mirror of http://192.168.1.51:8099/lmh188/twain3.0
911 lines
30 KiB
C
911 lines
30 KiB
C
/*====================================================================*
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- Copyright (C) 2001 Leptonica. All rights reserved.
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-
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- Redistribution and use in source and binary forms, with or without
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- modification, are permitted provided that the following conditions
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- are met:
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- 1. Redistributions of source code must retain the above copyright
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- notice, this list of conditions and the following disclaimer.
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- 2. Redistributions in binary form must reproduce the above
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- copyright notice, this list of conditions and the following
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- disclaimer in the documentation and/or other materials
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- provided with the distribution.
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-
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- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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- ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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- LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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- A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL ANY
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- CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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- EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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- PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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- PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
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- OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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- NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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- SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*====================================================================*/
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/*!
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* \file bilinear.c
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* <pre>
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*
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* Bilinear (4 pt) image transformation using a sampled
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* (to nearest integer) transform on each dest point
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* PIX *pixBilinearSampledPta()
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* PIX *pixBilinearSampled()
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*
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* Bilinear (4 pt) image transformation using interpolation
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* (or area mapping) for anti-aliasing images that are
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* 2, 4, or 8 bpp gray, or colormapped, or 32 bpp RGB
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* PIX *pixBilinearPta()
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* PIX *pixBilinear()
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* PIX *pixBilinearPtaColor()
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* PIX *pixBilinearColor()
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* PIX *pixBilinearPtaGray()
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* PIX *pixBilinearGray()
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*
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* Bilinear transform including alpha (blend) component
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* PIX *pixBilinearPtaWithAlpha()
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*
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* Bilinear coordinate transformation
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* l_int32 getBilinearXformCoeffs()
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* l_int32 bilinearXformSampledPt()
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* l_int32 bilinearXformPt()
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*
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* A bilinear transform can be specified as a specific functional
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* mapping between 4 points in the source and 4 points in the dest.
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* It can be used as an approximation to a (nonlinear) projective
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* transform, because for small warps it is very similar and
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* it is more stable. (Projective transforms have a division
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* by a quantity that can get arbitrarily small.)
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*
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* We give both a bilinear coordinate transformation and
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* a bilinear image transformation.
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*
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* For the former, we ask for the coordinate value (x',y')
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* in the transformed space for any point (x,y) in the original
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* space. The coefficients of the transformation are found by
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* solving 8 simultaneous equations for the 8 coordinates of
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* the 4 points in src and dest. The transformation can then
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* be used to compute the associated image transform, by
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* computing, for each dest pixel, the relevant pixel(s) in
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* the source. This can be done either by taking the closest
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* src pixel to each transformed dest pixel ("sampling") or
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* by doing an interpolation and averaging over 4 source
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* pixels with appropriate weightings ("interpolated").
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*
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* A typical application would be to remove some of the
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* keystoning due to a projective transform in the imaging system.
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*
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* The bilinear transform is given by specifying two equations:
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*
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* x' = ax + by + cxy + d
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* y' = ex + fy + gxy + h
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*
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* where the eight coefficients have been computed from four
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* sets of these equations, each for two corresponding data pts.
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* In practice, once the coefficients are known, we use the
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* equations "backwards": for each point (x,y) in the dest image,
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* these two equations are used to compute the corresponding point
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* (x',y') in the src. That computed point in the src is then used
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* to determine the corresponding dest pixel value in one of two ways:
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*
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* ~ sampling: simply take the value of the src pixel in which this
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* point falls
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* ~ interpolation: take appropriate linear combinations of the
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* four src pixels that this dest pixel would
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* overlap, with the coefficients proportional
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* to the amount of overlap
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*
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* For small warp, like rotation, area mapping in the
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* interpolation is equivalent to linear interpolation.
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*
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* Typical relative timing of transforms (sampled = 1.0):
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* 8 bpp: sampled 1.0
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* interpolated 1.6
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* 32 bpp: sampled 1.0
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* interpolated 1.8
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* Additionally, the computation time/pixel is nearly the same
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* for 8 bpp and 32 bpp, for both sampled and interpolated.
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* </pre>
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*/
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#include <string.h>
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#include <math.h>
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#include "allheaders.h"
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extern l_float32 AlphaMaskBorderVals[2];
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/*-------------------------------------------------------------*
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* Sampled bilinear image transformation *
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*-------------------------------------------------------------*/
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/*!
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* \brief pixBilinearSampledPta()
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*
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* \param[in] pixs all depths
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* \param[in] ptad 4 pts of final coordinate space
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* \param[in] ptas 4 pts of initial coordinate space
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* \param[in] incolor L_BRING_IN_WHITE, L_BRING_IN_BLACK
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* \return pixd, or NULL on error
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*
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* <pre>
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* Notes:
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* (1) Brings in either black or white pixels from the boundary.
