Are there any tools or software available to get length measurements in spherical panoramas? I know there is GigaMacro but that seems to only be good for photos of really small objects. I am working on a research project that involves photos of human sized objects and even buildings. If there is not software available, does anyone have an algorithm or know the math to do this?

Chris Fastie has done some very interesting work on this subject. Pardon the tongue in cheek presentation: http://youtu.be/gBQtVZfx9lc?t=17m50s

It is possible to derive the actual dimension of an object in a photograph (including gigapans) if three other dimensions are known:
1) the distance between the object and the camera
2) the focal length of the lens
3) the dimension of the image of the object projected onto the camera’s sensor.

Number 1 generally has to be measured in the field, but could be derived from the image if the dimension of another object at that distance is known.

Number 2 is often in the Stitcher notes.

Number 3 can be determined from the dimension of the object in pixels if the dimensions of the sensor (in pixels and mm) are known, and the photo is still in its native resolution.

The most relevant part of the video Ron linked to is here: http://www.youtube.com/watch?v=gBQtVZfx9lc&feat…