}
static MagickRealType Kaiser(const MagickRealType x,
- const ResizeFilter *magick_unused(resize_filter))
+ const ResizeFilter *resize_filter)
{
-#define Alpha 6.5
-#define I0A (1.0/I0(Alpha))
-
/*
- Kaiser Windowing Function (bessel windowing): Alpha is a free value
- from 5 to 8 (currently hardcoded to 6.5). Future: make alpha the IOA
- pre-calculation, an 'expert' setting.
+ Kaiser Windowing Function (bessel windowing)
+ Alpha (c[0]) is a free value from 5 to 8 (defaults to 6.5).
+ A scaling factor (c[1]) is not needed as filter is normalized
*/
- return(I0A*I0(Alpha*sqrt((double) (1.0-x*x))));
+ return(resize_filter->coefficient[1]*
+ I0(resize_filter->coefficient[0]*sqrt((double) (1.0-x*x))));
}
static MagickRealType Lagrange(const MagickRealType x,
MagickRealType
B,
C,
- sigma;
+ value;
register ResizeFilter
*resize_filter;
MagickRealType
(*function)(const MagickRealType,const ResizeFilter*),
lobes, /* Default lobes/support size of the weighting filter. */
- scale, /* Support when function used as a windowing function. Typically
- equal to the location of the first zero crossing. */
- B,
- C; /* BC-spline coefficients, ignored if not a CubicBC filter. */
+ scale, /* Support when function used as a windowing function
+ Typically equal to the location of the first zero crossing. */
+ B,C; /* BC-spline coefficients, ignored if not a CubicBC filter. */
} const filters[SentinelFilter] =
{
{ Box, 0.5, 0.5, 0.0, 0.0 }, /* Undefined (default to Box) */
{ SincFast, 3.0, 1.0, 0.0, 0.0 }, /* lanczos, Sharpened */
{ SincFast, 2.0, 1.0, 0.0, 0.0 }, /* Lanczos, 2-lobed */
{ SincFast, 2.0, 1.0, 0.0, 0.0 }, /* Lanczos2, sharpened */
- { CubicBC, 2.0, 1.1685777620836932, 0.37821575509399867,
- 0.31089212245300067 }
+ { CubicBC, 2.0, 1.1685777620836932,
+ 0.37821575509399867, 0.31089212245300067 }
/* Robidoux: Keys cubic close to Lanczos2D sharpened */
};
/*
filter_type=mapping[filter].filter;
window_type=mapping[filter].window;
resize_filter->blur = blur; /* function argument blur factor */
- sigma=0.5; /* gaussian sigma of half a pixel by default */
+ /* Promote 1D Windowed Sinc Filters to a 2D Windowed Jinc filters */
if ((cylindrical != MagickFalse) && (filter_type == SincFastFilter) &&
(filter != SincFastFilter))
filter_type=JincFilter; /* 1D Windowed Sinc => 2D Windowed Jinc filters */
+ /* Expert filter setting override */
artifact=GetImageArtifact(image,"filter:filter");
if (artifact != (const char *) NULL)
{
ssize_t
option;
- /*
- Expert filter setting override.
- */
option=ParseCommandOption(MagickFilterOptions,MagickFalse,artifact);
if ((UndefinedFilter < option) && (option < SentinelFilter))
- {
- /*
- Raw filter request - no window function.
- */
+ { /* Raw filter request - no window function. */
filter_type=(FilterTypes) option;
window_type=BoxFilter;
}
+ /* Filter override with a specific window function. */
artifact=GetImageArtifact(image,"filter:window");
if (artifact != (const char *) NULL)
{
- /*
- Filter override with a specific window function.
- */
option=ParseCommandOption(MagickFilterOptions,MagickFalse,artifact);
if ((UndefinedFilter < option) && (option < SentinelFilter))
window_type=(FilterTypes) option;
}
else
{
+ /* Window specified, but no filter function? Assume Sinc/Jinc. */
artifact=GetImageArtifact(image,"filter:window");
if (artifact != (const char *) NULL)
{
ssize_t
option;
- /*
- Window specified, but no filter function? Assume Sinc/Jinc.
- */
option=ParseCommandOption(MagickFilterOptions,MagickFalse,artifact);
if ((UndefinedFilter < option) && (option < SentinelFilter))
{
}
}
}
- /*
- Assign the real functions to use for the filters selected.
- */
+
+ /* Assign the real functions to use for the filters selected. */
resize_filter->filter=filters[filter_type].function;
resize_filter->support=filters[filter_type].lobes;
resize_filter->window=filters[window_type].function;
resize_filter->scale=filters[window_type].scale;
resize_filter->signature=MagickSignature;
- /*
- Filter Modifications for orthogonal/cylindrical usage.
- */
+
+ /* Filter Modifications for orthogonal/cylindrical usage */
if (cylindrical != MagickFalse)
switch (filter_type)
{
case BoxFilter:
- {
- /*
- Support for Cylindrical Box should be sqrt(2)/2.