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* (2) Retains colormap, which you can do for a sampled transform..
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* (3) No 3 of the 4 points may be collinear.
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* (4) For 8 and 32 bpp pix, better quality is obtained by the
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* somewhat slower pixBilinearPta(). See that
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* function for relative timings between sampled and interpolated.
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* </pre>
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*/
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PIX *
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pixBilinearSampledPta(PIX *pixs,
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PTA *ptad,
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PTA *ptas,
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l_int32 incolor)
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{
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l_float32 *vc;
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PIX *pixd;
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PROCNAME("pixBilinearSampledPta");
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if (!pixs)
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return (PIX *)ERROR_PTR("pixs not defined", procName, NULL);
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if (!ptas)
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return (PIX *)ERROR_PTR("ptas not defined", procName, NULL);
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if (!ptad)
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return (PIX *)ERROR_PTR("ptad not defined", procName, NULL);
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if (incolor != L_BRING_IN_WHITE && incolor != L_BRING_IN_BLACK)
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return (PIX *)ERROR_PTR("invalid incolor", procName, NULL);
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if (ptaGetCount(ptas) != 4)
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return (PIX *)ERROR_PTR("ptas count not 4", procName, NULL);
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if (ptaGetCount(ptad) != 4)
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return (PIX *)ERROR_PTR("ptad count not 4", procName, NULL);
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/* Get backwards transform from dest to src, and apply it */
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getBilinearXformCoeffs(ptad, ptas, &vc);
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pixd = pixBilinearSampled(pixs, vc, incolor);
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LEPT_FREE(vc);
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return pixd;
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}
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/*!
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* \brief pixBilinearSampled()
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*
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* \param[in] pixs all depths
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* \param[in] vc vector of 8 coefficients for bilinear transformation
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* \param[in] incolor L_BRING_IN_WHITE, L_BRING_IN_BLACK
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* \return pixd, or NULL on error
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*
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* <pre>
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* Notes:
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* (1) Brings in either black or white pixels from the boundary.
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* (2) Retains colormap, which you can do for a sampled transform..
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* (3) For 8 or 32 bpp, much better quality is obtained by the
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* somewhat slower pixBilinear(). See that function
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* for relative timings between sampled and interpolated.
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* </pre>
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*/
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PIX *
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pixBilinearSampled(PIX *pixs,
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l_float32 *vc,
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l_int32 incolor)
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{
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l_int32 i, j, w, h, d, x, y, wpls, wpld, color, cmapindex;
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l_uint32 val;
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l_uint32 *datas, *datad, *lines, *lined;
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PIX *pixd;
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PIXCMAP *cmap;
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PROCNAME("pixBilinearSampled");
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if (!pixs)
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return (PIX *)ERROR_PTR("pixs not defined", procName, NULL);
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if (!vc)
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return (PIX *)ERROR_PTR("vc not defined", procName, NULL);
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if (incolor != L_BRING_IN_WHITE && incolor != L_BRING_IN_BLACK)
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return (PIX *)ERROR_PTR("invalid incolor", procName, NULL);
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pixGetDimensions(pixs, &w, &h, &d);
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if (d != 1 && d != 2 && d != 4 && d != 8 && d != 32)
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return (PIX *)ERROR_PTR("depth not 1, 2, 4, 8 or 16", procName, NULL);
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/* Init all dest pixels to color to be brought in from outside */
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pixd = pixCreateTemplate(pixs);
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if ((cmap = pixGetColormap(pixs)) != NULL) {
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if (incolor == L_BRING_IN_WHITE)
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color = 1;
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else
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color = 0;
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pixcmapAddBlackOrWhite(cmap, color, &cmapindex);
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pixSetAllArbitrary(pixd, cmapindex);
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} else {
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if ((d == 1 && incolor == L_BRING_IN_WHITE) ||
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(d > 1 && incolor == L_BRING_IN_BLACK)) {
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pixClearAll(pixd);
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} else {
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pixSetAll(pixd);
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}
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}
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/* Scan over the dest pixels */
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datas = pixGetData(pixs);
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wpls = pixGetWpl(pixs);
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datad = pixGetData(pixd);
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wpld = pixGetWpl(pixd);
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for (i = 0; i < h; i++) {
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lined = datad + i * wpld;
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for (j = 0; j < w; j++) {
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bilinearXformSampledPt(vc, j, i, &x, &y);
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if (x < 0 || y < 0 || x >=w || y >= h)
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continue;
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lines = datas + y * wpls;
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if (d == 1) {
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val = GET_DATA_BIT(lines, x);
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SET_DATA_BIT_VAL(lined, j, val);
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} else if (d == 8) {
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val = GET_DATA_BYTE(lines, x);
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SET_DATA_BYTE(lined, j, val);
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} else if (d == 32) {
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lined[j] = lines[x];
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} else if (d == 2) {
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val = GET_DATA_DIBIT(lines, x);
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SET_DATA_DIBIT(lined, j, val);
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} else if (d == 4) {
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val = GET_DATA_QBIT(lines, x);
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SET_DATA_QBIT(lined, j, val);
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}
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}
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}
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return pixd;
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}
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/*---------------------------------------------------------------------*
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* Interpolated bilinear image transformation *
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*---------------------------------------------------------------------*/
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/*!
