Title :
Reduction of blocking artifacts by a modeled lowpass filter output
Author :
Cho, Nam Ik ; Roh, Bong Gyun ; Lee, Sang Uk
Author_Institution :
Sch. of Electr. Eng., Seoul Nat. Univ., South Korea
Abstract :
This paper proposes an algorithm for the reduction of blocking artifacts in the transform coded images and videos. The algorithm is based on the filtering of block boundaries. But, the proposed technique is not the actual filtering in the sense that the output is not obtained by multiplying the pixel values with the filter coefficients. Instead of filtering the pixel values through the filter coefficients, the output of the filter is modeled as a typical step response function of the lowpass filter or a functions with similar shapes. Then the blocky signal is just replaced by the modeled output signal which is generated by the library function such as exp or sin. The algorithm can be easily implemented by a lookup-table and very few multiplications, while the objective and subjective performance is comparable to those of other algorithms based on the conventional filtering and POCS (projection onto convex sets)
Keywords :
block codes; discrete cosine transforms; filtering theory; image coding; image enhancement; low-pass filters; step response; table lookup; transform coding; video coding; JPEG images; artifacts reduction algorithm; block DCT; blocking artifacts reduction; filtering of block boundaries; image enhancement; library function; lookup-table; modeled lowpass filter output; step response function; transform coded images; Adaptive filters; Discrete transforms; Filtering algorithms; Image coding; Image enhancement; Image restoration; Libraries; Shape control; Signal generators; Videos;
Conference_Titel :
Circuits and Systems, 2000. Proceedings. ISCAS 2000 Geneva. The 2000 IEEE International Symposium on
Conference_Location :
Geneva
Print_ISBN :
0-7803-5482-6
DOI :
10.1109/ISCAS.2000.858841