DESC:Field of the invention:
The present invention relates to the field of a method for scalable video coding using a wavelet based error resilient probabilistic approach for heterogeneous display devices with varied bit rate, quality and resolutions support.

Background of the invention:
Advances in video coding technology and standardization along with the rapid developments and improvements of network infrastructures, storage capacity, and computing power are enabling an increasing number of video applications. Highly scalable compression imposes an important restriction on the encoder. Specifically, it must operate without prior knowledge of the rate at which the compressed video will be decoded. For this reason, the predictive feedback paradigm inherent in traditional motion-compensated video compression algorithms is fundamentally incompatible with highly scalable compression [14]. Hence is desired to have efficient video coder for such video applications where the end-users are required to have various capabilities.
Prior art:
Traditional DCT based spatial compression and MC/DCT temporal coding schemes proved to be inadequate for scalable video coding. These techniques are replaced by wavelet sub-band decomposition in spatio-temporal domain to explore efficient compression and coding gain [1][2]. Using the wavelet transforms, scalability is greatly improved and expanded in the JPEG 2000 standard [5][6].Generally SVC is realized with layered coding,[3][4] each successive bit stream layer incrementally enhances the image/video signal recovered from the accumulated previous layers in resolution level and/or pixel accuracy. Containing an error-feed-back loop from hybrid coding, SNR and resolution scalable video coding standardized in MPEG-2, 4 [7] [8] [9] and H.263 [10] are troubled by `drift', and a significant loss in compression. Scalability supported in MPEG-4 has no substantial improvement over earlier standards [15]. Recent breakthroughs in motion-compensated temporal wavelet filtering (MCTF), which entirely abandons any recursion in encoding and decoding, have finally enabled implementation of highly efficient scalable video codecs [16].
To, Pickering and Frutec [17] proposed a new measure of motion confidence based on phase information from Fourier transform of a video frame. Using this measure, blocks associated with unreliable motion estimation are detected efficiently and accurately. Block matching motion estimation scheme in the probabilistic framework as a Maximum Likelihood estimation scheme is demonstrated [18] along with confidence measures in terms of the posterior probabilities and the likelihoods of the estimated vectors. Various attacks on the encoded bit stream during transmission are expected to be anticipated while video coding for reliable transmission [11]. EBCOT [13] exhibits state-of-the-art compression performance while producing a bit-stream with a rich set of features, including resolution and SNR scalability together with a “random access” property. Lifting schemes in wavelets adopted by Sweden [19], Taubman [14] proved it’s effectiveness by reducing ringing artifacts at low bit rate and decrease in computation workload with result in subsequent fast implementation. Taubman further in LIMAT [14] Framework provided a flexible solution to most challenging motion modeling problem by deploying deformable mesh model against traditional block based motion model This calls for encoding motion information differently than existing methods. As against of conventional block matching based approach for motion estimation, probabilistic approach proved to be reliable as motion confidence measure[18] and robust against error theoretically. Review reported in above section reveals the inadequacy of scalable extension with existing video standards and need to elevate the approaches for motion estimation for reliable motion modeling to facilitate scalable video coding efficiently.

Therefore, there is a need to provide a method for scalable video coding using a wavelet based error resilient probabilistic approach for heterogeneous display devices with varied bit rate, quality and resolutions support.

Object of the invention:
Object of the present invention is to provide a method for scalable video coding: a wavelet based error resilient probabilistic approach.

Another object of the present invention is to provide a method for scalable video coding: a wavelet based error resilient probabilistic approach, which provides a solution to the problems posed by the characteristics of modern video transmission systems, heterogeneous display devices, varied bit rate, quality and resolution.
Yet another object of the present invention is to provide a method for scalable video coding: a wavelet based error resilient probabilistic approach, which provides a probabilistic model for motion estimation that supports for error resilient coding.

Summary of the invention
The present invention is a method for scalable video coding using a wavelet based error resilient probabilistic approach for heterogeneous display devices with varied bit rate, quality and resolutions support, the method comprising steps of processing the video stream by using a system by using a parameter unsupervised model, acquiring channel parameters by using mixture model, updating algorithm for making scalable bit streams error resilient, computing the error parameters, and using stochastic approximation for mapping uncertainties leads to efficient error resilient video encoding.