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* \brief pixBilinearPta()
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*
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* \param[in] pixs all depths; colormap ok
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* \param[in] ptad 4 pts of final coordinate space
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* \param[in] ptas 4 pts of initial coordinate space
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* \param[in] incolor L_BRING_IN_WHITE, L_BRING_IN_BLACK
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* \return pixd, or NULL on error
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*
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* <pre>
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* Notes:
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* (1) Brings in either black or white pixels from the boundary
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* (2) Removes any existing colormap, if necessary, before transforming
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* </pre>
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*/
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PIX *
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pixBilinearPta(PIX *pixs,
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PTA *ptad,
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PTA *ptas,
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l_int32 incolor)
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{
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l_int32 d;
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l_uint32 colorval;
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PIX *pixt1, *pixt2, *pixd;
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PROCNAME("pixBilinearPta");
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if (!pixs)
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return (PIX *)ERROR_PTR("pixs not defined", procName, NULL);
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if (!ptas)
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return (PIX *)ERROR_PTR("ptas not defined", procName, NULL);
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if (!ptad)
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return (PIX *)ERROR_PTR("ptad not defined", procName, NULL);
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if (incolor != L_BRING_IN_WHITE && incolor != L_BRING_IN_BLACK)
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return (PIX *)ERROR_PTR("invalid incolor", procName, NULL);
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if (ptaGetCount(ptas) != 4)
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return (PIX *)ERROR_PTR("ptas count not 4", procName, NULL);
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if (ptaGetCount(ptad) != 4)
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return (PIX *)ERROR_PTR("ptad count not 4", procName, NULL);
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if (pixGetDepth(pixs) == 1)
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return pixBilinearSampledPta(pixs, ptad, ptas, incolor);
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/* Remove cmap if it exists, and unpack to 8 bpp if necessary */
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pixt1 = pixRemoveColormap(pixs, REMOVE_CMAP_BASED_ON_SRC);
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d = pixGetDepth(pixt1);
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if (d < 8)
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pixt2 = pixConvertTo8(pixt1, FALSE);
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else
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pixt2 = pixClone(pixt1);
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d = pixGetDepth(pixt2);
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/* Compute actual color to bring in from edges */
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colorval = 0;
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if (incolor == L_BRING_IN_WHITE) {
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if (d == 8)
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colorval = 255;
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else /* d == 32 */
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colorval = 0xffffff00;
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}
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if (d == 8)
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pixd = pixBilinearPtaGray(pixt2, ptad, ptas, colorval);
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else /* d == 32 */
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pixd = pixBilinearPtaColor(pixt2, ptad, ptas, colorval);
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pixDestroy(&pixt1);
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pixDestroy(&pixt2);
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return pixd;
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}
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/*!
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* \brief pixBilinear()
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*
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* \param[in] pixs all depths; colormap ok
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* \param[in] vc vector of 8 coefficients for bilinear transformation
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* \param[in] incolor L_BRING_IN_WHITE, L_BRING_IN_BLACK
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* \return pixd, or NULL on error
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*
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* <pre>
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* Notes:
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* (1) Brings in either black or white pixels from the boundary
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* (2) Removes any existing colormap, if necessary, before transforming
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* </pre>
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*/
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PIX *
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pixBilinear(PIX *pixs,
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l_float32 *vc,
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l_int32 incolor)
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{
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l_int32 d;
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l_uint32 colorval;
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PIX *pixt1, *pixt2, *pixd;
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PROCNAME("pixBilinear");
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if (!pixs)
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return (PIX *)ERROR_PTR("pixs not defined", procName, NULL);
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if (!vc)
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return (PIX *)ERROR_PTR("vc not defined", procName, NULL);
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if (pixGetDepth(pixs) == 1)
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return pixBilinearSampled(pixs, vc, incolor);
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/* Remove cmap if it exists, and unpack to 8 bpp if necessary */
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pixt1 = pixRemoveColormap(pixs, REMOVE_CMAP_BASED_ON_SRC);
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d = pixGetDepth(pixt1);
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if (d < 8)
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pixt2 = pixConvertTo8(pixt1, FALSE);
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else
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pixt2 = pixClone(pixt1);
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d = pixGetDepth(pixt2);
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/* Compute actual color to bring in from edges */
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colorval = 0;
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if (incolor == L_BRING_IN_WHITE) {
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if (d == 8)
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colorval = 255;
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else /* d == 32 */
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colorval = 0xffffff00;
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}
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if (d == 8)
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pixd = pixBilinearGray(pixt2, vc, colorval);
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else /* d == 32 */
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pixd = pixBilinearColor(pixt2, vc, colorval);
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pixDestroy(&pixt1);
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pixDestroy(&pixt2);
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return pixd;
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}
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/*!
