This demonstration compares the standard interpolation functions with the ones developped by the Biomedical Imaging Group [1] when a rotation is successively applied to an image. The rotation is implemented in a separable fashion using the digital filtering algorithm described in [2].

Standard methods:

• Constant: Nearest-Neighbor
• Linear: B-Spline
• Quadratic: Dodgson
• Cubic: Keys
• Cubic: Schaum

BIG methods:

• Constant: B-spline
• Linear: B-spline
• Quadratic: B-spline
• Quadratic: Omoms
• Cubic: B-spline
• Cubic: Omoms
• High Quality: B-spline 11

[1] P. Thévenaz, T. Blu, M. Unser, "Image Interpolation and Resampling," Handbook of Medical Imaging, Processing and Analysis, I.N. Bankman, Ed., Academic Press, San Diego Ca, USA, pp. 393-420, 2000.

[2] M. Unser, P. Thévenaz, L.P. Yaroslavsky, "Convolution-Based Interpolation for Fast, High-Quality Rotation of Images," IEEE Transactions on Image Processing, vol. 4, no. 10, pp. 1371-1381, October 1995

1. Choose an input image in the list.
2. Choose the number of rotations (iterations).
3. Choose methods of interpolation.
4. Press ">" to run one step or ">>" to run all the steps. Press "<" to run one step in counter-clockwise and "<<" to run all steps.

Toolbar in the image display

	Get the coordinates and value of a pixel.
	Get the maximum, minimum and the value of the image.
	Open a new window containing the image.
	Zoom out by a factor 2.
	Zoom in by a factor 2.
	Move the zoomed part of the image.