Patent ID: 7113645

Claim:
An image decompression apparatus, comprising: an input unit to input a code sequence of wavelet coefficients; a decoding unit to decode the input code sequence; an inverse-quantization unit to perform inverse-quantization on the decoded wavelet coefficients; an inverse-wavelet-transform unit to perform inverse wavelet transform on the inverse-quantized wavelet coefficients so as to obtain pixel values; a control unit to control operations of the input unit, the decoding unit, the inverse-quantization unit, and the inverse wavelet transform unit to limit operations into those such that a decompressed image of a specific LL subband be obtained therefrom; a display region specifying unit to specify a display region on a predetermined display device using a number of pixels in a vertical direction or a number of pixels in a horizontal direction; and a decomposition level determining unit to determine a decomposition level, on which level the specific LL subband occurs, based on the display region specified by the display region specifying unit.