A frame decimator 102 decimates the frames of the input moving image signal 101 by one-half. This operation is illustrated in FIG. 2(a). A, B, C, D are the continued frames of the input moving image signal, of which B and D are the frames to be decimated by the frame decimator 102, and A and C are the frames to be inputted to the frame encoder 103. In the following explanation, frames A and C are called the "encoded frames". The frame encoder 103 encodes each . .encoded.!. frame to .Iadd.obtain .Iaddend.a frame code 1038. The frame decoder 104 decodes the frame code to obtain a reproduced frame 1046. The frame interpolator 105 synthesizes interpolated frames 1051 each positioned between two reproduced frames. The relationship between the reproduced frames and the interpolated frames is explained in FIG. 2(b). A' and C' are the reproduced frames, and these correspond to the encoded frames A and C. The encoded frames A and C are encoded by the frame encoder 103 and then decoded by the frame decoder 104 to be the reproduced frames A' and C'. Bi and Di are the interpolated frames outputted by the frame interpolator 105. The error evaluator and coder 106 encodes an error of each interpolator frame obtained as a difference between the interpolated frame and a corresponding frame of the input moving image signal, and outputs it as an interpolated frame code 1066. The multiplexer and transmitter 107 multiplexes the frame codes and the interpolated frame codes, and outputs the multiplexed result as an output signal 108 of the moving image signal encoding apparatus.

Next, the operations of the moving image signal decoding apparatus 2 are explained. The moving image signal decoding apparatus 2 is to decode the inputted signal 201 and output a reproduced moving image signal. The inputted signal 201 is the output signal 108 of the moving image signal encoding apparatus 1. The receiver and demultiplexer 202 extracts the frame codes 2021 and the interpolated frame codes 2022 from the inputted signal. These codes are respectively equal to the frame codes 1038 and the interpolated frame codes 1066 of the moving image signal encoding apparatus 1. The frame decoder 203 decodes the frame codes and outputs reproduced frames 2036. The frame interpolator 204 synthesizes interpolated frames 2041 each positioned between two reproduced frames. The relationship between the reproduced frames and the interpolated frames is the same as in the case of the moving image signal encoding apparatus 1 as shown in FIG. 2(b). The error corrector 205 corrects the errors of the interpolated frames by using the interpolated frame codes 2022. The selector 206 alternately selects the reproduced frames 2036 and the error-corrected interpolated frames 2037 to obtain the output signal 207 of the moving image signal encoding apparatus. A display apparatus 208 displays the reproduced image based on the output signal 207 of the moving image signal encoding apparatus 2.

FIG. 3 shows a block diagram of a moving image signal encoding apparatus in accordance with a second embodiment of the present invention. In FIG. 3, element 101 is an input moving image signal; element 102 is a frame decimator; element 103 is a frame encoder; element 1033 is a subtraction circuit; element 1035 is a DCT (discrete cosine transform) operation circuit; element 1037 is a quantizer; element 104 is a local frame decoder; element 1041 is a dequantizer; element 1043 is an inverse DCT (IDCT) operation circuit; element 1045 is an addition circuit; element 1047 is a frame memory; element 1048 is a motion compensator; element 105 is a frame interpolator; element 106 is an error evaluator and coder; element 1061 is a subtraction circuit; element 1063 is a DCT operation circuit, 1065 is a quantizer; element 107 is a multiplexer and transmitter; element 108 is an output signal of the moving image signal encoding apparatus, and element 1091 is a motion estimator.

The operations of the moving image signal encoding apparatus constituted as above are explained by way of FIG. 3.

The motion estimator 1091 estimates the motion of the input moving image signal 101 and outputs a motion vector 1092.

The frame decimator 102 decimates the frames of the input moving image signal by one-half.Iadd.. .Iaddend.The operation of the frame decimator 102 is the same as that of the first embodiment.

The frame encoder 103 encodes the . .encoded.!. frames 1031 to .Iadd.obtain .Iaddend.frame codes 1038. The encoding method is an interframe coding. The subtraction circuit 1033 obtains a predicted error signal 1034 which is a differential value between the encoded frame 1031 and a predicted frame 1032 formed by the later-described local decoder 104 The DCT operation circuit 1035 transforms the predicted error signal 1034 to a DCT coefficient 1036. The quantizer 1037 quantizes the DCT coefficient 1036 to obtain the frame code 1038.

