用到的一些算法收集

卷积：

static int filter0(uint8_t *src, uint8_t *dst,int w, int h) {
  double start, end;
  int i =1;
  int j =1;
  if(w > WIDTH || h > HEIGHT)
    return 1;
  start = now_ms();
  for (i=1; i < h - 1; ++i) {
    for (j=1; j < w - 1; ++j) {
      int index = j + i * w;
      uint8_t lu = src[index - 1 - w];
      uint8_t lm = src[index - 1];
      uint8_t ld = src[index - 1 + w];
      uint8_t mu = src[index - w];
      uint8_t mm = src[index];
      uint8_t md = src[index + w];
      uint8_t ru = src[index + 1 - w];
      uint8_t rm = src[index + 1];
      uint8_t rd = src[index + 1 + w];
      int sum = lu + lm + ld + mu + mm + md + ru + rm + rd;
      dst[index] = (uint8_t)sum / 9 + 1;
    }
  }
  end = now_ms();
  printf("filter  %f 
", end - start);
  return 0;
}