Which process involves giving an image z-values to match the heights in a digital terrain model?

The process of draping involves assigning z-values from a digital terrain model (DTM) to an image so that the image aligns with the terrain's elevation. This technique creates a more realistic representation of how an image would appear on the surface of the earth, taking into account the variations in height or depth.

When an image is draped over a DTM, it is usually projected to conform to the underlying surface's elevations, which helps visualize the image in the context of the terrain. This is particularly useful in fields such as landscape visualization, urban planning, and environmental studies, where understanding the relationship between the terrain and imagery is crucial.

Buffering refers to creating a zone around a feature at a specified distance, which does not involve changing the elevation attributes of a surface. Georeferencing is the process of aligning spatial data to a known coordinate system, allowing it to be accurately placed within a GIS framework but does not specifically involve z-values or elevation adjustments. Clipping involves cutting out a specific portion of a dataset but does not relate to the elevation aspect of imagery in relation to terrain.