learn objective-c source code first.

This is my first attempt. I will be uploading more useful code in the near future.-This is my first attempt. I will be uploading more useful code in the near future.

Code to print sum of first 1000 primes

图像颜色特征提取（三阶矩）完整代码；stricker和0reng0提出了颜色矩的方法，颜色矩是一种简单有效的颜色特征表示方法，有一阶矩(均值)、二阶矩(标准差)和三阶矩(斜度)等，由于颜色信息主要分布于低阶矩中，所以用一阶矩，二阶矩和三阶矩足以表达图像的颜色分布，颜色矩已证明可有效地表示图像中的颜色分布(Image color feature extraction (three moments) complete code;Stricker and 0reng0 proposed a metho