图像矩阵[122 68 117 151 115 141 123 153 87] x方向算子[-1 0 +1 -2 0 +2 -1 0 +1] y方向算子[+1 +2 +1 0 0 0 -1 -2 -1] Gx_temp1 = 117 + 141*2 + 87 = 486 Gx_temp2 = 122 + 151*2 + 123 = 547 Gx_data = 547-486