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COMPARATIVE STUDY OF H.264 INTRA FRAME CODING, JPEG, JPEG-LS, JPEG-2000 AND JPEG-XR. EE 5359 Multimedia Project -Shreyanka Subbarayappa Electrical Engineering Department. Need for Compression.
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COMPARATIVE STUDY OF H.264 INTRA FRAME CODING, JPEG, JPEG-LS, JPEG-2000 AND JPEG-XR EE 5359 Multimedia Project -Shreyanka Subbarayappa Electrical Engineering Department
Need for Compression • Reduce redundancy of the image or video data in order to be able to store or transmit data in an efficient form. • Compressed video can effectively reduce the bandwidth required to transmit video via terrestrial broadcast, via cable TV, or via satellite TV services • Increasing importance of multimedia communication NEED FOR IMAGE OR VIDEO COMPRESION
Lossless or Lossy Compression • Lossless compression • There is no information loss, and the image can be reconstructed exactly the same as the original • Applications: Medical imagery, Archiving • Lossy compression • Information loss is tolerable. • Applications: commercial distribution (DVD) and rate constrained environment where lossless methods cannot provide enough compression ratio
JPEG ENCODER AND DECODER ENCODER [12] DECODER[12]
JPEG-Baseline • The name "JPEG" stands for Joint Photographic Experts Group. • 8x8 block based DCT • Scalar quantization • Different quantization tables for luminance and chrominance components • Huffman coding • JPEG2000 • Extensions are .jp2, .j2k, .jpf, .jpx, .jpm,.mj2 • Relies on wavelet transform • Another difference, in comparison with JPEG, is in terms of visual artifacts JPEG 2000 produces ringing artifacts. The codestream obtained after compression of an image with JPEG 2000 is scalable in nature, meaning that it can be decoded in a number of ways; for instance, by truncating the codestream at any point.
JPEG-LS • It uses a predictive scheme based on the three nearest (causal) neighbors (upper, left, and upper-left. • The lossless coding process employs a simple predictive coding model called differential pulse code modulation (DPCM) • Once all the samples are predicted, the differences between the samples can be obtained and entropy-coded in a lossless fashion using Huffman coding or arithmetic coding. Block Diagram of JPEG-LS Encoder [13] • JPEG-XR • JPEG XR (Joint Photographic Experts Group- Extended Range) was formerly known as Windows Media Photo and HD Photo • File extensions are given as .hdp, .jxr, .wdp • HD Photo uses a type of integer transform employing a lifting scheme, which resembles a 4 × 4 DCT but is lossless (exactly invertible).
H.264 BLOCK DIAGRAM Encoder[14]
H.264/MPEG-4 AVC • H.264/MPEG-4 AVC is a block-oriented motion-compensation-based codec standard developed by the ITU-T Video Coding Experts Group (VCEG) together with the ISO/IEC Moving Picture Experts Group (MPEG) • Provides good video quality at substantially lower bit rates than previous standards. • H.264 is used in such applications as players for Blu-ray Discs, videos from YouTube and the iTunes Store, web software such as Adobe Flash Player and Microsoft Silverlight.
Image Quality Measures • Criteria to evaluate compression quality • Two types of quality measures Objective quality measure- PSNR, MSE Structural quality measure- SSIM • MSE and PSNR for a NxM pixel image are defined as (1) (2) where x is the original image and y is the reconstructed image. M and N are the width and height of an image and ‘L’ is the maximum pixel value in the NxM pixel image.
Structural Similarity Method[SSIM] • SSIM emphasizes that the human visual system is highly adapted to extract structural information from visual scenes. Therefore, structural similarity measurement should provide a good approximation to perceptual image quality. • The SSIM index is defined as a product of luminance (l), contrast (c) and structural (s) comparison functions. • ….[1] • where , α>0, β>0 and γ >0 are parameters used to adjust the relative importance of the three components
…[2] ….[3] • where μ is the mean intensity, and σis the standard deviation as a round estimate of the signal contrast. C1 and C2 are constants. M is the number of samples in the quality map.
References [1] AIC website: http://www.bilsen.com/aic/ [2] T. Wiegand, G. Sullivan, G. Bjontegaard and A. Luthra, “Overview of the H.264/AVC Video Coding Standard”, IEEE Transactions on Circuits and Systems for Video Technology, vol. 13, pp.560-576, July 2003 [3] K. Sayood, “Introduction to Data Compression”, Third Edition, Morgan Kaufmann Publishers, 2006. [4] P. Topiwala, T. Tran and W.Dai, “Performance comparison of JPEG2000 and H.264/AVC high profile intra-frame coding on HD video sequences,” Proc. SPIE Int’l Symposium, Digital Image Processing, San Diego, Aug. 2006. [5] G. K. Wallace, “The JPEG still picture compression standard,” Communication of the ACM, vol. 34, pp. 31-44, April 1991. [6] I. Richardson, “The H.264 advanced video compression standard”, Wiley publication, 2nd edition, 2010.
[7] JPEG reference software website: ftp://ftp.simtel.net/pub/simtelnet/msdos/graphics/jpegsr6.zip [8] JPEG2000 latest reference software (Jasper Version 1.900.0) Website: http://www.ece.uvic.ca/~mdadams/jasper/ [9] JPEG-LS reference software website http://www.hpl.hp.com/loco/ [10] Microsoft HD photo specification: http://www.microsoft.com/whdc/xps/wmphotoeula.mspx [11] H.264/AVC reference software (JM 17.2) Website: http://iphome.hhi.de/suehring/tml/download/ [12] JPEG Encoder and Decoder Block Diagram : http://www.cmlab.csie.ntu.edu.tw/cml/dsp/training/coding/jpeg/jpeg/decoder.htm [13] JPEG-LS Block Diagram: http://pam.wikipedia.org/wiki/Lossless_JPEG [14] H.264 Encoder Block Diagram : http://conf.ncku.edu.tw/research/articles/e/20071102/2.html
[15] H.264 Decoder Block Diagram : http://www.allgosystems.com/html/h264_arm11.htm [16]A.Skodras, C. Christopoulos and T. Ebrahimi, “The JPEG 2000 still Image Compression Standard”, IEEE Signal Processing, vol.17, pp.1-144, Jan. 2002. [17] M. J. Weinberger, G. Seroussi, G. Sapiro, “The LOCO-I lossless image compression algorithm: principles and standardization into JPEG-LS”, IEEE Trans. on Image Processing, vol.9, pp.1309-1324, Aug. 2000. [18] C. Christopoulos, A. Skodras, T.Ebrahimi, “The JPEG2000 still image coding system: an overview”, IEEE Trans. on Consumer Electronics, vol.46, pp.1103-1127, Nov. 2000. [19] G. K. Wallace, “The JPEG still picture compression standard,” Communication of the ACM, vol. 34, pp. 31-44, April 1991. [20] P. Schelkens, A. Skodras and T. Ebrahimi, “The JPEG 2000 suite”, Hoboken, NJ: Wiley, 2009. [21] P. Topiwala, “Comparative study of JPEG2000 and H.264/AVC FRExt I-frame coding on high definition video sequences,” Proc. SPIE Int’l Symposium, Digital Image Processing, vol. 5909, issue.1, San Diego ,Aug. 2005.