LSSTApplications  20.0.0
LSSTDataManagementBasePackage
offsetImage.cc
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1 // -*- lsst-c++ -*-
2 
3 /*
4  * LSST Data Management System
5  * Copyright 2008, 2009, 2010 LSST Corporation.
6  *
7  * This product includes software developed by the
8  * LSST Project (http://www.lsst.org/).
9  *
10  * This program is free software: you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation, either version 3 of the License, or
13  * (at your option) any later version.
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18  * GNU General Public License for more details.
19  *
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22  * see <http://www.lsstcorp.org/LegalNotices/>.
23  */
24 
25 /*
26  * Offset an Image (or Mask or MaskedImage) by a constant vector (dx, dy)
27  */
28 #include <iterator>
29 #include "lsst/geom.h"
33 
34 namespace afwImage = lsst::afw::image;
35 
36 namespace lsst {
37 namespace afw {
38 namespace math {
39 
40 template <typename ImageT>
41 std::shared_ptr<ImageT> offsetImage(ImageT const& inImage, float dx, float dy,
42  std::string const& algorithmName, unsigned int buffer
43 
44 ) {
45  std::shared_ptr<SeparableKernel> offsetKernel = makeWarpingKernel(algorithmName);
46 
47  std::shared_ptr<ImageT> buffImage;
48  if (buffer > 0) {
49  // Paste input image into buffered image
50  lsst::geom::Extent2I const& dims = inImage.getDimensions();
51  std::shared_ptr<ImageT> buffered(new ImageT(dims.getX() + 2 * buffer, dims.getY() + 2 * buffer));
52  buffImage = buffered;
53  lsst::geom::Box2I box(lsst::geom::Point2I(buffer, buffer), dims);
54  buffImage->assign(inImage, box);
55  } else {
56  buffImage = std::make_shared<ImageT>(inImage);
57  }
58 
59  if (offsetKernel->getWidth() > buffImage->getWidth() ||
60  offsetKernel->getHeight() > buffImage->getHeight()) {
62  (boost::format("Image of size %dx%d is too small to offset using a %s kernel"
63  "(minimum %dx%d)") %
64  buffImage->getWidth() % buffImage->getHeight() % algorithmName %
65  offsetKernel->getWidth() % offsetKernel->getHeight())
66  .str());
67  }
68 
69  // std::shared_ptr<ImageT> convImage(new ImageT(buffImage, true)); // output image, a deep copy
70  std::shared_ptr<ImageT> convImage(new ImageT(buffImage->getDimensions())); // Convolved image
71 
72  int dOrigX, dOrigY;
73  double fracX, fracY;
74  // If the offset in both axes is in (-1, 1) use it as is, and don't shift the origin
75  if (dx > -1 && dx < 1 && dy > -1 && dy < 1) {
76  dOrigX = 0;
77  dOrigY = 0;
78  fracX = dx;
79  fracY = dy;
80  } else {
81  dOrigX = static_cast<int>(std::floor(dx + 0.5));
82  dOrigY = static_cast<int>(std::floor(dy + 0.5));
83  fracX = dx - dOrigX;
84  fracY = dy - dOrigY;
85  }
86 
87  // We seem to have to pass -fracX, -fracY to setKernelParameters, for reasons RHL doesn't understand
88  double dKerX = -fracX;
89  double dKerY = -fracY;
90 
91  //
92  // If the shift is -ve, the generated shift kernel (e.g. Lanczos5) is quite asymmetric, with the
93  // largest coefficients to the left of centre. We therefore move the centre of calculated shift kernel
94  // one to the right to center up the largest coefficients
95  //
96  if (dKerX < 0) {
97  offsetKernel->setCtr(offsetKernel->getCtr() + lsst::geom::Extent2I(1, 0));
98  }
99  if (dKerY < 0) {
100  offsetKernel->setCtr(offsetKernel->getCtr() + lsst::geom::Extent2I(0, 1));
101  }
102 
103  offsetKernel->setKernelParameters(std::make_pair(dKerX, dKerY));
104 
105  convolve(*convImage, *buffImage, *offsetKernel, true, true);
106 
107  std::shared_ptr<ImageT> outImage;
108  if (buffer > 0) {
109  lsst::geom::Box2I box(lsst::geom::Point2I(buffer, buffer), inImage.getDimensions());
110  std::shared_ptr<ImageT> out(new ImageT(*convImage, box, afwImage::LOCAL, true));
111  outImage = out;
112  } else {
113  outImage = convImage;
114  }
115 
116  // adjust the origin; do this after convolution since convolution also sets XY0
117  outImage->setXY0(lsst::geom::Point2I(inImage.getX0() + dOrigX, inImage.getY0() + dOrigY));
118 
119  return outImage;
120 }
121 
122 //
123 // Explicit instantiations
124 //
126 #define INSTANTIATE(TYPE) \
127  template std::shared_ptr<afwImage::Image<TYPE>> offsetImage(afwImage::Image<TYPE> const&, float, float, \
128  std::string const&, unsigned int); \
129  template std::shared_ptr<afwImage::MaskedImage<TYPE>> offsetImage( \
130  afwImage::MaskedImage<TYPE> const&, float, float, std::string const&, unsigned int);
131 
132 INSTANTIATE(double)
133 INSTANTIATE(float)
134 INSTANTIATE(int)
136 } // namespace math
137 } // namespace afw
138 } // namespace lsst
lsst::afw::image
Backwards-compatibility support for depersisting the old Calib (FluxMag0/FluxMag0Err) objects.
