Kuula supports not only 360x180 photos, but also partial panoramas - i.e. images that do not extend all around the spherical view. Partial panoramas can be captured with some spherical cameras or with mobile phones. They are also very common in drone photography where the top of the photo (the sky) is often missing.
Unlike Facebook, which requires special metadata embedded in your photo, Kuula assumes every photos is a spherical one when you upload it. However, when it comes to partial panoramas, Kuula needs a little extra input from you.
There are two main ways to deal with spherical panoramas: embedding XMP metadata in your file or adjusting the photo manually during upload.
If your panorama is not a full 360x180 image, stitching software such as Hugin or PtGUI will automatically add special XMP metadata that describes the cropping of the image. The section of the XMP metadata that describes this looks similar to that:
<GPano:CroppedAreaImageHeightPixels>4509</GPano:CroppedAreaImageHeightPixels> <GPano:CroppedAreaImageWidthPixels>13776</GPano:CroppedAreaImageWidthPixels> <GPano:CroppedAreaLeftPixels>0</GPano:CroppedAreaLeftPixels> <GPano:CroppedAreaTopPixels>2360</GPano:CroppedAreaTopPixels> <GPano:FullPanoHeightPixels>6888</GPano:FullPanoHeightPixels> <GPano:FullPanoWidthPixels>13776</GPano:FullPanoWidthPixels>
You can inspect the XMP meta tags using Photoshop (File > File Info > Raw Data) or using one of the EXIF editors out there, such as EXIF Pilot.
XMP works great if you can make sure it is correctly formatted and doesn't get lost on the way during photo edits or color correction. If your partial panorama doesn't include the metadata, it's not trivial to add it manually. No worries though - you can also fix the image in the Kuula editor.
Manual panorama adjustment
With no XMP data, Kuula will still extract the correct size of the photo from the aspect ratio of the uploaded image. What our algorithm will not always correctly figure out is the position of the panorama.
For example, partial drone panoramas are typically aligned to the bottom - i.e. they cover the bottom hemisphere but not the top one.
Other partials, for example made with mobile phones or with DSLR cameras, will typically cover the middle section of the sphere, leaving the nadir and zenith empty.
Without XMP data - we have no way of guessing which scenario it is. If your image has a bent horizon line, like on the image below, this might be caused by wrong alignment of the partial panorama.
You can adjust this with the Vertical alignment slider in the editor:
Sky and ground color
One more nice feature is that Kuula will automatically extract a matching sky and ground color to fill in the empty space. No more black holes, instead you will see a patch of solid color smoothly overlayed on the missing parts.
For drone photographers: in order to make the best use of this feature, try to remove the black stripe that some stitching software leaves on the top part of photos, like this one below. Either crop the photo from the top or fill this area with the clone stamp tool in Photoshop.