Brief description figures:
The advantages and features of the present invention will be better understood with reference to the following detailed description and claims taken in conjunction with the accompanying drawings, wherein like elements are identified with like symbols, and in which:

Figure 1 shows a schematic diagram of a unique bit stream produced by the Coder;

Figure 2 shows error propagation in base and enhancement layer for
50 % spatial-50 % temporal;

Figure 3 shows error propagation in base and enhancement layer for
90 % spatial-50 % temporal;

Figure 4 shows error propagation in base and enhancement layer for
90 % spatial-90 % temporal;

Figure 5 shows error propagation in base and enhancement layer for
90 % spatial-10 % temporal;

Figure 6 shows error propagation in base and enhancement layer for
10 % spatial-90 % temporal;

Figure 7 shows error propagation in base and enhancement layer for
50 % spatial-50 % temporal error with Quantization step size varied from 5 to 30 for bus sequence;

Figure 8 shows error propagation in base and enhancement layer for 50 % spatial-50 % temporal error with Quantization step size varied from 5 to 30 for football sequence;

Figure 9 shows error propagation in base and enhancement layer for
90 % spatial-50 % temporal error with Quantization step size varied from 5 to 30 for bus sequence;

Figure 10 shows error propagation in base and enhancement layer for
90 % spatial-50 % temporal error with Quantization step size varied from 5 to 30 for football sequence;

Figure 11 shows error propagation in base and enhancement layer for
90 % spatial-90 % temporal error with Quantization step size varied from 5 to 30 for bus sequence;

Figure 12 shows error propagation in base and enhancement layer for
50 % spatial-50 % temporal error with Quantization step size 5, intra frequency change from 25 to 50 for bus sequence and

Figure 13 shows error propagation in base and enhancement layer for
50 % spatial-50 % temporal error with Quantization step size 5, intra frequency change from 25 to 50 for football sequence in accordance with the present invention.

Detailed description of the invention:
An embodiment of this invention, illustrating its features, will now be described in detail. The words "comprising," "having," "containing," and "including," and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items.
The terms “first,” “second,” and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another, and the terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.
The disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms.The present invention provides modeling of all Indian instruments and in a later stage the synthesis of the instruments is the key area of research which is not been explored to a great extent in the present scenario.
The present invention is a method for scalable video coding: a wavelet based error resilient probabilistic approach. The method for scalable video coding: a wavelet based error resilient probabilistic approach provides a solution to the problems posed by the characteristics of modern video transmission systems, heterogeneous display devices, varied bit rate, quality and resolution. Further, the method for scalable video coding: a wavelet based error resilient probabilistic approach provides a probabilistic model for motion estimation that supports for error resilient coding.

Now referring to figure 1, a method (hereinafter referred as “method 100”) and method for scalable video coding: a wavelet based error resilient probabilistic approach in accordance with the present invention is illustrated. The Scalable Video Coding (SVC) is a solution to the problems posed by the characteristics of modern video transmission systems, heterogeneous display devices, varied bit rate, quality and resolution support. Proposed probabilistic motion estimation method 100 works as follows:

The first step of the method 100 is processing the video stream using the parametric unsupervised model.
=
At step two, mixture model is adapted to quantify the channel parameters.


= arg max
= arg max
At step three, an algorithm for making scalable bit streams error resilient is updated.

P

At step six, computation of error Parameter is done initial estimates.




At step seven, a stochastic approximation is used for mapping uncertainties that leads to efficient error resilient video encoding.

