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little more close to IM/GM/Lepto and co

master
Pierre Joye 2021-08-16 17:02:51 +07:00
parent 672475e540
commit f49d0aef3b
1 changed files with 7 additions and 10 deletions
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17
src/gd_interpolation.c
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@ -422,18 +422,15 @@ static double filter_lanczos8(const double x1, const double support)
return 0.0;
}
/* Lanczos3 filter, default radius 3 */
static double filter_lanczos3(const double x1, const double support)
{
const double x = x1 < 0.0 ? -x1 : x1;
if ( x == 0.0) return 1;
if ( x < support)
{
return support * sin(x*M_PI) * sin(x * M_PI / support) / (x * M_PI * x * M_PI);
}
return 0.0;
if (x1 < -3.0)
return(0.0);
if (x1 < 0.0)
return(filter_sinc(-x1,support)*filter_sinc(-x1/3.0,support));
if (x1 < 3.0)
return(filter_sinc(x1,support)*filter_sinc(x1/3.0,support));
return(0.0);
}
/* Hermite filter, default radius 1 */