The local decoder 104 decodes the frame code 1038 to obtain a reproduced frame 1046 and the predicted frame 1032. The dequantizer 1041 dequantizes the frame code 1038 to obtain a reproduced DCT coefficient 1042. The inverse DCT operation circuit 1043 inverse discrete cosine transforms the reproduced DCT coefficient 1042 to obtain a reproduced predicted error signal 1044. The addition circuit 1045 adds the reproduced predicted error signal 1044 and the predicted frame 1032 to obtain the reproduced frame 1046. The frame memory 1047 stores the reproduced frame 1046. The motion compensator 1048 carries out a motion compensation of the reproduced frame read out from the frame memory 1047 according to the motion vector 1092 to obtain the predicted frame 1032.

The frame interpolator 105 synthesizes an interpolated frame 1051 from the motion vector 1092 and the reproduced frame 1046. The relationship between the reproduced frames and the interpolated frames is the same as that explained in the first embodiment.

The error evaluator and coder 106 encodes the error of the interpolated frame 1051 to obtain an interpolated frame code 1066. The subtraction circuit 1061 calculates a differential value between the interpolated frame 1051 and a corresponding frame of the input moving image signal 101 to obtain an interpolated frame error signal 1062. The DCT (Discrete Cosine Transform) operation circuit 1063 transforms the interpolated frame error signal 1062 to a DCT coefficient 1064. The quantizer 1065 quantizes the DCT coefficient 1064 to obtain the interpolated frame code 1066.

The multiplexer and transmitter 107 multiplexes and outputs the frame code 1038, the motion vector 1092, and the interpolated frame code 1066 as the output signal 108 of the moving image signal encoding apparatus.

FIG. 4 shows a block diagram of a moving image signal decoding apparatus in accordance with the second embodiment of the present invention. In FIG. 4, element 201 is an input signal of the moving image signal decoding apparatus; element 202 is a receiver and multiplexer; element 203 is a frame decoder; element 2031 is a dequantizer; element 2033 is an inverse DCT operation circuit. .,.!..Iadd.; element .Iaddend.2035 is an addition circuit. .,.!..Iadd.; element .Iaddend.2037 is a frame memory. .,.!..Iadd.; element .Iaddend.2038 is a motion compensator; element 204 is a frame interpolator; element 205 is an error corrector; element 2051 is a dequantizer; element 2053 is an inverse DCT operation circuit; element 2055 is an addition circuit; element 206 is a selector, and element 207 is an output signal of the moving image signal decoding circuit.

The operations of the moving image signal decoding apparatus constituted as above are explained by way of FIG. 4.

The input signal 201 is an output signal of the moving image signal encoding apparatus of FIG. 3. The receiver and demultiplexer 202 extracts a frame code 2021, an interpolated frame code 2022, and a motion vector 2023 from the input signal 201. These codes are equal to the frame code 1038, the interpolated frame code 1066, and the motion vector 1092, respectively, of the moving image signal encoding apparatus in FIG. 3.

The frame decoder 203 decodes the frame code 2021 to obtain a reproduced frame 2036. The dequantizer 2031 dequantizes the frame code 2031 to obtain a reproduced DCT coefficient 2032. The inverse DCT operation circuit 2035 inverse discrete cosine transforms the reproduced DCT coefficient 2032 to obtain a reproduced predicted error signal 2034. The addition circuit 2035 adds the reproduced predicted error signal 2034 and a predicted frame 2039 formed by the later-described motion compensator 2038 and to obtain the reproduced frame 2036. The frame memory 2037 stores the reproduced frame 2036. The motion compensator 2032 carries out a motion compensation of the reproduced frame read out from the frame memory 2037 according to the motion vector 2023 to obtain the predicted frame 2039.

The frame interpolator 204 synthesizes an interpolated frame 2041 from the motion vector 2023 and the reproduced frame 2036. The relationship between the reproduced frame and the interpolated frame is the same as explained in the first embodiment.

The error corrector 205 corrects the error of the interpolated frame 2041 by using the interpolated frame code 2022. The dequantizer 2051 dequantizes the interpolated frame code 2022 to obtain a reproduced DCT coefficient 2052. The inverse DCT operation circuit 2053 inversely discrete cosine transforms the reproduced DCT coefficient 2052 to obtain an interpolated frame error signal 2054. The addition circuit 2055 adds the reproduced interpolated frame error signal 2054 and the interpolated frame 2041 to obtain a reproduced interpolated frame 2056. The selector 206 alternately selects the reproduced frames 2036 and the reproduced interpolated frames 2056 to obtain the output signal 207 of the moving image signal decoding apparatus and supplies the output signal 207 to the display apparatus 208.

