Highly recommend a function to smooth the image.

[Pittow2]

The origin palette function does make a bad sence to human vision , the dark and cycled color let eyes go tired .

I'd like to recommend a new function to paint here .

It is based on the times of iteration . While the number of colors is much less than the times of iter , it is important to alloc a reasonable range of color to each iter time . The "number of pixels - iter times" function is just like y=1/x , less iter time means more area , while the larger iter time corresponds to the detail of fractal . So it can make the final image more beautiful by letting each color occupy the same area of the above function .

It definitely makes a better view .

struct image{
	int *step;//iteration times
	byte *black;//it is 3 when the point goes to infinity
};
bool check(int n,int *cnt,int p,int *lim,int g){//(pixels*iter time range) should be equal to each color .
	u64 lc=0,lp=0,mul=1;
	int i,j,k,cc;
	for(i=0,k=0;i<n;++i){
		for(j=0,cc=0;j<cnt[i];++j){
			++lc;
			if(lc*((j+1)*mul+lp*cnt[i])>g*mul*cnt[i]){
				lc=0;lp=0;
				mul=cnt[i];
				lim[k++]=i;
				if(++cc>16)--k;//to limit each iter time up to 16 colors
				if(k>=p)return 0;
			}
		}
		if(lc>=cnt[i])lp+=mul;
		else lp+=lc;
	}return 1;
}
int splix(int n,int *cnt,int p,int *lim){
	int l=0,r=n*p,m;
	while(l+1!=r){
		m=(l+r)>>1;
		if(check(n,cnt,p,lim,m))r=m;
		else l=m;
	}check(n,cnt,p,lim,r);
	return r;
}
void smooth(image g){
	int max=0,min=1<<30,n=0,k=sx*sy,*cnt,*lim,i,j;
	for(i=0;i<k;++i)if(g.black[i]==3){
		if(max<g.step[i])max=g.step[i];
		if(min>g.step[i])min=g.step[i];
	}
	if(min==(1<<30))return;
	max=max-min+1;
	cnt=new int[max];
	for(i=0;i<max;++i)cnt[i]=0;
	for(i=0;i<k;++i)if(g.black[i]==3)++cnt[g.step[i]-min];
	lim=new int[512];//say we have 512 colors in total
	splix(max,cnt,512,lim);
	for(i=j=0;i<512;++i)for(;j<=lim[i]&&j<max;++j)cnt[j]=i;
	for(i=0;i<k;++i)if(g.black[i]==3)g.step[i]=cnt[g.step[i]-min];
	delete cnt;
	delete lim;
}

The colors should be picked up in the color ring . Bright colors refresh eyes .

rgb getrgb(double h){//h is in [0,1)
	while(h>=1)h-=1;
	double x=h*6,r=0,g=0,b=0;
	while(x>=2)x-=2;
	if(x>1)x=2-x;
	int a=h*6;
	if(a==0||a==5)r=1;
	else if(a==1||a==2)g=1;
	else b=1;
	if(a==1||a==4)r=x;
	else if(a==0||a==3)g=x;
	else b=x;
	byte r0=r*255,g0=g*255,b0=b*255;
	return (rgb){r0,g0,b0};
}