cal/cal/pq.cal

{ RCSid $Id: pq.cal,v 1.1 2021/03/17 23:49:20 greg Exp $ }
{
        Convert absolute luminance in cd/m^2 to/from Dolby's
        Perceptual Quantization
}
peak`PQ : 10000;
n`PQ : 2610.0/(4096.0*4.0);
m`PQ : 2523.0/4096.0*128.0;
c1`PQ : 3424.0/4096.0;
c2`PQ : 2413.0/4096.0*32.0;
c3`PQ : 2392.0/4096.0*32.0;

bound(a,x,b) : if(a-x, a, if(x-b, b, x));

toPQ1(Yn) : ((c1`PQ + c2`PQ*Yn)/(1 + c3`PQ*Yn))^m`PQ;
toPQ(Y) : toPQ1(bound(0,Y/peak`PQ,1)^n`PQ);

fromPQ1(PQm) : (max(PQm-c1`PQ,0)/(c2`PQ - c3`PQ*PQm))^(1/n`PQ) * peak`PQ;
fromPQ(q) : fromPQ1(bound(0,q,1)^(1/m`PQ));
Revision:	1.2
Committed:	Wed Mar 17 23:51:19 2021 UTC (3 years, 2 months ago) by greg
Branch:	MAIN
CVS Tags:	rad5R4, HEAD
Changes since 1.1:	+1 -2 lines
Log Message:	perf: removed max() definition as it's in library, now
#	Content
1	{ RCSid $Id: pq.cal,v 1.1 2021/03/17 23:49:20 greg Exp $ }
2	{
3	Convert absolute luminance in cd/m^2 to/from Dolby's
4	Perceptual Quantization
5	}
6	peak`PQ : 10000;
7	n`PQ : 2610.0/(4096.0*4.0);
8	m`PQ : 2523.0/4096.0*128.0;
9	c1`PQ : 3424.0/4096.0;
10	c2`PQ : 2413.0/4096.0*32.0;
11	c3`PQ : 2392.0/4096.0*32.0;
12
13	bound(a,x,b) : if(a-x, a, if(x-b, b, x));
14
15	toPQ1(Yn) : ((c1`PQ + c2`PQYn)/(1 + c3`PQYn))^m`PQ;
16	toPQ(Y) : toPQ1(bound(0,Y/peak`PQ,1)^n`PQ);
17
18	fromPQ1(PQm) : (max(PQm-c1`PQ,0)/(c2`PQ - c3`PQPQm))^(1/n`PQ) peak`PQ;
19	fromPQ(q) : fromPQ1(bound(0,q,1)^(1/m`PQ));