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* \brief pixBilinearPtaColor()
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*
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* \param[in] pixs 32 bpp
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* \param[in] ptad 4 pts of final coordinate space
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* \param[in] ptas 4 pts of initial coordinate space
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* \param[in] colorval e.g., 0 to bring in BLACK, 0xffffff00 for WHITE
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* \return pixd, or NULL on error
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*/
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PIX *
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pixBilinearPtaColor(PIX *pixs,
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PTA *ptad,
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PTA *ptas,
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l_uint32 colorval)
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{
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l_float32 *vc;
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PIX *pixd;
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PROCNAME("pixBilinearPtaColor");
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if (!pixs)
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return (PIX *)ERROR_PTR("pixs not defined", procName, NULL);
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if (!ptas)
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return (PIX *)ERROR_PTR("ptas not defined", procName, NULL);
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if (!ptad)
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return (PIX *)ERROR_PTR("ptad not defined", procName, NULL);
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if (pixGetDepth(pixs) != 32)
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return (PIX *)ERROR_PTR("pixs must be 32 bpp", procName, NULL);
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if (ptaGetCount(ptas) != 4)
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return (PIX *)ERROR_PTR("ptas count not 4", procName, NULL);
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if (ptaGetCount(ptad) != 4)
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return (PIX *)ERROR_PTR("ptad count not 4", procName, NULL);
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/* Get backwards transform from dest to src, and apply it */
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getBilinearXformCoeffs(ptad, ptas, &vc);
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pixd = pixBilinearColor(pixs, vc, colorval);
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LEPT_FREE(vc);
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return pixd;
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}
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/*!
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* \brief pixBilinearColor()
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*
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* \param[in] pixs 32 bpp
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* \param[in] vc vector of 8 coefficients for bilinear transformation
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* \param[in] colorval e.g., 0 to bring in BLACK, 0xffffff00 for WHITE
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* \return pixd, or NULL on error
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*/
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PIX *
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pixBilinearColor(PIX *pixs,
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l_float32 *vc,
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l_uint32 colorval)
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{
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l_int32 i, j, w, h, d, wpls, wpld;
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l_uint32 val;
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l_uint32 *datas, *datad, *lined;
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l_float32 x, y;
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PIX *pix1, *pix2, *pixd;
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PROCNAME("pixBilinearColor");
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if (!pixs)
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return (PIX *)ERROR_PTR("pixs not defined", procName, NULL);
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pixGetDimensions(pixs, &w, &h, &d);
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if (d != 32)
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return (PIX *)ERROR_PTR("pixs must be 32 bpp", procName, NULL);
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if (!vc)
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return (PIX *)ERROR_PTR("vc not defined", procName, NULL);
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datas = pixGetData(pixs);
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wpls = pixGetWpl(pixs);
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pixd = pixCreateTemplate(pixs);
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pixSetAllArbitrary(pixd, colorval);
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datad = pixGetData(pixd);
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wpld = pixGetWpl(pixd);
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/* Iterate over destination pixels */
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for (i = 0; i < h; i++) {
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lined = datad + i * wpld;
|
|
for (j = 0; j < w; j++) {
|
|
/* Compute float src pixel location corresponding to (i,j) */
|
|
bilinearXformPt(vc, j, i, &x, &y);
|
|
linearInterpolatePixelColor(datas, wpls, w, h, x, y, colorval,
|
|
&val);
|
|
*(lined + j) = val;
|
|
}
|
|
}
|
|
|
|
/* If rgba, transform the pixs alpha channel and insert in pixd */
|
|
if (pixGetSpp(pixs) == 4) {
|
|
pix1 = pixGetRGBComponent(pixs, L_ALPHA_CHANNEL);
|
|
pix2 = pixBilinearGray(pix1, vc, 255); /* bring in opaque */
|
|
pixSetRGBComponent(pixd, pix2, L_ALPHA_CHANNEL);
|
|
pixDestroy(&pix1);
|
|
pixDestroy(&pix2);
|
|
}
|
|
|
|
return pixd;
|
|
}
|
|
|
|
|
|
/*!
