The luminance of an image is interpreted as height for the plot. Internally the image is scaled to a square image using nearest neighbor sampling. For selections the bounding box of the selection is used for the surface plot.

The viewing position of the plot can be adjusted with the mouse. Double click on the plot to show it from the top, triple click on it to show it from the front.

The plugin has several modes for displaying surface plots:

• Drawing Mode:
  • Dots: All pixels are drawn as small dots.
  • Lines: All pixels are connected in the x-direction.
  • Mesh: All pixels are connected in the x- and y-direction.
  • Filled: All pixels are connected without leaving holes
• Display Colors can be chosen from the original color, grayscale, different LUTs and orange.
• Axes: If checked, axes and text are shown.
• Invert: If checked, inverts the luminance of the plot data (the Lum height).

Using the 'Load Texture button opens another image that will be used as texture map. This feature can be used to warp images.

The 'Perspective' and 'Scale' sliders allow the 3D-projection and the size of the surface plot to be changed. The plot height may be scaled with the ZRatio slider. The 'Min and 'Max sliders will limit the height range of the plot data.

Noisy images can be smoothed with the 'Smoothing' slider. The 'Lighting' slider gives the impression that the plot was illuminated and so improves the visibility of small differences. The 'Save Plot' button generates a new image containing a screenshot of the surface plot.

This plugin can be called from a macro. Here is an example that plots an image from 10 different angles: