Windowing and Scrolling Speed
This article explains how to make windowing, zooming and panning as fast and smooth as possible
As of version 4.2, there has been the ability to show images with smoothing and/or moving_average_interpolation. The default is to using smoothing for minimised images, where ActualZoom is < 1 (ensuring that all image pixels contribute to the display), but not to use it for images scaled up (in order to minimise regulatory concerns about "enhanced" images and possible artefacts). See MagnificationMode & MinificationMode for more details.
Whilst this was a feature much requested by users, it does have a performance penalty, and if left enabled during fast update operations, the display appears "slow" or "jerky".
For maximum performance, please ensure that smoothing is entirely disabled, whilst such operations are in progress by setting the image's MagnificationMode and MinificationMode properties both to doFilterReplicate (1). They can be reset to their previous values (according to your preferences) once the operation is complete. As most operations of this sort are accomplished using a mouse (either on a slider control or over the image window), the best way to achieve this is to set the values to doFilterReplicate in the MouseDown event and reset to preferred display values in the MouseUp event.