Today, Adobe released a new version of Lightroom Classic (v9) that has an addition to the panorama merge function: fill pixels (using content aware fill).

Lightroom v9 Fill Edges Panorama

The new version of Photoshop (2020) also has this functionality but the images created in this post were created by Lightroom.

Photoshop 2020 Merge to Panorama - Content Aware Fill

First, I did some basic edits to 16 raw files captured with a Nikon Z7 and Nikkor Z 24-70 f/4 S lens.  Vertical orientation, hand held while on a hike at Chain Lakes in Washington State, USA.  That’s Mount Shuksan in the distance.  I loaded these images into the panorama module and it created this basic stitch (border added to see effect):Lightroom Classic v9.0, Camera Raw 12 : Panorama Merge - Basic Panorama Stitch - No Alteration

The resulting image is 26442 x 8257 pixels (218 megapixels), but it contains missing data around the perimeter (common issue when stitching).  To correct for this, Lightroom gives you several options.

Auto Crop – this will create a rectangular crop of maximum size while removing all of the areas with missing information.  Lightroom Classic Panorama Merge - Basic Panorama with Auto Crop Pixels26190 x 7282 (190 megapixels)

Boundary Warp – the image is stretched to fill the missing data.  Pixels are moved and interpolated but the resulting image is larger than the cropped version.

Lightroom Classic Panorama Merge - Boundary Warp Only

26153 x 7946 (208 megapixels)

Fill Edges (new) – attempts to use Content Aware Fill to fill in the missing data (with limited success in this case, see below).

Lightroom Classic Panorama Merge - Fill Edges Only

26442 x 8257 (218 megapixels)

So the new “Fill Edges” option created the largest file and preserved the pixels (no stretching) but also created odd artifacts in the file (as Content Aware Fill is known to do).  See the lines in the 100% crop below from the edge of the frame.  These are not present in the crop or boundary warp methods.

Detail

Lightroom Classic Panorama Merge - Fill Pixels Detail 2

To make comparing some of the options a bit easier, here are some before/after sliders so you can more easily see the difference.

Original vs Boundary Warp

Lightroom Classic v9.0, Camera Raw 12 : Panorama Merge - Basic Panorama Stitch - No Alteration Lightroom Classic Panorama Merge - Boundary Warp Only

Original vs Fill Edges

Lightroom Classic v9.0, Camera Raw 12 : Panorama Merge - Basic Panorama Stitch - No Alteration Lightroom Classic Panorama Merge - Fill Edges Only

Boundary Warp vs Fill Edges

Lightroom Classic Panorama Merge - Boundary Warp Only Lightroom Classic Panorama Merge - Fill Edges Only

I thought Boundary Warp might distort the image to the point that quality is degraded substantially but that doesn’t seem to be the case.  After looking at both images side by side in Lightroom at 100% (1:1 view), especially at the edges where Boundary Warp has the greatest effect, I don’t see any major difference between the two techniques in terms of quality.  So “Fill Edges” might work well for blue sky or other images where the edges are not detailed, but I’ll mostly stick to using Boundary Warp and Crop.

Boundary Warp vs Fill Edges

The final image (which I will edit further) is a combination of Boundary Warp (setting 40) and Auto Crop.  This seems to give me the highest level of quality while preserving as much of the image size as possible.

Lightroom Classic v9.0, Camera Raw 12 : Panorama Merge - Basic Panorama Stitch - No Alteration Lightroom Classic Panorama Merge - Warp 40 and Auto Crop