| 摘要 |
<p>The decompression method includes the steps of receiving the encoded quantised transform coefficient blocks for the original image, removing any lossless encoding of the quantised transform coefficient blocks for the original image and multiplying each quantised transform coefficient in a block by a corresponding quantising value from the quantisation table to obtain a block of received transform coefficients. The image is recovered by applying an inverse transform operation to the received transform coefficients and adaptively selecting on a block by block basis a filter threshold. Edges within the block are detected and a mapping of the edges is formed. The image is iteratively filtered for a set number of times with a smoothing filter, the filtering operation controlled by the derived edge map so as not to operate on image edges. Each block of new transform coefficients is compared to a corresponding block of received transform coefficients and the selected quantisation table, to determine whether the filtered recovered image is derivable from the original image. Upon the determination being made, the filtered recovered image is transferred to an output buffer.</p> |
