Accurate Image Alignment and Registration Using OpenCV
magamig.github.io
Accurate Image Alignment and Registration Using OpenCV
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Re: Accurate Image Alignment and Registration Using OpenCV
#2Image alignment allows for some fun image manipulations like these. I think one of the coolest novel applications of image alignment in recent years must be multi-frame super-resolution. For example, the Pixel phones use it to improve low-light and zoomed in photos[0].
Re: Accurate Image Alignment and Registration Using OpenCV
#3Image alignment allows for some fun image manipulations like these. I think one of the coolest novel applications of image alignment in recent years must be multi-frame super-resolution. For example, the Pixel phones use it to improve low-light and zoomed in photos[0]. [0] https://sites.google.com/view/handheld-super-res/
Cool! I'm planning on using image alignment for enhancing the spatial resolution of hyperspectral (HS) images, through the fusion of RGB and HS images.
Re: Accurate Image Alignment and Registration Using OpenCV
#4Image alignment allows for some fun image manipulations like these. I think one of the coolest novel applications of image alignment in recent years must be multi-frame super-resolution. For example, the Pixel phones use it to improve low-light and zoomed in photos[0]. [0] https://sites.google.com/view/handheld-super-res/
This is called drizzle (with dithering, e.g. the raw photos are taken with offsets) in the astrophotography sphere and is very effective when the images are undersampled. Although, astronomy images have the advantage of being filled with stars that are relatively easy to align very accurately.
Re: Accurate Image Alignment and Registration Using OpenCV
#5Image alignment allows for some fun image manipulations like these. I think one of the coolest novel applications of image alignment in recent years must be multi-frame super-resolution. For example, the Pixel phones use it to improve low-light and zoomed in photos[0]. [0] https://sites.google.com/view/handheld-super-res/
This is called drizzle (with dithering, e.g. the raw photos are taken with offsets) in the astrophotography sphere and is very effective when the images are undersampled. Although, astronomy images have the advantage of being filled with stars that are relatively easy to align very accurately.
I imagine the minuscule vibrations of a shutter make it a natural fit to the already existing image stacking pipeline, correct?
Re: Accurate Image Alignment and Registration Using OpenCV
#6Earlier quoted context omitted.
This is called drizzle (with dithering, e.g. the raw photos are taken with offsets) in the astrophotography sphere and is very effective when the images are undersampled. Although, astronomy images have the advantage of being filled with stars that are relatively easy to align very accurately.
I imagine the minuscule vibrations of a shutter make it a natural fit to the already existing image stacking pipeline, correct?
I'm not sure what you mean. Mechanical shutters have no upsides I'm aware of :). Astro cameras use electronic shutters.
EDIT: The dithering, or offsetting, is done by moving the telescope slightly between exposures. During exposures you want it to track the object you're photographing as accurately as possible. I imagine vibrations are a detriment even in the Pixel phone processing. It would be better if the phone could move instantly in slightly different directions and take steady raw photos in each.
Re: Accurate Image Alignment and Registration Using OpenCV
#7Earlier quoted context omitted.
I imagine the minuscule vibrations of a shutter make it a natural fit to the already existing image stacking pipeline, correct?
I'm not sure what you mean. Mechanical shutters have no upsides I'm aware of :). Astro cameras use electronic shutters. EDIT: The dithering, or offsetting, is done by moving the telescope slightly between exposures. During exposures you want it to track the object you're photographing as accurately as possible. I imagine vibrations are a detriment even in the Pixel phone processing. It would be better if the phone co…
Ah, I was thinking of amateur astrophotography - although these days you can just set the mechanical shutter in many consumer DSLRs to stay open too I think.
Re: Accurate Image Alignment and Registration Using OpenCV
#8The biggest issue in real life use cases is lens distortion - these alignment algorithms usually don't correct barrel, pin-cushion or more complex lens distortions, making the alignment imperfect.
Re: Accurate Image Alignment and Registration Using OpenCV
#9Earlier quoted context omitted.
I'm not sure what you mean. Mechanical shutters have no upsides I'm aware of :). Astro cameras use electronic shutters. EDIT: The dithering, or offsetting, is done by moving the telescope slightly between exposures. During exposures you want it to track the object you're photographing as accurately as possible. I imagine vibrations are a detriment even in the Pixel phone processing. It would be better if the phone co…
Ah, I was thinking of amateur astrophotography - although these days you can just set the mechanical shutter in many consumer DSLRs to stay open too I think.
I think maybe you were considering the vibrations a source of noise for compressed sensing? For CS to work well you generally want to know the convolved noise. So a super accurate accelerometer might be able to measure random vibrations and do even better when they are present than absent. Not sure if phone accelerometers are that good.
Re: Accurate Image Alignment and Registration Using OpenCV
#10Image alignment allows for some fun image manipulations like these. I think one of the coolest novel applications of image alignment in recent years must be multi-frame super-resolution. For example, the Pixel phones use it to improve low-light and zoomed in photos[0]. [0] https://sites.google.com/view/handheld-super-res/
This is called drizzle (with dithering, e.g. the raw photos are taken with offsets) in the astrophotography sphere and is very effective when the images are undersampled. Although, astronomy images have the advantage of being filled with stars that are relatively easy to align very accurately.
'When undersampled' -- time to get a more modern sensor?
3.76um pixels + 800mm focal length is about 1 arcsecond per pixel, so that will end up seeing limited much of the time.