Is the interpolation method 'cubic' in georesize function same as bicubic interpolation? Why is the default interpolation method of georesize and geointerp not the same?

I noticed that the default interpolation method of georesize function is 'cubic' which means cubic interpolation in Help Document. I am curious how it works. Is cubic the same as bicubic interpolation. The Matlab Help says the 'cubic' means Bicubic interpolation in geointerp.　I am wondering íf the cubic method is the same in georesize and geointerp functions.

Another thing I am interested is that why the default interpolation method in georesize and geointerp is not the same. For georesize, it is cubic, while for geointerp it is linear.

Hope someone can solve my questions. I appreciate is so much.

Answer 1

[Muskan]

Hi Carie,

As per my understanding, yes, the 'cubic' interpolation method in the georesize function of the Mapping Toolbox in MATLAB is the same as the bicubic interpolation method in MATLAB.

However, the difference between the 'cubic' interpolation method in georesize and the bicubic interpolation method in MATLAB is very small. In both cases, the cubic spline interpolation uses the same algorithm to approximate pixel values and the difference is only in the number of pixels used in the interpolation.

The default interpolation method in 'georesize' and 'geointerp' functions of the Mapping Toolbox in MATLAB is different because these functions are designed for different use cases.

You can further refer to the following documentation for a better understanding.

Resize geographic raster - MATLAB georesize (mathworks.com)

Geographic raster interpolation - MATLAB geointerp (mathworks.com)

Thanks

[Carrie HE]

Thank you for your answer!