| 摘要 |
<p>PURPOSE: To obtain an image quality of ideal fast image reproduction by adaptively extracting image data of an appropriate amount through an I frame according to a record space, which is allocated with the degree of complication of image contents and corresponding fast image reproduction data. CONSTITUTION: First, an image in an I frame is divided into plural blocks consisting of 8×8 pixels. A DCT coefficient of one series is taken after each block undergoes discrete cosine transformation, and the DCT coefficient consists of one DC coefficient and an AC coefficient of many runs. In the case of image recording, a DC coefficient and AC coefficient of only one run are extracted from a tape for fast image reproduction. After comparing an extracted AC coefficient with one preset threshold, what holds the coefficient is eliminated.</p> |
