Why do Hotspots seem to shift position slightly at extreme zoom?
Very large images present a special challenge with respect to the accurate placement of hotspots. This is due at least in part to the fact that the coordinates for a hotspot will have to be extremely exact – and in some cases, more exact than Flash Player may allow. The basic unit of measure for coordinates in Flash is 1/20-th of a screen pixel, or a TWIP. Coordinates with finer precision than .05 are simply rounded to the nearest .05. The fractional pixel positions are approximated using anti-aliasing. This would not normally present a problem, but with the extreme range of resolutions in the Zoomify Viewer, and the fact that the label “tier” (i.e. layer) has to correspond to the lowest resolution “tier” the coordinate calculations can result in th rounding process creating a noticable shifting effect as an image is panned slightly in one direction and then back again. Zoomify is working to implement an alternate approach in upcoming releasese which, it is expected, will resolve this
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- Why do Hotspots seem to shift position slightly at extreme zoom?
