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Globe Flattening

Aim:

The aim of the program is to extract a spherical surface and transform it into a flat rectangle.

Input:

The image of a globe.

Output:

A flattened image of the globe.

Hints:

An image presenting a globe can be flattened in several ways, but the easiest method is to think of the globe as a sphere and consider one of the Image Spatial Transforms Maps filters to create a proper map and then display it as an image.

Labeling connections is explained in this article.

Solution (FIS):

In Workspace Explorer, open the workspace Examples, and in the Filmstrip window, select the Globe dataset. Drag the Image channel to the ACQUIRE section.
Add the CreateSphereMap filter.
- Connect the outImage from the previous filter with the inImageFormat of the current one.
- Click on the inSphereRectangle filter and then specify the area to be flattened by clicking inSphereRectangle in the Properties window:
- Set the inSphereRadiusCorrection to 60. It determines how many pixels the sphere radius is larger than the visible circle radius.
- Set the inMargin to 260 to display only the remapped area without unnecessary margin. The Margin is the width of the sphere extreme points zone excluded from the spatial map.
Add the RemapImage filter.
- Connect the outImage from the ReadFilmstrip filter with the inImage of the current one.
- Connect the outSpatialMap from the previous filter with the inSpatialMap of the current one.

Macrofilter Main

Used Filters

Icon	Name	Description
	CreateSphereMap	Inspection of the surface of balls and other spherical objects. The result is used by RemapImage.
	RemapImage	Fast (precomputed) image transformations, especially for view undistortion or object geometry correction (e.g. pos recognition of labels on cylindrical bottles).