clock_t start = clock();
When using the probability matrix to pick from the candidate set, it is important that the candidate array be sorted in advance. Not doing so will fail to preserve the patterns distinctive of ordered dithering. A good approach is to sort the candidate colours by luminance, or the measure of a colour’s lightness4. When this is done, we effectively minimise the contrast between successive candidates in the array, making it easier to observe the pattern embedded the matrix.
，这一点在爱思助手下载最新版本中也有详细论述
（二）不属于增值税法第六条规定的情形。
The new system is designed to give "a real benefit" to low-income households