Title :
Indexing the output points of an LBVQ used for image transform coding
Author :
Khataie, Manijeh ; Soleymani, M.R.
Author_Institution :
Dept. of Electr. & Comput. Eng., Concordia Univ., Montreal, Que., Canada
fDate :
5/1/2000 12:00:00 AM
Abstract :
A new method for indexing the points of a lattice-based vector quantizer (LBVQ) used to quantize the DCT coefficients of images is presented. With this method, a large number of lattice points can be selected as codewords. As a result, the quality of the compressed data can be very high. The problem is that the large number of points results in a high bit rate. To reduce the bit rate, a shorter representation is assigned to the more frequently used lattice points. These points are grouped and a prefix code is used to index these lattice points. Our method outperforms JPEG, particularly, in the case of images with high frequency components
Keywords :
discrete cosine transforms; image coding; transform coding; vector quantisation; DCT coefficients quantization; JPEG; LBVQ; bit rate reduction; codewords; compressed data quality; high bit rate; high frequency components; image transform coding; lattice-based vector quantizer; output points indexing; prefix code; Bit rate; Discrete cosine transforms; Discrete transforms; Dynamic range; Entropy; Frequency; Image coding; Indexing; Lattices; Transform coding;
Journal_Title :
Image Processing, IEEE Transactions on
