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dstndstn / unwise-coadds

Unofficial coadds of the WISE mid-infrared satellite imaging
GNU General Public License v2.0
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Downsampling with PSF #1

Open bluetooth12 opened 5 years ago

bluetooth12 commented 5 years ago

Hello, I have two sets of images: One at a high resolution and one at a low resolution. I want both sets of images to be at the same resolution and, to do so, I need to downsample the high resolution image with a PSF. The result should be a blurred image that is "zoomed-out" so that the high resolution image looks like the low resolution image. Can your code do this? If not, can you suggest a resource I could use (paper/code) to achieve this result?

dstndstn commented 5 years ago

Hi,

I think you want to do this in two steps. First, convolve the high-resolution image by a kernel that will take the high-resolution PSF to the low-resolution PSF. Next, resample the high-resolution image to the pixel grid of the low-resolution image.

The first step you can do using, eg, scipy.ndimage https://docs.scipy.org/doc/scipy-0.16.1/reference/ndimage.html

The second step you could do using my code, eg, astrometry.util.resample's resample_with_wcs. https://github.com/dstndstn/astrometry.net/blob/master/util/resample.py#L16