|
|
* \brief pixBilinearPtaGray()
|
|
*
|
|
* \param[in] pixs 8 bpp
|
|
* \param[in] ptad 4 pts of final coordinate space
|
|
* \param[in] ptas 4 pts of initial coordinate space
|
|
* \param[in] grayval e.g., 0 to bring in BLACK, 255 for WHITE
|
|
* \return pixd, or NULL on error
|
|
*/
|
|
PIX *
|
|
pixBilinearPtaGray(PIX *pixs,
|
|
PTA *ptad,
|
|
PTA *ptas,
|
|
l_uint8 grayval)
|
|
{
|
|
l_float32 *vc;
|
|
PIX *pixd;
|
|
|
|
PROCNAME("pixBilinearPtaGray");
|
|
|
|
if (!pixs)
|
|
return (PIX *)ERROR_PTR("pixs not defined", procName, NULL);
|
|
if (!ptas)
|
|
return (PIX *)ERROR_PTR("ptas not defined", procName, NULL);
|
|
if (!ptad)
|
|
return (PIX *)ERROR_PTR("ptad not defined", procName, NULL);
|
|
if (pixGetDepth(pixs) != 8)
|
|
return (PIX *)ERROR_PTR("pixs must be 8 bpp", procName, NULL);
|
|
if (ptaGetCount(ptas) != 4)
|
|
return (PIX *)ERROR_PTR("ptas count not 4", procName, NULL);
|
|
if (ptaGetCount(ptad) != 4)
|
|
return (PIX *)ERROR_PTR("ptad count not 4", procName, NULL);
|
|
|
|
/* Get backwards transform from dest to src, and apply it */
|
|
getBilinearXformCoeffs(ptad, ptas, &vc);
|
|
pixd = pixBilinearGray(pixs, vc, grayval);
|
|
LEPT_FREE(vc);
|
|
|
|
return pixd;
|
|
}
|
|
|
|
|
|
/*!
|
|
* \brief pixBilinearGray()
|
|
*
|
|
* \param[in] pixs 8 bpp
|
|
* \param[in] vc vector of 8 coefficients for bilinear transformation
|
|
* \param[in] grayval e.g., 0 to bring in BLACK, 255 for WHITE
|
|
* \return pixd, or NULL on error
|
|
*/
|
|
PIX *
|
|
pixBilinearGray(PIX *pixs,
|
|
l_float32 *vc,
|
|
l_uint8 grayval)
|
|
{
|
|
l_int32 i, j, w, h, wpls, wpld, val;
|
|
l_uint32 *datas, *datad, *lined;
|
|
l_float32 x, y;
|
|
PIX *pixd;
|
|
|
|
PROCNAME("pixBilinearGray");
|
|
|
|
if (!pixs)
|
|
return (PIX *)ERROR_PTR("pixs not defined", procName, NULL);
|
|
pixGetDimensions(pixs, &w, &h, NULL);
|
|
if (pixGetDepth(pixs) != 8)
|
|
return (PIX *)ERROR_PTR("pixs must be 8 bpp", procName, NULL);
|
|
if (!vc)
|
|
return (PIX *)ERROR_PTR("vc not defined", procName, NULL);
|
|
|
|
datas = pixGetData(pixs);
|
|
wpls = pixGetWpl(pixs);
|
|
pixd = pixCreateTemplate(pixs);
|
|
pixSetAllArbitrary(pixd, grayval);
|
|
datad = pixGetData(pixd);
|
|
wpld = pixGetWpl(pixd);
|
|
|
|
/* Iterate over destination pixels */
|
|
for (i = 0; i < h; i++) {
|
|
lined = datad + i * wpld;
|
|
for (j = 0; j < w; j++) {
|
|
/* Compute float src pixel location corresponding to (i,j) */
|
|
bilinearXformPt(vc, j, i, &x, &y);
|
|
linearInterpolatePixelGray(datas, wpls, w, h, x, y, grayval, &val);
|
|
SET_DATA_BYTE(lined, j, val);
|
|
}
|
|
}
|
|
|
|
return pixd;
|
|
}
|
|
|
|
|
|
/*-------------------------------------------------------------------------*
|
|
* Bilinear transform including alpha (blend) component *
|
|
*-------------------------------------------------------------------------*/
|
|
/*!
|
|
* \brief pixBilinearPtaWithAlpha()
|
|
*
|
|
* \param[in] pixs 32 bpp rgb
|
|
* \param[in] ptad 4 pts of final coordinate space
|
|
* \param[in] ptas 4 pts of initial coordinate space
|
|
* \param[in] pixg [optional] 8 bpp, can be null
|
|
* \param[in] fract between 0.0 and 1.0, with 0.0 fully transparent
|
|
* and 1.0 fully opaque
|
|
* \param[in] border of pixels added to capture transformed source pixels
|
|
* \return pixd, or NULL on error
|
|
*
|
|
* <pre>
|
|
* Notes:
|
|
* (1) The alpha channel is transformed separately from pixs,
|
|
* and aligns with it, being fully transparent outside the
|
|
* boundary of the transformed pixs. For pixels that are fully
|
|
* transparent, a blending function like pixBlendWithGrayMask()
|
|
* will give zero weight to corresponding pixels in pixs.
