Um esquema de codificação adaptativa de imagens usando transformada cosseno discreta

AUTOR(ES)
DATA DE PUBLICAÇÃO

2001

RESUMO

Initial image coding studies with conventional VQ have shown some problems such as edge degradation and highly computational complexity. One new efficient method of adaptive coding using Fast Discrete Cosine Transform (FDCT) which reduces image compression rate is proposed. This method is based on composite source model, which helps in reduction of degradation effects. The blocks are analyzed according to their ac energy level and ordered in classes according to its activity level. Each class with its distinct perceptual characteristics, such as edge, are generated. One classifier determines the subclass of each block according to the present edge orientation of the same block. The adaptativity is obtained through the bits distribution between the classes, favoring the class of higher activity level. We have proved that with this proposed method, we can get visual image quality of the same produced quality by the existent coders of the bit rate of 1 bit/pixel but we get better Signal to Noise Ratio.

ASSUNTO(S)

compressão de imagens transmissão de imagem compressão de dados (telecomunicações)

ACESSO AO ARTIGO

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