s/nohalo1/templates.h replace hassign by withsign and cosmetic
This commit is contained in:
Nicolas Robidoux
parent
b2542a4152
commit
1cd38646b8
|
|
@ -2,11 +2,12 @@
|
|||
*
|
||||
* Hacked for vips by J. Cupitt, 20/1/09
|
||||
*
|
||||
* Rename as nohalo1 and move "restrict" support to configure, 16/3/09
|
||||
* Rename as nohalo1 and move "restrict" support to configure by
|
||||
* J. Cupitt, 16/3/09
|
||||
*
|
||||
* Tweaks by N. Robidoux and J. Cupitt 4-17/3/09
|
||||
*
|
||||
* Tweaks by N. Robidoux 25/5/09
|
||||
* Tweaks by N. Robidoux 25-28/5/09
|
||||
*/
|
||||
|
||||
/*
|
||||
|
|
@ -39,8 +40,8 @@
|
|||
/*
|
||||
* 2009 (c) Nicolas Robidoux
|
||||
*
|
||||
* Nicolas thanks Geert Jordaens, John Cupitt, Minglun Gong, Øyvind
|
||||
* Kolås, Ralf Meyer and Sven Neumann for useful comments and code.
|
||||
* Nicolas thanks John Cupitt, Geert Jordaens, Øyvind Kolås, Ralf
|
||||
* Meyer, Minglun Gong, and Sven Neumann for useful comments and code.
|
||||
*
|
||||
* Nicolas Robidoux's research on Nohalo funded in part by an NSERC
|
||||
* (National Science and Engineering Research Council of Canada)
|
||||
|
|
@ -91,9 +92,9 @@
|
|||
* it. (Nohalo is not smoothing like, say, B-Spline
|
||||
* pseudo-interpolation.)
|
||||
*
|
||||
* ========================================================
|
||||
* Nohalo is co-monotone (this is why it's called "nohalo")
|
||||
* ========================================================
|
||||
* ==================================================================
|
||||
* Nohalo is co-monotone (this is why it's called "nohalo" = no halo)
|
||||
* ==================================================================
|
||||
*
|
||||
* What monotonicity more or less means here is that the resampled
|
||||
* value is in the range of the four closest input values. This
|
||||
|
|
@ -105,15 +106,21 @@
|
|||
* Note: If the abyss policy is an extrapolating one---for example,
|
||||
* linear or bilinear extrapolation---clamping is still unnecessary
|
||||
* unless one attempts to resample outside of the convex hull of the
|
||||
* input pixel positions. Consequence: the "corner" image size
|
||||
* convention does not require clamping when using linear
|
||||
* input pixel positions. Consequence: the usual "interpolatory" image
|
||||
* size convention (oft associated with "pixel center-based
|
||||
* coordinates") does not require clamping when using linear
|
||||
* extrapolation abyss policy when performing image resizing, but the
|
||||
* "center" one does, when upscaling, at locations very close to the
|
||||
* boundary. If computing values at locations outside of the convex
|
||||
* hull of the pixel locations of the input image, nearest neighbour
|
||||
* abyss policy is most likely better anyway, because linear
|
||||
* extrapolation produces "streaks" if positions far outside the
|
||||
* original image boundary are resampled.
|
||||
* usual "exact area" image size convention (oft associated with
|
||||
* "pixel corner-based coordinates) does require clamping at locations
|
||||
* very close to the boundary when upscaling. If computing values at
|
||||
* locations outside of the convex hull of the pixel center locations
|
||||
* of the input image, nearest neighbour abyss policy is most likely
|
||||
* better anyway, because linear extrapolation produces "streaks" if
|
||||
* positions far outside the original image boundary are sampled. Note
|
||||
* that the nearest neighbor abyss policy ("clamp" in GPU parlance) is
|
||||
* the most common one. Again, for this abyss policy, nohalo is
|
||||
* monotone through and through and no pixel value clamping is
|
||||
* necessary.
|
||||
*
|
||||
* ========================
|
||||
* Nohalo is a local method
|
||||
|
|
@ -189,7 +196,19 @@
|
|||
* used and the magnification factor is 2, that is, if the resampled
|
||||
* points sit exactly on the binary subdivided grid, then nohalo level
|
||||
* 1 gives the same result as as level=infinity, and consequently the
|
||||
* intensity surface can be treated as if smooth.)
|
||||
* intensity surface can be treated as if smooth.) Note that these
|
||||
* gradient discontinuities are nearly invisible when the
|
||||
* magnification ratio is modest.
|
||||
*
|
||||
* ============================
|
||||
* CONVENTIONS USED IN THE CODE
|
||||
* ============================
|
||||
*
|
||||
* This code uses the "center-based coordinate convention, for which,
|
||||
* the very first actual image pixel is understood to be located at
|
||||
* (0,0), and the last one at (N-1,M-1), where M is the number of
|
||||
* pixel rows of the input image, and N is its number of pixel
|
||||
* columns.