|
|
* (2) If %pixg is NULL, it is generated as an alpha layer that is
|
|
* partially opaque, using %fract. Otherwise, it is cropped
|
|
* to %pixs if required and %fract is ignored. The alpha channel
|
|
* in %pixs is never used.
|
|
* (3) Colormaps are removed.
|
|
* (4) When pixs is transformed, it doesn't matter what color is brought
|
|
* in because the alpha channel will be transparent (0) there.
|
|
* (5) To avoid losing source pixels in the destination, it may be
|
|
* necessary to add a border to the source pix before doing
|
|
* the bilinear transformation. This can be any non-negative number.
|
|
* (6) The input %ptad and %ptas are in a coordinate space before
|
|
* the border is added. Internally, we compensate for this
|
|
* before doing the bilinear transform on the image after
|
|
* the border is added.
|
|
* (7) The default setting for the border values in the alpha channel
|
|
* is 0 (transparent) for the outermost ring of pixels and
|
|
* (0.5 * fract * 255) for the second ring. When blended over
|
|
* a second image, this
|
|
* (a) shrinks the visible image to make a clean overlap edge
|
|
* with an image below, and
|
|
* (b) softens the edges by weakening the aliasing there.
|
|
* Use l_setAlphaMaskBorder() to change these values.
|
|
* </pre>
|
|
*/
|
|
PIX *
|
|
pixBilinearPtaWithAlpha(PIX *pixs,
|
|
PTA *ptad,
|
|
PTA *ptas,
|
|
PIX *pixg,
|
|
l_float32 fract,
|
|
l_int32 border)
|
|
{
|
|
l_int32 ws, hs, d;
|
|
PIX *pixd, *pixb1, *pixb2, *pixg2, *pixga;
|
|
PTA *ptad2, *ptas2;
|
|
|
|
PROCNAME("pixBilinearPtaWithAlpha");
|
|
|
|
if (!pixs)
|
|
return (PIX *)ERROR_PTR("pixs not defined", procName, NULL);
|
|
pixGetDimensions(pixs, &ws, &hs, &d);
|
|
if (d != 32 && pixGetColormap(pixs) == NULL)
|
|
return (PIX *)ERROR_PTR("pixs not cmapped or 32 bpp", procName, NULL);
|
|
if (pixg && pixGetDepth(pixg) != 8) {
|
|
L_WARNING("pixg not 8 bpp; using 'fract' transparent alpha\n",
|
|
procName);
|
|
pixg = NULL;
|
|
}
|
|
if (!pixg && (fract < 0.0 || fract > 1.0)) {
|
|
L_WARNING("invalid fract; using 1.0 (fully transparent)\n", procName);
|
|
fract = 1.0;
|
|
}
|
|
if (!pixg && fract == 0.0)
|
|
L_WARNING("fully opaque alpha; image cannot be blended\n", procName);
|
|
if (!ptad)
|
|
return (PIX *)ERROR_PTR("ptad not defined", procName, NULL);
|
|
if (!ptas)
|
|
return (PIX *)ERROR_PTR("ptas not defined", procName, NULL);
|
|
|
|
/* Add border; the color doesn't matter */
|
|
pixb1 = pixAddBorder(pixs, border, 0);
|
|
|
|
/* Transform the ptr arrays to work on the bordered image */
|
|
ptad2 = ptaTransform(ptad, border, border, 1.0, 1.0);
|
|
ptas2 = ptaTransform(ptas, border, border, 1.0, 1.0);
|
|
|
|
/* Do separate bilinear transform of rgb channels of pixs and of pixg */
|
|
pixd = pixBilinearPtaColor(pixb1, ptad2, ptas2, 0);
|
|
if (!pixg) {
|
|
pixg2 = pixCreate(ws, hs, 8);
|
|
if (fract == 1.0)
|
|
pixSetAll(pixg2);
|
|
else
|
|
pixSetAllArbitrary(pixg2, (l_int32)(255.0 * fract));
|
|
} else {
|
|
pixg2 = pixResizeToMatch(pixg, NULL, ws, hs);
|
|
}
|
|
if (ws > 10 && hs > 10) { /* see note 7 */
|
|
pixSetBorderRingVal(pixg2, 1,
|
|
(l_int32)(255.0 * fract * AlphaMaskBorderVals[0]));
|
|
pixSetBorderRingVal(pixg2, 2,
|
|
(l_int32)(255.0 * fract * AlphaMaskBorderVals[1]));
|
|
|
|
}
|
|
pixb2 = pixAddBorder(pixg2, border, 0); /* must be black border */
|
|
pixga = pixBilinearPtaGray(pixb2, ptad2, ptas2, 0);
|
|
pixSetRGBComponent(pixd, pixga, L_ALPHA_CHANNEL);
|
|
pixSetSpp(pixd, 4);
|
|
|
|
pixDestroy(&pixg2);
|
|
pixDestroy(&pixb1);
|
|
pixDestroy(&pixb2);
|
|
pixDestroy(&pixga);
|
|
ptaDestroy(&ptad2);
|
|
ptaDestroy(&ptas2);
|
|
return pixd;
|
|
}
|
|
|
|
|
|
/*-------------------------------------------------------------*
|
|
* Bilinear coordinate transformation *
|
|
*-------------------------------------------------------------*/
|
|
/*!
