Image Data Compression Using 2-Level Weighted Vector Quantization

Image Compression Using Hybrid Vector Quantization

In this paper, image compression using hybrid vector quantization scheme such as Multistage Vector Quantization (MSVQ) and Pyramid Vector Quantization (PVQ) are introduced. A combined MSVQ and PVQ are utilized to take advantages provided by both of them. In the wavelet decomposition of the image, most of the information often resides in the lowest frequency subband. MSVQ is applied to significa...

Image Compression Using Learned Vector Quantization

This paper presents a study and implementation of still image compression using learned vector quantization. Grey scale, still images are compressed by 16:1 and transmitted at 0.5 bits per pixel, while maintaining a peak signal-to-noise ratio of 30 dB. The vector quantization is learned using Kohonen’s self organizing feature map (SOFM). While not only being representative of the training set, ...

Vector Quantization for Image Compression-Concept Quantization

Vector Quantization Based Image Compression

An image compression method combining discrete wavelet transform (DWT) and vector quantization (VQ) is presented. First, a three-level DWT is performed on the original image resulting in ten separate sub bands. These sub bands are then vector quantized. VQ indices are Huffman coded to increase the compression ratio. Lloyd extended scalar quantization technique is used to design memory less vect...

Speech Data Compression using Vector Quantization

Mostly transforms are used for speech data compressions which are lossy algorithms. Such algorithms are tolerable for speech data compression since the loss in quality is not perceived by the human ear. However the vector quantization (VQ) has a potential to give more data compression maintaining the same quality. In this paper we propose speech data compression algorithm using vector quantizat...