Definition: imageAlgorithm.dox:1
offsetImage.h
std::floor
T floor(T... args)
lsst::afw::image::LOCAL
@ LOCAL
Definition: ImageBase.h:94
std::string
STL class.
std::shared_ptr< ImageT >
lsst::afw::math::Kernel::getHeight
int getHeight() const
Return the Kernel's height.
Definition: Kernel.h:230
pex.config.history.format
def format(config, name=None, writeSourceLine=True, prefix="", verbose=False)
Definition: history.py:174
lsst::afw::math::makeWarpingKernel
std::shared_ptr< SeparableKernel > makeWarpingKernel(std::string name)
Return a warping kernel given its name.
Definition: warpExposure.cc:161
lsst::afw
Definition: imageAlgorithm.dox:1
INSTANTIATE
#define INSTANTIATE(FROMSYS, TOSYS)
Definition: Detector.cc:484
geom.h
lsst::afw::math::Kernel::getCtr
lsst::geom::Point2I getCtr() const
Return index of kernel's center.
Definition: Kernel.h:235
lsst::afw::math::Kernel::setCtr
void setCtr(lsst::geom::Point2I ctr)
Set index of kernel's center.
Definition: Kernel.h:335
image
afw::table::Key< afw::table::Array< ImagePixelT > > image
Definition: HeavyFootprint.cc:216
lsst::pex::exceptions::LengthError
Reports attempts to exceed implementation-defined length limits for some classes.
Definition: Runtime.h:76
lsst::afw::math::Kernel::getWidth
int getWidth() const
Return the Kernel's width.
Definition: Kernel.h:225
lsst
A base class for image defects.
Definition: imageAlgorithm.dox:1
LSST_EXCEPT
#define LSST_EXCEPT(type,...)
Create an exception with a given type.
Definition: Exception.h:48
lsst::afw::math::convolve
void convolve(OutImageT &convolvedImage, InImageT const &inImage, KernelT const &kernel, ConvolutionControl const &convolutionControl=ConvolutionControl())
Convolve an Image or MaskedImage with a Kernel, setting pixels of an existing output image.
Definition: ConvolveImage.cc:190
lsst::geom::Extent2I
Extent< int, 2 > Extent2I
Definition: Extent.h:397
lsst::geom::Point< int, 2 >
lsst::afw::math::offsetImage
std::shared_ptr< ImageT > offsetImage(ImageT const &image, float dx, float dy, std::string const &algorithmName="lanczos5", unsigned int buffer=0)
Return an image offset by (dx, dy) using the specified algorithm.
Definition: offsetImage.cc:41
lsst::geom::Box2I
An integer coordinate rectangle.
Definition: Box.h:55
ImageUtils.h
std::make_pair
T make_pair(T... args)
lsst::afw::math::Kernel::setKernelParameters
void setKernelParameters(std::vector< double > const &params)
Set the kernel parameters of a spatially invariant kernel.
Definition: Kernel.h:388
lsst::geom::Extent< int, 2 >
warpExposure.h