def main():
# a 31x31 postage stamp image
nx, ny = 31, 31
# move xy0 to simulate it being a shallow bbox'd sub-image
xorig, yorig = 100, 300
xy0 = afwGeom.Point2I(xorig, yorig)
psfSigma = 3.0
x0, y0 = xorig + nx / 2, yorig + ny / 2
p0 = afwGeom.Point2D(x0, y0)
img = afwImage.ImageF(nx, ny, 0)
img.setXY0(xy0)
for i in range(ny):
for j in range(nx):
ic = i - (y0 - yorig)
jc = j - (x0 - xorig)
r = math.sqrt(ic * ic + jc * jc)
img.set(j, i, 1.0 * math.exp(-r**2 / (2.0 * psfSigma**2)))
# now warp it about the centroid using a linear transform
linTran = afwGeom.LinearTransform().makeScaling(
1.2) # a simple scale-by-20%
# extent a bit along x-dir
linTran[0] *= 1.2
wimg = afwImage.ImageF(nx, ny, 0) # output 'warped' image
wimg.setXY0(xy0)
kernel = afwMath.LanczosWarpingKernel(5) # warping kernel
afwMath.warpCenteredImage(wimg, img, kernel, linTran, p0)
img.writeFits("img.fits")
wimg.writeFits("wimg.fits")
def main():
# a 31x31 postage stamp image
nx, ny = 31, 31
# move xy0 to simulate it being a shallow bbox'd sub-image
xorig, yorig = 100, 300
xy0 = lsst.geom.Point2I(xorig, yorig)
psfSigma = 3.0
x0, y0 = xorig + nx/2, yorig + ny/2
p0 = lsst.geom.Point2D(x0, y0)
img = afwImage.ImageF(nx, ny, 0)
img.setXY0(xy0)
for i in range(ny):
for j in range(nx):
ic = i - (y0 - yorig)
jc = j - (x0 - xorig)
r = math.sqrt(ic*ic + jc*jc)
img[j, i, afwImage.LOCAL] = 1.0*math.exp(-r**2/(2.0*psfSigma**2))
# now warp it about the centroid using a linear transform
linTran = lsst.geom.LinearTransform().makeScaling(
1.2) # a simple scale-by-20%
# extent a bit along x-dir
linTran[0] *= 1.2
wimg = afwImage.ImageF(nx, ny, 0) # output 'warped' image
wimg.setXY0(xy0)
kernel = afwMath.LanczosWarpingKernel(5) # warping kernel
afwMath.warpCenteredImage(wimg, img, kernel, linTran, p0)
img.writeFits("img.fits")
wimg.writeFits("wimg.fits")