|
||||
*/
|
||||
|
||||
#ifdef HAVE_CONFIG_H
|
||||
|
|
@ -552,7 +571,7 @@ nohalo1( const double uno_two,
|
|||
}
|
||||
|
||||
NOHALO1_INTER( fptypes )
|
||||
NOHALO1_INTER( hassign )
|
||||
NOHALO1_INTER( withsign )
|
||||
NOHALO1_INTER( nosign )
|
||||
|
||||
/* We need C linkage for this.
|
||||
|
|
@ -570,7 +589,7 @@ vips_interpolate_nohalo1_interpolate( VipsInterpolate* restrict interpolate,
|
|||
double absolute_y )
|
||||
{
|
||||
/*
|
||||
* VIPS versions of Nicolas's pixel addressing values.
|
||||
* Unit buffer pointer shifts:
|
||||
*/
|
||||
const int actual_bands = in->im->Bands;
|
||||
const int lskip = IM_REGION_LSKIP( in ) / IM_IMAGE_SIZEOF_ELEMENT( in->im );
|
||||
|
|
@ -622,7 +641,7 @@ vips_interpolate_nohalo1_interpolate( VipsInterpolate* restrict interpolate,
|
|||
break;
|
||||
|
||||
case IM_BANDFMT_CHAR:
|
||||
CALL( signed char, hassign );
|
||||
CALL( signed char, withsign );
|
||||
break;
|
||||
|
||||
case IM_BANDFMT_USHORT:
|
||||
|
|
@ -630,7 +649,7 @@ vips_interpolate_nohalo1_interpolate( VipsInterpolate* restrict interpolate,
|
|||
break;
|
||||
|
||||
case IM_BANDFMT_SHORT:
|
||||
CALL( signed short, hassign );
|
||||
CALL( signed short, withsign );
|
||||
break;
|
||||
|
||||
case IM_BANDFMT_UINT:
|
||||
|
|
@ -638,7 +657,7 @@ vips_interpolate_nohalo1_interpolate( VipsInterpolate* restrict interpolate,
|
|||
break;
|
||||
|
||||
case IM_BANDFMT_INT:
|
||||
CALL( signed int, hassign );
|
||||
CALL( signed int, withsign );
|
||||
break;
|
||||
|
||||
/* Complex images handled by doubling of bands, see above.
|
||||
|
|
|
|||
|
|
@ -1,8 +1,10 @@
|
|||
/* snohalo (smooth nohalo) level 1 interpolator
|
||||
/* snohalo level 1 interpolator
|
||||
*
|
||||
* (smooth nohalo = nohalo with custom antialiasing blur)
|
||||
*
|
||||
* Tweaks by N. Robidoux and J. Cupitt 4-17/3/09
|
||||
*
|
||||
* Tweaks by N. Robidoux 25/5/09
|
||||
* Tweaks by N. Robidoux 25-28/5/09
|
||||
*/
|
||||
|
||||
/*
|
||||
|
|
@ -485,7 +487,7 @@ snohalo1( const double blur,
|
|||
}
|
||||
|
||||
SNOHALO1_INTER( fptypes )
|
||||
SNOHALO1_INTER( hassign )
|
||||
SNOHALO1_INTER( withsign )
|
||||
SNOHALO1_INTER( nosign )
|
||||
|
||||
/* We need C linkage for this.
|
||||
|
|
@ -558,7 +560,7 @@ vips_interpolate_snohalo1_interpolate( VipsInterpolate* restrict interpolate,
|
|||
break;
|
||||
|
||||
case IM_BANDFMT_CHAR:
|
||||
CALL( signed char, hassign );
|
||||
CALL( signed char, withsign );
|
||||
break;
|
||||
|
||||
case IM_BANDFMT_USHORT:
|
||||
|
|
@ -566,7 +568,7 @@ vips_interpolate_snohalo1_interpolate( VipsInterpolate* restrict interpolate,
|
|||
break;
|
||||
|
||||
case IM_BANDFMT_SHORT:
|
||||
CALL( signed short, hassign );
|
||||
CALL( signed short, withsign );
|
||||
break;
|
||||
|
||||
case IM_BANDFMT_UINT:
|
||||
|
|
@ -574,7 +576,7 @@ vips_interpolate_snohalo1_interpolate( VipsInterpolate* restrict interpolate,
|
|||
break;
|
||||
|
||||
case IM_BANDFMT_INT:
|
||||
CALL( signed int, hassign );
|
||||
CALL( signed int, withsign );
|
||||
break;
|
||||
|
||||
/* Complex images handled by doubling of bands, see above.
|
||||
|
|
|
|||
|
|
@ -68,7 +68,7 @@ bilinear_fptypes(
|
|||
/* Interpolate for signed integer types.
|
||||
*/
|
||||
template <typename T> static T inline
|
||||
bilinear_hassign(
|
||||
bilinear_withsign(
|
||||
const double w_times_z,
|
||||
const double x_times_z,
|
||||
const double w_times_y,
|
||||
|
|
|
|||
Loading…
Reference in New Issue