FIG. 5 shows a block diagram of an error evaluator and coder of a moving image signal encoding apparatus in accordance with a third embodiment of the present invention. The constructions of the other parts are the same as those in the second embodiment shown in FIG. 3. In FIG. 5, element 1051 is an input interpolated frame; element 101 is an input moving image signal of the moving image signal encoding apparatus; element 1061 is a subtraction circuit; element 1063 is a DCT operation circuit; element 1065 is a quantizer; element 1068 is an error calculator; element 10611 is a comparator, element 10610 is a reference level; element 10613 is a switch, and element 1066 is an interpolated frame code.

The operations of the error evaluator and coder circuit constituted as above are explained by way of FIG. 5. The subtraction circuit 1061 obtains an interpolated frame error signal 1062 which is a differential value between the input interpolated frame 1051 and the input moving image signal 101. The DCT operation circuit 1063 transforms the interpolated frame error signal 1062 to a DCT coefficient 1064. The quantizer 1065 quantizes the DCT coefficient 1064 to obtain a code 10614. The error calculator 1068 obtains the value of the interpolated frame error signal 1062 on a block by block by block basis to obtain an error value 1069. This block is explained with reference to FIG. 6. In FIG. 6, element 3001 is interpolated frame, and element 3002 is a block in this frame. The interpolated frame is divided at intervals of 8 image elements both vertically and horizontally to obtain each block. The comparator 1061 compares the error value 1069 with a specified reference level 10610, and closes the switch 1061 when the error value 1069 exceeds the reference level 10610. When the switch is closed, the output code 10614 of the quantizer 1065 becomes the interpolated frame code 1066 which is an output of the interpolated frame encoding circuit.

FIG. 7 shows a block diagram of a moving image signal encoding apparatus in accordance with a fourth embodiment of the present invention. In FIG. 7, element 101 is an input moving image signal; element 102 is a frame decimator; element 103 is a frame encoder; element 104 is a frame decoder; element 105 is a frame interpolator; element 107 is a transmitter and multiplexer; element 108 is an output signal of the moving image signal encoding apparatus; element 1091 is a motion estimator; element 1093 is an error evaluator, and element 1094 is a selector.

The operations of the moving image signal encoding apparatus constituted as above are explained by way of FIG. 7.

The frame decimator 102 decimates the frames of the input moving image signal 101 by one-half. The operation of the frame decimator 102 is the same as that of the first embodiment.

The frame encoder 103 encodes the . .encoded.!. frame to obtain the frame code 1038. The frame decoder 104 decodes the . .encoded.!. frame .Iadd.code .Iaddend.to obtain the reproduced frame 1046. The frame interpolator 105 produces the interpolated frame 1051 from the motion vector 1092 and the reproduced frame 1046. The relationship between the reproduced frame and the interpolated frame is the same as that explained in the first embodiment.

The error evaluator 1093 obtains the error of the interpolated frame 1051 and outputs a mode selection signal 10931. When the error of the interpolated frame is smaller than a predetermined reference level, the mode selector signal becomes a code indicating a frame interpolation mode. When the error is larger than the reference level, the mode selection signal becomes a code indicating a previous value retaining mode. The selector 1094 outputs as its output 1096 the motion vector 1092 when the mode selection signal indicates the frame interpolation mode, and outputs a flag signal when the mode selection signal indicates the previous value retaining mode.

The multiplexer and transmitter 107 multiplexes and outputs the frame code 1038 and the output 1096 of the selector 1094 as the output signal 108 of the moving image signal encoding apparatus.

FIG. 8 shows a block diagram of the decoding apparatus in accordance with the fourth embodiment of the present invention. In FIG. 8, .Iadd.element .Iaddend.201 is an input signal of the moving image signal decoding apparatus. .,.!..Iadd.; element .Iaddend.202 is a receiver and demultiplexer. .,.!..Iadd.; element .Iaddend.203 is a frame decoder. .,.!..Iadd.; element .Iaddend.204 is a frame interpolator. .,.!..Iadd.; element .Iaddend.206 is a selector, and .Iadd.element .Iaddend.207 is an output signal of the moving image signal decoding apparatus.

The operations of the moving image signal decoding apparatus constituted as above are explained by way of FIG. 8.

The moving image signal decoding apparatus 2 is to decode the inputted signal 201 and output the moving image signal 207. The inputted signal 201 is the output signal 108 of the moving image signal encoding apparatus of FIG. 6. The receiver and demultiplexer 202 extracts from the inputted signal 201 a frame code 2021 and a signal 2024 which is the motion vector or the flag signal.

