LSSTApplications  10.0-2-g4f67435,11.0.rc2+1,11.0.rc2+12,11.0.rc2+3,11.0.rc2+4,11.0.rc2+5,11.0.rc2+6,11.0.rc2+7,11.0.rc2+8
LSSTDataManagementBasePackage
image2.cc
// -*- lsst-c++ -*-
/*
* LSST Data Management System
* Copyright 2008, 2009, 2010 LSST Corporation.
*
* This product includes software developed by the
* LSST Project (http://www.lsst.org/).
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the LSST License Statement and
* the GNU General Public License along with this program. If not,
* see <http://www.lsstcorp.org/LegalNotices/>.
*/
namespace geom=lsst::afw::geom;
namespace image = lsst::afw::image;
typedef image::Image<int> ImageT;
int main() {
ImageT in(geom::Extent2I(10, 6));
// Set data to a ramp
for (int y = 0; y != in.getHeight(); ++y) {
for (ImageT::xy_locator ptr = in.xy_at(0, y), end = in.xy_at(in.getWidth(), y);
ptr != end; ++ptr.x()) {
*ptr = y;
}
}
//
// Convolve with a pseudo-Gaussian kernel ((1, 2, 1), (2, 4, 2), (1, 2, 1))
//
ImageT out(in.getDimensions()); // Make an output image the same size as the input image
out <<= in;
for (int y = 1; y != in.getHeight() - 1; ++y) {
for (ImageT::xy_locator ptr = in.xy_at(1, y), end = in.xy_at(in.getWidth() - 1, y),
optr = out.xy_at(1, y); ptr != end; ++ptr.x(), ++optr.x()) {
*optr = ptr(-1,-1) + 2*ptr(0,-1) + ptr(1,-1) +
2*ptr(-1, 0) + 4*ptr(0, 0) + 2*ptr(1, 0) +
ptr(-1, 1) + 2*ptr(0, 1) + ptr(1, 1);
}
}
//
// Do the same thing a faster way, using cached_location_t
//
ImageT::Ptr out2(new ImageT(in.getDimensions()));
*out2 <<= in;
typedef ImageT::const_xy_locator xy_loc;
for (int y = 1; y != in.getHeight() - 1; ++y) {
// "dot" means "cursor location" in emacs
xy_loc dot = in.xy_at(1, y), end = in.xy_at(in.getWidth() - 1, y);
xy_loc::cached_location_t nw = dot.cache_location(-1,-1);
xy_loc::cached_location_t n = dot.cache_location( 0,-1);
xy_loc::cached_location_t ne = dot.cache_location( 1,-1);
xy_loc::cached_location_t w = dot.cache_location(-1, 0);
xy_loc::cached_location_t c = dot.cache_location( 0, 0);
xy_loc::cached_location_t e = dot.cache_location( 1, 0);
xy_loc::cached_location_t sw = dot.cache_location(-1, 1);
xy_loc::cached_location_t s = dot.cache_location( 0, 1);
xy_loc::cached_location_t se = dot.cache_location( 1, 1);
for (ImageT::x_iterator optr = out2->row_begin(y) + 1; dot != end; ++dot.x(), ++optr) {
*optr = dot[nw] + 2*dot[n] + dot[ne] +
2*dot[w] + 4*dot[c] + 2*dot[e] +
dot[sw] + 2*dot[s] + dot[se];
}
}
//
// Do the same calculation, but set nw etc. outside the loop
//
xy_loc pix11 = in.xy_at(1, 1);
xy_loc::cached_location_t nw = pix11.cache_location(-1,-1);
xy_loc::cached_location_t n = pix11.cache_location( 0,-1);
xy_loc::cached_location_t ne = pix11.cache_location( 1,-1);
xy_loc::cached_location_t w = pix11.cache_location(-1, 0);
xy_loc::cached_location_t c = pix11.cache_location( 0, 0);
xy_loc::cached_location_t e = pix11.cache_location( 1, 0);
xy_loc::cached_location_t sw = pix11.cache_location(-1, 1);
xy_loc::cached_location_t s = pix11.cache_location( 0, 1);
xy_loc::cached_location_t se = pix11.cache_location( 1, 1);
for (int y = 1; y != in.getHeight() - 1; ++y) {
// "dot" means "cursor location" in emacs
xy_loc dot = in.xy_at(1, y), end = in.xy_at(in.getWidth() - 1, y);
for (ImageT::x_iterator optr = out2->row_begin(y) + 1; dot != end; ++dot.x(), ++optr) {
*optr = dot[nw] + 2*dot[n] + dot[ne] +
2*dot[w] + 4*dot[c] + 2*dot[e] +
dot[sw] + 2*dot[s] + dot[se];
}
}
//
// Normalise the kernel. I.e. divide the smoothed parts of image2 by 16
//
{
ImageT center = ImageT(
*out2,
geom::Point2I(1, 1), in.getDimensions() - geom::Extent2I(2)
),
);
center /= 16;
}
//
// Clear in using the x_iterator embedded in the locator
//
for (int y = 0; y != in.getHeight(); ++y) {
for (ImageT::xy_x_iterator ptr = in.xy_at(0, y).x(), end = in.xy_at(in.getWidth(), y).x();
ptr != end; ++ptr) {
*ptr = 0;
}
}
//
// Save those images to disk
//
out.writeFits("foo.fits");
out2->writeFits("foo2.fits");
return 0;
}