Well, I don't know how to cancel (unless you write your own loading code, witch is what ACDC does), but I do have a suggestion. In our photography application that we give to everyone we do shoots for (did I mention we have a studio on top of all of my other skills) we check the CRW and Exif blocks of the images for rotation. This is an easy flag to find, and is typically 1, 2, 3, 4 or 0, 90, 180, 270. So matching this up you can autorotate

Personllay, I went with custom loading code, but I'm not willing (able) to give it away. I kinda lost the source , next time I need an update I'll have to re-invent the wheel. Luckily until I upgrade my cameras I don't have to worry about an update