##1.RGB转HSV：转换之后需要h的值来计算心率
void RGBtoHSV( float r, float g, float b, float *h, float *s, float *v ) {
float min, max, delta;
min = MIN( r, MIN(g, b ));
max = MAX( r, MAX(g, b ));
*v = max;
delta = max - min;
if(delta == 0){
*h= 0;
}else if((max == r)&&(g>b || g==b)){
*h = 60 *(g-b)/delta;
}else if((max == r)&&(g<b)){
*h = 60 *(g-b)/delta + 360;
}else if(max == g){
*h = 60 *(b-r)/delta + 120;
}else if (max == b){
*h = 60 *(r-g)/delta + 240;
}
}
2.根据H值返回一个相邻的H的差值的浮点值p:
// 记录浮点变化的前一次的值
static float lastH = 0;
// 用于判断是否是第一个福点值
static int count = 0;
float HeartRate (float h) {
float low = 0;
count++;
lastH = (count==1)?h:lastH;
low = (h-lastH);
lastH = h;
return low;
}
3.用map形式来保存每个是个返回的浮点值p
例如：{“time”:"2017-5-26 12:30:56","p":"0.5"}
4.根据手指覆盖摄像头闪光灯来通过p计算心率。否则 之前采集的所有点丢掉，重新采集。
if (r < 0.784) {
//红色值小于0.784 清除所有数据
提示手指移开摄像头和闪光灯
}else{
if (p >= 1.0f || p<= -1.0f) {
return;
}
}
5.分析波峰波谷求心率
#pragma mark - 分析瞬时心率
- (void)analysisPointsWith:(NSDictionary *)point {
[self.points addObject:point];
if (self.points.count<=30) return;
int count = (int)self.points.count;
if (self.points.count%10 == 0) {
int d_i_c = 0; //最低峰值的位置 姑且算在中间位置 c->center
int d_i_l = 0; //最低峰值左面的最低峰值位置 l->left
int d_i_r = 0; //最低峰值右面的最低峰值位置 r->right
float trough_c = 0; //最低峰值的浮点值
float trough_l = 0; //最低峰值左面的最低峰值浮点值
float trough_r = 0; //最低峰值右面的最低峰值浮点值
// 1.先确定数据中的最低峰值
for (int i = 0; i < count; i++) {
float trough = [[[self.points[i] allObjects] firstObject] floatValue];
if (trough < trough_c) {
trough_c = trough;
d_i_c = i;
}
}
// 2.找到最低峰值以后 以最低峰值为中心 找到前0.5-1.5周期中的最低峰值 和后0.5-1.5周期的最低峰值
if (d_i_c >= 1.5*T) {
// a.如果最低峰值处在中心位置， 即距离前后都至少有1.5个周期
if (d_i_c <= count-1.5*T) {
// 左面最低峰值
for (int j = d_i_c - 0.5*T; j > d_i_c - 1.5*T; j--) {
float trough = [[[self.points[j] allObjects] firstObject] floatValue];
// if ((trough < trough_l)&&(d_i_c-j)<=T) {
if (trough < trough_l) {
trough_l = trough;
d_i_l = j;
}
}
// 右面最低峰值
for (int k = d_i_c + 0.5*T; k < d_i_c + 1.5*T; k++) {
float trough = [[[self.points[k] allObjects] firstObject] floatValue];
// if ((trough < trough_r)&&(k-d_i_c<=T)) {
if (trough < trough_r) {
trough_r = trough;
d_i_r = k;
}
}
}
// b.如果最低峰值右面不够1.5个周期 分两种情况 不够0.5个周期和够0.5个周期
else {
// b.1 够0.5个周期
if (d_i_c <count-0.5*T) {
// 左面最低峰值
for (int j = d_i_c - 0.5*T; j > d_i_c - 1.5*T; j--) {
float trough = [[[self.points[j] allObjects] firstObject] floatValue];
if ((trough < trough_l)&&(d_i_c-j)<=T) {
trough_l = trough;
d_i_l = j;
}
}
// 右面最低峰值
for (int k = d_i_c + 0.5*T; k < count; k++) {
float trough = [[[self.points[k] allObjects] firstObject] floatValue];
if ((trough < trough_r)&&(k-d_i_c<=T)) {
trough_r = trough;
d_i_r = k;
}
}
}
// b.2 不够0.5个周期
else {
// 左面最低峰值
for (int j = d_i_c - 0.5*T; j > d_i_c - 1.5*T; j--) {
float trough = [[[self.points[j] allObjects] firstObject] floatValue];
if ((trough < trough_l)&&(d_i_c-j)<=T) {
trough_l = trough;
d_i_l = j;
}
}
}
}
}
// c. 如果左面不够1.5个周期 一样分两种情况 够0.5个周期 不够0.5个周期
else {
// c.1 够0.5个周期
if (d_i_c>0.5*T) {
// 左面最低峰值
for (int j = d_i_c - 0.5*T; j > 0; j--) {
float trough = [[[self.points[j] allObjects] firstObject] floatValue];
if ((trough < trough_l)&&(d_i_c-j)<=T) {
trough_l = trough;
d_i_l = j;
}
}
// 右面最低峰值
for (int k = d_i_c + 0.5*T; k < d_i_c + 1.5*T; k++) {
float trough = [[[self.points[k] allObjects] firstObject] floatValue];
if ((trough < trough_r)&&(k-d_i_c<=T)) {
trough_r = trough;
d_i_r = k;
}
}
}
// c.2 不够0.5个周期
else {
// 右面最低峰值
for (int k = d_i_c + 0.5*T; k < d_i_c + 1.5*T; k++) {
float trough = [[[self.points[k] allObjects] firstObject] floatValue];
if ((trough < trough_r)&&(k-d_i_c<=T)) {
trough_r = trough;
d_i_r = k;
}
}
}
}
// 3. 确定哪一个与最低峰值更接近 用最接近的一个最低峰值测出瞬时心率 60*1000两个峰值的时间差
if (trough_l-trough_c < trough_r-trough_c) {
NSDictionary *point_c = self.points[d_i_c];
NSDictionary *point_l = self.points[d_i_l];
double t_c = [[[point_c allKeys] firstObject] doubleValue];
NSLog(@"hhehehhhe:%lf",t_c);
double t_l = [[[point_l allKeys] firstObject] doubleValue];
NSInteger fre = (NSInteger)(60*1000)/(t_c - t_l);
if (self.frequency)
self.frequency(fre);
if ([self.delegate respondsToSelector:@selector(startHeartDelegateRateFrequency:)])
NSLog(@"手指移开 左： %ld",fre);
[self.delegate startHeartDelegateRateFrequency:fre];
} else {
NSDictionary *point_c = self.points[d_i_c];
NSDictionary *point_r = self.points[d_i_r];
double t_c = [[[point_c allKeys] firstObject] doubleValue];
double t_r = [[[point_r allKeys] firstObject] doubleValue];
NSInteger fre = (NSInteger)(60*1000)/(t_r - t_c);
if (self.frequency)
self.frequency(fre);
if ([self.delegate respondsToSelector:@selector(startHeartDelegateRateFrequency:)])
[self.delegate startHeartDelegateRateFrequency:fre];
NSLog(@"手指移开 右： %ld",fre);
}
// 4.删除过期数据
for (int i = 0; i< 10; i++) {
[self.points removeObjectAtIndex:0];
}
}
}
