DCT approximation for low bit rate coding using a conditional transform
نویسنده
چکیده
A transform approximation is explored for speeding up the software compression of images and video. It is used to replace the regular DCT whenever only few DCT coefficients are actually encoded. A conditional transform is proposed to only transform the data that it determines to be relevant. The approximation is applicable to environments combining the requirements of high compression and low complexity.
منابع مشابه
Projection methods in motion estimation and compensation
The standard approach to exploiting motion elds in block-based hybrid video coding schemes is motion compensation of the current frame using the motion eld, followed by DCT coding of the residue. In this paper we argue that this separation of approximation methods (non-linear prediction followed by transform coding) is unfortunate in low bit-rate applications. In low bit-rate applications, only...
متن کاملA Digital Hardware Fast Algorithm and FPGA-based Prototype for a Novel 16-point Approximate DCT for Image Compression Applications
The discrete cosine transform (DCT) is the key step in many image and video coding standards. The 8-point DCT is an important special case, possessing several low-complexity approximations widely investigated. However, 16-point DCT transform has energy compaction advantages. In this sense, this paper presents a new 16-point DCT approximation with null multiplicative complexity. The proposed tra...
متن کاملWarped Discrete Cosine Transform-Based Low Bit-Rate Block Coding Using Image Downsampling
This paper presents warped discrete cosine transform (WDCT)-based low bit-rate block coding using image downsampling.While WDCT aims to improve the performance of conventional DCT by frequency warping, the WDCT has only been applicable to high bit-rate coding applications because of the overhead required to define the parameters of the warping filter. Recently, low bit-rate block coding based o...
متن کاملScalable Image Coder Mixing DCT and Triangular Meshes
In this paper a new very low bit rate scalable encoding principle is presented. It is based on hierarchical triangular mesh encoding combined with triangle based DCT coding. Affine or DCT approximation is selected according to best rate distorsion trade-off. In this way our coder demonstrates advantages at very low bit rates avoiding the traditional block or ringing artefacts of current DCT or ...
متن کاملHybrid Dct/wavelet I-frame Coding for Efficient H.263+ Rate Control at Low Bit Rates
At low bit rates, the bit budget for I-frame coding in H.263+ can be too high to be practical. A hybrid DCT/wavelet transform based I-frame coding is proposed in this work as a solution to the rate control problem. This new coder is compatible with the H.263+ bit stream syntax, and aims at an R-D optimized performance with a reasonable amount of computational complexity. By employing fast estim...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2002