When the motion vector is extracted from the receiver and demultiplexer 202, the operation sequence is as follows. The frame decoder 203 decodes the frame code 2021 to obtain the reproduced frame 2036. The frame interpolator 204 interpolates a frame between the reproduced frames. The selector 206 alternately selects the reproduced frames 2036 and the interpolated frames 2087 to obtain the output signal 207 of the moving image signal decoding apparatus. In FIG. 9(a) the output signal of the moving image signal decoding apparatus is shown, in which A' and C' are the reproduced frames, and Bi' and Di' are the interpolated frames.

Further, when the flag signal is extracted as the output 2024 of the receiver and demultiplexer 202, the operation sequence is as follows. The frame decoder 203 decodes the frame code 2021 to obtain the reproduced frame 2036. The frame interpolator 204 obtains the frame positioned between the reproduced frames by holding the preceding frame. The held previous reproduced frame is outputted as the output frame 2087. This operation is shown in FIG. 9(b). The frames A' and C' at the time t0 and t2 are the reproduced frames, and the frames A' and C' at the time t1 and t3 are those in which the frames A' and C' at the time t0 and t2 are respectively held for 1 frame period of time, i.e; the reproduced frames A' and C' are repeated. The selector 206 alternately selects the reproduced frames 2036 and the output frames 2087 of the from interpolator 204 to obtain the output signal 207 of the moving image signal decoding apparatus. The output signal 207 is displayed as a reproduced image by the display apparatus 208.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US4383272 *13 Apr 198110 May 1983Bell Telephone Laboratories, IncorporatedVideo signal interpolation using motion estimation
US4575756 *25 Jul 198411 Mar 1986Nec CorporationDecoder for a frame or field skipped TV signal with a representative movement vector used for individual vectors
US4727422 *3 Jun 198523 Feb 1988Picturetel CorporationMethod and apparatus for efficiently communicating image sequence having improved motion compensation
US4958226 *27 Sep 198918 Sep 1990At&T Bell LaboratoriesConditional motion compensated interpolation of digital motion video
US4982285 *26 Apr 19901 Jan 1991Victor Company Of Japan, Ltd.Apparatus for adaptive inter-frame predictive encoding of video signal
JP5970378A * Title not available
JPH0628392A * Title not available
JPS58190184A * Title not available
JPS59123383A * Title not available
JPS60229494A * Title not available
JPS63122387A * Title not available
Non-Patent Citations
Reference
1M. Tanimoto et al., "Bandwith Compression System by Using Time-Axis Transformation for High Definition Television Signal", vol. 8, No. 2, pp. 47-54, Apr. 1984.
2 *M. Tanimoto et al., Bandwith Compression System by Using Time Axis Transformation for High Definition Television Signal , vol. 8, No. 2, pp. 47 54, Apr. 1984.
3 *Smpte Journal, vol. 98, No. 7, Jul. 1989 (pp. 504 511); A Modular Digital Video Coding Architecture For Present and Advanced TV Systems .
4Smpte Journal, vol. 98, No. 7, Jul. 1989 (pp. 504-511); "A Modular Digital Video Coding Architecture For Present and Advanced TV Systems".
5 *Synposium Record Broadcast Sessions, 16th International TV Symposium, Jun. 17, 1989, (pp. 387 409); Image Coding Techniques for 64 KBIT/S Channels .
6Synposium Record Broadcast Sessions, 16th International TV Symposium, Jun. 17, 1989, (pp. 387-409); "Image Coding Techniques for 64 KBIT/S Channels".
7Takahiko Fukinuki, "Digital Signal Processing of Images", pp. 204-207, Jul. 15, 1985.
8 *Takahiko Fukinuki, Digital Signal Processing of Images , pp. 204 207, Jul. 15, 1985.
9 *The Transactions of the I.E.C.E. of Japan, vol. 70, No. 7, Jul. 1987, Tokyo, Japan, (pp. 611 613); A Hybrid Scheme of Subsampled DPCM and Interpolative DPCM for the HDTV Coding .
10The Transactions of the I.E.C.E. of Japan, vol. 70, No. 7, Jul. 1987, Tokyo, Japan, (pp. 611-613); "A Hybrid Scheme of Subsampled DPCM and Interpolative DPCM for the HDTV Coding".
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US635154514 Dec 199926 Feb 2002Dynapel Systems, Inc.Motion picture enhancing system
US66184396 Jul 19999 Sep 2003Industrial Technology Research InstituteFast motion-compensated video frame interpolator
US728070013 Jun 20039 Oct 2007Microsoft CorporationOptimization techniques for data compression
