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Psf.cc
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1// -*- LSST-C++ -*-
2#include <limits>
3#include <cmath>
4#include <memory>
5
6#include "lsst/utils/Cache.h"
10
11namespace lsst {
12namespace afw {
13
16
17namespace detection {
18namespace detail {
19
20// Key for caching PSFs with lsst::utils::Cache
21//
22// We cache PSFs by their x,y position. Although there are placeholders
23// in the `Psf` class and here for `image::Color`, these are not used
24// in the cache because `image::Color` is not currently well-defined
25// or used.
29
31 : position(position_), color(color_) {}
32
33 bool operator==(PsfCacheKey const &other) const {
34 return position == other.position; // Currently don't care about color
35 }
36
37 friend std::ostream &operator<<(std::ostream &os, PsfCacheKey const &key) { return os << key.position; }
38};
39
40} // namespace detail
41} // namespace detection
42} // namespace afw
43} // namespace lsst
44
45namespace std {
46
47// Template specialisation for hashing PsfCacheKey
48//
49// We currently ignore the color, consistent with operator==.
50template <>
55 return std::hash<lsst::geom::Point2D>()(key.position);
56 }
57};
58
59} // namespace std
60
61namespace lsst {
62namespace afw {
63namespace detection {
64
65namespace {
66
67bool isPointNull(lsst::geom::Point2D const &p) { return std::isnan(p.getX()) && std::isnan(p.getY()); }
68
69} // namespace
70
71Psf::Psf(bool isFixed, std::size_t capacity) : _isFixed(isFixed) {
72 _imageCache = std::make_unique<PsfCache>(capacity);
73 _kernelImageCache = std::make_unique<PsfCache>(capacity);
74}
75
76Psf::~Psf() = default;
77
78Psf::Psf(Psf const &other) : Psf(other._isFixed, other.getCacheCapacity()) {}
79
80Psf::Psf(Psf &&other)
81 : _isFixed(other._isFixed),
82 _imageCache(std::move(other._imageCache)),
83 _kernelImageCache(std::move(other._kernelImageCache)) {}
84
86 lsst::geom::Point2D const &position,
87 std::string const &warpAlgorithm,
88 unsigned int warpBuffer) {
89 // "ir" : (integer, residual)
90 std::pair<int, double> const irX = image::positionToIndex(position.getX(), true);
91 std::pair<int, double> const irY = image::positionToIndex(position.getY(), true);
92
93 if (irX.second != 0.0 || irY.second != 0.0) {
94 im = math::offsetImage(*im, irX.second, irY.second, warpAlgorithm, warpBuffer);
95 }
96
97 im->setXY0(irX.first + im->getX0(), irY.first + im->getY0());
98 return im;
99}
100
102 return computeImage(makeNullPoint());
103}
104
106 ImageOwnerEnum owner) const {
107 if (isPointNull(position)) position = getAveragePosition();
108 if (color.isIndeterminate()) color = getAverageColor();
109 std::shared_ptr<Psf::Image> result = (*_imageCache)(
110 detail::PsfCacheKey(position, color),
111 [this](detail::PsfCacheKey const &key) { return doComputeImage(key.position, key.color); });
112 if (owner == COPY) {
113 result = std::make_shared<Image>(*result, true);
114 }
115 return result;
116}
117
119 return computeKernelImage(makeNullPoint());
120}
121
123 ImageOwnerEnum owner) const {
124 if (_isFixed || isPointNull(position)) position = getAveragePosition();
125 if (_isFixed || color.isIndeterminate()) color = getAverageColor();
126 std::shared_ptr<Psf::Image> result = (*_kernelImageCache)(
127 detail::PsfCacheKey(position, color),
128 [this](detail::PsfCacheKey const &key) { return doComputeKernelImage(key.position, key.color); });
129 if (owner == COPY) {
130 result = std::make_shared<Image>(*result, true);
131 }
132 return result;
133}
134
136 return computeBBox(makeNullPoint());
137}
138
140 if (isPointNull(position)) position = getAveragePosition();
141 if (color.isIndeterminate()) color = getAverageColor();
142 auto cached_image = _kernelImageCache->get(detail::PsfCacheKey(position, color));
143 if (cached_image.has_value()) {
144 return cached_image.value()->getBBox();
145 } else {
146 return doComputeBBox(position, color);
147 }
148}
149
151 return computeImageBBox(makeNullPoint());
152}
153
155 if (isPointNull(position)) position = getAveragePosition();
156 if (color.isIndeterminate()) color = getAverageColor();
157 auto cached_image = _imageCache->get(detail::PsfCacheKey(position, color));
158 if (cached_image.has_value()) {
159 return cached_image.value()->getBBox();
160 } else {
161 return doComputeImageBBox(position, color);
162 }
163}
164
166 return getLocalKernel(makeNullPoint());
167}
168
170 image::Color color) const {
171 if (isPointNull(position)) position = getAveragePosition();
172 if (color.isIndeterminate()) color = getAverageColor();
173 // FixedKernel ctor will deep copy image, so we can use INTERNAL.
