摘要 |
<p>A pixel map signal is converted into a coefficient signal of block coefficient signals, each representing the pixels in a pixel map block (420) with the coefficients in a hybrid polynomial. The hybrid polynomial contains discrete cosine terms, a constant term separated from the discrete cosine terms, and polynomial terms. Each block coefficient signal contains a background component representing a coefficient of the constant term, a linear component representing the coefficients of the polynomial terms, and a nonlinear component representing the coefficients of the discrete cosine terms. The background component represents constant, unchanging pixel values in a pixel map block (420), the linear component represents linearly changing pixel values in a pixel map block (420), and the nonlinear component represents nonlinear patterns in a pixel map block (420).</p> |