- */
+ /* Support for Cylindrical Box should be sqrt(2)/2 */
resize_filter->support=(MagickRealType) MagickSQ1_2;
break;
- }
case LanczosFilter:
case LanczosSharpFilter:
case Lanczos2Filter:
case Lanczos2SharpFilter:
- {
- /*
- Number of lobes (support window size) remain unchanged.
- */
resize_filter->filter=filters[JincFilter].function;
resize_filter->window=filters[JincFilter].function;
resize_filter->scale=filters[JincFilter].scale;
+ /* number of lobes (support window size) remain unchanged */
break;
- }
default:
break;
}
- /*
- Global Sharpening (regardless of orthoginal/cylindrical).
- */
+ /* Global Sharpening (regardless of orthoginal/cylindrical) */
switch (filter_type)
{
case LanczosSharpFilter:
- {
resize_filter->blur*=0.9812505644269356;
break;
- }
case Lanczos2SharpFilter:
- {
resize_filter->blur*=0.9549963639785485;
break;
- }
default:
break;
}
+
+ /*
+ ** Other Expert Option Modifications
+ */
+
+ /* User Gaussian Sigma Override - no support change */
+ value = 0.5; /* guassian sigma default, half pixel */
+ if ( GaussianFilter ) {
artifact=GetImageArtifact(image,"filter:sigma");
if (artifact != (const char *) NULL)
- sigma=StringToDouble(artifact,(char **) NULL); /* override sigma */
- if (GaussianFilter)
- {
- /*
- Define coefficents for Gaussian.
- */
- resize_filter->coefficient[0]=1.0/(2.0*sigma*sigma);
- resize_filter->coefficient[1]=(MagickRealType) (1.0/(Magick2PI*sigma*
- sigma)); /* normalization multiplier - unneeded for filters */
- }
+ value=StringToDouble(artifact,(char **) NULL);
+ /* Define coefficents for Gaussian */
+ resize_filter->coefficient[0]=1.0/(2.0*value*value); /* X scaling */
+ resize_filter->coefficient[1]=(MagickRealType) (1.0/(Magick2PI*value*
+ value)); /* normalization */
+ }
+ /* User Kaiser Alpha Override - no support change */
+ if ( KaiserFilter ) {
+ value=6.5; /* default alpha value for Kaiser bessel windowing function */
+ artifact=GetImageArtifact(image,"filter:alpha");
+ if (artifact != (const char *) NULL)
+ value=StringToDouble(artifact,(char **) NULL);
+ /* Define coefficents for Kaiser Windowing Function */
+ resize_filter->coefficient[0]=value; /* X scaling */
+ resize_filter->coefficient[1]=1.0/I0(value); /* normalization */
+ }
+
+ /* Blur Override */
artifact=GetImageArtifact(image,"filter:blur");
if (artifact != (const char *) NULL)
- resize_filter->blur*=StringToDouble(artifact,(char **) NULL); /* override blur */
+ resize_filter->blur*=StringToDouble(artifact,(char **) NULL);
if (resize_filter->blur < MagickEpsilon)
resize_filter->blur=(MagickRealType) MagickEpsilon;
+
+ /* Support Overrides */
artifact=GetImageArtifact(image,"filter:lobes");
if (artifact != (const char *) NULL)
{
ssize_t
lobes;
- /*
- Override lobes.
- */
lobes=(ssize_t) StringToLong(artifact);
if (lobes < 1)
lobes=1;
resize_filter->support=(MagickRealType) lobes;
}
+ /* Convert a Jinc function lobes value to a real support value */
if (resize_filter->filter == Jinc)
{
- /*
- Convert a Jinc function lobes value to a real support value.
- */
if (resize_filter->support > 16)
resize_filter->support=jinc_zeros[15]; /* largest entry in table */
else
resize_filter->support=jinc_zeros[((long)resize_filter->support)-1];
}
+ /* expert override of the support setting */
artifact=GetImageArtifact(image,"filter:support");
if (artifact != (const char *) NULL)
- resize_filter->support=fabs(StringToDouble(artifact,(char **) NULL)); /* override support */
+ resize_filter->support=fabs(StringToDouble(artifact,(char **) NULL));
/*
- Scale windowing function separately to the support 'clipping' window that
- calling operator is planning to actually use (expert override).
+ Scale windowing function separately to the support 'clipping'
+ window that calling operator is planning to actually use. (Expert
+ override)
*/
resize_filter->window_support=resize_filter->support; /* default */
artifact=GetImageArtifact(image,"filter:win-support");
if (artifact != (const char *) NULL)
resize_filter->window_support=fabs(StringToDouble(artifact,(char **) NULL));
/*
- Adjust window function scaling to match windowing support for weighting
- function. This avoids a division on every filter call.
+ Adjust window function scaling to match windowing support for
+ weighting function. This avoids a division on every filter call.
