Interpolation-free subpixel motion estimation techniques in DCT domain

Koc, Ut-Va; Liu, K.J.R.

doi:10.1109/76.709412

Cited by 23 publications

(10 citation statements)

References 34 publications

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“…4) and also since the noise power is given by the percentage of nonoverlapped area in each image, we can estimate the following upper bound for the noise variance in terms of image dimensions after down-sampling, i.e., and : (14) Similarly, a lower bound for the total signal power would be (15) These estimations are shown schematically in Fig. 4.…”

Section: B Estimating the Sum Of Polyphase Componentsmentioning

confidence: 99%

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Extension of phase correlation to subpixel registration

Foroosh

Zerubia

Berthod

2002

IEEE Trans. on Image Process.

837

517

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Abstract-In this paper, we have derived analytic expressions for the phase correlation of downsampled images. We have shown that for downsampled images the signal power in the phase correlation is not concentrated in a single peak, but rather in several coherent peaks mostly adjacent to each other. These coherent peaks correspond to the polyphase transform of a filtered unit impulse centered at the point of registration. The analytic results provide a closed-form solution to subpixel translation estimation, and are used for detailed error analysis. Excellent results have been obtained for subpixel translation estimation of images of different nature and across different spectral bands.

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Section: B Estimating the Sum Of Polyphase Componentsmentioning

confidence: 99%

“…There are also other techniques that are based on the local normalized correlation [1], polynomial regression [32], the discrete cosine transform [15], and the use of control points using a model-based approach [7].…”

Section: Introductionmentioning

confidence: 99%

Extension of phase correlation to subpixel registration

Foroosh

Zerubia

Berthod

2002

IEEE Trans. on Image Process.

837

517

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“…With the assumption that and have zero mean and are independent from quantization error of blocks (24) The error variance increases in real case and the MSE becomes (25) …”

Section: Quality Enhancement For Real Video Sequencesmentioning

confidence: 99%

“…The MSE between the reconstructed and original blocks is calculated as in (25) for all cases of backward motion vectors from (0,0) to (7,7) and forward motion vectors from to (0,0). These MSE values are shown in Fig.…”

Section: A Motion Vectors For Enhancement Processmentioning

confidence: 99%

Quality Enhancement for Motion JPEG Using Temporal Redundancies

Võ

Nguyen

2008

IEEE Trans. Circuits Syst. Video Technol.

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The paper proposes a pixel-based post-processing algorithm to enhance the quality of motion JPEG (MJPEG) by exploiting the temporal redundancies of the decoded frames. The technique permits reconstruction of the high frequency coefficients lost during quantization, thereby reducing ringing artifacts. Based on the linearization of the quantization function, the error between the estimated and original coefficients is analyzed for both cases of ideal and real video sequences. Blocking artifact reduction is verified by a reduction in the variance of this coefficient error. The condition of valid motion vectors to get quality improvement is considered based on these errors. The algorithm is also extended to find the optimal filter for a general estimation scheme based on an arbitrary number of frames. Results in visual and peak signal-to-noise ratio improvement using both integer and subpixel motion vectors are verified by simulations on video sequences.Index Terms-Blocking artifact, discrete cosine transform (DCT), motion JPEG (MJPEG), quantization error, ringing artifact.

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“…The alternative fully DCT-based video coder and decoder architectures, as shown in Figures 2a and 2b, respectively, have been proposed and explored in [5,6,7,8] structures. In the fully DCT-based video codec, motion estimation and compensation are performed on the compressed bit stream in the transform (DCT) domain, and thus these functional blocks are called transform-domain motion estimator (TD-ME) and transform-domain motion compensator (TD-ME), respectively, to be distinguished from their spatial-domain counterparts.…”

Section: Introductionmentioning

confidence: 99%

Motion Compensation on DCT Domain

Koc¹,

Liu

2001

EURASIP J. Adv. Signal Process.

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Alternative fully DCT-based video codec architectures have been proposed in the past to address the shortcomings of the conventional hybrid motion compensated DCT video codec structures traditionally chosen as the basis of implementation of standardcompliant codecs. However, no prior effort has been made to ensure interoperability of these two drastically different architectures so that fully DCT-based video codecs are fully compatible with the existing video coding standards. In this paper, we establish the criteria for matching conventional codecs with fully DCT-based codecs. We find that the key to this interoperability lies in the heart of the implementation of motion compensation modules performed in the spatial and transform domains at both the encoder and the decoder. Specifically, if the spatial-domain motion compensation is compatible with the transform-domain motion compensation, then the states in both the coder and the decoder will keep track of each other even after a long series of P-frames. Otherwise, the states will diverge in proportion to the number of P-frames between two I-frames. This sets an important criterion for the development of any DCT-based motion compensation schemes. We also discuss and develop some DCT-based motion compensation schemes as important building blocks of fully DCT-based codecs. For the case of subpixel motion compensation, DCT-based approaches allow more accurate interpolation without any increase in computation. Furthermore, a scare number of DCT coefficients after quantization significantly decreases the number of calculations required for motion compensation. Coupled with the DCT-based motion estimation algorithms, it is possible to realize fully DCT-based codecs to overcome the disadvantages of conventional hybrid codecs.

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Interpolation-free subpixel motion estimation techniques in DCT domain

Cited by 23 publications

References 34 publications

Extension of phase correlation to subpixel registration

Extension of phase correlation to subpixel registration

Quality Enhancement for Motion JPEG Using Temporal Redundancies

Motion Compensation on DCT Domain

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