Create an action sequence by stacking panned photos

[Granddaddy]

Here I outline a procedure that illustrates the power of image stacking in Affinity Photo to create an action sequence from multiple images captured as the camera is panned to follow a moving subject.

Almost all tutorials I've seen about image stacking in Affinity Photo deal with simple tasks like noise reduction or focus stacking or removing people from a scene or getting multiple exposures of an object that moves across a stationery background. The tutorials emphasize using a tripod or, when shooting handheld, taking photos in quick succession so that the backgrounds behind the subject are consistent. It is emphasized that the camera orientation must be maintained throughout the sequence. The Affinity Photo Help for Image Stacks emphasizes that stacks are used to "blend together a series of images based the same scene or almost identical subject matter."

In fact, stacking in Affinity Photo is more robust than these tutorials and statements imply. Stacking can be used to make a composite image from photos captured while panning the camera to follow a moving subject. You can construct an action sequence by stacking several images taken from different positions or orientations as the camera moves to follow the subject. All this can be done non-destructively.

Here I'm using family photos, so I'm not uploading full size photos nor the afphoto file. The instructions and thumbnails posted here should be enough to get anyone started on making a similar composite photo action sequence.

At the climbing gym, my granddaughter showed me how she can lift herself off the ground, swing her leg over her head to get on the wall, and then traverse the climbing wall. I snapped several photos with a handheld camera. I made no effort at all to keep the images aligned in any way since at the time I had no thought of making an action sequence. I simply moved the camera to keep my subject in the center of each photo. Though I stood in a relatively fixed position, I rotated the camera to follow her movement across the wall.

Despite my carelessness, APhoto was able to stack three images into a pleasing composite image.

Here are the three unretouched photos I chose for stacking. I chose photos so that the subject did not overlap herself when the photos were stacked.

Here is the procedure I used to combine these three photos into a single composite image.

1.) Take a series of photos with a moving subject with sufficient overlap to enable APhoto to align the separate images in a stack. This is much like taking a handheld panorama. Note that in this series I made no attempt at alignment because I had never before stacked images for any purpose and I was not thinking of making a composite action sequence.

2.) Select File/New Stack…. In the resulting New Stack dialog, add the three photos. Then check Automatically Align Images, check Live Alignment, and choose Perspective (the default) in the drop down list box. Then click OK.

3.) On the resulting Live Stack Group layer in the Layers panel, click the Stack operator icon and select Outlier from the drop-down list so the climber is not averaged out of the composite.

The result is as follows:

This is not a bad beginning. Hard to see in this small representation are numerous color artifacts on the climber's black outfit and the partially obscured portions on the climber where multiple images overlap the climber. There are also places where the overlap of handholds on the wall is sloppy or fuzzy.

4.) Apply a mask as a child layer to each of the three photos. Paint on the masks to hide areas on one photo that overlap the climber on another photo. Also mask areas where details are obscured by small mismatches in alignment or orientation so that only a single photo is contributing to the overall image at that point. For example, the climber in the middle image is overlapped by the right side of the left photo and the left side of the right photo. Portions of the left and right photo that overlap the middle climber must be masked out.

5.) Crop the resulting stacked image to taste and to eliminate blank areas that aren't needed.

6.) Inpaint and Clone to fill in any remaining blank areas required for a final image. Here I Inpainted and Cloned to fill in the right foreground so as to get sufficient continuity from the leftmost photo where the floor extends much lower than it does on the rightmost photo.

7.) Apply further tonal adjustments to the overall image.

Here is my final image. Both my granddaughter and I were delighted with this result.

It should be obvious from this example that stacking can also be used to make panoramas non-destructively in Affinity Photo. I found one video tutorial doing just that at

https://www.youtube.com/watch?v=6eSLyZA0Zao