175 return std::make_shared<math::FixedKernel>(*image);
176}
177
178double Psf::computePeak() const {
179 return computePeak(makeNullPoint());
180}
181
182double Psf::computePeak(lsst::geom::Point2D position, image::Color color) const {
183 if (isPointNull(position)) position = getAveragePosition();
184 if (color.isIndeterminate()) color = getAverageColor();
186 return (*image)(-image->getX0(), -image->getY0());
187}
188
189double Psf::computeApertureFlux(double radius) const {
190 return computeApertureFlux(radius, makeNullPoint());
191}
192
193double Psf::computeApertureFlux(double radius, lsst::geom::Point2D position, image::Color color) const {
194 if (isPointNull(position)) position = getAveragePosition();
195 if (color.isIndeterminate()) color = getAverageColor();
196 return doComputeApertureFlux(radius, position, color);
197}
198
200 return computeShape(makeNullPoint());
201}
202
204 if (isPointNull(position)) position = getAveragePosition();
205 if (color.isIndeterminate()) color = getAverageColor();
206 return doComputeShape(position, color);
207}
208
210 image::Color const &color) const {
212 return recenterKernelImage(im, position);
213}
214
216 image::Color const& color) const {
218 return im->getBBox();
219}
220
222
223std::size_t Psf::getCacheCapacity() const { return _kernelImageCache->capacity(); }
224
226 _imageCache->reserve(capacity);
227 _kernelImageCache->reserve(capacity);
228}
229
230} // namespace detection
231} // namespace afw
232} // namespace lsst
std::ostream * os
Definition: Schema.cc:557
A polymorphic base class for representing an image's Point Spread Function.
Definition: Psf.h:76
static std::shared_ptr< Image > recenterKernelImage(std::shared_ptr< Image > im, lsst::geom::Point2D const &position, std::string const &warpAlgorithm="lanczos5", unsigned int warpBuffer=5)
Helper function for Psf::doComputeImage(): converts a kernel image (centered at (0,...
Definition: Psf.cc:85
lsst::geom::Box2I computeBBox() const
Definition: Psf.cc:135
virtual std::shared_ptr< Image > doComputeImage(lsst::geom::Point2D const &position, image::Color const &color) const
These virtual members are protected (rather than private) so that python-implemented derived classes ...
Definition: Psf.cc:209
std::shared_ptr< Image > computeKernelImage(lsst::geom::Point2D position, image::Color color=image::Color(), ImageOwnerEnum owner=COPY) const
Return an Image of the PSF, in a form suitable for convolution.
Definition: Psf.cc:122
lsst::geom::Box2I computeImageBBox() const
Definition: Psf.cc:150
virtual std::shared_ptr< Image > doComputeKernelImage(lsst::geom::Point2D const &position, image::Color const &color) const =0
These virtual member functions are private, not protected, because we only want derived classes to im...
std::size_t getCacheCapacity() const
Return the capacity of the caches.
Definition: Psf.cc:223
double computeApertureFlux(double radius, lsst::geom::Point2D position, image::Color color=image::Color()) const
Compute the "flux" of the Psf model within a circular aperture of the given radius.
Definition: Psf.cc:193
std::shared_ptr< Image > computeImage() const
Definition: Psf.cc:101
std::shared_ptr< Image > computeKernelImage() const
Definition: Psf.cc:118
Psf(Psf const &)
Definition: Psf.cc:78
std::shared_ptr< Image > computeImage(lsst::geom::Point2D position, image::Color color=image::Color(), ImageOwnerEnum owner=COPY) const
Return an Image of the PSF, in a form that can be compared directly with star images.
Definition: Psf.cc:105
double computePeak() const
Definition: Psf.cc:178
image::Color getAverageColor() const
Return the average Color of the stars used to construct the Psf.
Definition: Psf.h:274
virtual lsst::geom::Box2I doComputeImageBBox(lsst::geom::Point2D const &position, image::Color const &color) const
Definition: Psf.cc:215
ImageOwnerEnum
Enum passed to computeImage and computeKernelImage to determine image ownership.
Definition: Psf.h:86
@ COPY
The image will be copied before returning; caller will own it.
Definition: Psf.h:87
@ INTERNAL
An internal image will be returned without copying.
Definition: Psf.h:88
virtual lsst::geom::Box2I doComputeBBox(lsst::geom::Point2D const &position, image::Color const &color) const =0
void setCacheCapacity(std::size_t capacity)
Set the capacity of the caches.
Definition: Psf.cc:225
geom::ellipses::Quadrupole computeShape() const
Definition: Psf.cc:199
virtual double doComputeApertureFlux(double radius, lsst::geom::Point2D const &position, image::Color const &color) const =0
virtual lsst::geom::Point2D getAveragePosition() const
Return the average position of the stars used to construct the Psf.
Definition: Psf.cc:221
virtual geom::ellipses::Quadrupole doComputeShape(lsst::geom::Point2D const &position, image::Color const &color) const =0
std::shared_ptr< math::Kernel const > getLocalKernel() const
Definition: Psf.cc:165
An ellipse core with quadrupole moments as parameters.
Definition: Quadrupole.h:47
Describe the colour of a source.
Definition: Color.h:25
bool isIndeterminate() const noexcept
Whether the color is the special value that indicates that it is unspecified.
Definition: Color.h:36
static std::shared_ptr< T > dynamicCast(std::shared_ptr< Persistable > const &ptr)
Dynamically cast a shared_ptr.
Definition: Persistable.cc:18
T get(T... args)
T isnan(T... args)
int positionToIndex(double pos)
Convert image position to nearest integer index.
Definition: ImageUtils.h:69
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
Point< double, 2 > Point2D
STL namespace.
lsst::geom::Point2D const position
Definition: Psf.cc:27
bool operator==(PsfCacheKey const &other) const
Definition: Psf.cc:33
PsfCacheKey(lsst::geom::Point2D const &position_, image::Color color_=image::Color())
Definition: Psf.cc:30
friend std::ostream & operator<<(std::ostream &os, PsfCacheKey const &key)
Definition: Psf.cc:37
std::size_t operator()(lsst::afw::detection::detail::PsfCacheKey const &key) const noexcept
Definition: Psf.cc:54