Isosyöte back country 8.4.2006
Here's the story: a nice day, few centimeters of new snow, non-skiing friends were walking on the top. I gave them our basic Ixus camera and they shot some of my lines. Not bad. But how they end up as motion panoramas or sequences photographs? The camera moved a lot between the shots and exposure was on automatic mode?
I used hugin to form the background panorama without interpicture deviations: exported the whole thing with enblend so I get both the individual photos and the end result.
Then I used gimp to open all of these as layers in one big, really big, I-mean-it-BIG picture. I merged a copy of each photo layer in difference mode with a copy of the next one in sequence in normal mode (or previous one if overlap was poor). From the resulting difference layer I could extract the target selection with some hand drawn selections and the magic wand selector. This selection can then be used on the original frame to get the 'sequence' I wanted. Then I pasted this sequence as another layer and made sure that it looks nice with the panorama background, and perhaps touched the brightness and contrast settings for the new layer. And so on.
Speculation: if exposure was the same on all images, just adding each image as difference mode layers in gimp would perhaps be less laborous. Note that hugin is needed to compensate for the camera movement and enblend to compensate for the exposure differences.
I have no idea how professional photographers do this. Perhaps they pay a lot to Adobe. It took me a while to get this process together, but now I'm rather pleased with the results.