imresize with bicubic DOWNsampling

Dear MATLAB users,

imresize offers 'bilinear' and 'bicubic' methods for resizing images. For upsampling it is clear that these are interpolation methods that use 2x2 or 4x4 neighborhoods to establish a surface and sample at the new location.

However, for downsampling the neighborhoods need to be larger, i.e. a filter needs to be applied. I don't understand what 'bilinear' and 'bicubic' should be in this context and I cannot find a description anywhere. Could you explain or point me to the right documentation?

Best,

Eddy

[T.]

4 years later and the question still remains! Having an input with range [0 ... 255] one example result for scale = 0.25 is in the range [-3 ... 66]. What is computed inside this function?

Answer 1

[KALYAN ACHARJYA]

Please look here (Slide Nos: 30 to 36)

[Li Yinghuan]

Thank you for your PPT, I had saw the contain, that (Slide Nos: 30 to 36) may displays the averaging down-sample method, but haven't the "bicubic" down-sample method.Could you point me the related documentation?