|
|
* \brief getBilinearXformCoeffs()
|
|
*
|
|
* \param[in] ptas source 4 points; unprimed
|
|
* \param[in] ptad transformed 4 points; primed
|
|
* \param[out] pvc vector of coefficients of transform
|
|
* \return 0 if OK; 1 on error
|
|
*
|
|
* <pre>
|
|
* We have a set of 8 equations, describing the bilinear
|
|
* transformation that takes 4 points ptas into 4 other
|
|
* points ptad. These equations are:
|
|
*
|
|
* x1' = c[0]*x1 + c[1]*y1 + c[2]*x1*y1 + c[3]
|
|
* y1' = c[4]*x1 + c[5]*y1 + c[6]*x1*y1 + c[7]
|
|
* x2' = c[0]*x2 + c[1]*y2 + c[2]*x2*y2 + c[3]
|
|
* y2' = c[4]*x2 + c[5]*y2 + c[6]*x2*y2 + c[7]
|
|
* x3' = c[0]*x3 + c[1]*y3 + c[2]*x3*y3 + c[3]
|
|
* y3' = c[4]*x3 + c[5]*y3 + c[6]*x3*y3 + c[7]
|
|
* x4' = c[0]*x4 + c[1]*y4 + c[2]*x4*y4 + c[3]
|
|
* y4' = c[4]*x4 + c[5]*y4 + c[6]*x4*y4 + c[7]
|
|
*
|
|
* This can be represented as
|
|
*
|
|
* AC = B
|
|
*
|
|
* where B and C are column vectors
|
|
*
|
|
* B = [ x1' y1' x2' y2' x3' y3' x4' y4' ]
|
|
* C = [ c[0] c[1] c[2] c[3] c[4] c[5] c[6] c[7] ]
|
|
*
|
|
* and A is the 8x8 matrix
|
|
*
|
|
* x1 y1 x1*y1 1 0 0 0 0
|
|
* 0 0 0 0 x1 y1 x1*y1 1
|
|
* x2 y2 x2*y2 1 0 0 0 0
|
|
* 0 0 0 0 x2 y2 x2*y2 1
|
|
* x3 y3 x3*y3 1 0 0 0 0
|
|
* 0 0 0 0 x3 y3 x3*y3 1
|
|
* x4 y4 x4*y4 1 0 0 0 0
|
|
* 0 0 0 0 x4 y4 x4*y4 1
|
|
*
|
|
* These eight equations are solved here for the coefficients C.
|
|
*
|
|
* These eight coefficients can then be used to find the mapping
|
|
* x,y) --> (x',y':
|
|
*
|
|
* x' = c[0]x + c[1]y + c[2]xy + c[3]
|
|
* y' = c[4]x + c[5]y + c[6]xy + c[7]
|
|
*
|
|
* that are implemented in bilinearXformSampledPt and
|
|
* bilinearXFormPt.