*/
resize_filter->scale/=resize_filter->window_support;
+
/*
- Set Cubic Spline B,C values, calculate cubic coefficients.
+ * Set Cubic Spline B,C values, calculate Cubic coefficients.
*/
B=0.0;
C=0.0;
B=1.0-2.0*C; /* Calculate B to get a Keys cubic filter. */
}
}
- {
+ /* Convert B,C values into Cubic Coefficents. See CubicBC(). */
double
B_squared;
- /*
- Convert B,C values into Cubic Coefficents. See CubicBC().
- */
B_squared=B+B;
resize_filter->coefficient[0]=1.0-(1.0/3.0)*B;
resize_filter->coefficient[1]=-3.0+B_squared+C;
resize_filter->coefficient[6]=(-1.0/6.0)*B-C;
}
}
+
/*
- Expert option request for verbose details of the resulting filter.
+ Expert Option Request for verbose details of the resulting filter.
*/
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp master
x;
/*
- Set the weighting function properly when the weighting function may
- not exactly match the filter of the same name. EG: a point filter
- really uses a box weighting function with a different support than is
- typically used.
+ Set the weighting function properly when the weighting
+ function may not exactly match the filter of the same name.
+ EG: a Point filter is really uses a Box weighting function
+ with a different support than is typically used.
*/
- if (resize_filter->filter == Box)
- filter_type=BoxFilter;
- if (resize_filter->filter == Sinc)
- filter_type=SincFilter;
- if (resize_filter->filter == SincFast)
- filter_type=SincFastFilter;
- if (resize_filter->filter == Jinc)
- filter_type=JincFilter;
- if (resize_filter->filter == CubicBC)
- filter_type=CubicFilter;
- if (resize_filter->window == Box)
- window_type=BoxFilter;
- if (resize_filter->window == Sinc)
- window_type=SincFilter;
- if (resize_filter->window == SincFast)
- window_type=SincFastFilter;
- if (resize_filter->window == Jinc)
- window_type=JincFilter;
- if (resize_filter->window == CubicBC)
- window_type=CubicFilter;
+ if (resize_filter->filter == Box) filter_type=BoxFilter;
+ if (resize_filter->filter == Sinc) filter_type=SincFilter;
+ if (resize_filter->filter == SincFast) filter_type=SincFastFilter;
+ if (resize_filter->filter == Jinc) filter_type=JincFilter;
+ if (resize_filter->filter == CubicBC) filter_type=CubicFilter;
+ if (resize_filter->window == Box) window_type=BoxFilter;
+ if (resize_filter->window == Sinc) window_type=SincFilter;
+ if (resize_filter->window == SincFast) window_type=SincFastFilter;
+ if (resize_filter->window == Jinc) window_type=JincFilter;
+ if (resize_filter->window == CubicBC) window_type=CubicFilter;
/*
- Report filter details.
+ Report Filter Details.
*/
support=GetResizeFilterSupport(resize_filter); /* practical_support */
(void) FormatLocaleFile(stdout,"# Resize Filter (for graphing)\n#\n");
GetMagickPrecision(), (double)resize_filter->blur);
if (filter_type == GaussianFilter)
(void) FormatLocaleFile(stdout,"# gaussian_sigma = %.*g\n",
- GetMagickPrecision(), (double)sigma);
+ GetMagickPrecision(), (double)value);
+ if ( filter_type == KaiserFilter )
+ (void) FormatLocaleFile(stdout,"# kaiser_alpha = %.*g\n",
+ GetMagickPrecision(), (double)value);
(void) FormatLocaleFile(stdout,"# practical_support = %.*g\n",
GetMagickPrecision(), (double)support);
if ( filter_type == CubicFilter || window_type == CubicFilter )
GetMagickPrecision(),(double)B, GetMagickPrecision(),(double)C);
(void) FormatLocaleFile(stdout,"\n");
/*
- Output values of resulting filter graph -- for graphing filter result.
+ Output values of resulting filter graph -- for graphing
+ filter result.
*/
for (x=0.0; x <= support; x+=0.01f)
- (void) FormatLocaleFile(stdout,"%5.2lf\t%.*g\n",x,
- GetMagickPrecision(),(double) GetResizeFilterWeight(resize_filter,
- x));
- /*
- A final value so gnuplot can graph the 'stop' properly.
- */
+ (void) FormatLocaleFile(stdout,"%5.2lf\t%.*g\n",x,GetMagickPrecision(),
+ (double) GetResizeFilterWeight(resize_filter,x));
+ /* A final value so gnuplot can graph the 'stop' properly. */
(void) FormatLocaleFile(stdout,"%5.2lf\t%.*g\n",support,
GetMagickPrecision(),0.0);
}
- /*
- Output the above once only for each image - remove setting.
- */
+ /* Output the above once only for each image - remove setting */
(void) DeleteImageArtifact((Image *) image,"filter:verbose");
#if defined(MAGICKCORE_OPENMP_SUPPORT)
}
projects / imagemagick / commitdiff