US73178392 Sep 20048 Jan 2008Microsoft CorporationChroma motion vector derivation for interlaced forward-predicted fields
US73529052 Sep 20041 Apr 2008Microsoft CorporationChroma motion vector derivation
US737949619 Aug 200327 May 2008Microsoft CorporationMulti-resolution video coding and decoding
US740898613 Jun 20035 Aug 2008Microsoft CorporationIncreasing motion smoothness using frame interpolation with motion analysis
US740899030 Jun 20045 Aug 2008Microsoft CorporationEfficient motion vector coding for video compression
US74211294 Sep 20032 Sep 2008Microsoft CorporationImage compression and synthesis for video effects
US742630818 Jul 200316 Sep 2008Microsoft CorporationIntraframe and interframe interlace coding and decoding
US749949516 Jul 20043 Mar 2009Microsoft CorporationExtended range motion vectors
US75482456 Sep 200716 Jun 2009Microsoft CorporationImage formats for video capture, processing and display
US755832013 Jun 20037 Jul 2009Microsoft CorporationQuality control in frame interpolation with motion analysis
US756761727 May 200428 Jul 2009Microsoft CorporationPredicting motion vectors for fields of forward-predicted interlaced video frames
US75772006 Oct 200418 Aug 2009Microsoft CorporationExtended range variable length coding/decoding of differential motion vector information
US759017915 Sep 200415 Sep 2009Microsoft CorporationBitplane coding of prediction mode information in bi-directionally predicted interlaced pictures
US760976318 Jul 200327 Oct 2009Microsoft CorporationAdvanced bi-directional predictive coding of video frames
US76392656 Sep 200729 Dec 2009Microsoft CorporationImage formats for video capture, processing and display
US76468109 Dec 200512 Jan 2010Microsoft CorporationVideo coding
US764953910 Mar 200419 Jan 2010Microsoft CorporationImage formats for video capture, processing and display
US766417715 Sep 200416 Feb 2010Microsoft CorporationIntra-coded fields for bi-directional frames
US768018515 Sep 200416 Mar 2010Microsoft CorporationSelf-referencing bi-directionally predicted frames
US773855417 Jul 200415 Jun 2010Microsoft CorporationDC coefficient signaling at small quantization step sizes
US78221236 Oct 200426 Oct 2010Microsoft CorporationEfficient repeat padding for hybrid video sequence with arbitrary video resolution
US78399336 Oct 200423 Nov 2010Microsoft CorporationAdaptive vertical macroblock alignment for mixed frame video sequences
US79257747 Aug 200812 Apr 2011Microsoft CorporationMedia streaming using an index file
US79497757 Aug 200824 May 2011Microsoft CorporationStream selection for enhanced media streaming
US79569305 Jan 20077 Jun 2011Microsoft CorporationResampling and picture resizing operations for multi-resolution video coding and decoding
US805488629 Jun 20078 Nov 2011Microsoft CorporationSignaling and use of chroma sample positioning information
US810757120 Mar 200731 Jan 2012Microsoft CorporationParameterized filters and signaling techniques
US82135035 Sep 20083 Jul 2012Microsoft CorporationSkip modes for inter-layer residual video coding and decoding
US824382029 Apr 200514 Aug 2012Microsoft CorporationDecoding variable coded resolution video with native range/resolution post-processing operation
US834017710 May 200525 Dec 2012Microsoft CorporationEmbedded base layer codec for 3D sub-band coding
US83708877 Aug 20085 Feb 2013Microsoft CorporationMedia streaming with enhanced seek operation
US837423810 May 200512 Feb 2013Microsoft CorporationSpatial scalability in 3D sub-band decoding of SDMCTF-encoded video
US837424520 Sep 200612 Feb 2013Microsoft CorporationSpatiotemporal prediction for bidirectionally predictive(B) pictures and motion vector prediction for multi-picture reference motion compensation
US837972221 Aug 200619 Feb 2013Microsoft CorporationTimestamp-independent motion vector prediction for predictive (P) and bidirectionally predictive (B) pictures
US840630029 May 200926 Mar 2013Microsoft CorporationVideo coding
US844210810 May 200514 May 2013Microsoft CorporationAdaptive updates in motion-compensated temporal filtering
US84935136 May 201123 Jul 2013Microsoft CorporationResampling and picture resizing operations for multi-resolution video coding and decoding
US86388534 Feb 201028 Jan 2014Microsoft CorporationVideo coding
Classifications
U.S. Classification348/416.1, 348/699, 348/384.1
International ClassificationH04N7/46, H04N7/50, H04N7/26
Cooperative ClassificationH04N19/00424, H04N19/00751
European ClassificationH04N7/26E2, H04N7/46T