Sony Corporation

Takunari Inagaki

Katsuharu Shimura

Rui Miyamoto

This apparatus performs search for a bit plane where the first significant coefficient appears, as preprocessing of EBCOT coding processing of JPEG2000. This apparatus has a register for holding bit position data for each code block. In this apparatus, a code block of absolute value data of each inputted wavelet coefficient is identified and OR of the inputted absolute value data and the bit position data stored in the register is calculated. In this apparatus, the result of the calculation is stored again into the register as new bit position data. In this apparatus, the above-described OR calculation is performed to all the data in a wavelet transform area as a coding target, and the most significant bit plane of bit planes including a bit having a valid value is calculated for each block on the basis of the ultimately obtained bit position data.

Bit plane coding apparatus

An image compression controller capable of simplifying the quantization coefficient control in an image compression process and attaining a high speed In image compression, including a first quantization circuit for first quantization based on a quantization coefficient on an output signal from a DCT circuit, a second quantization circuit for second quantization based on a second quantization coefficient, counters for counting the number of &ldquo;0's&rdquo; in the first quantization data, a quantization coefficient control circuit for generating a plurality of reference control coefficients and generating control coefficients based on counts of the counters and a &ldquo;0&rdquo; reference value, a first multiplier for generating a first quantization coefficient based on a reference quantization coefficient and a reference control coefficient, a second multiplier for generating a second quantization coefficient based on a control coefficient and a reference quantization coefficient, and an entropy coding circuit for entropy coding on the second quantization data.

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Saitama, Japan

Takunari Inagaki