公开(公告)号：US5790269A

公开(公告)日：1998-08-04

申请号：US570765

申请日：1995-12-12

申请人： Ichiro Masaki ,  Ujjaval Desai ,  Anantha Chandrakasan ,  Berthold Horn

发明人： Ichiro Masaki ,  Ujjaval Desai ,  Anantha Chandrakasan ,  Berthold Horn

IPC分类号： G06T9/20 ,  H04N7/26 ,  H04N1/40

CPC分类号： G06T9/20 ,  H04N19/20

摘要： Edge or contour information is extracted from an image array by filtering and encoded. In order to improve reproduction accuracy, two separate filters are used to detect edge information. One of the filters detects "sharp" edges, or edges in which the discontinuity in pixel intensity values occurs over a range of a few pixels. The other filter detects "level" edges in which the pixel intensity value discontinuity occurs over a larger range of pixels than the "sharp" edges. The "smooth" areas between edges or contours are assumed to vary continuously between the contours, but for efficient implementation, a one-dimensional linear interpolation is used to regenerate the contour information between edges. In addition, to further improve performance, a line is fitted to the pixel intensity data. The end values of this line are then used for the pixel intensity data. In order to still further improve performance, the pixel intensity values associated with each contour are divided into groups and each group is then encoded. Another improvement is accomplished by mean coding the residual error.

摘要翻译： 通过滤波和编码从图像阵列中提取边缘或轮廓信息。 为了提高再现精度，使用两个单独的滤波器来检测边缘信息。 其中一个滤波器检测“锐利”边缘，或者在几个像素范围内发生像素强度值不连续性的边缘。 另一个滤波器检测到像素强度值不连续发生在比“锐利”边缘更大的像素范围内的“电平”边缘。 假设边缘或轮廓之间的“平滑”区域在轮廓之间连续变化，但是为了有效实现，使用一维线性内插来重新生成边缘之间的轮廓信息。 此外，为了进一步提高性能，将线条拟合到像素强度数据。 然后将该行的结束值用于像素强度数据。 为了进一步提高性能，将与每个轮廓相关联的像素强度值分成组，然后对每个组进行编码。 另一个改进是通过平均编码残差来实现的。