srcp_below = srcp; // there is no line below
for (i = 0; i < linesize; i++) {
// this calculation is an integer representation of
- // '0.5 * current + 0.25 * above + 0.25 + below'
+ // '0.5 * current + 0.25 * above + 0.25 * below'
// '1 +' is for rounding.
dstp[i] = (1 + srcp[i] + srcp[i] + srcp_above[i] + srcp_below[i]) >> 2;
}