Autopano - Common cases that don't stitch automatically - Low details
You just shot a panorama of a beautiful cityscape and photos between buildings are all blue…
This is also the case when shooting a room with homogenic white walls without any detail. Here is the solution.
Example 1: Blue sky cityscape
This example shows a simple standard panorama (shot hand held) where some shots are totally blue. That said, the shooting grid is quite nice (2 rows of sorted images):
As it is a simple panorama, let's check what Autopano does with it:
Images are missing on the sky due to a lack of details. Autopano can't find any control point there.
No need to try to set the quality of detection or the number of control points, there is just NO details on these images.
The solution is to force the images to be a part of the panorama. Tick the related option and validate (OK):
Here is the result after having modify the setting:
The images missed (image 3 to image 9) are now a part of the panorama, but they are not stitched, they are simply stacked somewhere (here highlighted) on the panorama.
As the shooting grid is nice and well sorted, the idea is to try to use the Guess position option, that should place the images forced to their right place on the shooting grid.
To do that, open the Move Images mode:
Note: I prior enable the Move mode on Picture (and not Pano), simply to see the index of images on the Panorama Editor to better understand what Autopano would do, but it is not necessary.
Then, hit the Guess position option:
Images 3, 4, 5, 6, 7, 8 and 9 are well placed where they should be: this is due to the other images on the same row which are well stitched, because Autopano placed the images depending on the other images indexes (here Autopano checked the positions of the images 1 and 2 then 10, 11 and 12).
Have a look now to the linking:
Of course, there is no links between these images, but there's no need to add control points to link them.
As the images are totally blue, the Smart blending should perfectly do the job in this case.
By the way, one last thing to do here before to render: disable and enable again the color correction to update the color correction of the images moved.
Example 2: Blue sky landscape
The shooting was done with a manual pano-head with several rows and columns. The grid is perfect, but several images are totally blue, actually full rows of blue images.
Step 1: Stitching
As shown on the first example above, do not launch the detection yet, the panorama will be split over several panoramas or in a single panorama with missing images.
So I directly set the Force images option in the Group settings, same as example 1:
Here is the result after modifying the settings:
Images that can't be stitched are stacked on a few parts of the panorama, let's examine what Autopano did:
Step 2: Guess Position tool behavior
In this case, I know that I have several rows of images, including complete rows with only blue sky.
Using the Guess position tool alone doesn't work. Here is the result using it as is:
This is an organized mess! Autopano finds a logical way of sorting the images, that starts from Image 84, but it used the direction of the previous stitched images indexes to place the images 85 to 105, whereas Images 85 to 105 are the upper row from left to right.
The other images from 65 to 72 are just badly placed...
Step 3: How to fix it
Here is what to do (go back one step back to cancel the Guess Position effects first):
Enable the Move mode on Picture (and not Pano), then move the first missing image (check the indexes), here it is Image 64 that I have to find.
Trick: Sometimes the images are hard to find, so you can use the Layers Editor to find them (selecting an image in the Layers Editor selects it in the editing area):
Moving this image is not enough to guess the position of the other images as Autopano will think the missing images should go up instead of going left.
Moving an other image is necessary, the next one, Image 65.
Now that both 64 and 65 are moved, enable the Control Points tool and use the Contextual menu to create hard links like this:
Hard links are created, now I can use the Guess Position tool:
As expected, Autopano found the logical way to place Images 66 to 78, and found the same sorting for Images 85 to 105 as the first try (normal behavior, as shown above).
So all that remains is to simply hard link Images 85 and 86 to tell Autopano the right way to place them:
Now enable the Move tool, Picture mode and then hit the Guess Position wand again:
The panorama is nice. Now I have to update the Color correction to get proper color blending:
Open the Color Correction tool and switch from Auto to None.
Then enable the Color Correction again, on Auto and see the result:
In this case, as the shooting is quite perfect, the different images are shot with the same camera settings, the Color Correction is not necessary.
That being said, this step is important because images moved on the panorama keeps the color correction information of their previous position.
Alternative method for Step 3:
Instead of placing each orphan picture approximatively in Editor, you can place them using mathematical values in the Editor (adjust only Yaw, Pitch, and Roll based on near pictures and values you used on your panoramic head while shooting). Once done, you can follow rest of tutorial in same way for hardlinks.
Tip: Inside a row of pictures, only the Yaw value should change (same step as horizontal rotator setting of your panoramic head).