|
|
* </pre>
|
|
*/
|
|
l_ok
|
|
getBilinearXformCoeffs(PTA *ptas,
|
|
PTA *ptad,
|
|
l_float32 **pvc)
|
|
{
|
|
l_int32 i;
|
|
l_float32 x1, y1, x2, y2, x3, y3, x4, y4;
|
|
l_float32 *b; /* rhs vector of primed coords X'; coeffs returned in *pvc */
|
|
l_float32 *a[8]; /* 8x8 matrix A */
|
|
|
|
PROCNAME("getBilinearXformCoeffs");
|
|
|
|
if (!ptas)
|
|
return ERROR_INT("ptas not defined", procName, 1);
|
|
if (!ptad)
|
|
return ERROR_INT("ptad not defined", procName, 1);
|
|
if (!pvc)
|
|
return ERROR_INT("&vc not defined", procName, 1);
|
|
|
|
b = (l_float32 *)LEPT_CALLOC(8, sizeof(l_float32));
|
|
*pvc = b;
|
|
ptaGetPt(ptas, 0, &x1, &y1);
|
|
ptaGetPt(ptas, 1, &x2, &y2);
|
|
ptaGetPt(ptas, 2, &x3, &y3);
|
|
ptaGetPt(ptas, 3, &x4, &y4);
|
|
ptaGetPt(ptad, 0, &b[0], &b[1]);
|
|
ptaGetPt(ptad, 1, &b[2], &b[3]);
|
|
ptaGetPt(ptad, 2, &b[4], &b[5]);
|
|
ptaGetPt(ptad, 3, &b[6], &b[7]);
|
|
|
|
for (i = 0; i < 8; i++)
|
|
a[i] = (l_float32 *)LEPT_CALLOC(8, sizeof(l_float32));
|
|
a[0][0] = x1;
|
|
a[0][1] = y1;
|
|
a[0][2] = x1 * y1;
|
|
a[0][3] = 1.;
|
|
a[1][4] = x1;
|
|
a[1][5] = y1;
|
|
a[1][6] = x1 * y1;
|
|
a[1][7] = 1.;
|
|
a[2][0] = x2;
|
|
a[2][1] = y2;
|
|
a[2][2] = x2 * y2;
|
|
a[2][3] = 1.;
|
|
a[3][4] = x2;
|
|
a[3][5] = y2;
|
|
a[3][6] = x2 * y2;
|
|
a[3][7] = 1.;
|
|
a[4][0] = x3;
|
|
a[4][1] = y3;
|
|
a[4][2] = x3 * y3;
|
|
a[4][3] = 1.;
|
|
a[5][4] = x3;
|
|
a[5][5] = y3;
|
|
a[5][6] = x3 * y3;
|
|
a[5][7] = 1.;
|
|
a[6][0] = x4;
|
|
a[6][1] = y4;
|
|
a[6][2] = x4 * y4;
|
|
a[6][3] = 1.;
|
|
a[7][4] = x4;
|
|
a[7][5] = y4;
|
|
a[7][6] = x4 * y4;
|
|
a[7][7] = 1.;
|
|
|
|
gaussjordan(a, b, 8);
|
|
|
|
for (i = 0; i < 8; i++)
|
|
LEPT_FREE(a[i]);
|
|
return 0;
|
|
}
|
|
|
|
|
|
/*!
|
|
* \brief bilinearXformSampledPt()
|
|
*
|
|
* \param[in] vc vector of 8 coefficients
|
|
* \param[in] x, y initial point
|
|
* \param[out] pxp, pyp transformed point
|
|
* \return 0 if OK; 1 on error
|
|
*
|
|
* <pre>
|
|
* Notes:
|
|
* (1) This finds the nearest pixel coordinates of the transformed point.
|
|
* (2) It does not check ptrs for returned data!
|
|
* </pre>
|
|
*/
|
|
l_ok
|
|
bilinearXformSampledPt(l_float32 *vc,
|
|
l_int32 x,
|
|
l_int32 y,
|
|
l_int32 *pxp,
|
|
l_int32 *pyp)
|
|
{
|
|
|
|
PROCNAME("bilinearXformSampledPt");
|
|
|
|
if (!vc)
|
|
return ERROR_INT("vc not defined", procName, 1);
|
|
|
|
*pxp = (l_int32)(vc[0] * x + vc[1] * y + vc[2] * x * y + vc[3] + 0.5);
|
|
*pyp = (l_int32)(vc[4] * x + vc[5] * y + vc[6] * x * y + vc[7] + 0.5);
|
|
return 0;
|
|
}
|
|
|
|
|
|
/*!
|
|
* \brief bilinearXformPt()
|
|
*
|
|
* \param[in] vc vector of 8 coefficients
|
|
* \param[in] x, y initial point
|
|
* \param[out] pxp, pyp transformed point
|
|
* \return 0 if OK; 1 on error
|
|
*
|
|
* <pre>
|
|
* Notes:
|
|
* (1) This computes the floating point location of the transformed point.
|
|
* (2) It does not check ptrs for returned data!
|
|
* </pre>
|
|
*/
|
|
l_ok
|
|
bilinearXformPt(l_float32 *vc,
|
|
l_int32 x,
|
|
l_int32 y,
|
|
l_float32 *pxp,
|
|
l_float32 *pyp)
|
|
{
|
|
PROCNAME("bilinearXformPt");
|
|
|
|
if (!vc)
|
|
return ERROR_INT("vc not defined", procName, 1);
|
|
|
|
*pxp = vc[0] * x + vc[1] * y + vc[2] * x * y + vc[3];
|
|
*pyp = vc[4] * x + vc[5] * y + vc[6] * x * y + vc[7];
|
|
return 0;
|
|
}
|