The method 100 is used in experimentation, which is designed to observe and analyze the effect of error propagation in DCT based layered scalable implementation on quality of decoded frame with time/frame progression. Spatio-temporal scalability through base layer and enhancement layer coding with different frame resolution for spatial, different frame rate and block size for temporal is achieved. Resolution of frame used in base layer (BL) is 176 X 120 (QCIF) and enhancement layer (EL) is 352 X 240 (CIF). Error is introduced in base layer with different spatial and temporal proposition. Two standard test sequences viz. bus and football with characteristics of uniform motion and a low level of detail and high level of motion and a high level of detail is used. In line with the aim mentioned, experimentation is divided in two sets.
Set #1. With coding parameters constant, (intra frequency=25, quantization step size (q) =5, error introduced on 5th frame) proposition of percentage spatial and temporal error is varied from 10% to 90% and effect on error propagations on enhancement layer is observed.
Set #2. With fixed proposition of spatial and temporal error (50%), effect of change in coding parameters (intra frequency=25 to 50, quantization step size (q) =5 to 30) towards error propagation is observed.
Result and discussion of the experiment using method 100:
Comparative analysis of error propagation through layered scalable coder for two test sequences with different spatio-temporal characteristics mentioned in section IV is presented in this section. First the result on experimentation performed with methodology mentioned in Set #1 is discussed.
Referring now to figures 2 through figure 6, Spatial error is dominant (drop in PSNR) in BL and temporal error (variation of PSNR with frame progression)is in EL. Increase in Spatial error drops PSNR and increase in temporal error causes variation of PSNR as frame progresses. For low activity sequence (bus) dominance of spatial error is observed as against of temporal because of narrow spread of DCT spectrum bus sequence plot on left hand side. For high activity sequence (football) dominance of temporal error is observed as against of spatial because of wide spread of DCT spectrum football sequence plot on right hand side. Hence there is a need for better representation in spatial as well as temporal domain from the point of view of mapping uncertainties independently. Proposed probabilistic model in section III attempts to represent uncertainty in source information in spatial and temporal domain effectively.

Referring now to figures 7, 9 and 11, with reference to experimentation mentioned in Set #2 effect of coding parameter changes on the reconstruction quality is as follows: Effect of change in quantization step size is not observed in low spatial and activity sequence (bus). Variation in quantization step size has influence in high spatial and activity sequence (football) as shown in Figures 8 and10. Coarser quantization will limit PSNR variation but loose many details in the reconstruction good for low bandwidth budget channel. More the intra frequency less the effect of temporal error propagation, as shown in Figures 12 and Figure 13. This is because more the intra frequency less the times frame will be intra coded as a result of which prediction nearby intra coded frame will be less random. The actual accumulated error amount depends on the quantizer design and the intermediate operations between consecutive coding passes. This is also because of the fact that spatial and temporal error concealment technique adopted in coder uses distinct information instead of unified. error propagation in base and enhancement layer for 50 % spatial-50 % temporal error with Quantization step size 5, intra frequency change from 25 to 50 for football sequence as shown in figure 13.

Conclusion of the experimentation:
DCT and MC, popular video compression algorithms are in general not error-accumulation-free in layered coding. From the result discussed in section V it is evident that motion information achieved from conventional block based motion estimation is not suitable for scalable video encoding especially in error prone environment. As in scalable coder a priori information about decoder is missing, change in reconstruction quality with change in coding parameter as demonstrated in result is a threat to deploy conventional motion estimation schemes. This work demonstrates the motion estimation performed in probabilistic sense as modeled in section III.
Thus, with unified spatio-temporal transform, such as, wavelet along with mapping; the uncertainties in successive frames independently with probabilistic approach lead to efficient error resilient scalable video encoding.

The present invention is a method for scalable video coding: a wavelet based error resilient probabilistic approach. The method for scalable video coding: a wavelet based error resilient probabilistic approach provides a solution to the problems posed by the characteristics of modern video transmission systems, heterogeneous display devices, varied bit rate, quality and resolution. Further, the method for scalable video coding: a wavelet based error resilient probabilistic approach provides a probabilistic model for motion estimation that supports for error resilient coding.

The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention.

,CLAIMS:We Claim:
1. A method for scalable video coding using a wavelet based error resilient probabilistic approach for heterogeneous display devices with varied bit rate, quality and resolutions support, the method comprising steps of:
processing the video stream by using a system by using a parameter unsupervised model;
acquiring channel parameters by using mixture model;
updating algorithm for making scalable bit streams error resilient, and
computing the error parameters, and
using stochastic approximation for mapping uncertainties leads to efficient error resilient video encoding.