Patching the nadir
Contents
Concept
Patching the nadir is useful to have a correctly stitched equirectangular panorama.
There are several ways of achieving this:
using multiple viewpoints on your nadir shot if it was taken at an angle, hand held or not
- using the Masking Tool to keep the parts of your photos* that don't contain the tripod or whatever you need to remove
- placing a logo at the nadir.
Notice:
*It should be noted of course that to keep an object, it is necessary to have a full view of the source image, Autopano does not re-create any missing pixels, it lets you control the Anti-ghost and what is kept and removed from your photos.
And that to delete objects, you must have sufficient coverage in the background. which makes sense: if there is nothing to use behind the object, there will be a hole in the panorama.
How it's done
In a regular panorama using multiple viewpoints on the nadir photo
Here is an example of a simple case, in which the nadir shot was taken shifted to the side, so it is not taken at the nodal point.
Open the folder of the source images. We can see that they were taken with a fisheye lens and that we have one photo for the nadir.
Before the detection, open the Group Settings. In the Optimization tab, un-check Automatic Optimization Presets, and un-check "Bad points" and "Bad links".
Launch the detection and open the editor.
The RMS is not great because we haven't cleaned up the bad points, which we can do later.
Using the Move Tool slide the panorama so that the nadir is in the center.
Open the Control Points Editor, right click on your nadir shot and select "Optimize viewpoint of this image".
Check the links for the nadir shot are all linked to the center of the nadir, not extra elements, like the window that could have been concerned in this example.
Once that is done, optimize.
The stitching looks good, now we can clean up the points if needed: back in the Control points editor, in the Filters tab, adjust the Filter Points slider to a maximum of 5.00, click on the Clear Points button and then optimize one last time.
Set the image straight again with the Move Tool or Automatic Horizon tool before rendering.
Due to the oblique nadir shot, parallax issues can appear on objects close to your nadir, so a masking point or two may be needed to fix that. In this case: the bench leg.
In a regular panorama with the masking tool
Here is an example of a simple use of an often encountered user case: removing a tripod from an equirectangular panorama.
This type of treatment required the use of Photoshop masks, either on the source images, or in post-processing, and in either case this workflow could be rather tedious.
The Masking Tool allows you to define constraints to keep or remove objects from a panorama, much like you might do through layers and masks in Photoshop, but much simpler!
Open the folder of the source images. We can see that they were taken with a fisheye lens and that we have three shots for the nadir.
Doubling the shot is sufficient in most cases, but here, an extra photo was taken in to be sure to have the coverage to remove the tripod.
After the stitching, open the panorama editor.
Move the panorama using the Move Tool, to have the nadir neatly in the center.
In the Images Mode, we can see our three images that have been stitched.
Activate the Masking Tool, and add a red marker on the visible tripod for each picture, and a green marker on the image without the tripod. Validate the modifications.
Here is the result using the Preview Tool: the tripod has disappeared! 3 clicks were enough to achieve what would have required an average of 10 minutes with Photoshop!
In a partially bracketed panorama with the masking tool
In the case of Partial bracketing, the procedure is the same, except that the panorama contains a bracket.
Use the move tool to have the nadir in the center.
Place the red masking points on the tripod and legs, and green on the ground you want to keep.
This case is a good example to illustrate that the Masking tool doesn't do miracles, and if there is not the sufficient coverage that is required, some parts may remain.
In this case: one of the tips of the tripod's leg, none of our images allowed us to cover it completely.
This minor leftover is easy to edit out afterwards using Photoshop, than if you had to remove the tripod completely using Photoshop.
When placing a Logo image on the nadir
This tip can be used in both Autopano Pro and Giga.
Once you've stitched your panorama, open the Layers Editor to add your patch.
Select your logo.
Create a new layer for the patch.
Drag and drop the patch into the new layer.
To make sure the patch won't be blended with the panorama, rename the layer to "Patch".
Position the patch on your nadir using the Move Tool.
Done.
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