Discrete wavelet transform of finite-length signals must necessarily handle the signal boundaries. The state-of-the-art approaches treat such boundaries in a complicated and inflexible way, using special prolog or epilog phases. This holds true in particular for images decomposed into a number of scales, exemplary in JPEG 2000 coding system. In this paper, the state-of-the-art approaches are extended to perform the treatment using a compact streaming core, possibly in multi-scale fashion. We present the core focused on CDF 5 3 wavelet and the symmetric border extension method, both employed in the JPEG 2000. As a result of our work, every input sample is visited only once, while the results are produced immediately, i.e. without buffering.
Since this work is based on our previous works in @cite_0 @cite_15 @cite_20 , it should be explained what the difference between this work and the referenced papers is. In @cite_0 , we formulated two-dimensional cores using a different notation. However, they were not designed for any effective treatment of signal boundaries. In @cite_15 @cite_20 , we have proposed DWT transform engine for JPEG 2000 encoders. Also in this work we have not overcame the problem with effective treatment of signal boundaries. Instead, we have introduced several buffers in order to circumvent the problem.
@cite_0 @cite_15 @cite_20
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A novel approach to 2-D single-loop wavelet lifting with compatibility to JPEG 2000 is presented in this paper. A newly developed 2-D core of CDF 5 3 wavelet filter is presented that, using a new sequence of operations, simplify the design. Moreover, the proposed approach, that uses one pass for 2-D transform, directly produces final output and reduces significantly the need for storing intermediate results into memory. All the proposed structures can be efficiently pipelined in hardware. This paper describes the proposed approach, its implementation in FPGA, cost of such implementation, and brings an experimental evaluation as well as discussion of the features of the approach. JPEG 2000 is an image coding system based on the discrete wavelet transform. Unfortunately, there exist several major issues with the effective implementation of the codec. For high resolution data decomposed by a separable transform, immensely many CPU cache misses occur. Following the procedure as defined in the standard, the coefficients of a single resolution appears all at once. Consequently, the entropy coder (EBCOT) needs to once again return to the data already touched. We present a software architecture designed for JPEG 2000 coders. The proposed method employs a strip-based data processing technique while it performs a single-pass multi-scale wavelet transform. The overall compression chain is driven by incoming data while the fragments of the resulting bitstream can be produced immediately after loading the corresponding data and additionally in parallel. The method is friendly to the CPU cache and can nicely exploit the SIMD extensions. We present a novel and very efficient software architecture designed for JPEG 2000 coders. The proposed method employs a strip-based data processing technique while performing a single-pass multi-scale wavelet transform. The overall compression chain is driven by incoming data while the fragments of the resulting bitstream are produced immediately after loading the corresponding data and additionally in parallel. The method is friendly to the CPU cache and nicely exploits the SIMD capabilities of the modern CPUs. Implanted into reference OpenJPEG implementation, our method has significantly better performance in terms of the execution time.