Digital video quality at transmission over the noisy channel ( DCT and DWT - based codec )

نویسندگان

  • Matjaž Fras
  • Peter Planinšič
چکیده

Povzetek. Članek opisuje vpliv kvantizacijske stopnice na kakovost digitalnega videa pri transformacijskem kodiranju videosignala. Transformacijsko kodiranje smo izvedli enkrat s pomočjo diskretne kosinusne transformacije (DCT) in drugič z diskretno valčno transformacijo (DWT). Kodeka DCT in DWT smo implementirali v programskem paketu Matlab-Simulink. Simulirali smo vpliv kvantizacije na kakovost videosignala, prav tako pa smo proučili kakovost sprejetega digitalnega videosignala pri prenosu prek šumnega kanala. Če odmislimo pojav blokovnega efekta pri DCT-kodeku in efekt razmazanja pri DWT-kodeku zaradi kvantizacije, se pri prenosu digitalnega (kodiranega) videa preko prenosnega kanala poslabša njegova kakovost zaradi prisotnosti šumov. Pri DCT-kodeku je šum prenosnega kanala vplival na celoten kodiran blok, pri DWTkodeku pa le na okolico slikovnih elementov.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

A New Unequal Error Protection Technique Based on the Mutual Information of the MPEG-4 Video Frames over Wireless Networks

The performance of video transmission over wireless channels is limited by the channel noise. Thus many error resilience tools have been incorporated into the MPEG-4 video compression method. In addition to these tools, the unequal error protection (UEP) technique has been proposed to protect the different parts in an MPEG-4 video packet with different channel coding rates based on the rate...

متن کامل

Joint source-channel coding for motion-compensated DCT-based SNR scalable video

In this paper, we develop an approach toward joint source-channel coding for motion-compensated DCT-based scalable video coding and transmission. A framework for the optimal selection of the source and channel coding rates over all scalable layers is presented such that the overall distortion is minimized. The algorithm utilizes universal rate distortion characteristics which are obtained exper...

متن کامل

A Low-Complexity Joint Source-Channel Videocoding for 3-D DWT Codec

In this paper we propose a low-complexity errorresilient and joint source-channel video coding algorithms for video codec based on three-dimensional discrete wavelet transform (3-D DWT). First, we show that the video stream, generated by 3-D DWT codec with the proposed error-resilient, is significantly more robust to packet losses than video stream generated by scalable extension of the H.264/A...

متن کامل

Multiple Description Video Coding for Umts

We consider the problem of efficient real time video transmission over UMTS channels. Such a problem involves good compression rates and effectiveness in presence of channel failures. We propose a balanced MDC scheme for 3D scan-based DWT video coding. This MDC includes an efficient bit allocation procedure that dispatches the source video redundancy between the different channels[1, 2]. We pro...

متن کامل

Layered Wyner - Ziv Video Coding for Noisy Channels

Layered Wyner-Ziv Video Coding for Noisy Channels. (August 2004) Qian Xu, B.S., University of Science & Technology of China Chair of Advisory Committee: Dr. Zixiang Xiong The growing popularity of video sensor networks and video celluar phones has generated the need for low-complexity and power-efficient multimedia systems that can handle multiple video input and output streams. While standard ...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2008