Apple MA434Z/A User Manual - Page 787

AutoAlign Image Requirements Although the AutoAlign node is a very flexible tool, it produces the best results with material that is produced with this node in mind. • There should be at least a 15-to-20-percent overlap between any two images for the AutoAlign node to work properly (the amount that's necessary may vary depending on the image). • You may still be able to successfully line up images even when limited regions within each image don't line up, although this may affect the overall quality of the resulting alignment. Examples include clouds, waves, pedestrians, and birds. If you can arrange for it in advance, exact matches from simultaneously captured images are usually preferable. • The warping performed by the AutoAlign node is designed to align multiple panoramic images that have been shot by dollying the camera laterally. Multiple images created by panning the camera from a single position may result in undesirable curvature in the final result. • Interlaced images must be deinterlaced prior to analysis. • When aligning image sequences, the AutoAlign node aligns the input frames in time according to each image sequence's timeShift parameter, as represented in the Time View. Offsetting an image sequence in the Time View offsets which frames will be aligned with one another. • When aligning overlapping images, an object or person in one image that is not in the other may prevent successful analysis if it occupies too large an area. • Images with an animated width or height cannot be aligned. Image Stabilization Within the AutoAlign Node You must select one of the input images to be used as the positional reference for AutoAlign's analysis, using the lockedPlate pop-up menu. If the shot you want to designate as the lockedPlate is not already steady, the other input images will be transformed to match the motion in this shot. Example 1: A Procedure for Simple Image Alignment This example covers how to set up a panoramic stitching operation using the AutoAlign node. To automatically align two or three images: 1 In the Time View, adjust the offsets of the image sequences that you intend to use. 2 Create an AutoAlign node, and attach up to three images to it. The order in which you attach them doesn't matter. 3 Load the AutoAlign node's parameters into the Parameters tab. 4 If necessary, set the analysisRange to the frame range you want to analyze. 5 If you're analyzing images for the first time, set the mode parameter to precise. Chapter 26 Transformations, Motion Blur, and AutoAlign 787